Moderate alcohol drinking might be protective for systemic lupus erythematosus: a systematic review and meta-analysis

Conflicting evidence for the effect of moderate alcohol drinking on the development of systemic lupus erythematosus (SLE) existed at present. In the current study, we performed an extensive search of relevant studies and performed a meta-analysis to obtain a more precise estimate. Thirty-eight studies were identified from electronic databases and chosen for detailed review, then six articles from six case–control studies with one cohort study were included in our meta-analyses. Meta-analyses were divided into two subgroups in which patients in the study of Washio et al. treated for less than 5 years (subgroup A) or less than 10 years (subgroup B) were involved, respectively. The odds ratio (OR) of moderate alcohol drinking in the meta-analyses of subgroup B for the development of SLE was significantly decreased (OR 0.723, 95% confidence interval (95% CI) 0.547–0.954), while moderate alcohol drinking in the meta-analysis of subgroup A did not demonstrate a decreased risk of SLE (OR 0.780, 95% CI 0.491–1.240). Meta-analyses of six case–control studies in the two subgroups both demonstrated that moderate alcohol drinking had a protective effect on the development of SLE. Taken together, our results show that moderate alcohol drinking might be protective for SLE.