TNF-α -308 polymorphisms and male infertility risk: A meta-analysis and systematic review

This study aimed to conduct a systematic review and meta-analysis of prospective studies discussing tnf-α -308 polymorphism and male infertility. this study was conformed to preferred reported items for systematic reviews and meta-analyses guidelines. pubmed,embase and scopus databases were searched to identify relevant studies by two independent reviewers. hazard ratios were pooled using fixed-effect or random-effects models when appropriate. q-test was performed to evaluate study heterogeneity and publication bias appraised using funnel plots. the search yielded five studies (three of caucasians ethnicity and 2 of asian ethnicity) comprising 2939 men (2262 infertile men and 677 fertile controls). most of the studied cases were carried out on tnf-α promoter region at positions -308 g/a (four studies) where -308 c/t was dealt with in one study. overall,significant associations between tnf-α -308 gene polymorphisms and idiopathic male infertility risk were observed (fixed effect: or = 0.472,95% ci: 0.378-0.589; p = 0.001; random effect: or = 0.407,95% ci: 0.211-0.785; p = 0.007) with robust findings according to sensitivity analyses. funnel plot inspections did not give evidences of publication bias. a stratified analysis performed for ethnic groups revealed significant association in both caucasian and asian populations. it is concluded that there are evidences of associations between tnf-α -308 gene polymorphisms and male infertility risk. © 2015.