CLASSIFICATION OF DIABETES BY AETIOLOGY

CLASSIFICATION OF DIABETES BY AETIOLOGY (PROPOSED BY WHO AND WIDELY ACCEPTED):

1.     TYPE 1 DIABETES (β-cell dysfunction, absolute insulin deficiency)

A.      Immune mediated

B.      Idiopathic

2.     TYPE 2 DIABETES (Insulin resistance and may be associated with relative insulin deficiency or secretory defect)

3.     OTHER SPECIFIC TYPE

A.     PRIMARY (defect in β-cell function or genetic defect in insulin action)

a.  Chromosomal defect of glucokinase (chr. 7, MODY2), transcription factors leading to different types of MODY (1-6)

b.     Type A insulin resistance and others

c.      Anti insulin receptor antibodies

B.     SECONDARY (disease of exocrine pancreas, endocrinopathies, drugs or chemicals, infections, genetic syndrome associated with diabetes)

a.      Pancreatitis

b.      Cystic fibrosis, etc.

c.       Cushing’s syndrome

d.      Glucagonoma

e.      Hyperthyroidism

f.        Nicotinic acid

g.      Thyroid hormones

h.      Alpha interferon

i.        Congenital rubella

j.        Cytomegalovirus

k.       Down’s syndrome

l.        Klinefelter’s syndrome

m.    Porphyria, etc.

4.     GESTATIONAL DIABETES MELLITUS (GDM)

5.     PREDIABETICS (IGT AND IFG)

Statistical risk classes (subjects with normal glucose tolerance but increased risk of developing diabetes. E.g. previous abnormality of glucose tolerance and potential abnormality of glucose tolerance.