TY - JOUR
T1 - Combined effects of body mass index and unhealthy behaviors on disability 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
N1 - Funding Information:
1Department of Epidemiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan 2Center for Innovative Clinical Medicine, Okayama University Hospital, Okayama University, Okayama, Japan 3Department of Epidemiology and Preventive Medicine, Graduate School of Medicine, Gifu University, Gifu, Japan 4Sri Lanka Office, Japan International Cooperation Agency, Colombo, Sri Lanka 5Department of Human Ecology, Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan 6Department of Health Economics and Policy, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
Funding Information:
We thank Dr. Hiroaki Matsuoka at Okayama City Public Health Center and Staff of the municipal government of Okayama for providing data. We also thank Jingjing Zhang of the department of Regenerative and Reconstructive Medicine (Ophthalmology), Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University for her valuable discussion.
Publisher Copyright:
Copyright 2019 Liu et al.
PY - 2019
Y1 - 2019
N2 - Background: Body mass index (BMI) is a significant predictor of functional disability in older adults. However, when evaluated, the association between BMI and incident functional disability, considering behaviors only as covariates or not, may not be appropriate. The primary purpose of the study was to investigate the combined effects of BMI and unhealthy behaviors on the risk of incident functional disability. Methods: This was a retrospective cohort study that took place in Okayama City, Japan. Data on BMI and unhealthy behaviors were obtained using the health check-up questionnaire. The certification of Long-Term Care Insurance was used to measure functional disability. Cox proportional hazard models were used; adjusted hazard ratios (HRs) with 95% confidence interval (CI) were calculated for incidence of functional disability across categories of BMI and number of unhealthy behaviors. Results: The relationship between BMI and incident functional disability was U-shaped (HR = 1.18, 95% CI [1.11–1.25], among the underweight range; and 1.26 [1.19–1.34] among the osity range), and its risk was significantly higher within the normal-to-overweight range of BMI values with co-occurring unhealthy behaviors (with normal weight range and one, 1.17 [1.01–1.21]; two, 1.29 [1.18–1.41]; and three or four unhealthy behaviors 1.38 [1.24–1.54]; as well as among overweight range and one, 1.16 [1.05–1.27]; two, 1.26 [1.15–1.38]; and three or four unhealthy behaviors, 1.47 [1.31–1.64]). In each BMI category, the risk of incident functional disability increased with increasing number of unhealthy behaviors (p < 0.05 for linear tread), with the highest risk (1.87 [1.58–2.20]) occurring in combination with at least three unhealthy behaviors with BMI ≥ 27.5, for both sexes (2.20 [1.64–2.92] in men and 1.66 [1.35–2.04] in women). Conclusion: It is necessary to consider the combined effects of BMI and behaviors on incident functional disability. Furthermore, interventions targeting multiple behaviors should be considered as such interventions may offer greater benefits than simple interventions.
AB - Background: Body mass index (BMI) is a significant predictor of functional disability in older adults. However, when evaluated, the association between BMI and incident functional disability, considering behaviors only as covariates or not, may not be appropriate. The primary purpose of the study was to investigate the combined effects of BMI and unhealthy behaviors on the risk of incident functional disability. Methods: This was a retrospective cohort study that took place in Okayama City, Japan. Data on BMI and unhealthy behaviors were obtained using the health check-up questionnaire. The certification of Long-Term Care Insurance was used to measure functional disability. Cox proportional hazard models were used; adjusted hazard ratios (HRs) with 95% confidence interval (CI) were calculated for incidence of functional disability across categories of BMI and number of unhealthy behaviors. Results: The relationship between BMI and incident functional disability was U-shaped (HR = 1.18, 95% CI [1.11–1.25], among the underweight range; and 1.26 [1.19–1.34] among the osity range), and its risk was significantly higher within the normal-to-overweight range of BMI values with co-occurring unhealthy behaviors (with normal weight range and one, 1.17 [1.01–1.21]; two, 1.29 [1.18–1.41]; and three or four unhealthy behaviors 1.38 [1.24–1.54]; as well as among overweight range and one, 1.16 [1.05–1.27]; two, 1.26 [1.15–1.38]; and three or four unhealthy behaviors, 1.47 [1.31–1.64]). In each BMI category, the risk of incident functional disability increased with increasing number of unhealthy behaviors (p < 0.05 for linear tread), with the highest risk (1.87 [1.58–2.20]) occurring in combination with at least three unhealthy behaviors with BMI ≥ 27.5, for both sexes (2.20 [1.64–2.92] in men and 1.66 [1.35–2.04] in women). Conclusion: It is necessary to consider the combined effects of BMI and behaviors on incident functional disability. Furthermore, interventions targeting multiple behaviors should be considered as such interventions may offer greater benefits than simple interventions.
KW - Body mass index
KW - Disability
KW - Elderly
KW - Long-term care insurance
KW - Unhealthy behaviors
UR - http://www.scopus.com/inward/record.url?scp=85076285943&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85076285943&partnerID=8YFLogxK
U2 - 10.7717/peerj.8146
DO - 10.7717/peerj.8146
M3 - Article
AN - SCOPUS:85076285943
VL - 2019
JO - PeerJ
JF - PeerJ
SN - 2167-8359
IS - 11
M1 - e8146
ER -