Dietary selenium intake and risk of hospitalization for type 2 diabetes in the Moli-sani study cohort.

Background and aims: Experimental and non-experimental human studies have consistently shown a positive association between exposure to the trace element selenium, which occurs primarily through diet, and risk of type 2 diabetes mellitus. Plausible biological mechanisms include adverse effects of selenium and selenium-containing proteins on glucose metabolism. However, the levels of exposure above which risk increases are uncertain.

Methods and results: We examined the association between selenium intake and first hospitalization for type 2 diabetes during a median follow-up period of 8.2 years among 21,335 diabetes-free participants in the Moli-sani cohort, Italy. Selenium intake was ascertained at baseline using a food frequency questionnaire, showing a median value of 59 μg/day. During follow-up, we identified 135 incident cases of hospitalization for diabetes, based on population-based hospital discharge data. We used a Cox proportional hazards model to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for hospitalization for diabetes, adjusting for potential confounders. HRs (95% CIs) were 1.01 (0.60-1.70), 1.13 (0.66-1.96) and 1.75 (0.99-3.10) comparing the second, third, and fourth sex-specific quartiles with the first quartile, respectively. Risk was 64% greater in the fourth quartile as compared with the previous three. Spline regression analysis also indicated a steeper increase in risk occurring among men compared with women.

Conclusions: In a large population of Italian adults free of type 2 diabetes at cohort entry, high dietary selenium intake was associated with increased risk of hospitalization for diabetes.

Keywords: Cohort study; Diet; Epidemiology; Risk assessment; Selenium; Type 2 diabetes.

Nutr Metab Cardiovasc Dis. 2021 Jun 7;31(6):1738-1746. doi: 10.1016/j.numecd.2021.02.016. Epub 2021 Feb 25.