Toenail selenium and cardiovascular disease in men with diabetes

Objective: Selenium as a component of glutathione peroxidase may be beneficial in insulin resistance, hence potentially may modify the risk of diabetes and cardiovascular disease (CVD). The aim of this study is to evaluate the association between toenail selenium and CVD among men with diabetes. Methods: We performed cross-sectional and nested case-control analyses within the Health Professionals Follow-up Study, a cohort of men aged 40 to 75 years in 1986. The cross-sectional analysis compared healthy controls (n = 361) to men with diabetes only (n = 688), and men with prevalent diabetes and CVD (n = 198). The nested case-control study included 202 diabetic men who developed incident CVD during follow-up and 361 matched controls. Results: After controlling for potential confounders, the odds ratio (OR) for prevalent diabetes was 0.43 (95% Cl: 0.28, 0.64; p-trend <0.001) for the highest compared to the lowest quartile of selenium. Comparison between diabetic men with CVD and healthy controls yielded an OR of 0.86 (95% CI: 0.47, 1.56, p-trend = 0.37) between extreme quartiles. In the nested case-control analysis, the OR between extreme quartiles was 0.57 (95% CI: 0.29, 1.03; p-trend = 0.07), comparing diabetic men with incident CVD to healthy controls. Conclusions: Our results suggest that levels of toenail selenium are lower among diabetic men with or without CVD than among healthy controls. However, this study could not distinguish between the effects of selenium on diabetes and those on CVD. Randomized clinical trials are needed to study potential benefits of selenium supplementation in the prevention and treatment of diabetes and CVD.