Supplemental selenium and coenzyme Q10 reduce glycation along with cardiovascular mortality in an elderly population with low selenium status - A four-year, prospective, randomised, double-blind placebo-controlled trial

Background: A low intake of selenium has been shown to increase the risk of cardiovascular mortality, and supplementation of selenium and coenzyme Q10 influences this. The mechanism behind is unclear although effects on inflammation, oxidative stress and microRNA expression have been reported. Fructosamine, a marker of long-term glycaemic control, is also a marker of increased risk of heart disease and death, even in non-diabetics. Objective: To analyse the impact of selenium and coenzyme Q10 supplementation on the concentration of fructosamine. Also, the relation between pre-intervention serum selenium concentration and the effect on fructosamine of the intervention was studied. Methods: Fructosamine plasma concentration was determined in 219 participants after six and 42 months of intervention with selenium yeast (200 mu g/day) and coenzyme Q10 (200 mg/ day) (n = 118 of which 20 had diabetes at inclusion), or placebo (n = 101 of which 18 had diabetes at inclusion). Pre-intervention, the serum selenium levels were 67 mu g/L (active treatment group: 66.6 mu g/L; placebo group: 67.4 mu g/L), corresponding to an estimated intake of 35 mu g/day. Changes in concentrations of fructosamine following intervention were assessed by the use of T-tests, repeated measures of variance, and ANCOVA analyses. Results: Post-intervention selenium concentrations were 210 mu g/L in the active group and 72 mu g/L in the placebo group. A lower concentration of fructosamine could be seen as a result of the intervention in the total population (P = 0.001) in both the males (P = 0.04) and in the females (P = 0.01) in the non-diabetic population (P = 0.002), and in both the younger ( < 76 years) (P = 0.01) and the older (>= 6 years) participants (P = 0.03). No difference could be demonstrated in fructosamine concentration in the diabetic patients, but the total sample was small (n = 38). In subjects with a low pre-intervention level of serum selenium the intervention gave a more pronounced decrease in fructosamine compared with those with a higher baseline selenium level. Conclusion: A significantly lower concentration of fructosamine was observed in the elderly community-living participants supplemented with selenium and coenzyme Q10 for 42 months compared to those on the placebo. As oxidative mechanisms are involved in the glycation of proteins, less glycoxidation could be a result of the supplementation of selenium and coenzyme Q10, which could have contributed to lower cardiac mortality and less inflammation, as has earlier been reported.