Beneficial effects of vitamin e supplementation on endothelial dysfunction, inflammation, and oxidative stress biomarkers in patients receiving hemodialysis: A systematic review and meta-analysis of randomized controlled trials

Abstract

Inflammation and oxidative stress are closely related to cardiovascular complications and atherosclerosis, and have the potential to lead to an increase in death in patients receiving hemodialy-sis. Vitamin E has antioxidant and anti-inflammatory properties. We conducted a systematic review and meta-analysis to assess the effects of vitamin E supplementation on endothelial dysfunction, inflammation, and oxidative stress biomarkers in adult patients receiving hemodialysis. We searched the MEDLINE, EMBASE, Web of Science, and Cochrane Library databases and identified randomized controlled trials of adult patients receiving hemodialysis until 30 August 2021. A total of 11 trials with 491 randomized patients were included. The pooled data indicated that vitamin E supple-mentation significantly decreased intercellular adhesion molecule-1 [standardized mean difference (SMD): −1.35; 95% confidence interval (CI): −2.57, −0.13; p = 0.03, I2 = 89%], vascular cell adhesion molecule-1 (SMD: −1.08; 95% CI: −2.05, −0.11; p = 0.03, I2 = 81%), C-reactive protein (SMD: −0.41; 95% CI: −0.75, −0.07; p = 0.02, I2 = 64%), and malondialdehyde (SMD: −0.76; 95% CI: −1.26, −0.25; p = 0.003, I2 = 77%) levels, but not interleukin-6 levels compared to those in the control group. Our results suggest that vitamin E supplementation may help alleviate oxidative stress and both vascular and systemic inflammation in patients receiving hemodialysis.