Cgm case studies

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Cgm case studies

  1. 1. Current Trends in Professional Continuous Glucose Monitoring Guest Editor: Bruce W. Bode, M.D Atlanta Diabetes Associates Atlanta, Georgia Proceedings of ‘‘Current Trends in Professional Continuous Glucose Monitoring (CGM),’’ Keck School of Medicine, University of Southern California, Los Angeles, California, Sponsored by Medtronic.
  2. 2. Current Trends in Professional Continuous Glucose Monitoring has been compiled and produced from funding solely provided by Medtronic MiniMed, Inc. and Lifescan, Inc. Medtronic MiniMed, Inc. or its affiliates provided support for some of the studies reported in the other articles included in this special supplement.
  3. 3. Current Trends in Professional Continuous Glucose Monitoring contents 4 Introduction B.W. Bode, P. Phillips, B. Nardacci, K.C. Arnold, B.S. Horowitz, O. Odugbesan, S. Reddy 6 Case 1: A 62-Year-Old Woman with Complex Medical History and Hypoglycemia Unawareness P. Phillips 9 Case 2: A 60-Year-Old Woman with Diabetes Secondary to Necrotizing Pancreatitis with Highly Variable Blood Glucose Levels on Basal Bolus Therapy E. Nardacci 12 Case 3: A 41-Year-Old Man with Type 1 Diabetes with Good Glucose Control K.C. Arnold 14 Case 4: A 29-Year-Old Woman with Type 1 Diabetes, Pregnant with Triplets K.C. Arnold 16 Case 5: A 61-Year-Old Man with Type 1 Diabetes S. Reddy 18 Case 6: A Type 1 Diabetic College Student with a Crazy Lifestyle and Crazy Blood Sugars B.S. Horowitz 20 Case 7: A 38-Year-Old Woman with Type 1 Diabetes B.W. Bode 23 Case 8: A 69-Year-Old Woman with Type 2 Diabetes and Good Premeal Glucose, But a High A1c B.S. Horowitz 26 Case 9: A 37-Year-Old Woman with Type 2 Diabetes at 20 Weeks of Gestation K.C. Arnold 28 Case 10: A 41-Year-Old Woman with Type 2 Diabetes, High A1c O. Odugbesan 31 37 41 Discussion Regarding Use of Professional Continuous Glucose Monitoring Professional Continuous Glucose Monitoring (CGM) Progress Note HIGHLIGHTS FROM DIABETES TECHNOLOGY & THERAPEUTICS Continuous Glucose Monitoring in Non-Insulin-Using Individuals with Type 2 Diabetes: Acceptability, Feasibility, and Teaching Opportunities N.A. Allen, J.A. Fain, B. Braun, S.R. Chipkin 49 Sustained Efficacy of Continuous Subcutaneous Insulin Infusion in Type 1 Diabetes Subjects with Recurrent Non-Severe and Severe Hypoglycemia and Hypoglycemia Unawareness: A Pilot Study M. Gimenez, M. Lara, and I. Conget 54 Maximizing Reimbursement through Correct Coding Initiatives E. Orzeck
  4. 4. Introduction Bruce W. Bode, M.D.,1 Paula Phillips, M.D.,2 Elizabeth Nardacci, FNP-C,3 Kathleen C. Arnold, A.N.P.,4 Barry S. Horowitz, M.D.,5 Ola Odugbesan, M.D.,6 Sushma Reddy, M.D.7 case presentations, the role of professional CGM in the real world was discussed. 1 Atlanta Diabetes Associates, Atlanta, Georgia. Diabetes & Metabolism Specialists, San Antonio, Texas. 3 Albany Medical Center, Albany, New York. 4 The Diabetes Center, PLLC, Ocean Springs, Mississippi. 5 Palm Beach Diabetes and Endocrine Specialists, PA, West Palm Beach, Florida. 6 North Atlanta Endocrinology, Lawrenceville, Georgia. 7 Endocrinology & Diabetes Center, Fort Gratiot, Michigan. 2 D Abstract A total of 10 patients were discussed during this meeting entitled ‘‘Current Trends in Professional Continuous Glucose Monitoring (CGM).’’ Seven patients had type 1 diabetes and faced challenges with day-to-day glucose control, five with poor glucose and two with normal A1c. Two patients switched to insulin pump treatment after reviewing their progessional CGM data. Another subject with type 2 diabetes on oral agents switched to CSII and was able to achieve target A1c and deliver a healthy, normal-sized baby. Two other patients had type 2 diabetes: one on MDI using large amounts of insulin, and another on oral agents only. After uring the ‘‘Current Trends in Professional Continuous Glucose Monitoring (CGM)’’ symposium, held at the University of Southern California on November 20, 2009, seven distinguished experts in the field of CGM from around the country presented and discussed the use of professional CGM in 10 patients. After the case presentations, all seven faculty members discussed which patients are appropriate candidates for professional CGM, and how physicians and nurse practitioners do professional CGM in the real world, using professional CGM outputs to make appropriate therapy adjustments, and scheduling follow-up evaluations. Glucose monitoring has evolved from urine testing to selfmonitored blood glucose (SMBG) to CGM. The first continuous glucose sensor was introduced in 1999 (Fig. 1). This early device incorporated a sensor that measures interstitial glucose, continuously giving an average glucose reading of the interstitial fluid every 5 min up to 188 tests per day over a 3-day period. The initial data showed that the device significantly lowered HbA1c in people with elevated A1c, and reduced severe hypoglycemia in patients with normal A1c. There are four commercially available CGMs, two from Medtronic MiniMed (one professional and retrospective, and the other real-time), Freestyle Navigator and Dexcom SEVEN Plus (Fig. 2). Professional CGM is a blinded evaluation by the healthcare provider, who places a sensor with a transmitter on the patient in the Evolution of Diabetes Management Technologies Insulin pump therapy Urine glucose testing Continuos glucose sensor Point-in-time BG meters Integrated systems: Pumps/Meters/Software Discovery of insulin Artificial Pancreas 1900s 1922 1977 1978 1999 2003 Fig. 1. Evolution of diabetes management technologies. The first continuous glucose sensor was introduced in 1999. The first device that integrated insulin pumps, glucose sensors, and software was introduced in 2003. 4 CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING Fig. 2. The two types of continuous glucose monitoring target different users: health care professionals and empowering individual patients with diabetes. ª 2010 Medtronic Minimed, Inc. All rights reserved.
  5. 5. INTRODUCTION office. The provider instructs the patient to continue usual care and keep a log of SMBG readings; time and dosage of whichever insulin or oral agents being taken; meal times; and food intake, activity, and symptoms of high and low blood sugar. Patients are blinded to the glucose values, and return to the office after 3 days to download the data. After reviewing the data from the professional CGM device, the healthcare provider recommends necessary therapeutic changes. In contrast, personal CGM (also known as real-time CGM) devices are worn by the patient for longer periods and enable the patient to see real-time glucose values throughout the day, and make changes on their insulin dose or adjust food intake to avoid extreme hypoand hyperglycemia. Address correspondence to: Bruce W. Bode, M.D. Atlanta Diabetes Associates 77 Collier Road, Suite 2080 Atlanta, GA 30309 E-mail: bbode001@aol.com CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING 5
  6. 6. Case 1 A 62-Year-Old Woman with Complex Medical History and Hypoglycemia Unawareness Paula Phillips, M.D. Diabetes & Metabolism Specialists, San Antonio, Texas. Patient History The first case is an obese 62-year-old woman with type 1 diabetes (diagnosed at the age of 30 years) and hypoglycemia unawareness. On initial presentation in March 2008, the patient had inadequate glucose control with an A1c of 9.6%. She was on NPH 10 units in the morning, Glargine 15 units at bedtime, and a sliding scale of rapid-acting insulin analog before meals. She had wide glycemic excursions on four-timesa-day self-monitored blood glucose (SMBG) ranging from 37 to 542 mg=dL. Most of the hypoglycemic episodes (<50 mg=dL) were in the morning, and thus she never used the sliding scale at breakfast. By lunchtime, her blood glucose (BG) ranged between 300 and 350 mg=dL. Comorbidities and Diabetic Complications The patient’s history is significant for anoxic brain injury that occurred in June 2006 while wearing an insulin pump. Apparently, she had very little training on the insulin pump, did not change it every 3 days, and experienced infections at the site as a result. After the hypoglycemic episode, she had to be in a nursing home for 4 years before going home to her family. Additional comorbidities include diabetic neuropathy and gastroparesis. She was on metoclopramide treatment but for her gastrointestinal complaints. She functions relatively well considering her brain injury, with a minor tic, some speech difficulties, and poor memory. She is very meticulous recording BG and everything she eats. Her surgical history is significant for cholecystectomy and hysterectomy. Rationale for Initiating Professional CGM After initial presentation, the provider changed the patient’s regimen to basal bolus insulin with Glargine at bedtime and premeal insulin aspart with a supplemental scale. Subsequently, this was adjusted to split basal dosing, but she continued to have wide glycemic excursions. Before her initial professional CGM study in May 2009, her baseline A1c had improved by 1% to 8.6%. Her treatment at that time had evolved to Detemir twice a day at 8:00 am and 6:00 pm with a higher dose at bedtime if her BG level exceeded 250 mg=dL. She took insulin Aspart *6 units before meals on a sliding scale. 6 CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING On the basis of SMBG, she seemed to have relatively good BG before lunch and dinner, but her morning BGs were very high. If her bedtime BG was very elevated ([250 mg=dL), she tended to drop and there was a big difference between her bedtime BG and the BG value the next morning. If her BG was reasonably controlled at bedtime (<150 mg=dL), then she would have very high fasting blood sugars (400–500 mg=dL). Thus, the rationale for the initial professional CGM was to try to distinguish if this pattern was due to snacking at bedtime due to fear of hypoglycemia, or due to counter regulatory hormones in response to nocturnal hypoglycemia. Initial Professional CGM Results The initial professional CGM revealed no evidence of overnight hypoglycemia. Her CGM glucose averaged 193 mg=dL, and she is in the hyperglycemic range most of day as shown by the large red segments in the pie chart of the Sensor Summary (Fig. 3). The charts also had some blue segments, indicating minimal periods of hypoglycemia. The Sensor Summary highlights a poor glucose control. The Sensor Modal Day tracings were highly variable, with an inconsistent pattern in the morning (including two brief periods of hypoglycemia), and significant postmeal excursions both at breakfast and dinner, with a drop in BG late afternoon (Fig. 4). Therapy Adjustments=Treatment Alterations The provider adjusted the basal insulin to Detemir BID 7 units in the morning and 10 units at night (11 units if BG [ 220 mg=dL at night) due to high morning BG. Aspart was maintained at the same dose. The patient saw the certified diabetes educator and nurse practitioner every 1 to 3 weeks. Most of the patient’s meals and snacks were low on protein, so she was instructed to have protein with each meal and snack, but to limit snacks overall. Follow-Up Professional CGM Results= Response to Therapy Adjustments On follow-up professional CGM, the BG pattern showed fewer excursions after breakfast and lunch (Fig. 5). The patient continued to have hyperglycemia after dinner that continued for up to 6 h, particularly after meals with high-fat content. On two out of the three evenings, her BG monitor recorded over 449 mg=dL. Examination of professional CGM outputs and the patient’s handwritten diary revealed that the patient was recording her BG levels in her diary inaccurately. For example, if the SMBG meter reading was 95, the patient recorded it as 195, probably due to her brain injury. ª 2010 Medtronic Minimed, Inc. All rights reserved.
