1. Physical activity and incident dementia in older Japanese adults: The Okayama study
- Author
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Toshihide Tsuda, Jun Hamada, Michiyo Yamakawa, Toshiharu Mitsuhashi, Yangyang Liu, Hiroyuki Doi, and Megumi Sasai
- Subjects
Male ,Physical activity ,Subgroup analysis ,Japan ,Surveys and Questionnaires ,Humans ,Medicine ,Dementia ,Exercise ,Life Style ,Aged ,Proportional Hazards Models ,Retrospective Studies ,Aged, 80 and over ,business.industry ,Incidence ,Incidence (epidemiology) ,Hazard ratio ,Retrospective cohort study ,Middle Aged ,medicine.disease ,Confidence interval ,Psychiatry and Mental health ,Female ,Geriatrics and Gerontology ,business ,Demography ,Cohort study - Abstract
OBJECTIVE To evaluate the association between regular physical activity and the risk of incident dementia in older Japanese adults. METHODS This was a retrospective cohort study performed in Okayama City, Japan. Overall, 51 477 older Japanese adults were followed from 2008 to 2014. A health checkup questionnaire was used to assess regular physical activity. The Dementia Scale of long-term care insurance was used as a measure of incident dementia. Cox proportional hazard models were used to calculate adjusted hazard ratios, with their 95% confidence intervals, for the incidence of dementia across the categories of physical activity. RESULTS During a 7-year follow-up, 13 816 subjects were considered as having incident dementia. Compared with participants who performed physical activity less than or equal to one time per week, the multivariate adjusted hazard ratio values (95% confidence intervals) for participants who performed physical activity greater than or equal to two times per week but not every day and those who performed physical activity every day were 0.79 (0.75-0.84) and 0.94 (0.89-0.98), respectively. The interaction of physical activity and sex was statistically significant (P < .01). In subgroup analysis, the multivariate-adjusted hazard ratio values (95% confidence intervals) remained low, at 0.76 (0.70-0.84) in males and 0.81 (0.76-0.87) in females who performed physical activity greater than or equal to two times per week but not every day; they were 0.82 (0.76-0.89) in males and 1.01 (0.95-1.07) in females who performed physical activity every day. CONCLUSIONS Regular physical activity could reduce the risk of incident dementia in older Japanese adults, except females who performed physical activity every day.
- Published
- 2019