Physical activity and liver health among urban and rural Chinese adults: results from two independent surveys

Background: Increased physical activity has been associated with reduced risks of various physical and mental conditions. However, the association between physical activity and liver health in the Chinese general adult population is not clear. This study investigated whether physical activity, stratified by intensity (i.e. walking (light), moderate-to-vigorous), was associated with alanine aminotransferase (ALT) level in middle-aged and older Chinese adults. Methods: Two independent surveys of urban (n = 5,824, males 44%, mean (standard deviation) age 52 (10) years) and rural populations (n = 20,269, males 41%, mean (standard deviation) age 51 (10) years) were undertaken. Physical activity was measured using the International Physical Activity Questionnaire, and in metabolic equivalents of task (MET) × minutes. Elevated serum level of ALT, a clinical surrogate of abnormal liver function, was defined as >40 IU/L (males) and >30 IU/L (females). Multivariable regression models were used. Results: Amount of moderate-to-vigorous activity was inversely associated with serum level of ALT (β = −0.147 per 1k MET-minutes, p < 0.001), whereas walking was not associated. People who reached the lower limit of WHO recommendation (≥600 MET-minutes per week) had a reduced odds of ALT elevation, compared to those who did not (adjusted odds ratio: 0.85 95%CI (0.76, 0.95)). Conclusions: Meeting the moderate-to-vigorous recommendations for physical activity in adults may be associated with decreased likelihood of abnormal liver function both in Chinese urban and rural populations. Promoting such activities could be a low-cost strategy in maintaining liver health as well as providing many other health-related benefits.