UC San Diego

Background: As the US population of older women continues to increase, promoting healthy longevity has become a public health priority. Increasing physical activity (PA) and limiting sedentary behavior (SB) can be an effective strategy for facilitating healthy longevity, as it is known to reduce the risk of developing many chronic conditions, manage the progression of current conditions, and helps maintain independence and mobility. However, evidence on the associations between accelerometer-measured PA (i.e., light, moderate-to-vigorous, total, daily steps), SB (i.e., sitting time, mean sitting bout duration), and healthy longevity among older women is lacking.Methods: Aim 1 and Aim 2 use data from the Women’s Health Accelerometry Collaboration (WHAC). Aim 1 quantified the prospective associations between accelerometer-measured PA, SB, and survival to age 90 with intact mobility among women ages 78–89 years at baseline in WHAC. Aim 2 examined the prospective associations between accelerometer-measured PA, SB and all-cause, cancer, and cardiovascular disease mortality among cancer survivors in WHAC. In Aim 3, we characterized the longitudinal changes in accelerometer-measured PA among older women in the Women’s Health Initiative Strong and Healthy (WHISH) trial. Results: In Aim 1, increasing PA of any intensity, taking more steps, and reducing prolonged sitting were associated with increased odds of survival to age 90 with and without intact mobility. Among over 2,500 US cancer survivors examined in Aim 2, accelerometer-assessed PA and daily steps were associated with reduced risk of all cause and cardiovascular disease mortality, while higher levels of SB were associated with increased risks. In Aim 3, we showed that PA measures decreased over time. However, sociodemographic and health status factors were associated with different trajectories of PA over time. Conclusion: These data provide further evidence that more PA of any intensity and shortened prolonged sitting are associated with reducing mortality risk after cancer and healthy longevity among older women. Furthermore, we highlight the variability in PA trajectories over time related to demographic and health-related factors, which could support targeted screening and intervention efforts.