How Life-Course Trajectories of Physical Activity Track With Cognitive Decline.

BACKGROUND: Physical activity (PA) may help to delay or possibly prevent cognitive decline and dementia. However, few studies have adopted a life-course approach to prospectively examine repeated measures of PA in relation to cognitive decline. METHODS: Framingham Heart Study Offspring and Omni 1 participants without prevalent dementia who had ≥3 self-reported PA measures and ≥2 cognitive domain factor score measures were included (n = 2229). Memory, executive function, and language factor scores were previously derived using bifactor confirmatory factor analysis models. Group-based multitrajectory models characterized PA patterns over the adult life-course (ages 17-96 y). Linear mixed-effects models estimated annual changes in cognitive domain factor scores across PA trajectory groups over the same time period. RESULTS: We identified 4 PA trajectories: (1) stabilizers: decline from early adulthood through midlife and then stable after age 50 (n = 176), (2) decliners: constant decline over adulthood (n = 526), (3) reversers: increase from early adulthood through midlife and then decline after age 70 (n = 1145), and (4) plummeters: slow decline from early adulthood through midlife and then sharp decline after age 75 (n = 382; reference). Compared with the reference group, stabilizers had 0.012 SD/year (95% CI, 0.004-0.02) slower memory decline, 0.012 SD/year (95% CI, 0.005-0.02) slower executive function decline, and 0.015 SD/year (95% CI, 0.007-0.02) slower language decline. Decliners had slower cognitive decline across all domains, and reversers had slower language decline. CONCLUSIONS: Our findings suggest that sustaining PA in mid-to-late life and preventing later life declines may help mitigate cognitive decline with aging.