Elevated blood pressure reduction after α-lipoic acid supplementation: a meta-analysis of randomized controlled trials

The aim of the comprehensive meta-analysis was to systematically explore the reductive effect of α-lipoic acid (ALA) supplementation on systolic blood pressure (SBP) and diastolic blood pressure (DBP). The related records were selected from PubMed, Scopus, EMBASE, Cochrane library, and Persian databases including SID and Magiran from earliest date 1980 until August 2018. The heterogeneities were assessed by I2 test (I2 < 50%) and χ2 test on Cochrane’s Q statistic. Standardized mean difference (SMD) and their 95% confidence intervals (CIs) were estimated for change in SBP and DBP. Subgroup analyses were also carried out by baseline BP, clinical condition, dosage of supplementation, and duration of study. As a result, a total of seven studies with 478 participants were included in the meta-analysis. Compared to the controls, ALA supplementation significantly reduced both SBP (SMD？=？？0.81, 95% CI: ？1.20, ？0.41) and DBP (SMD？=？？1.50, 95% CI: ？2.86, ？0.15) with a reduction of 8.1 and 6.7？mmHg of the mean SBP and DBP, respectively. Significant heterogeneity was detected in SBP and DBP; however, subgroup analysis of baseline BP showed significant reduction in both SBP and DBP heterogeneities. Indeed, a statistically significant reduction in BP was observed in subsets of elevated BP as compared with hypertensive patients. In conclusion, the current meta-analysis revealed that ALA supplementation lowers BP in subjects, especially those with elevated BP