Modest alcohol consumption and risk of advanced liver fibrosis in nonalcoholic fatty liver disease: a systematic review and meta-analysis

BACKGROUND: Recent studies have suggested an association between modest alcohol consumption and a decreased risk of advanced liver fibrosis among patients with nonalcoholic fatty liver disease (NAFLD) although the results are inconsistent. The current systematic review and meta-analysis was conducted to comprehensively investigate this possible association by identifying all the relevant studies and combining their results. METHODS: A comprehensive literature review was conducted utilizing the MEDLINE and EMBASE databases through February 2019 to identify all cross-sectional studies that compared the prevalence of advanced liver fibrosis among NAFLD patients who were modest alcohol drinkers to NAFLD patients who were non-drinkers. Effect estimates from each study were extracted and combined together using the random-effect, generic inverse variance method of DerSimonian and Laird. RESULTS: A total of 6 studies with 8,936 participants fulfilled the eligibility criteria and were included in the meta-analysis. The risk of advanced liver fibrosis among patients with NAFLD who were modest alcohol drinkers was significantly lower compared to patients with NAFLD who were non-drinkers with a pooled odds ratio of 0.51 (95% confidence interval [CI] 0.35-0.75; I(2) 47%). The funnel plot was symmetric and was not suggestive of publication bias. CONCLUSION: A significantly lower risk of advanced liver fibrosis was observed among NAFLD patients who were modest alcohol drinkers compared to non-drinkers in this meta-analysis.