Sitting Time, Leisure-Time Physical Activity, and Risk of Mortality Among US Stroke Survivors: A Prospective Cohort Study From the NHANES 2007 to 2018.

Stroke survivors are highly sedentary and engage in minimal physical activity. This study aimed to investigate the independent and joint effects of daily sitting time and leisure-time physical activity on survival among stroke survivors. The nationally representative cohort included 1446 stroke survivors (weighted population, 6 968 723) from the National Health and Nutrition Examination Survey from 2007 to 2018. Mortality data were obtained through December 31, 2019. Leisure-time physical activity was categorized as inactive (0 min/wk), insufficiently active (1 to <150 min/wk), and sufficiently active (≥150 min/wk). Daily sitting time was categorized as <6, 6 to <8, and ≥8 h/d. Survival analyses of all-cause and specific mortality were performed by weighted Cox proportional hazards regression models. This cohort study comprised 55.0% females, 68.7% non-Hispanic White, and had a weighted mean (SE) age of 64.6 (0.5) years. Overall, 70.3% were inactive, 42.3% sat at least 8 h/d, and 34.9% were both inactive and sat at least 8 h/d. During a median of 5.2 years of follow-up, 494 deaths occurred, including 171 associated with cardiovascular disease (CVD) and 323 associated with non-CVD. Active stroke survivors had a lower risk of all-cause (hazard ratio [HR], 0.26 [95% CI, 0.17-0.40]), CVD (HR, 0.26 [95% CI, 0.13-0.53]), and non-CVD (HR, 0.26 [95% CI, 0.15-0.46]) mortality compared with inactive stroke survivors. Sitting at least 8 h/d was associated with higher risks of all-cause (HR, 1.50 [95% CI, 1.13-1.99]) and non-CVD (HR, 1.61 [95% CI, 1.18-2.20]) mortality compared with sitting <6 h/d. In the joint analyses, stroke survivors who were inactive or insufficiently active and sat for at least 8 h/d had the highest risks of all-cause (HR, 3.73 [95% CI, 2.07-6.73]), CVD (HR, 3.32 [95% CI, 1.33-8.29]), and non-CVD (HR, 3.91 [95% CI, 1.70-8.95]) mortality when compared with those who were active and sat for <6 h/d. When stratifying by leisure-time physical activity, daily sitting time was not associated with mortality among active stroke survivors. These observations were confirmed in sensitivity analyses. This study highlights the potential benefits of enhancing leisure-time physical activity and reducing sitting time to lower mortality rates among stroke survivors.