Diagnosis of diabetes mellitus

 Normal blood glucose: Fasting 70-100 mg dl; Following glucose load: <140 mg/dl

Pre-diabetes

Hyperglycemia not sufficient to meet the diagnostic criteria of diabetes mellitus

Impaired fasting glucose (IFG) 100 – 125 mg/dl

Impaired glucose tolerance (IGT) 140 -199 mg/dl (after 75 gm glucose load)

Both basal hyperglycemia and postprandial hyperglycemia can increase HbA1c and cardiovascular complications

Types of diabetes mellitus

Type 1 Diabetes Mellitus: beta cell deficiency

Type 2 Diabetes Mellitus: beta cell defect + insulin resistance

Gestational Diabetes Mellitus (GDM)

ADA 1997, WHO 1999 – Diagnostic criteria for diabetes mellitus

Symptoms of hyperglycemia (polyuria, polydipsia and unexplained weight loss) and casual plasma glucose > 200 mg/dl

Fasting (no calorie intake for 8 hours) plasma glucose > 126 mg/dl

2 hour post prandial plasma glucose > 200 mg / dl

Hemoglobin A1c is the gold standard for diagnosis of diabetes mellitus