Effects of alpha-lipoic acid supplementation on C-reactive protein level: A systematic review and meta-analysis of randomized controlled clinical trials

The aim of this meta-analysis was to assess effects of alpha-lipoic acid supplementation on C-reactive protein (CRP) levels in clinical trial studies.

A systematic search was carried out on clinical trial studies published in PubMed, ISI Web of Science, Cochrane Library and Scopus databases completed by manual search on reference list of eligible studies accomplished by November 4, 2017. Of a total number of 508 studies found in the first step of literature search, only 11 were included with 264 participants in supplementation groups and 287 in control groups. Estimated pooled random effects size analysis showed a significant reducing effect of alpha-lipoic acid supplementation on CRP level (-0.72 mg/l, 95% CI; -1.4, -0.04; P = 0.03) with a significant heterogeneity between the selected studies. Sub-group analysis showed that alpha-lipoic acid supplementation could significantly reduce serum CRP level when the baseline CRP level was greater than 3 mg/l (-1.02 mg/l, 95% CI: -1.3, -0.73) and when trial duration was >8 weeks (-0.99 mg/l, 95% CI: -1.29, -0.70). Results of subgroup analysis also showed that alpha lipoic acid supplementation could decrease CRP level only in non-diabetic patients (-1.02 mg/l, 95% CI: -1.31, -0.74).

Results of the current meta-analysis study showed that alpha-lipoic acid supplementation could significantly decrease CRP level in patients with elevated levels of this inflammatory marker.