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.

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 of the Branch.

• INCLUSION CRITERIA:

The study population is all persons aged 5 years and over residing on the Gila River Indian Reservation in Arizona. The vast majority of the eligible subjects are American Indians and there are similar numbers of males and females in the population. The study population was chosen because our previous work has shown that this population has the highest prevalence of Type 2 diabetes in the world. There are small numbers of other racial groups in the selected population who are also eligible to participate in the study. They are mainly members of the families in the community and therefore by participating they can contribute valuable research information to the study. All persons resident in the community aged 5 years and over are invited to participate in the study at two-yearly intervals. In addition, other tribal members and selected family members such as first or second degree relatives of the study population who reside, or have moved off the Reservation, are also eligible to participate.

Persons aged 5 years and over residing in districts 1-5 of the Gila River Indian Community in Arizona.