Association between physical activity levels and stroke risk among Chinese adults aged 45 and over based on CHARLS.

Stroke is one of the leading causes of death in developing countries, and China bears the largest global burden of stroke. This study aims to investigate the relationship between different dimensions of physical activity levels and stroke risk using a nationally representative database. We performed a cross-sectional analysis using data from the China Health and Retirement Longitudinal Study (CHARLS) 2020. Binary logistic regression models were used to analyze the associations between different dimensions of physical activity levels (intensity, frequency, duration, and total physical activity (TPA)) and stroke risk in Chinese middle-aged and older adults. Subgroups were analyzed according to participants' age, sex, residency, hypertension, dyslipidemia, and diabetes stratification. The results showed that after adjusting for all covariates, almost all frequencies and durations of moderate physical activity (MPA), and high-frequency and long-duration vigorous physical activity (VPA) were associated with lower stroke risk. No significant relationship was observed between light physical activity (LPA) and stroke risk. TPA was categorized into quartiles (Q1, Q2, Q3, Q4). Compared with the first quartile, the third and fourth quartiles were significantly associated with lower stroke risk, with risk reductions of 35% (OR 0.65, 95% CI 0.50-0.84) and 42% (OR 0.58, 95% CI 0.44-0.76), respectively. Subgroup analysis revealed differences in the association between TPA and stroke risk in different populations, and the interaction test indicated no significant interactions between these variables and TPA. Our findings suggested that appropriate participation in physical activity is effective in preventing stroke in middle-aged and older adults. Both MPA and high-frequency or long-duration VPA were significantly associated with lower stroke risk, and keeping TPA at a high level was significantly associated with lower stroke risk.