  7. 7. Sensor Summary 7/20/2009 7/21/2009 7/22/2009 7/23/2009 Totals # of Sensor Values 92 288 288 159 827 Average (mg/dL) 192 205 169 293 208 43-306 83-346 50-353 43-381 STDev (mg/dL) 99 58 74 181-381 63 # of Meter Values 2 4 4 2 12 Average (mg/dL) 191 157 149 283 181 66-315 177-192 56-235 196-369 56-369 Date Sensor Meter Min - Max (mg/dL) Min - Max (mg/dL) Designation Optimal Accuracy Criteria # of Paired Readings X: Use Clinical Judgment 83 X: Use Clinical Judgment 2 4 4 2 12 Mean Abs. Diff. [MAD %] 19.3 17.7 6.1 5.5 12.1 Correlation Coeff. [R] n/a 0.99 n/a 0.97 2 3 7 0 12 # of High Excursions* 1 3 6 0 10 # of Low Excursions* 1 0 1 0 2 Duration Above High Limit 04:30 (59%) 20:25 (85%) 14:30 (60%) 13:15 (100%) 52:40 (76%) Duration Within Limits 02:05 (27%) 03:35 (15%) 07:15 (31%) 00:00 (0%) 12:55 (19%) Duration Below Low Limit 01:05 (14%) 00:00 (0%) 02:15 (9%) 00:00 (0%) 03:20 (5%) Glucose Area Above High Limit (mg/dL*Day) 75 68 43 153 76 Glucose Area Below Low Limit (mg/dL*Day) Excursions High > 140mg/dL Low < 70mg/dL n/a # of Excursions* 3 0 1 0 1 Pie Chart Red: Above Limits Green: Within Limits Blue: Below Limits X: Please use your clinical judgment - this day does not satisfy the optimal accuracy criteria according to set thresholds: N [¼ 3, R [¼ 0.79 and MAD <¼ 28% [or <¼ 18% if the range (Min-Max) of meter values is less than 100 mg=dL (5.6 mmol=L) - see Criteria Note below]. C: This day does not have any paired sensor=meter data and no sensor plot is provided. As a result, ‘Meter Only’ data is available. S: Please use your clinical judgment - this day does not have any meter data. As a result, ‘Sensor Only’ data is available. Criteria Note: If the range (Min-Max) of Meter Values is less than 100 mg=dL (5.6 mmol=L) then ‘R’ will be reported as ‘N=A’. In this case the optimal accuracy threshold set for MAD is <¼18%. Excursion Note: Excursions are counted in the day that the excursion event started. Fig. 3. The red segments of the Sensor Summary pie chart show that the patient is hyperglycemic most of day. Fig. 4. The Sensor Modal Day report show two brief periods of hypoglycemia (shown in blue and green), and significant postmeal excursions. CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING 7
  8. 8. PHILLIPS Fig. 5. The Sensor Modal Time Report shows that the patient experienced hyperglycemia after dinner that continued for up to 6 h. Given the patient’s generally poor dietary habits, she would have benefited from a correction factor and a carbohydrate ratio instead of sliding scale insulin. However, given her cognitive deficits, she would likely be unable to master the calculations involved. Conclusions The follow-up professional CGM tracings revealed the need to adjust insulin or diet (or both) at dinner and decrease the amount of basal insulin at night. Because of her hypoglycemic unawareness and marked excursions in her glycemic control, the patient would benefit 8 CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING from a personal CGM with an audible warning. She would also benefit from insulin-pump therapy. Theoretically, given her gastroparesis and the way she responds to high-fat meals, the endocrinologist could prescribe square wave bolus or dual wave bolus, and variable basal rates starting at 3:00 am or 4:00 am onward, but it would be clinically challenging to pursue this option. Disclosure Statement Paula Phillips, M.D., is a speaker for Medtronic Diabetes.
  9. 9. Case 2 A 60-Year-Old Woman with Diabetes Secondary to Necrotizing Pancreatitis with Highly Variable Blood Glucose Levels on Basal Bolus Therapy Initial Professional CGM Results Elizabeth Nardacci, FNP-C Albany Medical Center, Albany, New York. Patient History This patient developed necrotizing pancreatitis and was found to have diabetes in January 2008, about a year before the initial professional continuous glucose monitoring (CGM) evaluation. Despite multiple visits with both the physician and the diabetes educators, the patient had continued difficulty in dosing her insulin correctly. Her baseline regimen was Aspart *4 to 6 units with meals. She would not adjust her insulin dose more than 2 units at a time. She was also on Glargine 14 units at bedtime, which occurred at very varied times. Her initial A1c was 10.2%. The average sensor value was 269 mg=dL, which corresponded with A1c of 10.2%. Only 13% of her glucose readings were within the target range (WTR 70–150 mg=dL), 2% below the target, and 85% of readings were above the target (>150 mg=dL). The Sensor Modal Day revealed no consistent BG pattern. BG ranging from 200 to above 400 mg=dL. The provider examined the diary with the patient, comparing it to the professional CGM tracings. According to her diary, the patient was taking her glargine at varying times, but admitted missing her injections. (Fig. 6). The blue plus signs on the Sensor Modal Details indicate when the patient does SMBG. The tracing indicated wide glucose excursions that were not detected by SMBG (Fig. 7). Therapy Adjustments=Treatment Alterations Rationale for Initiating Professional CGM The patient was inexperienced with insulin dosing and really wanted to do a better job, as she had wildly fluctuating blood glucose (BGs). She felt hypoglycemic everyday, complained of feeling poorly, and was having difficulty functioning, especially in caring for her 12-year-old grandson of whom she had custody. She checked her BG up to six times daily because of concern about her symptoms. She never missed appointments with our diabetes educators, whom she saw frequently. The diabetes educators initiated the professional CGM. After using the Professional CGM, the provider recommended an insulin pump, and the patient agreed. Follow-Up Professional CGM Results=Response to Therapy Adjustments Four months after initiating insulin pump therapy, the patient had better BG control because of the continuous infusion of the basal insulin. The patient said things were better generally, but she still felt like she was experiencing hypoglycemia at lunchtime. Fig. 6. The Sensor Modal Day output shows severe hyperglycemia. ª 2010 Medtronic Minimed, Inc. All rights reserved. CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING 9
  10. 10. NARDACCI Fig. 7. The Sensor Daily Details highlight peak blood glucose readings that were missed on self-monitoring of blood glucose. Fig. 8. Sensor Modal Day indicates less blood glucose variability overall compared to the earlier evaluation. 10 CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING
  11. 11. CASE 2: WOMAN WITH DIABETES SECONDARY TO NECROTIZING PANCREATITIS On follow-up professional CGM, the Sensor Modal Day was much improved (Fig. 8). The tracings confirmed the patient’s perceptions: she was overcorrecting and experiencing hypoglycemia in the afternoon. The mean sensor value dropped from 269 to 179 mg=dL, and the standard deviation went from 101 to 79, indicating reduced glucose excursions. The A1c declined from 10.2% initial, to 9.9% in January 2009, and to 7.8% in July 2008. The patient was able to maintain and improve control, experiencing brief periods of hyperglycemia during the day. Her postprandial BGs remained elevated. She was carbohydrate counting well, according to the dietician, so the provider altered the pump settings to increase the patient’s basal rates slightly at night, assuming that the patient probably experienced some hypoglycemia unawareness. The insulin of carbohydrate ratio was also adjusted. The patient was doing what the bolus wizard told her to do, but since the setting was incorrect she was overcorrecting. The clinician adjusted the sensitivity number upward to give her less of a correction. This case illustrates three major issues that illustrate the use of professional CGM to generate an ‘‘aha! moment.’’ (1) The process of going through the professional CGM output and looking at the diary often elucidates previously hidden behavior that plays a key role in glycemic control. This patient would not have admitted missing glargine doses without seeing the wide glucose excursions. (2) The patient had been taking her evening dose of insulin at varying times. The professional CGM tracings provided adequate information to accept an insulin pump, because the patient could maintain BG control despite bed times that could differ from night to night by 6–8 h. (3) Although ordinarily a very anxious patient might not be an ideal pump therapy candidate, this patient was highly motivated and able to do a good job with a lot of education and support. Using the bolus wizard was very critical in helping this patient become confident in making dosing decisions, compared to her earlier hesitation in adjusting her injections by only 2 units each time. These changes allowed to patient to lower and maintain her A1c values and confirmed that she was making better decisions. Conclusions Disclosure Statement Professional CGM identified multiple reasons for uncontrolled diabetes in this patient. Although the patient is not at goal, she has improved significantly. Elizabeth Nardacci, F.N.P., BC-ADM, is a speaker for Eli Lilly and Medtronic Diabetes. She is on the medical advisory board of Medtronic Diabetes. CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING 11
  12. 12. Case 3 A 41-Year-Old Man with Type 1 Diabetes with Good Glucose Control Kathleen C. Arnold, A.N.P. The Diabetes Center, PLLC, Ocean Springs, Mississippi. Patient History This patient is a 41-year-old man found to have type 1 diabetes in February 2008. He had no other significant medical history or diabetes complications, and his A1c was 5.9%. He was managed with Glargine, 15 units at bedtime, and Aspart with a correction formula and a carbohydrate ratio, and he tested his blood glucose (BG) four to five times daily. He was an avid bicyclist who took 1–4-h bike rides 3–5 days a week. Rationale for Initiating Professional Continuous Glucose Monitoring Fig. 9. Sensor Modal Time tracing for an avid cyclist. Red arrows indicate unrecognized hyperglycemia and hypoglycemia. Both the patient and the healthcare provider wanted professional continuous glucose monitoring (CGM) to evaluate the BG control on cycling days. Fig. 10. Sensor Daily Details reveal most blood glucose values are within range, even on days that the patient takes long bike rides. 12 CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING ª 2010 Medtronic Minimed, Inc. All rights reserved.
