[Different Types of Obesity Play a Modifying Role in the Association Between Physical Activity and Metabolic Dysfunction-Associated Fatty Liver Disease].

OBJECTIVE

To explore the association between physical activity levels and metabolic dysfunction-associated fatty liver disease (MAFLD) and the modifying effects of different types of obesity.

METHODS

A cross-sectional study was conducted on 19925 participants recruited from the Chengdu sub-cohort of the Southwest China Natural Population Cohort. The participants were recruited between 2018 and 2019. The association between physical activity and MAFLD prevalence was examined using the inverse probability weighting (IPW) method based on the generalized propensity score (GPS). The odds ratios (OR) and the 95% confidence interval (CI) for moderate and vigorous physical activity were calculated using the mild physical activity group as a reference. A restricted cubic spline function was used to model the exposure-response relationship between physical activity and MAFLD risk. The potential modifying effects of obesity types on the association between physical activity and MAFLD were evaluated in male and female populations.

RESULTS

The prevalence of MAFLD was 17.30%. Compared to those engaging in mild physical activity, individuals participating in vigorous and moderate physical activities had a lower risk of MAFLD, with OR (95% CI) being 0.76 (0.67, 0.86) and 0.85 (0.76, 0.94), respectively. The exposure-response relationship showed a nonlinear association between physical activity and MAFLD risks ( = 0.005). The protective effect of physical activity against MAFLD was observed when physical activity reached approximately 20 METs-h/d. However, when physical activity exceeded 70 METs-h/d, no significant effect on MAFLD risk was observed. Among the female population, obesity type significantly modified the association between physical activity and MAFLD ( < 0.05). In females with central obesity, the protective effect of physical activity on MAFLD showed a threshold effect, with the lowest disease risk observed at approximately 25 METs-h/d. However, physical activity exceeding 37.5 METs-h/d showed no statistically significant association with MAFLD risk. In contrast, for females with peripheral obesity, high levels of physical activity had limited effects on reducing MAFLD risks.

CONCLUSION

Moderate physical activity can significantly reduce the risk of MAFLD, and the obesity types can modify this association. It is recommended that individuals engage in approximately 20-70 METs-h/d of physical activity. For females with central obesity, physical activity should not exceed 37.5 METs-h/d, while for females with peripheral obesity, it should not exceed 30 METs-h/d.