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

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.

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).

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 (β) -0.033; P=0.24] or beta-cell glucose sensitivity (β -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.

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.