Smoking and Risk of Fatty Liver Disease: A Meta-Analysis of Cohort Studies

It remains inconclusive whether smoking is associated with an increased risk of fatty liver dis-ease (FLD). We investigated the association between smoking and the risk of FLD by using a meta-analysis of cohort studies. PubMed and EMBASE were searched using keywords from in-ception to September 2023 to identify relevant studies. Out of 806 articles searched from data-bases, a total of 20 cohort studies were included in the final analysis. In the meta-analysis, smoking was significantly associated with an increased risk of FLD (odds ratio/relative risk/hazard ratio, 1.14; 95% confidence interval, 1.05 – 1.24; n = 20). Subgroup analyses showed a significant positive association between them in prospective cohort studies (odds ratio/relative risk/hazard ratio, 1.15; 95% confidence interval, 1.05 – 1.18; n = 5), but not in retrospective cohort studies and cross-sectional studies based on cohort studies. In the subgroup meta-analysis by gender in Asians, smoking significantly increased the risk of FLD in men, while there was no significant association between them in women. This meta-analysis showed that smoking in-creases the risk of FLD. In addition to well-known risk factors of FLD such as obesity and alcohol consumption, clinicians should recommend smoking cessation for the management of FLD.