Non-Alcoholic Fatty Liver Disease Is Strongly Associated with Smoking Status and Is Improved by Smoking Cessation in Japanese Males: A Retrospective Study

摘要

BACKGROUND: Cigarette smoking is known to be a significant risk factor associated with nonalcoholic fatty liver disease (NAFLD). We aimed to examine the association between smoking status and theseverity of fatty liver with regard to sex and smoking cessation. METHODS: In total, 13,466 subjects (6,642males and 6,824 females) who had undergone abdominal ultrasonography for health check-up,multivariable logistic regression analysis was retrospectively conducted to assess the association betweensmoking status and the prevalence of NAFLD stratified by sex after adjusting for other potentialconfounders. RESULTS: Male sex (odds ratio [OR] 3.27, 95% confidence interval [CI] 3.00-3.57) andsmoking history (former smoker: OR 1.23, 95% CI 1.10-1.38, current smoker: OR 1.31, 95% CI 1.17-1.47)were significantly associated with NAFLD. In males with a smoking history, an increased pack-year wasstrongly associated with the prevalence and severity of NAFLD (prevalence of moderate to severe fattyliver: Pack-year from 0.01 to 9.99, 21.3%; Pack-year from 10.00 to 19.99, 27.2%; Pack-year ≥20.00, 33.7%;P0.0001), although the prevalence of moderate to severe fatty liver was inversely associated with theduration of smoking cessation (more than 10 years vs. within 5 years, OR 0.71, 95% CI 0.53-0.96). In femalesubjects, light current smoking was negatively associated with NAFLD (current smoker with a pack-yearfrom 0.01 to 9.99 vs. never smoker, OR 0.41, 95% CI 0.19-0.76). CONCLUSIONS: Smoking status andpack-year were strongly associated with the prevalence and severity of NAFLD, especially in Japanesemales. However, smoking cessation improved NAFLD in this population.