Depressive symptoms, insulin sensitivity and insulin secretion in the RISC cohort study

AIM: This study explored the association of depressive symptoms with indices of insulin sensitivity and insulin secretion in a cohort of non-diabetic men and women aged 30 to 64 years. METHODS: The study population was derived from the 3-year follow-up of the Relationship between Insulin Sensitivity and Cardiovascular Disease Risk (RISC) study. Presence of significant depressive symptoms was defined as a Center for Epidemiologic Studies Depression Scale (CES-D) score >/= 16. Standard oral glucose tolerance tests were performed. Insulin sensitivity was assessed with the oral glucose insulin sensitivity (OGIS) index. Insulin secretion was estimated using three model-based parameters of insulin secretion (beta-cell glucose sensitivity, the potentiation factor ratio, and beta-cell rate sensitivity). RESULTS: A total of 162 out of 1027 participants (16%) had significant depressive symptoms. Having significant depressive symptoms was not related to either OGIS [standardized beta (beta) -0.033; P=0.24] or beta-cell glucose sensitivity (beta -0.007; P=0.82). Significant depressive symptoms were related to decreased beta-cell rate sensitivity (odds ratio for significant depressive symptoms of the lowest vs. highest quartile of beta-cell rate sensitivity was 2.04; P=0.01). Also, significant depressive symptoms were associated with a statistically significant decrease in the potentiation factor ratio in unadjusted models, but not in the fully adjusted model. CONCLUSION: Depressive symptoms were not related to insulin sensitivity and tended to be weakly associated to some parameters of insulin secretion in non-diabetic individuals. Prospective studies are needed to study the temporal association between depression and insulin secretion.