Associations between Intensity, Frequency, Duration, and Volume of Physical Activity and the Risk of Stroke in Middle- and Older-Aged Chinese People: A Cross-Sectional Study

Context: Persuasive evidence has shown the inverse associations between physical activity (PA) and the risk of stroke. However, few studies have investigated the associations between different dimensions (intensity, frequency, duration, volume) of PA and the risk of stroke. Objective: To investigate the associations between different dimensions of PA and the risk of stroke in total participants and subgroups. Method: This study included 6250 individuals aged 45 years old and above from the China Health and Retirement Longitudinal Study (CHARLS). PA was divided into vigorous PA (VPA), moderate PA (MPA), and light PA (LPA), and described in different dimensions (intensity, frequency, duration, volume). Stroke was defined on the basis of self-reported diagnosis and related treatments. Binary logistic regression models were established to assess the associations between different dimensions of PA and the risk of stroke in total participants and subgroups stratified by sex. Results: Individuals taking VPA with a frequency of 3–5 d/w, duration of ≥240 min/d, volume of ≥300 min/w had lower risks of strokes in total participants (Odds ratio (OR) = 0.32, 95% confidence interval (CI): 0.13, 0.75; OR = 0.60, 95% CI: 0.38, 0.94; OR = 0.68, 95% CI: 0.46, 0.99, respectively). However, significant associations of VPA with the risk of stroke in men were only observed in the duration of ≥240 min/d and volume of ≥300 min/w (OR = 0.53, 95% CI: 0.30, 0.93; OR = 0.61, 95% CI: 0.38, 0.99, respectively) whereas no significance in women. Compared with individuals taking no MPA, inverse significant associations between the risk of stroke and any level of frequency, duration and volume in MPA were observed in total sample (OR ranging from 0.16–0.40, all p < 0.05), whereas significant associations between the risk of stroke and MPA were found in men except the duration of 10–29 min/d and volume of 150–299 min/w (OR ranging from 0.26–0.35, all p < 0.05), and in women except the frequency of 1–2 d/w and duration of ≥240 min/d (OR ranging from 0.14–0.49, all p < 0.05). No significant associations could be observed in total participants and subgroups between LPA and the risk of stroke. Conclusion: This study revealed some significant associations between different dimensions of PA, especially MPA, and the risk of stroke. Furthermore, the difference of association was observed in the groups with different sex. Further prospective study is needed to determine deeper associations between PA and the risk of stroke.