The role of environmental factors in insulin-dependent diabetes mellitus: an unresolved issue.

Insulin-dependent diabetes mellitus (IDDM) is an autoimmune disease characterized by the destruction of the insulin-secreting beta cells found in the islets of Langerhans. Reduced beta-cell mass results in overt diabetes, requiring lifelong exogenous insulin administration and the possibility of numerous sequelae. Incidence and development of IDDM depend upon a variety of genetic and nongenetic factors. Environmental factors such as chemicals, diet, and infection are suspected to influence the development of disease. This review describes the work performed to date to elucidate the role of these environmental factors in IDDM.