investigation and diagnosis of DM

1. DIABETES MELLITUS:
INVESTAGTION AND
DIAGNOSIS
MARYAM MAJID AL-EZAIREJ
INTERNAL MEDICINE
COLLAGE OF MEDICINE, RAKMHSU

2. DIABETES MELLITUS
 There are different test and devices to test and diagnosis diabetes mellitus and
those may differ according to the type of diabetes mellitus

3. How to investigate for DM
 If a patient is suspected to have diabetes of any type, several investigation can be
done either to confirm it or rule it out.
 blood sample is usually used and even though less commonly a urine sample may
be used but it is not diagnostic for diabetes.

4. Urine test
 Ketone test is preformed n the urine sample of the patient
 This test detects the presence of ketones, which are byproducts of metabolism
that form in the presence of severe hyperglycemia (elevated blood sugar). Ketones
are formed from fat that is burned by the body when there is insufficient insulin to
allow glucose to be used for fuel.
 Increasing ketones level indicates insufficient insulin
 Ketones occur most commonly in people with type 1diabetes, but uncommonly,
people with type 2 diabetes may test positive for ketones.

5. Urine test
 Reference value of ketone in normal people is Under
0.6 mmol/L above this the patient may have type 1
diabetes mellitus

6. Blood test
Blood test is the most appropriate and
most common method to diagnose all
types of diabetes mellitus

7. Blood test
 Plasma glucose level
 Fasting glucose level
 Post prandial glucose level
 HB1AC test
 C-peptide test

8. Plasma glucose test
 Fasting glucose test:
the patient must be fasting for more than 8 hours, a blood sample is taken
and glucose level is tested.
 Normal range 60-110 mg/dl

9. Plasma glucose test
 Post prandial glucose test:
the glucose level is tested from the patient blood sample has his
last meal within 2 hours from the test.
 Normal value must be lower than 140 mg/dl

10. Glycated hemoglobin (hemoglobin A1c)
 What is HbA1c ?
It is a form of hemoglobin that is measured primarily to identify the average plasma
glucose concentration over prolonged periods of time.
HbA1c test gives an average blood glucose levels over the previous 3 months prior to
the measurement
 Normal reference range 4-5.9%

11. C-PEPTIDE
 What is c-peptide test ?
a test that measure the level of this peptide which is produced in the beta-cells of the
pancreas, it is generally found equal to insulin.
o Absence of c-peptide response to carbohydrates ingestion may indicate total beta cells failure
therefore DM type 2 is diagnosed
o This test is important in differentiating between type 1 and type 2.
 Normal range 0.51–2.72 (ng/mL)

12. Diabetes mellitus type 1
 According to American diabetes association (ADA),
Diabetes mellitus type 1 diagnosis is made on the basis of
the following results
1. Fasting glucose level more than 126 mg/dl
2. Post prandial glucose level more than 200 mg/dl
3. A random plasma glucose ≥200 mg/dl in a patient with classic
symptoms of hyperglycemia or hyperglycemic crisis

13. Symptoms of diabetes mellitus type 1
 Polyuria
 Polydipsia
 polyphagia
 Unexplained weight loss

14. Diabetes mellitus type 2
 According to American diabetes association (ADA),
Diabetes mellitus type 2 diagnosis is made on the basis of
the following results
1. An HbA1c level of 6.5% or higher
2. A fasting plasma glucose (FPG) level of 126 mg/dL
3. Post prandial plasma glucose level of 200 mg/dL
4. A random plasma glucose of 200 mg/dL

15. Symptoms of diabetes mellitus type
 Polyuria
 Polydipsia
 Polyphagia
 Blurred vision
 Lower limb paresthesia
 Yeast infection

16. How to differentiate between type 1 and
type 2
 C-peptide test gives a very negative result in patient with
type 1, while it gives a normal result with type 2
 Urine ketone test gives a higher result in type 1
 autoantibodies or anti-insulin antibodies may give a positive
result in early stages of diabetes mellitus type 1.

17. Gestational diabetes mellitus
 the 2004 American Diabetes Association (ADA) position statement
provides the standards for screening and diagnosis of GDM that have
been carried forward into the Standards of Medical Care in Diabetes
 risk assessment for GDM should be performed at the first prenatal visit. This risk
assessment classifies women as
 very high risk,
 greater than low risk (average)
 low risk.

18. Gestational diabetes mellitus
 patients at very high risk for developing GDM should be
screened as soon as pregnancy is confirmed using standard
diagnostic testing.
 Women with average risk should be tested at 24 to 28 weeks
of gestation.
 Those who meet all the criteria for low risk do not require
testing.

19. Approach to diagnose GDM
 Diagnosis of GDM if at least two of the following plasma
glucose values are found:
 Fasting: ≥95 mg/dl
 1 h: ≥180 mg/dl post oral glucose
 2 h: ≥155 mg/dl post oral glucose
 3 h: ≥140 mg/dl post oral glucose

20. Any questions ?
Thank you 