Differential associations between depression, risk factors for insulin resistance and diabetes incidence in a large U.S. sample

Background: Depression frequently co-occurs with diabetes. The associations between risk factors for insulin resistance and depression and diabetes can help determine the relative importance of factors that contribute toward the comorbidity. Method: Analyses of the NHANES I (n = 10,025) to examine the cross-sectional relationships between depression and risk factors for insulin resistance at baseline using logistic regression and to explore the longitudinal relationships between risk factors for insulin resistance and diabetes incidence using Cox proportional hazards modeling. Results: Many risk factors for insulin resistance were associated with depression and diabetes incidence. Depression was cross-sectionally associated with diabetes, but did not increase the risk for diabetes incidence. These counterintuitive results can be explained primarily by the differing relationships between risk factors for insulin resistance, depression, and diabetes. Limitations: Lack of repeated measures of depression. Conclusions: Lack of physical activity, hypertension, and inadequate sleep were the risk factors for insulin resistance with the highest associations with both depression and diabetes incidence.