Table 1

Etiologic classification of diabetes mellitus

  1. Type 1 diabetes (β-cell destruction, usually leading to absolute insulin deficiency)

    1. Immune mediated

    2. Idiopathic

  2. Type 2 diabetes (may range from predominantly insulin resistance with relative insulin deficiency to a predominantly secretory defect with insulin resistance)

  3. Other specific types

    1. A. Genetic defects of β-cell function

      1. Chromosome 12, HNF-1α (MODY3)

      2. Chromosome 7, glucokinase (MODY2)

      3. Chromosome 20, HNF-4α (MODY1)

      4. Chromosome 13, insulin promoter factor-1 (IPF-1; MODY4)

      5. Chromosome 17, HNF-1β (MODY5)

      6. Chromosome 2, NeuroD1 (MODY6)

      7. Mitochondrial DNA

      8. Others

    2. Genetic defects in insulin action

      1. Type A insulin resistance

      2. Leprechaunism

      3. Rabson-Mendenhall syndrome

      4. Lipoatrophic diabetes

      5. Others

    3. Diseases of the exocrine pancreas

      1. Pancreatitis

      2. Trauma/pancreatectomy

      3. Neoplasia

      4. Cystic fibrosis

      5. Hemochromatosis

      6. Fibrocalculous pancreatopathy

      7. Others

    4. Endocrinopathies

      1. Acromegaly

      2. Cushing's syndrome

      3. Glucagonoma

      4. Pheochromocytoma

      5. Hyperthyroidism

      6. Somatostatinoma

      7. Aldosteronoma

      8. Others

    5. Drug or chemical induced

      1. Vacor

      2. Pentamidine

      3. Nicotinic acid

      4. Glucocorticoids

      5. Thyroid hormone

      6. Diazoxide

      7. β-adrenergic agonists

      8. Thiazides

      9. Dilantin

      10. γ-Interferon

      11. Others

    6. Infections

      1. Congenital rubella

      2. Cytomegalovirus

      3. Others

    7. Uncommon forms of immune-mediated diabetes

      1. “Stiff-man” syndrome

      2. Anti-insulin receptor antibodies

      3. Others

    8. Other genetic syndromes sometimes associated with diabetes

      1. Down syndrome

      2. Klinefelter syndrome

      3. Turner syndrome

      4. Wolfram syndrome

      5. Friedreich ataxia

      6. Huntington chorea

      7. Laurence-Moon-Biedl syndrome

      8. Myotonic dystrophy

      9. Porphyria

      10. Prader-Willi syndrome

      11. Others

  4. Gestational diabetes mellitus

  • Patients with any form of diabetes may require insulin treatment at some stage of their disease. Such use of insulin does not, of itself, classify the patient.