2006 Fiscal Year Final Research Report Summary
Relationship of bone health to yearlong physical activity in older Japanese adults : cross-sectional data from the Nakanojo Study
| Project/Area Number |
17500493
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied health science
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| Research Institution | Tokyo Metropolitan Foundation for Research on Aging and Promotion of Human Welfare |
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Principal Investigator |
AOYAGI Yukitoshi Tokyo Metropolitan Foundation for Research on Aging and Promotion of Human Welfare, Tokyo Metropolitan Institute of Gerontology, Sub Team Leader, 東京都老人総合研究所, 研究副部長 (50202495)
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| Project Period (FY) |
2005 – 2006
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| Keywords | Accelerometer / Aging / Fracture risk / Moderate-exercise duration / Osteoporosis / Step count |
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| Research Abstract |
We determined associations between bone health and the quantity and quality of habitual physical activity in a cohort of 172 free-living Japanese aged 65-83 years (76 men, 96 women). The number of steps taken and the intensity of physical activity were measured every 4 seconds throughout each 24-h period for one year, using a specially adapted accelerometer that distinguished up to 11 levels of physical activity (expressed in metabolic equivalents, METs). At the end of the year, a quantitative ultrasonic technique assessed each participant's osteosonic index (OSI, reflecting bone stiffness in the calcaneus). The data were significantly described by linear and exponential regression models which showed that in both sexes the OSI score increased with increasing daily physical activity, up to the observed maximum values of approximately 14000 steps/day, and 50 min/day at an intensity >3 METs. However, when data were categorized into quartiles of physical activity, OSI scores were not sign
… More
ificantly greater in persons exceeding recommended minimum standards of habitual physical activity (corresponding to counts of around 6900 and 6800 steps/day and durations >3 METs of around 18 and 16 min/day in men and women, respectively). All who met such criteria (with the exception of a few women) had OSI scores above the threshold for a clinical diagnosis of osteoporosis. Multivariate-adjusted logistic regression analyses predicted that men and especially women who engaged in <6800 steps/day and <16 min/day of moderate-intensity physical activity were respectively 4.9-8.4 and 2.2-3.5 times more likely to sustain fractures than those participating in >8200 steps/day and >25 min/day of activity >3 METs. Causation cannot be inferred from a cross-sectional study. Nevertheless, we suggest that from the viewpoint of bone health, elderly people should be encouraged to engage in low-and moderate-intensity habitual physical activity, taking >7000 steps/day, with a duration >15 min/day at >3 METs. Less
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Research Products
(10 results)
