Jan . 9 . 2010

Classification of Diabetes

Type 1 diabetes encompasses diabetes that is primarily a result of pancreatic beta cell destruction and that is prone to ketoacidosis. This form includes cases due to an autoimmune process and those for which the etiology of beta cell destruction is unknown.

Type 2 diabetes* may range from predominant insulin resistance with relative insulin deficiency to a predominant secretory defect with insulin resistance.

Gestational diabetes mellitus refers to glucose intolerance with first onset or recognition during pregnancy.

A wide variety of relatively uncommon conditions are listed under “other specific types.” These consist mainly of specific genetically defined forms of diabetes or diabetes associated with other diseases or drug use.

Etiologic classification of diabetes mellitus

Type 1 diabetes mellitus

Beta cell destruction, usually leading to absolute insulin deficiency

• Immune mediated

• Idiopathic

Type 2 diabetes mellitus

May range from predominant insulin resistance with relative insulin deficiency to predominant secretory defect with insulin resistance

Gestational diabetes mellitus

Onset or recognition of glucose intolerance in pregnancy

Other specific types
Genetic defects of beta cell function

Chromosome 20, HNF-4alpha (formerly MODY1)

Chromosome 7, glucokinase (formerly MODY2)

Chromosome 12, HNF-1alpha (formerly MODY3)

Mitochondrial DNA

Others

Genetic defects in insulin action

Alstrom syndrome

Leprechaunism

Lipoatrophic diabetes

Rabson-Mendenhall syndrome

Type A insulin resistance

Others

Diseases of the pancreas

Cystic fibrosis

Fibrocalculous pancreatopathy

Hemochromatosis

Neoplasia

Pancreatitis

Trauma/pancreatectomy

Others

Endocrinopathies

Acromegaly

Aldosteronoma

Cushing syndrome

Glucagonoma

Hyperthyroidism

Pheochromocytoma

Somatostatinoma

Others

Infections

Congenital rubella

Cytomegalovirus

Others

Uncommon forms of immune-mediated diabetes

Anti-insulin receptor antibodies

‘Stiff-man’ syndrome

Others

Drug or chemical induced

Atypical antipsychotics

Beta-adrenergic agonists

Diazoxide

Glucocorticoids

Interferon alfa

Nicotinic acid

Pentamidine

Phenytoin

Protease inhibitors

Thiazide diuretics

Others

Other genetic syndromes sometimes associated with diabetes

Down syndrome

Friedreich’s ataxia

Huntington’s chorea

Klinefelter syndrome

Laurence-Moon-Bardet-Biedl syndrome

Myotonic dystrophy

Porphyria

Prader-Willi syndrome

Turner syndrome

Wolfram syndrome

Others