  13. 13. CASE 3: MAN WITH DIABETES AND GOOD GLUCOSE CONTROL Initial Professional CGM Results The CGM tracings showed that the patient had overall good glycemic control, with the exception of hyperglycemia when he was prepping for long rides. For long rides he ‘‘carbo loaded’’ to keep his BG up when he is riding with a product called ‘‘goo,’’ which contains 80– 100 g of instant-acting carbohydrate. The Sensor Modal Day revealed hypoglycemic and hyperglycemic excursions, of which the patient was unaware. The patient tried to ride almost every day during his professional CGM evaluation, and he had no problems with sensor adherence while riding. The Sensor Daily Details reveal which days the patient was cycling by BG peaks (Fig. 9). He did have some unrecognized hyperglycemia during the night, and several episodes of unrecognized hypoglycemia. Therapy Adjustments=Treatment Alterations The only therapy adjustment for this patient was to change the way he carbohydrate loads before a ride. He now eats a longer-acting carbohydrate bar that includes some protein. No change in his insulin regimen was necessary. The patient is considering an insulin pump. He practiced with a smart pump with tubes, which was too bulky for his body type did not adhere well to his skin during bike rides. He has applied for an insulin pump with disposable components instead. Follow-Up Professional CGM Follow-up professional CGM revealed that most of his blood sugars are within the range, with fewer episodes of hypoglycemia (Fig. 10). He continues to ride but will take a break during the cold weather. Conclusions This case illustrates that even though the patient had good glucose control, this apparent level of control masked swings in BG subsequent to carbohydrate loading with the simple carbohydrate gel. Once he changed his preride carbohydrate source with protein, he was able to normalize his BG, not only during the day, but also overnight. Professional CGM also helped this patient to take the next step for better glycemic management by highlighting the benefits that an insulin pump would provide. Disclosure Statement Kathleen C. Arnold, A.N.P., BC-ADM, is a speaker for Lilly, Medtronic Diabetes, NovoNordisk, and Sanofi Aventis. CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING 13
  14. 14. Case 4 A 29-Year-Old Woman with Type 1 Diabetes, Pregnant with Triplets Kathleen C. Arnold, A.N.P. The Diabetes Center, PLLC, Ocean Springs, Mississippi. Patient History A 29-year-old patient with previously diagnosed type 1 diabetes presented with a nonplanned pregnancy with triplets. Her A1c at 14 weeks of gestation was 7.3%. Rationale for Initiating Professional Continuous Glucose Monitoring The provider usually manages pregnant women with type 1 diabetes using an insulin pump because of the rapidly changing needs for insulin during pregnancy. The patient had a hypoglycemic seizure due to insulin stacking and was transported to the hospital by ambulance. Her baseline treatment was a Medtronic Paradigm 722 pump, and she tested her blood glucose (BG) six to eight times daily. Initial Professional Continuous Glucose Monitoring Results Professional continuous glucose monitoring (CGM) revealed multiple hyperglycemic and hypoglycemic episodes, of which the patient was unaware of, because she did performed self-monitored blood glucose (SMBG) at times other than when the peaks or lows occurred (Fig. 11). Although the CGM device has 70 mg=dL as the default, the value should be changed to 60 for pregnancy. For pregnancy, target BG 2 hours postprandial is 120=mg=dL, and the patient did not always achieve that. Therapy Adjustments She initiated her pump very early in the pregnancy, and her pump downloads indicated hypoglycemia regularly. Premeal targets in pregnancy are 60 to 80 mg=dL, and she was having readings in the 50 mg=dL range. After looking at the professional CGM output and at the patient’s A1c, the provider recommended personal CGM. The patient’s A1c started out at 9.9% before pregnancy and then declined, first to 7.3% and then to 5.6%, once on insulin pump therapy. Response to Therapy Adjustments In early September, the patient had some complications. She underwent an intrauterine laser surgery to separate blood vessels of the two identical twins within this triplet pregnancy that were sharing a blood source; one of the fetuses was not growing. She subsequently developed preeclampsia. She delivered via C-section at 22 weeks’ gestation. One male infant weighed 1 pound 4 ounces, and another male 1 pound 3 ounces; the third infant died within 18 hours of birth. Both live infants were placed on ventilators. The patient developed postoperative pneumonia and Escherichia coli infection. While being treated for the infections, she was taken off her pump and given insulin infusions for a couple of days and then returned to the insulin pump. Conclusions Professional CGM helped this pregnant woman with type 1 diabetes, to realize that she was experiencing hypoglycemic excursions and hyperglycemia on a daily basis, and drove the decision to pre- Fig. 11. The Sensor Daily Details identify exactly when multiple hyperglycemic and hypoglycemic episodes occur. 14 CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING ª 2010 Medtronic Minimed, Inc. All rights reserved.
  15. 15. CASE 4: WOMAN WITH DIABETES, PREGNANT WITH TRIPLETS scribe a personal sensor. The CGM technology enabled day by day adjustments that resulted in a shift from an A1c of 9.9% to 5.6%. As the pregnant abdomen expands, placement of sensors has to change. Sometimes the patients may move the sensor from the abdominal area to the legs or buttocks. This patient was compliant with her regimen after the hypoglycemic episode. The patient used her Bolus Wizard 100% of the time, and performed SMBG four to five times daily. Often times with pregnancy in women with type 1 diabetes, especially with triplets, you may not have the best outcome. Her preterm labor was likely related either to the intervention they did at the hospital or to her extremely poor control before conception, at which time the patient was followed by a different provider. The two surviving babies are doing well. Disclosure Statement Kathleen C. Arnold, A.N.P., BC-ADM, is a speaker for Lilly, Medtronic Diabetes, NovoNordisk, and Sanofi Aventis. CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING 15
  16. 16. Case 5 A 61-Year-Old Man with Type 1 Diabetes Sushma Reddy, M.D. four times a day, he still experienced unrecognized hyperglycemic peaks that were missed with SMBG. Endocrinology & Diabetes Center, Fort Gratiot, Michigan. Patient History This case is a 61-year-old man with type 1 diabetes who originally presented with type 2 diabetes in 1989, and was initially treated with oral agents. In 1995, he was started on insulin. In 2001, a C-peptide test confirmed that the patient had type 1 diabetes. He was placed on basal-bolus therapy, and switched to an insulin pump in 2004. His job involves physical labor and he had low insulin requirements at breakfast and lunch. His major meal is dinner and he is sedentary afterward. His insulin-to-carbohydrate ratio at dinner was 1 unit for 8 grams of carbohydrate, in contrast to 1:12 at breakfast and lunch. Comorbidities and Diabetic Complications The patient had hypertension and hyperlipidemia, and was euthyroid secondary to hyperthyroidism 20 years before. He had diabetic retinopathy and peripheral neuropathy. Surgical history included angioplasty for coronary artery disease 1.5 years before. Rationale for Initiating Professional Continuous Glucose Monitoring He performed self-monitored blood glucose (SMBG) before dinner, 2 hours afterward, bedtime, and once in the middle of the night, at which time he had hyperglycemia. He had a higher basal rate of 2 to 2.1 units between 8 pm and 8 am. However, in spite of that, his A1c remained elevated at 9%. Initial Professional Continuous Glucose Monitoring Results Professional continuous glucose monitoring CGM revealed postprandial hyperglycemia, and nocturnal hyperglycemia between 8 pm and 2 am, indicating that the patient sometimes forgot to bolus after a night-time snack. The sensor summary indicated that the patient’s glucose level was within normal range only 24% of his time with a mean sensor glucose of 206 mg=dL (standard deviation, 81 mg=dL). The patient recognized how serious the problem was when the physician discussed each day’s tracings and discovered that on the day the patient had no bedtime snack, his BG levels were fairly well controlled (Fig. 12). Another tracing revealed that the patient was taking his insulin after breakfast, and another that he was not bolusing appropriately at dinner time. Although he performed SMBG 16 Therapy Adjustments=Treatment Alterations The Sensor Modal Day report revealed a dawn phenomenon (Fig. 13), which was corrected by a higher basal rate. The provider also adjusted the pump sensitivity and the insulin-to-carbohydrate ratio for the patient’s bedtime snack. He also reinforced the message that ‘‘whenever your hand goes to your mouth, it needs to go to your pump.’’ The patient also upgraded to a newer (model 722) insulin pump. Follow-Up Professional CGM Results=Response to Therapy Adjustments The patient’s A1c improved to 8.3%. The patient now uses a personal real-time CGM to help keep his BG under control. Remembering to bolus before his bedtime snack remains an ongoing challenge, and he experiences nocturnal hyperglycemia between 9 pm and 1 am about 2 days per week. Conclusions This case shows the typical evolution of type 1 diabetes in adulthood. He had type 1 diabetes from onset, which unfortunately went unrecognized. The professional CGM clearly demonstrated to the patient just how brittle his diabetes was and inspired him to improve his behavior, at least temporarily. Professional CGM is particularly helpful in managing patients in whom the A1c remains elevated despite multiple interventions. The professional CGM tracings highlights hyperglycemia based on which provider can recommend treatment changes to reduce hyperglycemia. In addition, professional CGM is particularly motivating for those patients who bolus after a meal despite being trained to bolus beforehand, because they are not sure what they are going to eat beforehand or they forget. A recent study sponsored by the Juvenile Diabetes Research Foundation showed an improvement in glucose control with realtime CGM use. There is a learning curve for the physician and patient to set a personal CGM device, so that the patient is not woken up too often that they become noncompliant. That is what happened with this patient, who routinely forgot to bolus with a bed time snack. Unfortunately, at a subsequent visit, this patient’s A1c reverted to 8.2% (lowest A1c was 7.2%), and the patient revealed that he had stopped using his personal CGM device. The patient immediately recognized that when he used his personal CGM regularly and remembered to bolus appropriately, he would not be awakened by alarms. CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING ª 2010 Medtronic Minimed, Inc. All rights reserved.
  17. 17. CASE 5: MAN WITH TYPE 1 DIABETES Fig. 12. Sensor Daily Details reveal that blood glucose is above 300 mg=dL throughout the day and at bedtime, and nearly normal on waking. Blood glucose peaks were not recognized with SMBG (shown as blue plus signs). Fig. 13. Sensor Modal Day reveals a dawn phenomenon between 3 am and 6 am (shown in black). Disclosure Statement Sushma Reddy, M.D., is a speaker for Eli Lilly, Medtronic Diabetes, Novo Nordisk, Sanofi-Aventis, Takeda, and Bristol Meyers Squibb. CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING 17
  18. 18. Case 6 A Type 1 Diabetic College Student with a Crazy Lifestyle and Crazy Blood Sugars Barry S. Horowitz, M.D. Palm Beach Diabetes and Endocrine Specialists, PA, West Palm Beach, Florida. Patient History This is the case of a college student with a crazy lifestyle with wide glucose excursions. This 18-year-old woman was found to have type 1 diabetes 3 years ago. She attends a community college and admits to a stressful life and poor dietary habits. Her baseline regimen was Aspart before meals. She was counting carbohydrates with a ratio of 0.5:3 at breakfast, 0.5:5 at lunch, and 12:9 at dinner. She was using a correction factor of 50 and was taking an inadequate glargine dose at bedtime. She checked her blood glucose (BG) inconsistently because of her schedule (2–6 T=day). Her BG ranged from 50 to 300 mg=dL and she was keeping poor records. tinuous glucose monitoring (CGM) was ordered to clarify the patterns and help the patient establish better control. Initial Professional CGM Results The sensor summary reveals that this patient is within her BG target ranges about 47% of the time. The Sensor Modal Day tracing showed a roller-coaster pattern of both highs and lows throughout the day. Sensor Daily Details revealed that the patient was having premeal hypoglycemia and postmeal hyperglycemia throughout the evaluation period (Fig. 14). Sensor Modal Time analysis showed that she was peaking in the middle of the night and then having hypoglycemia toward the morning. Examining the diary in conjunction with the CGM outputs revealed poor dietary habits, with meals that included very little protein and a lot of simple carbohydrates (e.g., granola bars, graham crackers, and popcorn), probably very typical for a college student. Her BGs often increased significantly after eating these high-carbohydrate meals. When she developed hypoglycemia she again consumed a lot of carbohydrates, which led to more hyperglycemia. Rationale for Initiating Professional Continuous Glucose Monitoring Therapy Adjustments=Treatment Alterations Her baseline A1c was 7.1%, which is almost at target, but the few reported BG measurements were so variable that professional con- We decreased her Glargine to 12 units because of the fasting hypoglycemia on awakening. The dietician recommended increasing Fig. 14. Sensor Daily Details reveal several unrecognized episodes of nocturnal hypoglycemia and several hyperglycemic peaks missed with self-monitored BG. 18 CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING ª 2010 Medtronic Minimed, Inc. All rights reserved.
