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Incidence and predictors of fractures in older adults with and without obesity defined by body mass index versus body fat percentage
Gandham, Anoohya Zengin, Ayse Bonham, Maxine P. Winzenberg, Tania Balogun, Saliu Wu, Feitong Aitken, Dawn Cicuttini, Flavia Ebeling, Peter R. Jones, Graeme
Gandham, Anoohya
Zengin, Ayse
Bonham, Maxine P.
Winzenberg, Tania
Balogun, Saliu
Wu, Feitong
Aitken, Dawn
Cicuttini, Flavia
Ebeling, Peter R.
Jones, Graeme
Abstract
Purpose
The aim of this study was to determine and compare risk factors associated with incident fractures in older adults with and without obesity, defined by both body mass index (BMI) and body fat percentage.
Methods
1,099 older adults (mean ± standard deviation age = 63.0 ± 7.5) years, participated in this prospective cohort study. Obesity status at baseline was defined by BMI (≥30 kg/m2) obtained by anthropometry and body fat percentage (≥30% for men and ≥40% for women) assessed by dual-energy X-ray absorptiometry (DXA). Total hip and lumbar spine areal bone mineral density (aBMD) were assessed by DXA up to five years. Incident fractures were self-reported up to 10 years.
Results
Prevalence of obesity was 28% according to BMI and 43% according to body fat percentage. Obese older adults by BMI, but not body fat percentage, had significantly higher aBMD at the total hip and spine compared with non-obese (both p-value<0.05). Obese older adults by body fat percentage had significantly higher likelihood of all incident fractures (OR: 1.71; CI:1.08, 2.71) and non-vertebral fractures (OR: 1.88; CI:1.16, 3.04) compared with non-obese after adjusting for confounders. Conversely, obese older adults by BMI had a significantly lower likelihood (OR: 0.54; CI:0.31, 0.94) of non-vertebral fractures although this was no longer significant after adjustment for total hip aBMD (all p-value > 0.05). Mediation analysis confirmed that aBMD meditated the effects of BMI, but not body fat percentage, on all incident fractures. Higher baseline falls risk score was the only consistent predictor of increased likelihood of incident fracture in obese individuals only, according to both BMI and body fat percentage (both p-value<0.05).
Conclusions
Obesity defined by body fat percentage is associated with increased likelihood of incident fractures in community-dwelling older adults, whereas those who are obese according to BMI have reduced likelihood of incident fracture which appears to be explained by higher aBMD. Falls risk assessment may improve identification of obese older adults at increased risk of incident fractures.
Keywords
obesity, older adults, bone, fracture, aging
Date
2020
Type
Journal article
Journal
Bone
Book
Volume
140
Issue
Page Range
1-7
Article Number
Article 115546
ACU Department
Mary MacKillop Institute for Health Research
Faculty of Health Sciences
Faculty of Health Sciences
Collections
Relation URI
Source URL
Event URL
Open Access Status
License
All rights reserved
File Access
Controlled