Hobby Engagement and Risk of Disabling Dementia

Background: The association between hobby engagement and risk of dementia reported from a short-term follow-up study for individuals aged ≥65 years may be susceptible to reverse causation. We examined the association between hobby engagement in age of 40–69 years and risk of dementia in a long-term follow-up study among Japanese, including individuals in mid-life, when the majority of individuals have normal cognitive function. Methods: A total of 22,377 individuals aged 40–69 years completed a self-administered questionnaire in 1993–1994. The participants answered whether they had hobbies according to the three following responses: having no hobbies, having a hobby, and having many hobbies. Follow-up for incident disabling dementia was conducted with long-term care insurance data from 2006 to 2016. Results: During a median of 11.0 years of follow-up, 3,095 participants developed disabling dementia. Adjusting for the demographic, behavioral, and psychosocial factors, the multivariable hazard ratios of incident disabling dementia compared with “having no hobbies” were 0.82 (95% confidence interval [CI], 0.75–0.89) for “having a hobby” and 0.78 (95% CI, 0.67–0.91) for “having many hobbies”. The inverse association was similarly observed in both middle (40–64 years) and older ages (65–69 years). For disabling dementia subtypes, hobby engagement was inversely associated with the risk of dementia without a history of stroke (probably non-vascular type dementia), but not with that of post-stroke dementia (probably vascular type dementia). Conclusion: Hobby engagement in both mid-life and late life was associated with a lower risk of disabling dementia without a history of stroke.