The effect of vitamin E supplementation on biomarkers of endothelial function and inflammation among hemodialysis patients: A double-blinded randomized clinical trial.

OBJECTIVES The present study was aimed to investigate the effect of alpha-tocopherol supplementation on biomarkers of endothelial function (Intercellular Adhesion Molecule 1 and Vascular Cell Adhesion Protein 1) and inflammatory markers (Interleukin 6 and high-sensitivity C-reactive protein) among the hemodialysis patients. METHODS To conduct this randomized, double-blinded, and placebo-controlled clinical trial, 49 hemodialysis patients, aged 20-60 years, were recruited and randomly divided into the intervention and control groups. The intervention group (n = 25) received 600 IU alpha-tocopherol soft gels (200 IU three times daily), while the controls (n = 24) consumed the identical placebo soft gels for 10 weeks. At the baseline and end of the study, 7 ml pre-dialysis blood samples were taken from all participants to measure their serum concentrations of ICAM-1, VCAM-1, IL-6, and hs-CRP. RESULTS Alpha-tocopherol supplementation reduced the serum levels of ICAM-1 and VCAM-1 significantly (-140.67 ± 57.25 ng/ml vs. -15.97 ± 79.19 ng/ml, P = 0.001 for ICAM-1 and --6.79 ± 4.76 ng/ml vs. 1.02 ± 3.22 ng/ml, P = 0.019 for VCAM-1). However, no significant difference was observed between the two groups regarding the serum levels of hs-CRP (-0.15 ± 0.19 mg/l vs. 0.02 ± 0.12 mg/l; P = 0.32) and IL-6 (-0.03 ± 0.1 pg/ml vs. - 0.06 ± 0.11 pg/ml; P = 0.65). CONCLUSIONS Our results showed that 10 weeks of supplementation with 600 IU alpha-tocopherol improved ICAM-1 and VCAM-1 levels, but did not have any effect on the serum concentration of IL-6 and hs-CRP in hemodialysis patients. Further studies are required to confirm these findings.