Association between serum cotinine level and prevalence of non-alcoholic fatty liver disease: a cross-sectional study from the Third National Health and Nutrition Examination Survey

The data on the effect of smoking on non-alcoholic fatty liver disease (NAFLD) has been controversial. The aim of this study was to investigate if an association exists between serum cotinine level (a tobacco biomarker) and NAFLD prevalence in the general US population. We conducted a cross-sectional analysis of data from the Third National Health and Nutrition Examination Survey (NHANES III). We included 11,003 adults aged 20-74 years who underwent ultrasonography. Of those, 4036 were identified as having NAFLD and 6967 were recognized as controls. The percentage of current smokers was significantly lower in subjects with NAFLD compared with those in controls (21.5% vs 26.0%, p