Association of smoking with liver fibrosis and mortality in primary biliary cholangitis

BACKGROUND: The outcome of primary biliary cholangitis (PBC) is affected by both genetic and environmental factors. OBJECTIVE: The aim of this study was to study the effect of smoking on liver histology and mortality in a genetically homogeneous population having PBC. PATIENTS AND METHODS: Smoking and drinking habits at diagnosis (based on standard criteria) were recorded in 171 Cretan patients with PBC (163 women). A total of 148 patients had a liver biopsy. Odds ratios were calculated with logistic regression analysis. Kaplan-Meier curves were used for mortality estimation. RESULTS: Smoking was associated with alcohol consumption of more than 20 g/day [adjusted odds ratio (AOR)=2.20, 95% CI: 1.029-4.099], severe steatosis (AOR=5.31, 95% CI: 2.019-9.919), and fibrosis stage F3-F4 (AOR=1.21, 95% CI: 1.015-3.031). Heavy smoking, years of passive smoking, and serious necroinflammatiοn were independent factors associated with advanced fibrosis after adjustment for sex, age, BMI, and alcohol consumption in multivariate analysis. For every pack-year increase in smoking intensity, there was a 3.2 times higher likelihood of advanced fibrosis (95% CI: 2.018-6.294). Increased mortality was found in smokers with advanced PBC. CONCLUSION: There is an association between smoking, whether active or passive, and advanced fibrosis in PBC. Mortality is increased in smokers with advanced disease at presentation.