Effect of selenium supplementation on changes in HbA1c: Results from a multiple‐dose, randomized controlled trial. Issue 3 (29th October 2018)

• Record Type: Journal Article
• Authors: Stranges, Saverio; Rayman, Margaret P.; Winther, Kristian H.; Guallar, Eliseo; Cold, Søren; Pastor‐Barriuso, Roberto
• Is Part Of: Diabetes, obesity & metabolism. Volume 21:Issue 3(2019)
• Page Start: 541
• Page End: 549
• Publication Date: 2018-10-29
• Subjects: diabetes -- HbA1c -- randomized controlled trial -- selenium -- selenium dose -- selenium toxicity; Diabetes -- Periodicals; Obesity -- Periodicals; Metabolism -- Disorders -- Periodicals; Clinical pharmacology -- Periodicals; 616.462
• DOI: 10.1111/dom.13549
• Languages: English
• ISSNs: 1462-8902

Abstract

Abstract : Aim: To investigate the effect of selenium supplementation at different dose levels on changes in HbA1c after 6 months and 2 years in a population of low selenium status. Materials and Methods: The Denmark PRECISE study was a single‐centre, randomized, double‐blinded, placebo‐controlled, multi‐arm, parallel clinical trial with four groups. In total, 491 volunteers aged 60 to 74 years were randomly assigned to treatment with 100, 200 or 300 μg selenium/day as selenium‐enriched yeast or placebo‐yeast. HbA1c measurements were available for 489 participants at baseline, 435 at 6 months, and 369 after 2 years of selenium supplementation. Analyses were performed by intention to treat. Results: The mean (SD) age, plasma‐selenium concentration, and blood HbA1c at baseline were 66.1 (4.1) years, 86.5 (16.3) ng/g and 36.6 (7.0) mmol/mol, respectively. During the initial 6‐month intervention period, mean HbA1c (95% CI) decreased by 1.5 (−2.8 to −0.2) mmol/mol for 100 μg/d of selenium supplementation and by 0.7 (−2.0 to 0.6) mmol/mol for the 200 and 300 μg/d groups compared with placebo ( P = 0.16 for homogeneity of changes across the four groups). After 2 years of selenium supplementation, HbA1c had decreased significantly in all treatment groups, with no difference between active treatment and placebo. Conclusions: Selenium supplementation in an elderly European population of low selenium status did not significantly affect HbA1c levels after 2 years. Our findings corroborate a possible U‐shaped response of selenium supplementation on glucose metabolism.