  19. 19. CASE 6: DIABETIC COLLEGE STUDENT WITH CRAZY LIFESTYLE Fig. 15. The Sensor Modal Time tracings revealed elimination of the hyperglycemia peaks at 2 am and the hypoglycemia on awakening seen in the previous professional CGM study. protein consumption and decreasing simple carbohydrates, and taught her how to avoid over treating the hypoglycemia. The certified diabetes educator helped her calculate premeal insulin dosing. The physician suggested that the patient go on an insulin pump to more accurately dose her insulin. The patient now uses Aspart with a Medtronic 522 pump with individualized basal rates, carbohydrate ratios, sensitivities, and glucose targets. Follow-Up Professional CGM Results=Response to Therapy Adjustments A follow-up professional CGM was performed about 3 months later. The patient’s BG was in normal ranges 77% of the time, compared with <50% of the time at the earlier evaluation. In contrast to the roller-coaster pattern seen in the first one, the BG pattern smoothed out, with very little hypoglycemia, and only occasional hyperglycemia. The Sensor Modal Time report shows that the earlier 2 am peaks and the hypoglycemia episodes on awakening are gone (Fig. 15). The preprandial hypoglycemia and postprandial hyperglycemias were essentially eliminated. The diary indicated improved dietary habits. The patient still has occasional excursions on the Sensor Daily Detail report, probably as a result of reverting to poor food habits. The patient’s glycemic control improved markedly, with her A1c improved from 7.1% to 5.7% at her most recent visit, and no accompanying hypoglycemic episodes. Conclusions The major take-home message from this case is that CGM reveals behavior patterns that inhibit good glycemic control. BG excursions that do not appear with routine monitoring become obvious often times when we do professional CGM. These results motivated the patient to consider a pump. Ultimately, this patient progressed to better control because of the professional CGM technology. Disclosure Statement Barry S. Horowitz, M.D., is a speaker for Abbott Pharmaceuticals, Amylin Pharmaceuticals, Astra-Zeneca Pharmaceuticals, Bristol Myers Squibb, Eli Lilly Pharmaceuticals, Merck & Co, Inc., Medtronic Diabetes, Novo Nordisk, Pfizer Pharmaceuticals, Sanofi-Aventis Pharmaceuticals, and Takeda Pharmaceuticals. CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING 19
  20. 20. Case 7 A 38-Year-Old Woman with Type 1 Diabetes Bruce W. Bode, M.D. Atlanta Diabetes Associates, Atlanta, Georgia. Patient History Yes, there was 1 day when her BG was consistently in the 150 to 200 mg=dL range. The patient was instructed not to change her usual patterns during the professional continuous glucose monitoring (CGM) evaluation, but she obviously did because her average BG was 150 mg=dL on her Sensor Summary (Fig. 17), and it does not correspond with an A1c of 9.2%. Clearly, the patient bolused and monitored more often than usual. Even so, the BG patterns are still erratic. Either she is eating at night to protect against lows overnight, or she needed an increased basal insulin dose. This is the case of a 38-year-old woman with type 1 diabetes diagnosed in 1988. The baseline regimen was insulin Aspart via insulin pump. The baseline A1c was 9.2%, although her A1c values were in the range during two prior pregnancies. The patient is generally not compliant: she has used the same insulin dose for years, forgets to bolus regularly, does not bring her blood glucose (BG) logbook to office visits, and rarely monitors herself (zero to two times daily). She claims to be too busy to monitor her BG, although she did so during pregnancy. The patient is concerned about weight gain, and about hypoglycemia if she attempts to improve her glycemic control. Initially, the provider increased the basal rate, followed by a second increase several weeks later. The patient finally agreed to a pump after seeing the reports that she would not go low. However, she would not agree to use the Bolus Wizard, nor would she reinstate her antidepression medication out of fear of weight gain. Comorbidities and Diabetic Complications Response to Therapy Adjustments The patient shows signs of preproliferative retinopathy. She also has a history of depression, but does not take antidepressants because she gained weight when on treatment in the past. Thus, her fear of potential weight gain prevents her from treating both her depression and her diabetes. The patient’s last A1c did not change much (9.1%), but at least she is monitoring twice a day. She usually boluses five times daily, which is an improvement. She has also applied for personal CGM coverage. Therapy Adjustments=Treatment Alterations Conclusions Rationale for Initiating Professional Continuous Glucose Monitoring The patient is on an insulin pump and manually boluses approximately five times a day with 2 to 7 units. She will purposely under bolus if she feels she might go low. The patient denies snacking after 9:00 pm but has very high glucose levels in the morning. Taking the patient at her word, the appropriate therapeutic choice would be to increase her basal insulin. The provider wished to know whether the patient experienced a rise in BG in the dawn phase. Professional CGM revealed previously unrecognized problems with this patient’s BG patterns overnight. This patient may benefit most from personal CGM, but she has to become much more accepting of her diabetes to take that proactive approach. Professional CGM may not give an accurate picture of each patient’s diabetes control, because patients may change their diabetesrelated behavior during the professional CGM evaluation, despite being told to maintain their usual routine. The following steps will improve the likelihood that patients will not change their behavior while on professional CGM. . Initial Professional Continuous Glucose Monitoring Results The Sensor Daily Detail report revealed a clear dawn rise starting earlier than what was previously recognized (Fig. 16). She often has normal BG at bedtime, but at *1 am her BG will start to rise from 150 to 300 mg=dL by the time she wakes up. If her BG at bedtime is around 120 mg=dL, it will rise to 280 mg=dL or so upon awakening. If her bed time BG is 100 mg=dL, it may rise to 180 mg=dL on awakening. She denies eating despite apparent evidence to the contrary. During the day, her BG rarely dips below 70 mg=dL, but she has many hyperglycemic excursions, some up to 346 mg=dL. 20 . Before insertion, explain that the reason we are doing the study is to see actual day-to-day diabetic control and stress not to change anything for the first couple of days. Specifically mention that you are not going to judge the patient. Acknowledge that it may be difficult for the patient to do everything as usual because he or she knows that the healthcare professional is going to see what the patient is actually doing, but that is why it is so important. According to a recent study, the second best predictor of success with CGM (after age >25 years) is frequency of BG self-monitoring. To be successful using a personal CGM, the patient must monitor CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING ª 2010 Medtronic Minimed, Inc. All rights reserved.
  21. 21. Fig. 16. Sensor Daily Details reveals a dawn phenomenon earlier than expected, and blood glucose peaks that are not recognized with SMBG. Sensor Summary 6/26/2009 6/27/2009 6/28/2009 6/29/2009 6/30/2009 7/1/2009 # of Sensor Values 102 288 288 288 288 217 Average (mg/dL) 133 188 209 155 164 150 47-197 87-307 86-346 57-286 69-226 STDev (mg/dL) 33 66 65 56-331 72 66 33 # of Meter Values 3 5 4 4 6 5 Average (mg/dL) 108 172 157 92 124 160 96-116 77-270 72-242 46-141 49-262 118-232 Date Sensor Meter Min - Max (mg/dL) Min - Max (mg/dL) Designation Optimal Accuracy Criteria X: Use Clinical Judgment 3 5 4 4 6 4 Mean Abs. Diff. [MAD %] 28.1 11.5 12.9 11.7 7.1 5.5 Correlation Coeff. [R] # of Paired Readings 0.99 0.99 n/a 1.00 0.95 4 3 1 5 6 3 # of High Excursions* 3 3 1 3 4 2 # of Low Excursions* 1 0 0 2 2 1 Duration Above High Limit 02:25 (28%) 14:25 (60%) 19:05 (80%) 10:25 (43%) 11:30 (48%) 08:30 (47%) Duration Within Limits 05:50 (69%) 09:35 (40%) 04:55 (20%) 13:10 (55%) 11:35 (48%) 09:30 (53%) Duration Below Low Limit 00:15 (3%) 00:00 (0%) 00.00 (0%) 00:25 (2%) 00:55 (4%) 00:05 (0%) Glucose Area Above High Limit (mg/dL*Day) 5 48 67 29 33 12 Glucose Area Below Low Limit (mg/dL*Day) Excursions High > 150mg/dL Low < 70mg/dL n/a # of Excursions* 1 0 0 0 0 0 Pie Chart Red: Above Limits Green: Within Limits Blue: Below Limits X: Please use your clinical judgment - this day does not satisfy the optimal accuracy criteria according to set thresholds: N >¼ 3, R >¼ 0.79 and MAD <¼ 28% [or <¼ 18% if the range (Min-Max) of meter values is less than 100 mg=dL (5.6 mmol=L) - see Criteria Note below]. C: This day does not have any paired sensor=meter data and no sensor plot is provided. As a result, ‘Meter Only’ data is available. S: Please use your clinical judgment - this day does not have any meter data. As a result, ‘Sensor Only’ data is available. Criteria Note: If the range (Min-Max) of Meter Values is less than 100 mg=dL (5.6 mmol=L) then ‘R’ will be reported as ‘N=A’. In this case the optimal accuracy threshold set for MAD is <¼ 18%. Excursion Note: Excursions are counted in the day that the excursion event started. Fig. 17. Sensor Summary reveals an average BG of 150 mg=dL. Patient experiences hyperglycemia from 28% to 80% of the day. CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING 21
  22. 22. BODE at least four times daily. Because this patient routinely does not selfmonitor as recommended, and is likely to hear multiple alarms because of her extreme glucose excursions, she might not be very successful on a personal CGM. On the other hand, since she changed her self-monitored blood glucose (SMBG) behavior during the professional CGM evaluation as well as during her previous pregnancies, she might be motivated enough to develop better control on personal CGM. Some patients use personal CGM data exclusively to make changes in insulin dosing instead of SMBG. This may be particularly important when treating adolescents who may be out of control. It is possible, however, that personal CGM may help teens moderate BG swings even if performing SMBG less often than recommended. Some adolescents use personal CGM successfully, especially when driving privileges may be withheld if they don’t. Disclosure Statement Bruce W. Bode, M.D., received fees for research grants, advisory boards, and consultant activities, and is on the speaker’s bureau for Johnson & Johnson, Medtronic Diabetes, Novo Nordisk, and SanofiAventis. 22 CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING
