Table 2 Diabetes classification

Type 1 diabetes mellitus (T1DM)

β-Cell destruction, usually leading to absolute insulin deficiency

Type 2 diabetes mellitus (T2DM)

Varying degrees of insulin resistance and long-term insulin deficiency

Gestational diabetes mellitus (GDM)

Pregnant women who have never had diabetes mellitus but who experience high blood glucose levels during pregnancy

Maturity-onset diabetes of the young (MODY)

Rare form of diabetes that is distinct from both type 1 and type 2 diabetes and strongly runs in families. It is caused by a mutation in a single gene. If a parent has this gene mutation, any child has a 50% chance of inheriting it

Latent autoimmune diabetes of the adult (LADA)

Disorder in which, despite the presence of islet antibodies at diagnosis of diabetes, the progression of autoimmune β-cell failure is slow

Diseases of exocrine pancreas

Includes pancreatitis, trauma, infection, neoplasia, cystic fibrosis, hemochromatosis, pancreatectomy, and others

Endocrinopathies

Includes acromegaly, Cushing’s syndrome, glucagonoma, hyperthyroidism, somatostatinoma, and others

Drug- or chemical-induced diabetes

Includes some immunotherapy, exogenous steroids, antipsychotics medication, statins, and others

Infections

Congenital rubella and other viruses have been implicated

Uncommon forms of immune-mediated diabetes

Rare cases of diabetes associated with new checkpoint inhibitor therapies

Stiff-man syndrome

An autoimmune disorder of the central nervous system, usually with high titers of glutamic acid decarboxylase [GAD] autoantibodies