High plasma selenium reduces risk for dysglycemia in older men
MedWire News: Study results show that high plasma selenium levels appear to be protective against impaired fasting glucose or Type 2 diabetes in elderly men, but not women.
“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,” say Tasnime Akbaraly (INSERM U888, Montpellier, France) and colleagues.
In contrast, data from other studies have suggested an adverse effect of high selenium on Type 2 diabetes risk, as well as on lipid levels, as previously reported by MedWire News.
To attempt to clarify the issue, Akbaraly and team investigated the association between baseline plasma selenium level and the incidence of dysglycemia (impaired fasting glucose or Type 2 diabetes) in 1389 men and women aged 59–71 years at baseline.
The Epidemiology of Vascular Ageing (EVA) study was carried out for 9 years and all the participants were normoglycemic and not taking anti-diabetic drugs at baseline. Fasting plasma glucose was measured by the researchers at baseline and again at 2, 4, and 9 years.
The participants were divided into tertiles for baseline plasma selenium levels. The median values for the first, second, and third tertiles were 0.90, 1.09, and 1.32 µmol/l, respectively, with no significant differences between women and men.
Writing in the journal Nutrition and Metabolism, the team reports that 127 new cases of dysglycemia (29 Type 2 diabetes diagnoses) occurred during the follow-up period, of which 70 were in men and 57 in women.
Compared with men in the lowest tertile for baseline plasma selenium, men in the highest tertile were a significant 52% less likely to develop dysglycemia over the study period. However, this association was not seen in women.
The association between selenium status and dysglycemia remained marginally significant in men after adjusting for socio-demographic, lifestyle, and cardiovascular factors (hazard ratio=0.50).
Akbaraly commented: “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.”
The authors conclude: “We need to identify the optimal range of selenium status and intake that will minimize potential adverse effects on glucose metabolism while optimizing Type 2 diabetes prevention. This may allow us to target a population that might benefit from selenium supplementation.”
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By Helen Albert