Impact of exercising alone and exercising with others on the risk of cognitive impairment among older Japanese adults

Abstract

Purpose: This longitudinal study investigates the influence of the stratified frequency of exercising alone and exercising with others on the prevention of cognitive impairment among older Japanese adults.

Methods: This four-year follow-up study targeted 4,358 individuals (mean age: 76.9 ± 5.6 years, female: 51.8%) who participated in an inventory mail survey in one region of Japan. The exercise forms surveyed involved the frequency of exercising alone and with others. Cognitive impairment was assessed using the nationally standardized dementia scale proposed by the Ministry of Health, Labour and Welfare of Japan. Adjusted Cox proportional-hazard models were used to examine the association between the exercise forms and the development of cognitive impairment, and calculate population-attributable fractions (PAFs).

Results: The cumulative incidence of cognitive impairment throughout the study was 7.7%. Participants who exercised ≥ 2 times/week alone (hazard ratio [HR] = 0.78; 95% confidence interval [CI] = 0.61-0.998) had a lower risk of developing cognitive impairment than those who did not exercise alone. Similarly, participants who exercised ≥ 2 times/week with others (HR = 0.66; 95% CI = 0.47-0.94) showed a lower risk of developing cognitive impairment than those who did not exercise with others. The scenarios involving PAFs demonstrated that, if all participants exercised alone or with others ≥ 2 times/week, the risk of cognitive impairment decreased by 15.1% and 29.2%, respectively.

Conclusion: Both forms of exercise reduced the development of cognitive impairment, with exercising with others potentially being highly effective in preventing cognitive impairment.

Keywords: Cognitive decline; Community-based survey; Group exercise; Physical activity; Social participation.