Domain-Specific Physical Activity and Stroke in Sweden

Importance Associations of domain-specific physical activity with stroke incidence and poststroke outcomes have not been extensively studied using long-term, population-based data. Objective To investigate associations of leisure time, work time, transport, and household physical activity with stroke incidence and death or dependency in activities of daily living (ADL) 3 months after stroke. Design, Setting, and Participants The prospective, population-based Interplay Between Genetic Susceptibility and External Factors (INTERGENE) cohort study was conducted among a random sample of individuals from an urban-rural area covering western Sweden; 3614 individuals aged 24 to 77 years were examined in 2001 to 2004, and 1394 individuals were reexamined in 2014 to 2016. The median (range) follow-up was 20.0 years (56 days to 21.9 years). Data were analyzed from September through October 2023. Exposure Physical activity levels were self-reported for leisure time, work time, transportation, and household domains. The mean number of steps taken over a 6-day period was collected in a subgroup of participants using a sealed pedometer. Main Outcomes and Measures Follow-up for stroke incidence and mortality rates continued until December 31, 2022. The composite outcome of death or ADL dependency was assessed at 3 months after stroke. Results Among 3614 individuals (mean SD age, 51.4 13.1 years; 1910 female 52.9%); 269 individuals (7.4%) developed stroke, of whom 120 individuals (44.6%) were dead or ADL dependent at 3 months. Intermediate (adjusted hazard ratio aHR, 0.54; 95% CI, 0.38-0.77) and high (aHR, 0.47; 95% CI, 0.31-0.73) levels of leisure time physical activity were associated with a reduced incidence of stroke compared with low levels, as was an intermediate level of physical activity in transportation (aHR, 0.69; 95% CI, 0.52-0.93). High levels of leisure time physical activity were also associated with a reduced risk of poststroke death or ADL dependency (adjusted odds ratio, 0.34; 95% CI, 0.16-0.71) compared with low levels. Work time and household physical activity were not associated with stroke incidence or stroke outcomes. In exploratory subgroup analyses, there were interactions between physical activity and smoking (current smoking or smoking in the past year associated with stroke risk only in participants with low or intermediate physical activity: aHR, 2.33; 95% CI, 1.72-3.15) and family history of stroke (first-degree relative with a history of stroke associated with stroke risk only in participants with low or intermediate physical activity: aHR, 1.73; 95% CI, 1.27-2.38). Conclusions and Relevance In this study, leisure time and transport-related physical activities were associated with a reduced risk of stroke. A high level of leisure time physical activity was also associated with a lower risk of death or ADL dependency 3 months after stroke.