Physical activity and incident dementia in older Japanese adults: The Okayama study

Yangyang Liu, Toshiharu Mitsuhashi, Michiyo Yamakawa, Megumi Sasai, Toshihide Tsuda, Hiroyuki Doi, Jun Hamada

Research output: Contribution to journalArticle

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.

Original languageEnglish
JournalInternational Journal of Geriatric Psychiatry
DOIs
Publication statusPublished - Jan 1 2019

Fingerprint

Dementia
Exercise
Confidence Intervals
Long-Term Care Insurance
Proportional Hazards Models
Japan
Cohort Studies
Retrospective Studies
Incidence
Health

Keywords

  • cohort study
  • dementia
  • elderly
  • Japanese
  • long-term care insurance
  • physical activity

ASJC Scopus subject areas

  • Geriatrics and Gerontology
  • Psychiatry and Mental health

Cite this

Physical activity and incident dementia in older Japanese adults : The Okayama study. / Liu, Yangyang; Mitsuhashi, Toshiharu; Yamakawa, Michiyo; Sasai, Megumi; Tsuda, Toshihide; Doi, Hiroyuki; Hamada, Jun.

In: International Journal of Geriatric Psychiatry, 01.01.2019.

Research output: Contribution to journalArticle

@article{3e2cde6f16ae433c92d7989b218ca2c3,
title = "Physical activity and incident dementia in older Japanese adults: The Okayama 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.",
keywords = "cohort study, dementia, elderly, Japanese, long-term care insurance, physical activity",
author = "Yangyang Liu and Toshiharu Mitsuhashi and Michiyo Yamakawa and Megumi Sasai and Toshihide Tsuda and Hiroyuki Doi and Jun Hamada",
year = "2019",
month = "1",
day = "1",
doi = "10.1002/gps.5135",
language = "English",
journal = "International Journal of Geriatric Psychiatry",
issn = "0885-6230",
publisher = "John Wiley and Sons Ltd",

}

TY - JOUR

T1 - Physical activity and incident dementia in older Japanese adults

T2 - The Okayama study

AU - Liu, Yangyang

AU - Mitsuhashi, Toshiharu

AU - Yamakawa, Michiyo

AU - Sasai, Megumi

AU - Tsuda, Toshihide

AU - Doi, Hiroyuki

AU - Hamada, Jun

PY - 2019/1/1

Y1 - 2019/1/1

N2 - 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.

AB - 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.

KW - cohort study

KW - dementia

KW - elderly

KW - Japanese

KW - long-term care insurance

KW - physical activity

UR - http://www.scopus.com/inward/record.url?scp=85065714518&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85065714518&partnerID=8YFLogxK

U2 - 10.1002/gps.5135

DO - 10.1002/gps.5135

M3 - Article

C2 - 31050010

AN - SCOPUS:85065714518

JO - International Journal of Geriatric Psychiatry

JF - International Journal of Geriatric Psychiatry

SN - 0885-6230

ER -