Association between physical activity and non-alcoholic fatty liver disease among adults aged 65 and above in longevity regions of China

Objective: To investigate the association between physical activity (PA) levels and types (leisure and household) and the risk of non-alcoholic fatty liver disease (NAFLD) among elderly adults aged 65 and above in 18 longevity regions in China. Methods: Participants were derived from the 2021 cross-sectional survey of the Healthy Ageing and Biomarkers Cohort Study (HABCS), involving a total of 3 283 elderly adults aged 65 and above. Demographic characteristics, lifestyle factors, and chronic disease history were collected through questionnaires and physical examinations. PA status was assessed using the Physical Activity Scale for the Elderly (PASE). NAFLD was defined based on the Fatty Liver Index (FLI) and daily alcohol intake. Multivariable logistic regression models were employed to analyze the associations between different PA levels and types with the risk of NAFLD. Restricted cubic splines (RCS) were used to analyze the exposure-response relationship between physical activity and NAFLD. Results: The mean age of the 3 283 participants was (85.57±10.77) years, with the median (Q₁, Q₃) PASE score of 68.60 (25.00, 111.80) and the prevalence of NAFLD about 29.5% (963). Multivariable logistic regression results showed that after adjusting for relevant confounders, each one interquartile range (IQR) increase in total PASE score was associated with a 20% reduction in the risk of NAFLD (OR=0.80, 95%CI: 0.69-0.91). No statistically significant associations were observed for individuals engaging in household activities only or leisure activities only. The RCS model indicated a negative association between physical activity levels and NAFLD risk (Poverall<0.001, Pnon-linear=0.295). Conclusion: Physical activity level is inversely associated with the prevalence of NAFLD among elderly adults aged 65 and above in 18 longevity regions of China.