the effects of n-acetylcysteine on inflammatory markers and homocysteine: a systematic review and meta-analysis of randomized controlled trials

Background: recently a number of trials investigated the effect of n-acetylcysteine (nac) administration on inflammatory markers and homocysteine (hcy). however, their findings are controversial. the aim of this paper is to present a meta-analysis and give a review of all randomized controlled trials (rcts) in order to determine the effects of nac on inflammatory markers and hcy. methods: an electronic search was conducted using pubmed, scopus, cochrane library, google scholar and web of science databases from inception until april 2019. a study quality assessment was performed using the jadad scale and heterogeneity between studies was statistically computed using cochrane’s q test and i-square (i2). data were pooled using a random-effects model and weighted mean difference (wmd) was considered as the overall effect size. results: out of 1115 potential citations, 10 studies (reported 13 effect sizes for different parameters) met the inclusion criteria and were eligible for this meta-analysis. nac supplementation resulted in a significant reduction in hcy levels (wmd: -2.05; 95% ci: -3.73, -0.37). nac administration did not affect c-reactive protein (crp) levels (wmd: 0.06; 95% ci: -0.21, 0.34), tumor necrosis factor-α (tnf-α) levels (wmd: 0.07; 95% ci: -0.27, 0.40), and interleukin 6 (il-6) (wmd: -0.23; 95% ci: -1.23, 0.77). conclusion: it could be concluded that this meta-analysis of rcts demonstrated that nac administration to various patients significantly improved circulating hcy, but did not affect crp il-6 and tnf-α levels.