Table 2.

Etiologic Classification of Diabetes

•  Type 1 diabetes* (β-cell destruction, usually leading to absolute insulin deficiency)
 Immune-mediated
 Idiopathic
•  Type 2 diabetes* (may range from predominantly insulin resistance with relative insulin deficiency to a predominantly secretory defect with insulin resistance)
•  Other specific types
 Genetic defects of β-cell function (e.g., MODY)
 Genetic defects in insulin action (e.g., lipoatrophic diabetes)
 Diseases of the exocrine pancreas (e.g., cystic fibrosis)
 Endocrinopathies (e.g., Cushing's syndrome)
 Drug- or chemical-induced (e.g., glucocorticoids)
 Infections (e.g., congenital rubella)
 Uncommon forms of immune-mediated diabetes
 Other genetic syndromes sometimes associated with diabetes (e.g., Prader-Willi syndrome)
•  Gestational diabetes mellitus (GDM)
  • * Patients with any form of diabetes may require insulin treatment at some stage of their disease. Use of insulin does not, of itself, classify the patient. Adapted from the Report of the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus (1).