Long-term physical activity participation trajectories were associated with subsequent cognitive decline, risk of dementia and all-cause mortality among adults aged ≥50 years: a population-based cohort study

Abstract

Aim: to evaluate self-reported physical activity (PA) participation trajectories over a 6-year span and to assess associations with subsequent cognitive decline, incident dementia and all-cause mortality.

Methods: population-based cohort of 8,842 community-dwelling adults aged ≥50 years in England. Group-based trajectory modelling was used to identify 6-year trajectories of PA participation. Cognitive decline, incident dementia and all-cause mortality were outcomes.

Results: five trajectories were identified, including persistently low (N = 2,511), initially low then improving (1,651), initially high then declining (249), persistently moderate (2,422) and persistently high (2,009). Compared with persistently low, participants of initially low then improving and persistently high PA participation experienced decelerated global cognitive decline of 0.012 standard deviation (SD)/year (95% confidence interval [CI]: 0.004-0.021, P = 0.004) and 0.021 SD/year (95% CI: 0.013-0.029, P < 0.001). They were also associated with lower dementia risk, with multivariate-adjusted hazard ratios (HRs) of 0.43 (95% CI: 0.31-0.60) and 0.35 (95% CI: 0.27-0.45). A similar pattern was observed for all-cause mortality, with HRs of 0.31 (95% CI: 0.13-0.74) and 0.25 (95% CI: 0.14-0.45). No significant differences were observed between persistently low and initially high then declining trajectories.

Conclusion: for middle-aged and older adults, both gradually improved and persistently active PA participation were associated with decelerated cognitive decline, lower risk of dementia and all-cause mortality. Strategies focusing on improving and maintaining PA participation could be of significance by attaining considerable neurocognitive and longevity benefits.

Keywords: cognitive decline; dementia prevention; longitudinal trajectories; mortality risk; older people; physical activity.