Associations between sitting time and non-alcoholic fatty liver diseases in Chinese male workers: a cross-sectional study

OBJECTIVES Various studies have revealed a close association between sedentary behaviour and metabolic diseases, yet the association between sedentary time and non-alcoholic fatty liver disease (NAFLD) remains unclear. In this study, we investigated the association between sitting time and NAFLD in a Chinese male population and explored its underlying mechanism. STUDY DESIGN A cross-sectional study. SETTING Chongqing, China. PARTICIPANTS Our study included 2054 male participants; all of the participants were of Han nationality. PRIMARY OUTCOME MEASURES Sitting time was assessed using a self-reported questionnaire concerning the time devoted to sitting behaviour. Various clinical and demographic biomarkers were measured. Logistic regression analyses were used to investigate the ORs and the 95% CIs between sitting time and NAFLD. RESULTS We found a higher proportion of NAFLD across the tertiles of sitting time (p trend=0.003). Multivariate linear regression analyses showed sitting time independently correlated with homoeostasis model assessment for insulin resistance (HOMA-IR), alanine aminotransferase, γ-glutamyl transpeptidase, body mass index, triglyceride and the high-sensitive C reactive protein (hsCRP) (all p<0.05). Further logistic regression analyses showed that longer sitting time (>7.1 hours/day) was associated with a higher prevalence of NAFLD (OR 1.09; 95% CI (1.04 to 1.67)) after adjusting for confounders. However, this association was insignificant after further adjusting for hsCRP (OR 1.03; 95% CI (0.92 to 1.84)). CONCLUSIONS Sitting time was positively associated with the prevalence of NAFLD, and this association might be affected by inflammation.