Diabetes Mellitus Prof Seamus SreenanDept of Diabetes and Endocrinology,Connolly Hospital, Blanchardstown Mini Med School November 30th, 2011
Learning Objectives At the end of this talk you should understand: – What diabetes mellitus means – The difference between types-1 and -2 diabetes – How the different types are treated – The reasons for the current epidemic of diabetes and how it can be prevented – What the complications of diabetes are and how they can be prevented
What is Diabetes?Diabetes Mellitus (sugar diabetes) is adisease characterized by high levels ofsugar (glucose) in the bloodFasting glucose ≥ 7.0 (mmol/L)
Blood sugar and healthSugar (glucose) isan important source Insulin is producedof energy by the pancreas when blood sugar is highWhat is eaten isabsorbed into Insulin keeps bloodthe blood sugar level within the normal range for health
Islet of Langerhans:Pancreas containsinsulin-makingcells in “islets” Insulin β-cells
Diabetes in a ‘nutshell’ Insufficient insulin to meet the body’s needs Either a complete lack (type 1) or relative lack (type 2) Results in raised blood glucose levels Untreated diabetes results in short-term symptoms and serious long-term complications Treatment aims to keep blood glucose levels as close to the normal range as safely possible
Complications of Diabetes Short term: – Symptoms of diabetes – Dehydration – Diabetic Coma – Infections Long term: – Kidney – Eye – Heart – Circulation – Amputation
Symptoms of DiabetesPeople with diabetes often have typical complaints(symptoms): Thirst and frequent drinking More frequent urination, particularly at night Unexplained weight loss Fatigue Blurred vision Frequent infections : skin, genital
Case 1 JN 32 year old male Referred to Emergency Dept by GP Complaining of thirst, excessive urination, half stone weight loss in the last 6 weeks No relevant past history First cousin has diabetes on insulin On no regular medications Thin man Blood sugar level = 24.7 mmol/L
What type of diabetes does JN have?There are 2 main types of diabetes: Type 1 (15%): Due to total lack of insulin – insulintreatment is required for life Type 2 (85%): Plenty of insulin which does not work very well in the body. Insulin treatment may berequired at some stage but is not required in all patients
Differences between type-1 and type-2 Diabetes Mellitus Type 1 Type 2 Young age Middle aged, elderly Normal BMI, not obese Usually overweight/obese No immediate family Family history usual history Symptoms may be present Short duration of for months/years symptoms (weeks) Do not present with Can present with diabetic diabetic coma coma (diabetic Insulin not necessarily ketoacidosis) required Insulin required Previous diabetes in pregnancy These differences are not absolute
JN Young age Thin No immediate family history Short duration of symptomsAll point to probable type-1 diabetes Insulin treatment required
The Miracle of InsulinPatient J.L., December 15, February 15, 19231922
Treatment of Type-1 Diabetes Mellitus: Insulin must be administered into the subcutaneous pocket between fat & muscle & avoid injection into fat or muscle. Can be administered by needle and syringe or by pen device
Alternative way to deliver insulin treatment:Continuous insulin infusion (insulin pump)
Islet replacement treatment Aim to replace the need for insulin treatment (Kidney) Pancreas transplantation Islet transplantation – not available in Ireland Anti-rejection drugs required Stem cell transplantation - experimental
Case 2 Ms AJ, a 45 year old woman is concerned she may have diabetes She had diabetes during her last pregnancy managed with diet Lately she has been feeling tired but otherwise has no complaints Her mother and one of her two sisters already have diabetes treated with tablets She has been overweight since her last pregnancy and has taken a tablet for blood pressure for the last 2 years She is obese, body mass index 34.5 Blood pressure is 140/90 but otherwise her examination is normal She undergoes a testing and her fasting glucose is 9.4 mmol/L Obese, strong family history, aged in 40s, previous history of diabetes in pregnancy all point to type-2 diabetes
Natural History of Type 2 Diabetes Normal Prediabetes Type 2 diabetes Insulin Increasing insulin resistance resistance Insulin Hyperinsulinemia, secretion then islet cell failureAfter meal Abnormal glucose glucose tolerance Fasting High sugar levels glucose Adapted from International Diabetes Center (IDC), Minneapolis, Minnesota.