  23. 23. Case 8 A 69-Year-Old Woman with Type 2 Diabetes and Good Premeal Glucose, But a High A1c Therapy Adjustments=Treatment Alterations Barry S. Horowitz, M.D. Palm Beach Diabetes and Endocrine Specialists, PA, West Palm Beach, Florida. Patient History This patient is a 69-year-old woman who was found to have type 2 diabetes about 6 years ago when she developed cardiomyopathy. Her current treatment regimen includes Aspart before meals with different units and Glargine at bedtime. She did not follow a 50:50 ratio of basal and bolus therapy, but her regimen presumably worked for her at the time. Comorbidities and Diabetic Complications Her comorbid conditions include cardiomyopathy, hypertension, and hyperlipidemia, for all of which she was taking medication. Rationale for Initiating Professional Continuous Glucose Monitoring Response to Therapy Adjustments The patient was checking her blood glucose (BG) four times daily. She stated that her blood sugars were in the low 100s premeals and at bedtime, but she routinely forgot her logbook. When she did bring her logbook, her premeal BG looked pretty good, but she was very noncompliant postprandial selfmonitored BG, despite multiple requests to do so. Her baseline A1c was 7.5%. The provider ordered professional continuous glucose monitoring (CGM) because he suspected that the patient was having some postprandial hyperglycemia. Initial Professional CGM Results The Sensor Summary from her first professional CGM showed that her CGM glucose values equally distributed in within, below, and above target range. The patient was completely unaware of hypoglycemia, although she experienced substantial nocturnal hypoglycemia everyday. The Sensor Modal Day showed that she was having some postprandial hyperglycemia and variability in her glycemic control in the evening (Fig. 18). The Sensor Daily Detail and Sensor Modal Time confirmed that her BG dropped throughout the night, leading to hypoglycemia toward the early morning. She also experienced postprandial hyperglycemia. ª 2010 Medtronic Minimed, Inc. All rights reserved. The patient’s diary revealed that she did not take premeal insulin when her premeal blood sugar was normal. She had had a misconception that if she had normal BG before meals, she did not need to take insulin. She also had subsequent postprandial hyperglycemia that was not captured with self-monitored BG. This patient is Hispanic and eats traditional, high-carbohydrate meals with lots of rice and beans. Comparing her diary entries to professional CGM outputs revealed that she took her usual dose of premeal insulin, even on days when she ate high-carbohydrate meals, and consequently developed postmeal hyperglycemia. The provider lowered her glargine dose at bedtime to reduce nocturnal hypoglycemia and provided additional education from a nutritionist and a diabetes educator. We again emphasized that she should dose her Aspart before meals regardless of what her blood sugars were. We also taught her how to count carbohydrates and use that along with the correction factor so she could be taking more insulin when she ate higher-carbohydrate meals and have better postprandial results. The patient began checking postmeal BG after seeing the postmeal hyperglycemia on the professional CGM report. She began counting carbohydrates with the correction factor for meals, which lead to better and less variable BG throughout the day. Follow-Up Professional CGM This follow-up CGM showed improved and more consistent glycemic control. The Sensor Summary revealed that the hypoglycemia was almost eliminated, with most BG values within the normal range and some hyperglycemia. The Sensor Modal Day report also shows some hypoglycemia overnight but not in the ranges that she was having before. The Sensor Modal Time report also revealed BG dips from 4 to 8 am, and some high BG after breakfast and dinner that was better than before. The Sensor Daily Detail report and diary showed that the patient was still often under dosing the mealtime insulin, but this was better compared to before when she was skipping doses entirely (Fig. 19). She was given some further counseling about her diet, and we cut back a little bit more on her glargine dose. Her most recent A1c had improved from 7.5% to 6.5%. Conclusions This subject with type 2 diabetes denied experiencing hypoglycemia, but she was low a third of the time during the first CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING 23
  24. 24. HOROWITZ Fig. 18. The Sensor Modal Day showed blood glucose dropping throughout the night and morning and postprandial hyperglycemia. Fig. 19. The Sensor Daily Detail report showed that the patient was still often under dosing her mealtime insulin, but at least was not skipping doses. professional CGM evaluation. Many researchers think that the increased mortality may be associated with unrecognized hypoglycemia with tight glycemic control in patients with type 2 diabetes as has been hypothesized in the ACCORD trial. Many patients are unwilling or unable to check BG at the most the clinically informative times (e.g., postprandially). The professional CGM showed this patient how her behavior patterns influenced her BG patterns. In this patient, the professional CGM resulted in behavior changes, leading to improvement in A1c from 7.5% to 6.5% with no associated hypoglycemia. 24 CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING
  25. 25. CASE 8: DIABETIC WOMAN WITH GOOD PREMEAL GLUCOSE, BUT HIGH A1C One panelist suggested that Dr. Horowitz might want to consider splitting the glargine into two doses, given the trend toward higher BG in the evening, but the postprandial hyperglycemia at dinner was not high enough. This patient was assigned a ratio of 3:1. Realistically, this patient was not going to abandon her traditional Hispanic diet, so she needed that ratio, and the professional CGM tracings reinforced that therapeutic decision. Disclosure Statement Barry Horowitz, M.D., is a speaker for Abbott Pharmaceuticals, Amylin Pharmaceuticals, Astra-Zeneca Pharmaceuticals, Bristol Myers Squibb, Eli Lilly Pharmaceuticals, Merck & Co, Inc., Medtronic Diabetes, Novo Nordisk, Pfizer Pharmaceuticals, Sanofi-Aventis Pharmaceuticals, and Takeda Pharmaceuticals. CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING 25
  26. 26. Case 9 A 37-Year-Old Woman with Type 2 Diabetes at 20 Weeks of Gestation Kathleen C. Arnold, A.N.P. Initial Professional Continuous Glucose Monitoring Results The Diabetes Center, PLLC, Ocean Springs, Mississippi. The Sensor Daily Detail revealed high postprandial BG values, some as high as 200 mg=dL, starting at breakfast and usually worsening at lunch and dinner (Fig. 20). T Patient History his is a case of a 37-year-old woman with type 2 diabetes associated with pregnancy. She had no known diabetes complications and her baseline A1c was 5.7%. She tests her blood glucose (BG) six to eight times daily. Her baseline treatment was NPH twice a day (14 units in the morning and 20 units at night), and Lispro. The BG target is lower for pregnancy, 80 divided by 40 and carbohydrates divided by 10. Therapy Adjustments=Treatment Alterations The clinician reviewed her dietary log and discussed the relationships between her high-carbohydrate and high-fat intake and her high postprandial BG readings. The dietician recommended dietary changes and her carbohydrate ratio was adjusted to carbohydrates divided by eight. Rationale for Initiating Professional Continuous Glucose Monitoring Follow-Up Professional Continuous Glucose Monitoring Results=Response to Therapy Adjustments The healthcare professional wanted to ensure that the patient was doing well day to day, in light of the challenges posed by BG control during pregnancy for patients with type 1 or type 2 diabetes. Before a follow-up professional continuous glucose monitoring to re-verify the ratio was scheduled, the patient was induced, and she delivered a healthy 6-pound boy at 38 weeks. Fig. 20. Sensor Daily Details revealed unrecognized postprandial hyperglycemia. 26 CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING ª 2010 Medtronic Minimed, Inc. All rights reserved.
  27. 27. CASE 9: WOMAN WITH DIABETES AT 20 WEEKS OF GESTATION Conclusions This case emphasizes that an A1c in the 5.6%–5.7% range through the entire pregnancy may mask underlying postprandial BG excursions, even in a patient who checked her BG six to eight times daily, including 2 h after meals. Although this patient had a healthy outcome (a normal-sized infant), diabetic women with decent A1cs may still deliver a macrosomic infant. A high A1c during pregnancy is a major risk factor for macrosomia, which is also thought to be related to obesity and insulin-resistant syndrome later in life. There’s a trend toward lowering the target A1c to <5% in pregnancy. The American Diabetes Association fasting target is now 95 mg=dL (ADA 2008). The guidelines may be revised to 80 mg=dL to try to get better glucose control. With this patient, early intervention contributed to a healthy outcome. To prevent macrosomia, ideally a clinician should intervene preconception, but failing that, one should intervene no later than early in the second trimester. Disclosure Statement Kathleen C. Arnold, A.N.P., BC-ADM, is a speaker for Lilly, Medtronic Diabetes, NovoNordisk, and Sanofi Aventis. CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING 27
  28. 28. Case 10 A 41-Year-Old Woman with Type 2 Diabetes, High A1c Ola Odugbesan, M.D. Comorbidities and Diabetic Complications North Atlanta Endocrinology, Lawrenceville, Georgia. The patient is on prednisone therapy for asthma and has irritable bowel syndrome. She developed profound hyperglycemia that required insulin therapy. A Patient History 41-year-old woman was initially found to have gestational diabetes during pregnancy and type 2 diabetes in 2003 after she miscarried. Her A1c measured 8.4% in early summer 2009. She is one of the clinical diabetes managers within the presenter’s practice, but her own diabetes was being managed by her internist. Rationale for Initiating Professional Continuous Glucose Monitoring At the time she agreed to be followed within the practice where she worked, she was on pioglitazone and metformin, but she was probably not compliant with this regimen, because of gastrointestinal side effects from metformin. Sensor Summary Date 5/29/2009 Totals 288 169 577 Average (mg/dL) 234 252 282 257 106-299 182-297 234-323 39 24 20 106-323 32 # of Meter Values Meter 5/28/2009 120 STDev (mg/dL) Sensor 5/27/2009 # of Sensor Values 4 5 2 11 Average (mg/dL) 227 259 290 253 173-306 239-268 271-308 173-308 Min - Max (mg/dL) Min - Max (mg/dL) X: Use Clinical Judgment Designation Optimal Accuracy Criteria 3 5 2 10 Mean Abs. Diff. [MAD %] 7.0 3.3 7.5 5.3 Correlation Coeff. [R] # of Paired Readings n/a n/a 0.84 2 0 0 2 # of High Excursions* 2 0 0 2 # of Low Excursions* 0 0 0 0 Duration Above High Limit 09:15 (92%) 24:00 (100%) 14:05 (100%) 47:20 (98%) Duration Within Limits 00:45 (8%) 00:00 (0%) 00:00 (0%) 00:45 (2%) Duration Below Low Limit 00:00 (0%) 00:00 (0%) 00.00 (0%) 00:00 (0%) Glucose Area Above High Limit (mg/dL*Day) 57 72 102 78 Glucose Area Below Low Limit (mg/dL*Day) Excursions High > 180mg/dL Low < 70mg/dL 0.94 # of Excursions* 0 0 0 0 Pie Chart Red: Above Limits Green: Within Limits Blue: Below Limits Fig. 21. The Sensor Summary revealed that the patient was hyperglycemic all day long. X: Please use your clinical judgment - this day does not satisfy the optimal accuracy criteria according to set thresholds: N >¼ 3, R >¼ 0.79 and MAD <¼ 28% [or <¼ 18% if the range (Min-Max) of meter values is less than 100 mg=dL (5.6 mmol=L) - see Criteria Note below]. C: This day does not have any paired sensor=meter data and no sensor plot is provided. As a result, ‘Meter Only’ data is available. S: Please use your clinical judgment - this day does not have any meter data. As a result, ‘Sensor Only’ data is available. Criteria Note: If the range (Min-Max) of Meter Values is less than 100 mg=dL (5.6 mmol=L) then ‘R’ will be reported as ‘N=A’. In this case the optimal accuracy threshold set for MAD is <¼ 18%. Excursion Note: Excursions are counted in the day that the excursion event started. 28 CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING ª 2010 Medtronic Minimed, Inc. All rights reserved.
