The association between trajectories of physical activity and all-cause and cause-specific mortality

Background: The benefits of physical activity (PA) for health have primarily been evaluated during midlife. Whether patterns of change in late-life PA associate with overall and cause-specific mortality remains unclear. Methods: We examined the association between PA trajectories and subsequent mortality among 3,767 men aged ≥65 years. Men self-reported PA using the Physical Activity Scale for the Elderly (PASE) at up to four time points from 2000 through 2009 (Year 7); mortality was assessed over an average of 7.1 years after the Year 7 contact. Group-based trajectory modeling identified patterns of PA change. Cox proportional hazards models described associations between patterns of change in PA, Year 7 PA, and subsequent mortality risk. Results: Three discrete PA patterns were identified, all with declining PA. Compared to low-activity declining men, moderate (hazard ratio [HR] = 0.78; 95% confidence interval [CI]: 0.70, 0.88) and high-activity (HR = 0.69, 95% CI: 0.57, 0.83) declining groups were associated with lower risk of all-cause mortality. Among models with a single time point, the last time point (Year 7 PA score) was a strong predictor of mortality with HR = 0.85 (95% CI: 0.78, 0.93) per SD increase in PASE score. PA patterns were not a risk factor for mortality after adjustment for the Year 7 PA score. Conclusions: Recent PA levels are a stronger indicator of subsequent mortality risk than PA patterns reported over the prior 7 years or prior PA level, suggesting that current PA rather than history of PA is the most relevant parameter in clinical settings.