Joint association of sleep quality and physical activity with metabolic dysfunction-associated fatty liver disease: a population-based cross-sectional study in Western China

BACKGROUND: Metabolic dysfunction-associated fatty liver disease (MAFLD) is a growing global health burden. Poor sleep and physical inactivity are common and independently associated with MAFLD, but their joint effects remain unclear. METHODS: In a population-based cross-sectional study conducted in Xinjiang, China (July 2019–September 2021), self-reported sleep behaviors and physical activity (PA) were collected via validated questionnaires, and MAFLD was diagnosed radiologically. RESULTS: Among 10,089 participants (mean age 47.0 years; 51.6% men), 38.2% had MAFLD. Poor sleep quality and physical inactivity were independently and jointly associated with higher MAFLD prevalence after adjustment for traditional risk factors (P < 0.05). Compared with participants meeting guideline-recommended moderate-to-vigorous PA (MVPA) and having good sleep quality, those with no recommended MVPA and poor sleep had the highest odds of MAFLD (OR = 2.36, 95% CI: 1.81–3.08). Improving sleep quality substantially attenuated MAFLD prevalence regardless of PA volume, whereas PA well above current guidelines did not adequately counteract the adverse impact of poor sleep. CONCLUSIONS: Public health strategies should simultaneously target sleep quality and PA to curb the rising prevalence of MAFLD.