  29. 29. CASE 10: WOMAN WITH DIABETES AND HIGH A1C Sensor Summary Date 9/17/2009 9/18/2009 Totals 288 288 159 773 Average (mg/dL) 145 138 149 139 143 137-165 63-181 88-193 63-193 6 21 20 98-165 12 # of Meter Values Meter 9/16/2009 38 STDev (mg/dL) Sensor 9/15/2009 # of Sensor Values 1 4 4 1 10 Average (mg/dL) 172 144 159 155 154 172-172 133-160 125-190 155-155 125-190 X: Use Clinical Judgment X: Use Clinical Judgment Min - Max (mg/dL) Min - Max (mg/dL) Designation Optimal Accuracy Criteria X: Use Clinical Judgment 19 1 4 4 1 10 Mean Abs. Diff. [MAD %] 17.0 6.3 23.2 13.4 14.8 Correlation Coeff. [R] # of Paired Readings n/a n/a n/a n/a n/a # of Excursions* 0 2 2 0 4 # of High Excursions* 0 1 2 0 3 # of Low Excursions* 0 1 0 0 1 00:00 (0%) 00:15 (1%) 01.55 (8%) 00:00 (0%) 02:10 (3%) 03:10 (100%) 23:10 (97%) 22.05 (92%) 13:15 (100%) 61:40 (96%) 00:00 (0%) 00:35 (2%) 00.00 (0%) 00:00 (0%) 00:35 (0%) Glucose Area Above High Limit (mg/dL*Day) 0 0 0 0 0 Glucose Area Below Low Limit (mg/dL*Day) 0 0 0 0 0 Duration Above High Limit Duration Within Limits Duration Below Low Limit Excursions High > 180mg/dL Low < 70mg/dL Pie Chart Red: Above Limits Green: Within Limits Blue: Below Limits X: Please use your clinical judgment - this day does not satisfy the optimal accuracy criteria according to set thresholds: N > ¼ 3, R > ¼ 0.79 and MAD <¼ 28% [or <¼ 18% if the range (Min-Max) of meter values is less than 100 mg=dL (5.6 mmol=L) - see Criteria Note below]. C: This day does not have any paired sensor=meter data and no sensor plot is provided. As a result, ‘Meter Only’ data is available. S: Please use your clinical judgment - this day does not have any meter data. As a result, ‘Sensor Only’ data is available. Criteria Note: If the range (Min-Max) of Meter Values is less than 100 mg=dL (5.6 mmol=L) then ‘R’ will be reported as ‘N=A’.In this case the optimal accuracy threshold set for MAD is <¼ 18%. Excursion Note: Excursions are counted in the day that the excursion event started. Fig. 22. Sensor Summary pie charts show the patient within targets 95%–100% of the time. She was also supposed to be taking Lispro PRN for episodes of hyperglycemia. She was supposed to be checking her blood glucose (BG) three to four times daily, but was apparently noncompliant with that also. While she was on vacation, she developed profound hyperglycemia, felt weak and diaphoretic, and may have exacerbated her asthma exacerbation, and also developed foot ulcers that took a little while to heal. She ended up in the hospital. She is the nurse who counsels the patients who come in for professional continuous glucose monitoring (CGM), and is actually the one who places and removes the devices. Initial Professional CGM Results As a nurse specializing in diabetes care, the patient saw the Sensor Summary and immediately recognized the implications (Fig. 21). In fact, she described herself as a ‘‘rolling ball of sugar.’’ The pie charts show that she is hyperglycemic all day long, with the rare episode of normoglycemia. There were no meal markers because she essentially grazed all day long. Therapy Adjustments=Treatment Alterations The physician maintained the patient’s pioglitazone prescription, because she does have profound insulin resistance, but metformin was discontinued because of the gastrointestinal side effects. She was switched to exenatide only, 5 mcg twice daily. Given her previous poor dietary habits, she still wanted to have Lispro on hand if she ate a very high carbohydrate meal. The patient saw the dietitian, and decided that she was going to be more active and try to achieve better diabetes control. Follow-Up Professional CGM Results=Response to Therapy Adjustments Follow-up professional CGM showed that the patient was more compliant with her treatment regimen and her BG was within target 95% of the time, with very little hyperglycemia, and virtually no hypoglycemia (Fig. 22 and 23). She did not have gastrointestinal side effects and so complied with her therapy. She lost about 20 pounds CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING 29
  30. 30. ODUGBESAN Fig. 23. Sensor Daily Details show blood glucose within range except for two episode of mild hyperglycemia (circled). over a 4-month period because of improved diet, increased exercise, and perhaps to some extent exenatide therapy. She feels better and has had a much better quality of life. The very rare episodes of hyperglycemia may reflect the days that the pharmaceutical company sales representatives brought lunch for the staff. Her latest A1c is within the normal range. This is a dramatic difference from where she was before having the therapy. vinces other patients of the value of professional CGM because she knows firsthand how it improved her glycemic control. The provider attributed the patient’s weight loss primarily to a combination of diet and increased levels of physical activity, rather than to the medication change, because the exenatide dose (5 mcg) was so small. Disclosure Statement Conclusions This patient was not managing herself at all and truly ignoring her diabetes. Her average BG was 257 and her A1c was 8.4%. Use of professional CGM demonstrated that she does not need to eat all day long and live in perpetual hyperglycemia. She now con- Ola Odugbesan, M.D., is a speaker for Abbott, Amylin, Astra Zeneca, Bristol-Myers Squibb, Glaxo SmithKline, Lilly, Medtronic Diabetes, Merck, Novo Nordis, Satauru, and Takeda. 30 CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING
  31. 31. Discussion Regarding Use of Professional Continuous Glucose Monitoring T he key points for optimizing patient management with professional continuous glucose monitoring (CGM) reached by consensus of the roundtable participants included CGM Terminology, the Consensus Statement, Selection Criteria for Professional CGM, Implementation of Professional CGM in a Practice Setting, Interpreting Professional CGM Outputs, Therapy Adjustments Guided by Professional CGM, and the Future of CGM. Consensus on CGM Terminology Professional CGM is the term used most often to describe CGM characterized by the following: . The aim of professional CGM is to assess the patient’s realworld behavior and how it influences glucose patterns and to determine the glucose patterns that are not visible when the patient performs self-monitored blood glucose (SMBG) only four to six times per day. The ultimate goal of professional CGM is to enable the healthcare professional make appropriate adjustments in diet, physical activity, and adjustments in the dosages of insulin and other medications. . The device is owned by the individual healthcare provider, the practice, or the hospital center. . The CGM device is put in place by a professional licensed person. . The patient is blinded to the readings and there are no audible alarms to alert patients to hypo- or hyperglycemia. . The device stays in place for 72 h. . Professional CGM is more of a diagnostic tool. . Upon downloading, the provider sees and interprets the readings retrospectively and discuss appropriate therapy adjustments with the patient. Other terms used to describe professional CGM include blinded CGM, blinded retrospective CGM, historical CGM, clinic CGM, CGM for physicians, 72-h CGM, and CGM system. Professional CGM is particularly useful for type 1 patients who take multiple insulin injections or are on pumps to fine-tune their dosage. In a patient with type 2 diabetes with an unexplained elevated A1c, professional CGM can pinpoint needed changes in treatment that would bring their A1c down. Professional CGM is particularly useful for those patients who might be considering personal CGM, those considering a change from MDI Insulin to pump therapy or from oral agents to insulin. Real-time CGM is the term used most often to describe CGM characterized by the following: . The device is owned by the individual patient. . The CGM device is put in place by a professional licensed person. ª 2010 Medtronic Minimed, Inc. All rights reserved. . The patient is not blinded to the readings and audible alarms alert the patient to hypo- or hyperglycemia. . Personal CGM is both a diagnostic and therapeutic tool. . Patients must be trained to make their own therapy adjustments. Data are displayed either on the pump or for patient not on a pump on the CGM device itself. Patients see and interpret the CGM data these in real time and make their own therapeutic decisions. . The device remains in place permanently (sensor changed every 3 days). According to data from the JDRF trials the best benefit accrues to patients who use the personal CGM device 6 days a week on an ongoing basis. . When the physician sees the data, they are interpreted retrospectively; the patient has already acted upon the data. Other terms used to describe personal CGM include real-time CGM, home-use CGM, patient CGM, and consumer CGM. Personal CGM is especially useful for patients who already monitor with SMBG frequently that are not at goal. It takes a lot more training and follow-up with personal CGM than it does with professional CGM to ensure that the patients interpret the real-time readings. If a patient is a candidate for personal CGM, the professional CGM evaluation is useful to document hypoglycemia, if the condition has not been adequately documented using SMBG alone. Some insurance carriers now require professional CGM as part of the authorization for a personal CGM device. There are patients who, even if their plan would authorize it, do not want a personal CGM device but would agree to wear a professional CGM device for 3 days to optimize therapy. Roundtable participants agreed that providers must use consistent terminology when distinguishing professional CGM from personal CGM for the following reasons: . When the term ‘‘professional’’ is attached to the term ‘‘CGM,’’ patients understand that it is the healthcare provider who collects data that are going to help manage their diabetes. . When the adjective ‘‘personal’’ is attached to the term CGM, patients understand that it is the patient who is most active in the process; in addition, patients may not understand what the term ‘‘real time’’ means. . Insurers do not necessarily understand the distinction between professional and personal CGM and may reimburse for something that was not requested. * * Consensus on Definition of Professional CGM Professional CGM is a diagnostic and therapeutic=management tool used by the healthcare professional that allows the collection of CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING 31
  32. 32. DISCUSSION REGARDING USE OF PROFESSIONAL CGM retrospective glucose data in patients with diabetes. It is indicated to optimize safe and effective glycemic control in patients in whom selfmonitoring of BG is inadequate. Consensus on Selection Criteria for Professional CGM The overarching reason to use professional CGM is to better understand a patient’s glycemic control when self-monitoring of BG proves inadequate to do so. A typical driver for consideration of professional CGM is a patient who does not maintain their BG within targeted ranges, or is not at their A1c goal, or both. The healthcare provider will need to determine patterns that undermine safe and effective therapy, and make appropriate therapeutic changes to get the patient to goal. The rationales for professional CGM for the 10 cases presented at this Roundtable are summarized in Table 1. Cases 1, 2, 5, and 7 were all patients with type 1 diabetes and an A1c that was too high. Two cases with type 1 diabetes had normal A1cs, but each patient faced challenges with day-to-day glycemic control—one because of intense athletic activities, and the other because of a demanding college schedule. In two cases (the college student and the women with type 1 pregnant with triplets), the professional CGM data influenced patients to switch to an insulin pump, resulting in A1c values that declined to 5.7% and 5.6%, respectively, without any hypoglycemia. Case 9, the type 2 diabetic woman on oral agents, switched to insulin therapy using a pump and was able to get to goal, and deliver a healthy child no evidence of macrosomia. Two cases had type 2 diabetes: case 8 was on multiple daily injections with large amounts of insulin, with BG unawareness at both extremes. Just by altering the regimen, she eliminated all hypoglycemia and achieved an A1c of 6.5%. Case 10 was on oral agents only and hyperglycemic 100% of the time. As a diabetes specialist nurse, she recognized the implications of her tracings, and she was finally motivated enough to change her diet and activity and thus achieved normal BG levels. Participants agreed that the goal of professional CGM should be to open a patient’s eyes to what is going on with their diabetes, to get that ‘‘aha!’’ moment when the patients realize why they need to do the things they know that they should be doing, but that they are not. Data from professional CGM may also be a trigger than can convince patients to switch from MDI to pump therapy, if