This project is a continuation of an extensive longitudinal population-based epidemiological investigation of the etiology and determinants of type 2 diabetes (and its complications) and formerly arthritis. The original baseline observations were made on the residents of the Gila Indian Reservation, predominantly Pima Indians, in 1965. We attempt to reexamine the population at two-yearly intervals, and have continued to recruit new respondents who, because of age and residence or familial relationships, become eligible for entry into the project. Eligible persons receive a battery of standardized examinations related to diabetes and its complications at two-yearly intervals, including a glucose tolerance test, biochemical determinations, such as serum cholesterol and creatinine, insulin, etc., a physical examination, and in those aged 15 years and above, retinal photographs, and an electrocardiogram. Persons known to have diabetes will be asked to undergo the examination at annual intervals to enable more complete and accurate documentation of their health status and to identify the development and progression of complications of the disease.

The data collected have been used to describe the natural history and determinants of diabetes and its complications, to investigate factors relating to the etiology of these diseases and investigate the genetics of diabetes, its complications and other phenotypes. In addition, the project serves to identify subjects with specific characteristics for the clinical research projects carried out by the Obesity and Diabetes Clinical Research Section and the Diabetes Epidemiology and Clinical Research Section fo the Branch.