Treatment of Type-2 Diabetes Diet/ Oral Oral Oral Insulin exercise monotherapy combination +/- insulinDiet and exercise my control condition for some timeVariety of tablets available when diet exercise no longer workTablets can be used in combination with each other or withinsulinInsulin can also be used alone
Prevalence of Diabetes Diabetes is very common It is becoming more common(particularly type-2) It affects about 200,000 Irish people 10% of the health budget spent ondiabetes
Reason for increasing prevalence of type-2 diabetesThe disease is reaching epidemic proportionsbecause: Rates of overweight/obesity have increased We have become a physically inactive species Our diets are increasingly unhealthy
Overweight and obesity are diagnosed bymeasuring weight and height (Body MassIndex (BMI)): Weight in Kg BMI = Height in metres2Normal = 20-25Overweight = 25-30Obese = more than 30Everyone should know their BMI!
Can Diabetes be Prevented?To be able to prevent a disease we need to be able toindentify people at particular risk of developing it
Risk factors for type 2 diabetesCertain people are more at risk of diabetes: Those who are overweight/obese People with a family history of diabetes Women who had diabetes during pregnancy orhave had a baby weighing more than 9lbs Physically inactive people Certain ethnic groups (african, american indian,asian) People who have high blood pressure or highcholesterol Age more than 45 years
Can Diabetes be Prevented?Risk of Type 2 Diabetes can be reduced: Losing weight Taking regular exercise : walking for 30 mins per day Eating healthier food: Less fat (burgers, fries, crisps, sweet foods) More fibre (fruit and vegetables, wholegrain alternatives for rice, bread) Cutting down on alcohol consumption Ultimate aim is to reduce the longterm complications
Can the longterm complications be prevented? Type-1 – 1993: Study showed for the first time that good sugar control can prevent long term complications affecting eyes/kidneys/nerves Type-2 – 1998: Similar study showed same conclusion for type-2 Importanttherefore to know that sugar control is good and monitor frequently
Diabetes Mellitus: Self Monitoring SMBG Patients can draw blood frequently to monitor their glucose levels. A glucose monitor is used to check the sugar as required
Glycosylated Hemoglobin: HbAlc Blood test that measures the amount of glucose that has been incorporated into the hemoglobin protein of the red blood cell (RBC). Reflects the lifespan of a RBC, so test will reveal the effectiveness of diabetes therapy for the preceding 8-12 weeks. HbA1c levels remain more stable than sugar levels. Not affected by short-term fluctuations in sugar Normal is 4-6% Evaluated periodically (1-2 per year if well controlled, more frequently if not)
A1c and relative risk of complications (type 1 diabetes) : 20 Retinopathy 15 Nephropathy NeuropathyRelative Risk (%) 13 Microalbuminuria Aim for AIc of < 7% 11 9 7 5 3 1 6 7 8 9 10 11 12 A1c (%) DCCT, Diabetes Control and Complications Trial. 1. Adapted from Skyler JS. Endocrinol Metab Clin North Am. 1996;25:243-254. 2. DCCT. N Eng J Med. 1993;329:977-986. 3. DCCT. Diabetes. 1995;44:968-983.
How to prevent the complicationsFactors other than blood sugar increase likelihood ofcomplications and should be managedComplications can be delayed/prevented by: Controlling blood sugars: sticking to diet/exerciseprogramme, taking medication as prescribed Controlling blood pressure: diet, salt restriction,medication Controlling cholesterol levels: diet, statin tablets Stopping smoking Taking aspirin?
Useful websites Diabetes Federation of Ireland: – www.diabetes.ie American Diabetes Association – www.diabetes.org Irish Nutrition and Dietetic Institute – www.indi.ie Juvenile Diabetes Research Foundation – www.jdrf.org