Incidence of Diabetes in American Indians of Three Geographic Areas

OBJECTIVE: To estimate incidence rates of diabetes and associated risk factors among participants of the Strong Heart Study. RESEARCH DESIGN AND METHODS: Of the 4,549 Strong Heart Study participants examined at baseline, 3,638 returned for a similar examination after an average of 4 years. The 1985 World Health Organization criteria for diabetes were used to identify new diabetes cases. Rates of diabetes among participants who did not have diabetes at baseline examination were determined. The relationships between the incidence rates of diabetes and a number of risk factors measured at baseline examination were studied. RESULTS: Significant variables associated with the development of diabetes included triglycerides, obesity, fasting plasma glucose, insulin, and degree of American Indian blood among participants with NGT at baseline. For those with IGT at baseline, significant predictors included fasting plasma glucose, 2-h glucose, BMI, degree of American Indian blood, and albuminuria. CONCLUSIONS: The high incidence rates found in this study were alarming. To slow down the rapid increase of this disease in the American Indian population, preventive programs must be designed and implemented. Patients with IGT should be treated with diabetes medication or put on a rigid weight-reduction program to reduce the risk of progression to diabetes.