Stimulating leisure-time activities and the risk of dementia : A multi-cohort study

Background: Stimulating activities are associated with a decreased risk of dementia. However, the extent to which this reflects a protective effect of activity or non-participation resulting from dementia is debated. We investigated the association of stimulating leisure-time activity in late adulthood with the risk of dementia across up to two decades' follow-up. Methods: We used data from five prospective cohort studies from Finland and Sweden. Mental, social, outdoor, consumptive and physical leisure-time activities were self-reported. Incident dementia was ascertained from clinical diagnoses or healthcare and death registers. Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Results: Of the 33 263 dementia-free individuals aged ≥50 years at baseline, 1408 had dementia during a mean follow-up of 7.0 years. Active participation in mental (HR: 0.52, 95% CI: 0.41 to 0.65), social (HR: 0.56 95% CI: 0.46 to 0.72), outdoor (HR: 0.70, 95% CI: 0.58 to 0.85), consumptive (HR: 0.67, 95% CI: 0.53 to 0.94) and physical (HR: 0.62, 95% CI: 0.51 to 0.75) activity, as well as variety (HR: 0.54, 95% CI: 0.43 to 0.68) and the overall frequency of activity (HR: 0.41, 95% CI: 0.34 to 0.49) were associated with a reduced risk of dementia in <10 years' follow-up. In ≥10 years' follow-up all associations attenuated toward the null. Conclusion: Stimulating leisure-time activities are associated with a reduced risk of dementia in short-term but not long-term follow-up. These findings may reflect a reduction in leisure-time activity following preclinical dementia or dilution of the association over time.
CC BY 4.0 Deed© 2024 The Author(s)Correspondence Address: K. Heikkilä; Department of Public Health, University of Turku, Turku, Kiinamyllynkatu 10, 20520, Finland; email: katriina.heikkila@utu.fi; CODEN: AANGASNAC-K receives financial support from the Swedish Research Council (Vetenskapsrådet, 2011-6,243; 2017-06088), the Swedish Research Council for Health, Working Life and Welfare (FORTE, 2016-07175), and is supported by the Swedish Ministry of Health and Social Affairs and the participating County Councils and Municipalities. MK was supported by Wellcome Trust (221854/Z/20/Z), UK Medical Research Council (S011676, Y014154), US National Institute on Aging (NIH, R01AG056477, R01AG062553), and Research Council Finland (350426). JV was supported by the Academy of Finland (321409 and 329240). S Stenholm was supported by Research Council Finland (332030), Juho Vainio Foundation and Signe and Ane Gyllenberg Foundation. S Stenlund was supported by Signe and Ane Gyllenberg Foundation. The authors thank the research teams that collected, linked and curated data and especially all the individuals who participated in the longitudinal cohort studies.