Physical activity dynamically moderates the impact of multimorbidity on the trajectory of healthy aging over sixteen years

Abstract

Abstract Background Research examining the healthy aging trajectory of retired older adults with multimorbidity is limited, leaving uncertainties regarding the optimal physical activity (PA) intensity and frequency necessary to sustain healthy aging during retirement. Methods Our study investigated the moderating effects of PA on the healthy aging trajectories of retired older adults living with multimorbidity in the United States (US). We utilized data from 1,238 retired individuals aged 50 to 102 who contributed 11,142 observations over 16 years from the Health and Retirement Study (HRS). We employed mixed effects modeling to assess the impact of various classes of multimorbidity on this group and examine how different PA, PA intensities, and PA frequencies influence the disability, physical, and cognitive functioning domains of healthy aging. Results The results reveal that while outcomes differed significantly, retired older adults in the US attained healthy aging at baseline. However, their ability to maintain healthy aging declined over time, with multimorbidity, especially musculoskeletal and neurological conditions, accelerating this decline. Fortunately, PA, especially light to moderate intensities, is associated with improving healthy aging and moderating the impact of multimorbidity on the disability and cognitive functioning domains of healthy aging. However, the specific moderating effects of PA depend on its frequency, intensity, and chronic conditions. Conclusions The significant variability in healthy aging attainment among retired older adults underlies the need to consider these differences when addressing healthy aging issues in the US. Accounting for these variations would aid in evaluating the potential impact of future interventions and contribute to achieving health equity. Fortunately, our dynamic findings facilitate this objective by identifying specific frequencies and intensities of PA tailored to different aspects of multimorbidity and healthy aging. This highlights PA, especially light-to-moderate intensity, as an essential, cost-effective, and amenable strategy for alleviating the impact of multimorbidity on healthy aging.