The association between intensity-specific physical activity and the number of multiple chronic diseases among Chinese elderly: A study based on the China Health and Retirement Longitudinal study (CHARLS)

With ageing, the elderly are facing a complex situation where multiple chronic diseases coexist. This paper aims to investigate the effect of intensity-specific physical activity on the number of multiple chronic diseases in the elderly. Our data came from wave 4 of the China Health and Retirement Longitudinal Survey (CHARLS), which involved 10,341 residents aged ≥ 60 years. The intensity-specific physical activity was divided into two categories: moderate-intensity physical activity (MPA) lasting ≥ 150 min/week and vigorous-intensity physical activity (VPA) lasting ≥ 75 min/week. Data on 14 types of chronic diseases were collected. Propensity score matching (PSM) with controlling nine confounding factors were used to analyse the effects of intensity-specific physical activity. Among 10,341 samples, 40.12% of the elderly often participated in MPA and 25.72% participated in VPA. The PSM results showed that performing 150 min/week of MPA leads to 0.0675(P<0.05) fewer multiple chronic diseases than not achieving this standard, and VPA up to 75 min/week leads to 0.0785(P<0.05) fewer multiple chronic disease than that does not meet this criterion. Additionally, VPA is more effective than MPA. Both MPA of at least 150 min/week and VPA of at least 75 min/week can significantly reduce the number of multiple chronic diseases in elderly. Elderly people should increase their exercise intensity as much as possible while ensuring safety.