that is what the physician has been recommending, or from pump therapy alone to pump therapy with personal CGM. One participant always recommends professional CGM for patients who experience any severe hypoglycemic event requiring assistance of another person. Another rationale for professional CGM is for patients whose A1c is not at goal in spite of frequent glucose monitoring, or if their A1c is at goal with a high variability in their BG meter download. Patients who do not comply with recommendations for routine glucose monitoring frequency may be willing to do SMBG four times daily for 3 days, even if they generally come to physician visits with no fingerstick data. The clinician needs to make sure that patient is safe, and professional CGM can motivate them to do better. Professional CGM can be justified in all diabetic patients who take medications that can lead to hypoglycemia, even if they have A1c values in a healthy range. Thus, all type 1 patients, and those type 2s on insulin or oral agents that cause hypoglycemia (e.g., sulfonylureas) are candidates for professional CGM. For patients with type 2 diabetes who are not on insulin and whose A1c is not at goal, professional CGM is useful to determine whether to offer the patient an alternative oral or switch to insulin. For type 2 diabetic patients on basal insulin only, professional CGM can help identify whether the patient may need to add rapid-acting insulin for a meal, or to titrate multiple insulin doses as needed. Insulin-requiring patients who have had type 2 diabetes for a long time may have brittle disease that is very similar to type 1 characteristics. One important take-home message is that patients may have A1c values that are nominally at goal, but may actually have poor glycemic control. The A1c is an average value and, as such, may mask widely fluctuating BG, especially at the extremes. If the SMBG record indicates wide variations, the patient would be an excellent candidate for professional CGM. Roundtable participants emphasized that the terms ‘‘controlled’’ or ‘‘uncontrolled’’ diabetes should not be determined solely by the A1c, particularly in type 1 diabetes. If a patient’s A1c is 6.5% but their BG ranges between 40 and 400, then their diabetes in uncontrolled, and it should be coded that way. This designation is particularly important during pregnancy because of the risk of unrecognized postprandial hyperglycemia, especially in type 1 diabetics that are near normal. There is a correlation between postprandial glycemia control and complications in gestational diabetes (HAPO 2008 N Engl J Med). Patients still experience significant morbidity from hypoglycemia up to and including the possibility of death. Unfortunately, there was no professional CGM component in the large cardiovascular outcome trials in type 2 diabetes, specifically Action to Control Cardiovascular Risk in Diabetes trial (Gerstein 2008 NEJM). After thorough discussion of the cases that were presented, roundtable participants discussed the types of patients for whom professional CGM is indicated to optimize glycemic control. Characteristics of patients who are good candidates for professional CGM are listed in Table 2. Consensus on Implementation of Professional CGM in the Private Practice Setting The Value of Retrospective Data with Professional CGM When considering whether to implement professional CGM in their practices, healthcare professionals should be aware of the advantages of establishing such procedures as part of their service offerings. These advantages are summarized in Table 3. Staff One of the key components of initiating a professional CGM component to a provider’s practice is having a dedicated staff. Particularly helpful is to have either a licensed professional in your 32 CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING
  33. 33. DISCUSSION REGARDING USE OF PROFESSIONAL CGM Table 1. Rationales for Initiating Professional Continuous Glucose Monitoring for Cases Presented PRESENTER BASELINE TREATMENT RATIONALE FOR PROFESSIONAL CGM DIABETES TYPE GENDER A1c AT BASELINE Phillips 1 F 9.6% NPH 10 U qam Glargine 15 U qhs R insulin SSI premeal Hypoglycemia unawareness; gastroparesis Nardacci 2 F 10.2% Aspart 4–6 U w=meals Glargine 14 U qhs Highly variable BG on basal bolus therapy Arnold 1 M 5.9% Glargine 15 U qhs Aspart BS-100 Avid cyclist considering pump Arnold 2 F 5.7% NPH 14–20 U Lispro BS-80 Pregnant; 20 weeks gestation Arnold 1 F 7.3% MDT Pardigm 722 pump Pregnant with triplets; hypoglycemic seizure secondary to insulin stacking Horowitz 2 F 7.5% Aspart pre meals Glargine 50 U qhs Good premeal sugars but high A1c. Postprandial hyperglycemia Horowitz 1 F 7.1% Aspart pre meals Glargine 15 U qam 18-year-old college student with variable BG Odugbesan 2 F 8.4% Pioglitazone 30 mg qd Exenatide 5 mg bid Lispro PRN Nonadherence Reddy 1 and 2 M 9.0% Insulin pump High A1c Bode 1 F 9.2% Aspart via CSII Hyperglycemia 24=7 Dawn phenomenon BG, blood glucose; CGM, continuous glucose monitoring. practice who is enthusiastic enough to champion the technology, a medical assistant willing to be in charge of this program, or a motivated, well-educated patient who is willing to volunteer with patients who might be candidates for professional CGM. Ideally, at least two staff members, including medical assistants, should be cross-trained to insert and remove the professional CGM devices. Then, if the champion or team leader is absent, there is continuity. Space Space is a big issue in most practices. If a dedicated room is not available, then a rolling cart to hold the computer and related equipment is one option. In one participant’s practice, the professional CGM devices are set up with the hospital, and all patients are referred there, where the devices are inserted in a dedicated room. Scheduling A schedule needs to be established to ensure getting the equipment back and cleaned so that it can be used by the next patient. In some practices, all professional CGM insertions are done on Thursday with return of the devices on Monday or Tuesday. Most participants indicated that the patient physically returns the CGM device at the end of the 72-h evaluation period, with the possible exception of some pediatric patients who mail the devices back because they live far away and do not want to miss school. Other practices, particularly those with a higher volume of diabetic patients on insulin pumps, do professional CGM insertions on Monday mornings with return on Thursday morning, followed by new patient insertions on Thursday afternoon with removals on Monday morning. Relaying Information to the Patient The ideal scenario is to share professional CGM results with the patient face to face. Some practices insist that patients come in for interpretation, because getting the patient to see the professional CGM data is very motivating and empowering. In these practices, physicians may interpret and relay the information to the patient directly. In other practices, the physician interprets the professional CGM output and relays the information about suggested therapeutic changes to the nurse practitioner or diabetes educator to communicate to the patient. Then, the patient comes back a few weeks after CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING 33
  34. 34. DISCUSSION REGARDING USE OF PROFESSIONAL CGM Table 2. Professional Continuous Glucose Monitoring Candidates Table 3. The Value of Retrospective Data with Professional Continuous Glucose Monitoring Diabetic patients unable to achieve an optimal, safe, and effective glycemic goal with self-monitoring of blood glucose Minimal time required for training and patient start-up No user interface allows for added simplicity of use Diabetic patients with hemoglobin A1c within target range, but with highly variable blood glucose Unaltered glucose patterns without intervention or alerts affecting the glucose levels Patients with repeated episodes of hypoglycemia or hypoglycemic unawareness Levels help guide appropriate therapy adjustments Insulin-requiring patients Observe the impact of patient’s diet, exercise, behavior, and medications on their glucose levels Diabetes in pregnancy Direct attachment to the body can reduce the possibility of missed data Not all patients are ready to understand and respond to real-time glucose data those changes are implemented. At that visit, the physician shows the patient the professional CGM output and explains the rationale for the changes. Time slots for relaying professional CGM results should be kept open on the schedule so that patients can get their results in a timely manner. In another practice, 90% of the interpretation is done by a certified diabetes educator (who is a licensed nurse practitioner) who goes over the results and the recommended changes directly with the patients, with physician oversight after the fact. In reality, given both patients’ schedules, insurance plans with very high copays for office visits, and how far in advance one’s practice is booked with new patient visits, it can be difficult to arrange face-toface follow-up visits on a rapid basis after the professional CGM evaluation. In some practices, a licensed staff member calls the patient to relay the initial results, and then actually gives the patient a copy of the data at the next visit. . . * . Equipment The practice should have available enough equipment for the patient load and some backup devices in case a patient is late for their appointment for the download when another patient is awaiting an installation. Roundtable participants agreed that, on average, it takes 10– 15 min to set up each patient with professional CGM device. All participants also emphasize that each patient keeps a diary that records what and when they are eating, taking medications, and participating in physical activities. For the patients who are on pumps, plan to download the pump data simultaneously with the professional CGM device. One panelist described a colleague who insists on using a personal CGM device as a professional CGM device, and I have had multiple discussions with him. This physician gives as his rationale for doing this that the personal CGM is approved for a 7-day use, and you need 7 days to see what is going on with the patient’s glycemic control during the week compared with weekends. General consensus is that it is inappropriate to use a personal CGM device as a substitute for a professional CGM evaluation for the following reasons: The use of personal CGM device eliminates the blinded nature of a professional CGM, which is key to developing those ‘‘aha!’’ moments with the patient when going over the professional CGM results. When scheduled appropriately, 3 days of data are adequate for evaluating glucose control over time. For patients who have markedly different schedules for weekends and weekdays, the provider can start the patient with the professional CGM device on a Thursday and thus catch both a weekday and a weekend day during the evaluation period A personal CGM device requires more training for the patient to be able to use it safely. The patient must perform SMBG before making a therapeutic decision and then you have to teach them also how to calibrate and that you got to calibrate it appropriately. To get a complete picture of glycemic patterns within a 3-day period, the provider may train the patient to perform overnight basal rate testing the first day only, because the overnight testing is a lot to ask day in and day out. On subsequent 2 days, the patient might skip breakfast 1 day, and skip lunch or dinner another day. . Billing and Reimbursement Reimbursement policies must be established before initiating the professional CGM evaluation, to ensure that the procedure will be reimbursed. Medicare reimburses professional CGM for insulinrequiring diabetic patients. In some cases, Medicare will also reimburse for patients who are not on insulin if you can demonstrate that they are not in control. Non-Medicare health plans have differing policies governing professional CGM reimbursement. In addition, Medicare and some private insurers will reimburse for two to four yearly professional CGM evaluations. The lead staff member in charge of professional CGM must contact the local insurance providers and obtain their procedures and referral forms for professional CGM authorization. Not all insurance 34 CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING
