HEALTH NEWS

Study Title:

Selenium Protects Men Against Type 2 Diabetes

Study Abstract

Background
A preventive role of selenium on the risk of diabetes has been reported and ascribed to the "insulin-like" activity of selenium and the antioxidant properties of the selenoenzymes. By contrast, data from cross-sectional studies and clinical trials have suggested an adverse effect of high selenium status and selenium supplementation on type-2 diabetes risk. Given these controversial results, we investigated prospectively the relationship between baseline plasma selenium concentration and occurrence of dysglycemia (impaired fasting glucose or type 2 diabetes) in an elderly French cohort.

Methods
The Epidemiology of Vascular Ageing (EVA) study (n=1389, 59-71 years) is a 9-year longitudinal study in which, fasting plasma glucose was measured at baseline, 2, 4 and 9 years. Analyses were performed on 1162 participants with complete data.

Results
At baseline plasma selenium mean levels were 1.08 (0.21) umol/l in men and 1.10 (0.20) umol/l in women. During the 9-year follow-up, 127 cases of dysglycemia occurred. A significant interaction was found between plasma selenium and sex. Risk of dysglycemia was significantly lower in men with plasma selenium in the highest tertile (T3:1.19-1.97) compared to those in the lowest tertile (T1:0.18-1.00) [HR=0.48 (0.25-0.92)], but no significant relationship was observed in women. After controlling for socio-demographic factors, lifestyle factors, cardiovascular diseases, body mass index, hypertension and lipid profile, plasma selenium remained marginally significantly associated with occurrence of dysglycemia in men [T3 vs. T1, HR=0.50 (0.24-1.04)] and unrelated in women.

Conclusions
This prospective study suggests a sex-specific protective effect of higher selenium status at baseline on later occurrence of dysglycemia.

From press release:

The role of selenium in diabetes has been controversial, with some studies suggesting that it raises diabetes risk and others finding that it is protective. Now, research published in BioMed Central's open access journal Nutrition and Metabolism, has shown that, for men, high plasma selenium concentrations are associated with a lower occurrence of dysglycemia.

Tasnime Akbaraly, from the University of Montpellier, worked with a team of researchers to follow 1162 healthy French men and women for nine years, monitoring plasma selenium concentrations and incidence of dysglycemia.

She said, "Our results showed that for French elderly males, having plasma selenium concentrations in the top tertile of the population distribution (1.19-1.97 μmol/L) was significantly associated with a lower risk of developing dysglycemia over the following nine years."

During the study period, 127 new cases of dysglycemia occurred, of which 70 were in men and 57 in women. According to Akbaraly, "The reason we observed a protective effect of selenium in men but not in women is not completely clear, but might be attributed to women being healthier at baseline, having better antioxidant status in general and possible differences in how men and women process selenium."

Study Information

1.Tasnime N Akbaraly, Josiane Arnaud, Margaret P Rayman, Isabelle Hininger-Favier, Anne-Marie Roussel, Claudine Berr and Annick Fontbonne
Plasma selenium and risk of dysglycemia in an elderly French population: Results from the prospective Epidemiology of Vascular Ageing Study
Nutrition & Metabolism
2010 March
University of Montpellier