A US cohort study suggested that more active time, especially at moderate intensities, and less sedentary time, particularly in longer bouts, may reduce the risk of stroke. The study included 7607 participants (mean age 63.4 years; 54.5% female, 31.6% Black, and 68.4% White), including 54.7% of them resided in the regions of high stroke mortality rate. There were 286 incident stroke cases (ischemic 85.3%) during a mean of 7.4 years of follow-up. The fully adjusted hazard ratios (HRs) for incident stroke in the highest tertile compared with the lowest tertile were 0.74 for light-intensity physical activity (LIPA) and 0.57 for moderate- to vigorous-intensity physical activity (MVPA) measured by a hip-mounted accelerometer worn for 7 consecutive days. Longer sedentary time was associated with a higher risk of incident stroke (HR, 1.44). When comparing the highest with the lowest tertile, mean sedentary bout duration was associated with a significantly higher risk of incident stroke (HR, 1.53). After adjustment for sedentary time, the highest tertile of unbouted MVPA (shorter bouts [1-9 minutes]) was associated with a significantly lower risk of incident stroke compared with the lowest tertile (HR, 0.62; P = .02), but not bouted MVPA (longer bouts [at least 10 minutes], HR, 0.78; P = .17). When expressed as continuous variables, sedentary time was positively associated with incident stroke risk (HR per 1-hour/day increase in sedentary time: 1.14), and LIPA was negatively associated with incident stroke risk (HR per 1-hour/day increase in LIPA: 0.86). The findings add to the mounting evidence demonstrating the health hazards of prolonged sitting and are consistent with existing physical activity guidelines. Source: https://jamanetwork.com/
