Late Adulthood Physical Activity Trajectories In Relation To All-cause Mortality

Abstract

PURPOSE: Despite the known benefits of being physically active, about half of U.S. adults (and nearly two-thirds of adults age 65+ years) do not meet current U.S. Physical Activity Guidelines for Americans of 150-300 minutes of moderate (75-150 minutes of vigorous) physical activity (MVPA) per week. Given the aging U.S. population and rising healthcare costs, identifying factors associated with healthy aging is critical. There is limited epidemiologic evidence examining whether increasing or initiating MVPA in later adulthood can increase longevity. This study examined the association between late adulthood MVPA trajectories and all-cause mortality in a large U.S. prospective cohort. METHODS: This analysis included 71,862 Cancer Prevention Study-II Nutrition Cohort participants (mean age 74.1 years; range 52-89 years) who were free of major chronic diseases. Participants self-reported MVPA at two time points approximately 5-years apart and were categorized based on their level of adherence to MVPA guidelines at each time point (inactive, “insufficiently active”, “sufficient”, and “>double minimum recommended”). 12 trajectories were defined (4 each for consistent, increasing, or decreasing MVPA); participants who were consistently “insufficiently active” served as the reference category. Multivariable Cox proportional hazards regression modeling was used to estimate hazard ratios (HR) and 95% confidence intervals (CI). RESULTS: After an average of 9.9 years of follow-up, 22,736 deaths occurred. The most active participants (>double recommended) at both time points had a 24% lower mortality risk compared to insufficiently active participants (95% CI 0.73-0.79). Those who increased MVPA over time (insufficient to sufficient) also had a lower mortality risk (HR=0.85, 95% CI 0.80-0.91). Conversely, those who decreased activity (sufficient to inactive) had a higher mortality risk (HR=1.18, 95% CI 1.10-1.26). Associations were similar for men and women, and for cardiovascular disease and cancer-specific mortality. CONCLUSIONS: Maintaining a physically active lifestyle at older ages is optimal for longevity. Public health messaging should encourage active individuals to maintain their physical activity level as they age and reinforce that it is never too late to start being active.