Is the 10‐Year Trajectory of Physical Activity Associated With the Incidence of Mild Cognitive Impairment in Older Adults?

OBJECTIVE: To identify leisure-time physical activity trajectories in older adults and examine their association with the incidence of mild cognitive impairment (MCI) over a decade. METHODS: This longitudinal study used data from the EpiFloripa Aging Cohort Study (2009-2019). The sample included older adults of both sexes, aged 60 years or older, residing in Florianópolis, Santa Catarina, Brazil. MCI was assessed using the Mini-Mental State Examination, and incidence was defined as new cases identified after baseline. Leisure-time physical activity was measured using the International Physical Activity Questionnaire. Older adults reporting no participation (≤ 10 min/week) in moderate-to-vigorous physical activity (MVPA) or walking were classified as following an 'inactive trajectory', while those maintaining ≥ 10 min/week of MVPA or walking were considered to follow an 'active trajectory'. Incidence rate ratios (IRR) and their 95% confidence intervals (95% CI) were calculated to test the associations. RESULTS: A total of 731 older adults were followed (66.6% women). The incidence of MCI was 104 new cases (18.5%; 95% CI: 14.8-20.9). Older adults who maintained an active trajectory of MVPA and walking in leisure time had a 40% lower risk (IRR: 0.60; 95% CI: 0.38-0.92) and a 34% lower risk (IRR: 0.76; 95% CI: 0.47-0.96), respectively, of developing MCI during the follow-up period. CONCLUSION: Maintaining an active trajectory of physical activity was associated with a reduced risk of developing MCI after 10 years of follow-up. Leisure-time MVPA and walking programs may represent promising strategies to promote cognitive function in older adults.