Associations of mortality with leisure-time physical activity and sitting time in postmenopausal women: Insights from NHANES.

OBJECTIVE

Postmenopausal women are vulnerable to insufficient physical activity and prolonged sitting. While both behaviors have been individually associated with mortality, their joint effects remain unclear.

METHODS

We analyzed 5355 postmenopausal women (median age 63 years [interquartile range 56-71]) from the National Health and Nutrition Examination Survey (NHANES) 2007-2018. Leisure-time physical activity was categorized as insufficient (<600 metabolic equivalent of task minutes per week) or sufficient (≥600 metabolic equivalent of task minutes per week). Sitting time was classified as <6 h/day, 6-8 h/day, or ≥ 8 h/day. Survey-weighted Cox proportional hazards models examined the independent and joint associations of physical activity and sitting time with all-cause, cardiovascular disease, cancer and other-cause mortality.

RESULTS

During a median follow-up of 78 months, 673 (13.8%) deaths occurred, including 201 from cardiovascular disease, 162 from cancer, and 310 from other causes. Both sufficient leisure-time physical activity and shorter sitting time were independently associated with lower risks of all-cause, cardiovascular disease, and other-cause mortality, but not cancer mortality. In joint analyses, participants with sufficient physical activity and < 6 h/day sitting had the lowest all-cause (adjusted hazard ratio 0.25, 95% confidence interval 0.16-0.39), cardiovascular disease (adjusted hazard ratio 0.15, 95% confidence interval 0.08-0.30) and other-cause (adjusted hazard ratio 0.17, 95% confidence interval 0.08-0.37) mortality, compared with those with insufficient physical activity and ≥ 8 h/day sitting.

CONCLUSION

In this prospective cohort study of US postmenopausal women, the combination of sufficient physical activity and lower sitting time was associated with lower risks of all-cause and cardiovascular disease mortality.