Asociación entre el tiempo de sedentarismo y la actividad física con la supervivencia en supervivientes de ictus: un...

To assess the independent and joint effects of sitting time and moderate-to-vigorous intensity physical activity (MVPA) on mortality in stroke survivors.

Retrospective study of prospective cohort data from the National Health and Nutrition Examination Survey (NHANES) 2007-2018.

NHANES, a nationally representative U.S. survey that combines in-home interviews and standardized physical examinations conducted in mobile examination centers.

A total of 1,312 adult stroke survivors were included, representing a weighted population of 6,617,365 individuals. Participants were followed for mortality outcomes through December 31, 2019.

Not applicable.

All-cause and cardiovascular disease (CVD)-specific mortality ascertained from the National Death Index.

Over a median follow-up of 4.85 years, there were 438 deaths, including 151 due to CVD. Sitting ≥8 h/day was associated with higher risks of all-cause mortality (HR, 1.73; 95% CI, 1.25-2.40) and CVD-specific mortality (HR, 1.97; 95% CI, 1.04-3.74). A statistically significant interaction between sitting time and MVPA was observed for all-cause mortality (P for interaction = 0.006). Participants with both prolonged sitting and <150 min/week of MVPA had significantly increased risks of all-cause mortality (HR, 3.86; 95% CI, 2.20-6.78), compared with stroke survivors who were sufficiently active and reported shorter sitting time (MVPA ≥150 min/week & sitting time <4 h/d). Importantly, the association between prolonged sitting and increased all-cause mortality was observed only among those with insufficient MVPA (HR, 1.04; 95% CI, 1.01-1.07), but not among those who were sufficiently active (HR, 1.00; 95% CI, 0.91-1.10).

This study of U.S. stroke survivors reveals that the combination of insufficient physical activity and prolonged sitting is associated with the highest mortality risk, and sufficient MVPA may attenuate the all-cause mortality risk associated with prolonged sitting.