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 mg/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. (c) 2021 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.