Depression, diabetes, and glycemic control in an American Indian community.

Objective: American Indians have a high prevalence of diabetes and its complications, and so it may be clinically important to identify psychiatric risk factors for the development of diabetes and its complications in this population. The objectives of this cross-sectional study were (1) to determine whether depression and diabetes are associated in the Pima Indians and (2) to determine if depression is associated with variables indicating risk for development of diabetes or diabetic complications.

Method: Adults (aged >or= 18 years) who attended research examinations in the Gila River Indian Community in Arizona from July 2003 through January 2007 were included. A sample of 2902 individuals (1121 with diabetes, 1781 without diabetes) was evaluated with the depression module of the Patient Health Questionnaire (DSM-IV criteria), physical examination, and laboratory tests.

Results: The prevalence of depression was slightly, but not significantly, higher among participants with diabetes than those without diabetes (12.8% vs. 9.4%, p = .053). Among participants with diabetes, mean glycosylated hemoglobin levels were significantly higher among depressed individuals than among those who were not depressed (9.0% vs. 8.4%, p = .02), even when controlling for age, sex, duration of diabetes, and body mass index (p = .03). In participants without diabetes, mean glycosylated hemoglobin levels were similar among depressed and nondepressed participants (5.4% vs. 5.4%, p = .24).

Conclusion: Overall, participants with diabetes had a slightly, but not significantly, higher prevalence of depression than those without diabetes. Among those with diabetes, depression was associated with worse glycemic control. Treatment of depression in Pima Indians with diabetes may improve glycemic control and thereby reduce the risk of diabetic complications.