Host and environmental interactions in diabetes mellitus.

A number of current issues in diabetes research are reviewed from an epidemiologic viewpoint. Though many advances have been made in our understanding of the causes of insulin-dependent diabetes mellitus (IDDM), there are many unresolved issues which could benefit from epidemiologic research. These include study of the 36-fold geographic variation in IDDM incidence seen across the world, perhaps by the development of registries, and the placing into a population perspective recent genetic and autoimmune findings concerning IDDM etiology. Epidemiologic considerations should also be incorporated into future trials of immunotherapy for IDDM. Despite considerable research, very little is known about risk factors and genetic environmental interactions in non-insulin dependent diabetes. Large scale prospective epidemiologic studies are, therefore, needed to delineate the potential roles of factors such as diet and physical activity, and how these interact with genetic predisposition.