  35. 35. DISCUSSION REGARDING USE OF PROFESSIONAL CGM companies are familiar with requests for professional CGM, and rationales for performing the procedure must be filled out as required. The forms must document exactly how the patient meets the criteria established by each insurer’s plan. In particular, diagnoses of uncontrolled diabetes or other rationales must be coded accurately. The device’s manufacturer may provide a resource guide for practices that want to utilize the technology. There was general agreement about coding for reimbursement for professional CGM. Pre-CGM evaluation can be billed using codes 99212–99215. The procedure itself, including placement of the sensor, removal of the sensor, and downloading the data, is coded as professional CGM 95250. The initial visit during which the device is inserted is just a visit and not a charge. The 90250 charge is done at the time of the download. The interpretation of both personal CGM and professional CGM is coded as 95251, billed on the day that you interpret it. This latter charge is billable whether the interpretation is shared with the patient by telephone or in person, so long as the interpretation of the download with recommendation of therapeutic adjustments is done by a licensed practitioner (e.g., Medical Doctor, Doctor of Osteopathy, Nurse Practitioner, or Physician Assistant). Within the practice, a system of checks and balances are needed to ensure that all patients who were scheduled for professional CGM received the equipment and returned it, and that all services provided are billed for at the end of every week. In one practice, the billing department meets quarterly with the healthcare provider to discuss the implementation of the professional CGM service. Consensus on Follow-Up Professional CGM Recommendations Participants agreed that repeating a professional CGM evaluation is important for two main reasons: (1) the patient and healthcare provider get to evaluate the success of therapeutic changes guided by the first evaluation; (2) glycemic control is an evolving story for many diabetics, and regular evaluations are necessary to ensure that patients continue to integrate data into their behaviors that govern glycemic control over time. Several participants indicated that, although follow-up professional CGM evaluation is clinically important, and is covered by Medicare, in reality, repeat professional CGM is underutilized. One participant’s practice is just starting to incorporate follow-up CGM evaluations within 3 or 6 months to ensure that the therapeutic changes that have been made actually improved the BG pattern overall, and not just the A1c. The roundtable moderator just finished participating in a trial in which eligible subjects had type 2 diabetes treated with basal insulin. Subjects were placed on an insulin pump and professional CGM was used to optimally titrate their basal and bolus insulin so they had no hypoglycemia. Subjects came back weekly for evaluation of the sensor data, with alteration to the basal and bolus insulin as needed to get everyone to goal. Every subject’s A1c dropped an average of 1.5–2.0 points no matter what regimen they were on. Consensus on Interpreting Professional CGM Outputs Participants described the systematic ways in which they interpret output from the professional CGM device. The basic concept is to go from a big picture to a small picture and stop at the level at which you have enough information. One participant starts with the pie charts of the Sensor Summary, and the average glucose on the meter as well as the sensor, to make sure it is an adequate study. Second, he checks the Sensor Modal Day output for trends in highs and lows. Then, the Sensor Modal Time chart gives a clear sense of what happened overnight, and before and after meals. Then, he compares the Sensor Modal Day output with the diary listings day by day, and adds handwritten notes. Thus, he might observe an uptrend in BG on a day that the patient ate rice and beans and did not bolus enough. With practice, this level of interpretation can take as little as 5 minutes. He summarizes the data on a preprinted sheet to indicate that if it is an adequate study, if there is any hyperglycemia or hypoglycemia overnight or at meals, what changes need to be made, and a place to sign off. The sheet goes to the nurse, who calls the patient and relays the recommendations for changes. Another practitioner also writes notes on the output and gives patients a copy. The original goes in the chart in a section clearly labeled sensor downloads so that it can be retrieved easily as needed. Whether the discussion of professional CGM results is done by the physician or another licensed member of the team, it should include showing the patient what certain foods, activities, or medication dosing do to the BG pattern. This discussion will help the patient understand how the clinician can identify instances of overtreating, or fear of hypoglycemia and the defensive behavior in eating patients engage in to prevent hypoglycemia overnight. Consensus on Therapy Adjustments Guided by Professional CGM Overall, participants agreed that the three main adjustments that might be triggered by professional CGM results are the basal insulin dose, dosing before meals, and dosing after meals. Patients may see how underutilizing insulin for meals, and improper use of the carbohydrate ratio really affect their BG. If the patient does not wake up with a normal fasting glucose, the clinician needs to optimize the basal insulin delivery. The most common changes are more meal-related changes. Some patients need changes in insulin dose to cover meals better because the basal dose is too high. They are having hypoglycemia before the next meal. Some patients go to bed high and then wake up normal and do a lot of defensive eating at night. Another important interpretation is to identify when during the night a patient becomes hypoglycemic, to adjust the insulin dosage to prevent further episodes of nocturnal hypoglycemia. The glucose patterns after a meal will govern establishment of the appropriate doses of preprandial insulin to cover the carbohydrate load for meals. CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING 35
  36. 36. DISCUSSION REGARDING USE OF PROFESSIONAL CGM For type 2 patients with elevated A1cs, one participant may change a patient’s oral agent or change their insulin regimen when she finds hyperglycemia where she least expects it based on output from professional CGM. It is important to be cautious about making too many dietary or medication changes at one visit to ensure that you can identify what change made the difference. If several changes are appropriate, one participant recommended choosing the change the patient is willing to do first. Expert Recommendations on the Future of Professional CGM During this discussion, roundtable participants brainstormed about how professional CGM might improve over time. The ideal system would not require the patient to test glucose with a fingerstick. Second, when the CGM sensor detects hypoglycemia, a device that shuts the pump off when the patient does not respond to the alarm need to be approved in the United States. Such a device is already approved in Europe. One of the problems with miniaturizing components is that there is a tradeoff based on physics—to get things really small, the battery life will be shorter. One participant was frustrated because his professional CGM equipment failed after only 14 months. He suggested that if a longer or unlimited battery life cannot be built, then the battery needs to be rechargeable, because primary care doctors and endocrinologists will not embrace the technology if they feel like they have to replace expensive devices every 2 years. Ideally, professional CGM would evolve into a handheld device into which the patient could input insulin dosing that would collect and display meal markers to replace the handwritten diary. Perhaps the device could even take and upload pictures of the food being eaten. Ideally, this future device would use artificial intelligence to analyze some of those patterns and highlight them—sort of like an EKG interpretation. The system would allow the clinician to agree or disagree with the automatically generated interpretation, and the output would display the diary overlaid on the BG tracings in a oneor two-page format and permit the clinician to make therapeutic changes as appropriate. The devices need to be connected to (1) the patients’ significant others, (2) the doctor’s office, or (3) a central monitoring station. This would be particularly useful for those elderly patients who live alone and value their independence. The device would predict BG trends and notify patients of severe hypoglycemia and hyperglycemia before they happen. The ultimate improvement, of course, will be the closed loop system with a sensor and pump working together. Conclusions The 10 varied cases presented at this roundtable discussion provided an excellent tutorial in how to interpret data generated by professional CGM evaluations. This technology can benefit a wide range of diabetic patients. Healthcare providers must educate third-party payers that there is more to glucose control than just an A1C value. Professional and personal CGM both have an important role in guiding therapy adjustments to optimize our patient’s overall BG control. 36 CURRENT TRENDS IN PROFESSIONAL CONTINUOUS GLUCOSE MONITORING
  37. 37. DIABETES TECHNOLOGY & THERAPEUTICS Volume 11, Number 3, 2009 ª Mary Ann Liebert, Inc. DOI: 10.1089=dia.2008.0053 Continuous Glucose Monitoring in Non–Insulin-Using Individuals with Type 2 Diabetes: Acceptability, Feasibility, and Teaching Opportunities 1 Nancy A. Allen, Ph.D., James A. Fain, Ph.D.,2 Barry Braun, Ph.D.,3 and Stuart R. Chipkin, M.D.3 Abstract Background: Continuous glucose monitoring (CGM) has the potential to provide useful data for behavioral interventions targeting non–insulin-using, sedentary individuals with type 2 diabetes mellitus (T2DM). The aims of this study were to describe CGM in terms of (1) feasibility and acceptability and (2) dietary- and exerciseteaching events. Methods: Cross-sectional data were analyzed from 27 non–insulin-using adults with T2DM who wore CGM for 72 h as part of a larger study on using CGM for exercise counseling in this population. Feasibility data included accuracy of entering daily self-monitored blood glucose (SMBG) readings and events (e.g., meals, exercise), sensor failures, alarms, optimal accuracy of glucose data, and download failures. Acceptability data included CGM satisfaction and wearing difficulties. Dietary- and exercise-teaching events were identified from CGM and activity monitor data. Results: CGM graphs showed 141 dietary- and 71 exercise-teaching events. About half the participants (52%) reported difficulty remembering to enter events into CGM monitors, but most (82%) kept an accurate paper log of events. Insufficient SMBG entries resulted in 32 CGM graphs with ‘‘use clinical judgment’’ warnings. Eighty-three percent of missed SMBG entries were from 18 participants 55–77 years old. Missing correlation coefficients resulted from glucose concentrations varying <100 mg=dL. A majority of participants (n ¼ 19) were willing to wear CGM again despite reporting minor discomfort at sensor site and with wearing the monitor. Conclusions: CGM data provided several teaching opportunities in non–insulin-using adults with T2DM. Overall, CGM was acceptable and feasible. Some identified problems may be eliminated by newer technology. 2006–2007). However, few studies have addressed how clinicians can use this technology to counsel non–insulin-using individuals with type 2 diabetes mellitus (T2DM) to change behaviors and to improve diabetes self-management skills. Although technology-related interventions might change behaviors and improve health-related outcomes, feasibility studies are necessary before advancing to costly clinical trials. To determine the feasibility of using CGM in a larger, randomized control pilot study to change lifestyle behaviors in individuals with T2DM,10 we first conducted a preliminary focus group study with nine non–insulin-using individuals with T2DM who wore CGM.11 The results of that study were used to develop the feasibility and acceptability measures for this cross-sectional pilot study with 27 sedentary, non–insulin-using individuals with T2DM.10 Data from those 27 individuals were examined in the present study to determine (1) Introduction C ontinuous glucose monitoring (CGM) technology has the potential to change approaches to educating individuals with diabetes. Since the first CGM device was approved by the U.S. Food and Drug Administration in 1999,1 other models have been developed and distributed,2,3 with improved accuracy of glucose sensors.4 These devices provide different types of CGM data, retrospective and real-time, for counseling individuals with diabetes.5–9 The increasing importance of CGM technology in diabetes health care is reflected by the term ‘‘continuous glucose monitoring’’ as the topic of 26 research presentations and three symposia at the 2007 American Diabetes Association’s 67th Scientific Session and by this search term in Medline retrieving an increasing number of articles (10 articles in 1998–1999, 146 articles in 1 Yale University, New Haven, Connecticut. University of Massachusetts Dartmouth, Dartmouth, Massachusetts. University of Massachusetts Amherst, Amherst, Massachusetts. 2 3 41

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