The association between fracture and obesity is site-dependent: A population-based study in postmenopausal women

Authors

  • Daniel Prieto-Alhambra,

    Corresponding author
    1. IDIAP Jordi Gol, Primary Health Care Research Institute, Barcelona, Spain
    2. Institut Català de la Salut, Barcelona, Spain
    3. URFOA, Institut Municipal d'Investigacions Mèdiques (IMIM), Barcelona, Spain
    4. Medicine Department, Universitat Autònoma de Barcelona, Barcelona, Spain
    5. RETICEF (Red Temática de Investigación Cooperativa en Envejecimiento y Fragilidad), Instituto Carlos III, Madrid, Spain
    • Av/Gran Via Corts Catalanes, 587 Àtic. 08007, Barcelona, Spain.
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  • Melissa O Premaor,

    1. Department of Clinical Medicine, Health Sciences Center, Federal University of Santa Maria, Santa Maria, Brazil
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  • Francesc Fina Avilés,

    1. IDIAP Jordi Gol, Primary Health Care Research Institute, Barcelona, Spain
    2. Institut Català de la Salut, Barcelona, Spain
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  • Eduard Hermosilla,

    1. IDIAP Jordi Gol, Primary Health Care Research Institute, Barcelona, Spain
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  • Daniel Martinez-Laguna,

    1. Institut Català de la Salut, Barcelona, Spain
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  • Cristina Carbonell-Abella,

    1. Institut Català de la Salut, Barcelona, Spain
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  • Xavier Nogués,

    1. URFOA, Institut Municipal d'Investigacions Mèdiques (IMIM), Barcelona, Spain
    2. Medicine Department, Universitat Autònoma de Barcelona, Barcelona, Spain
    3. RETICEF (Red Temática de Investigación Cooperativa en Envejecimiento y Fragilidad), Instituto Carlos III, Madrid, Spain
    4. Internal Medicine Department, Parc de Salut Mar, Barcelona, Spain
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  • Juliet E Compston,

    1. Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
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  • Adolfo Díez-Pérez

    1. URFOA, Institut Municipal d'Investigacions Mèdiques (IMIM), Barcelona, Spain
    2. Medicine Department, Universitat Autònoma de Barcelona, Barcelona, Spain
    3. RETICEF (Red Temática de Investigación Cooperativa en Envejecimiento y Fragilidad), Instituto Carlos III, Madrid, Spain
    4. Internal Medicine Department, Parc de Salut Mar, Barcelona, Spain
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Abstract

The association between obesity and fracture is controversial. We investigated the relationship between body mass index (BMI) and fracture at different skeletal sites in women aged ≥50 years using data from the Sistema d' Informació per al Desenvolupament de la Investigació en Atenció Primària (SIDIAP) database. SIDIAP contains the computerized medical records of >3400 general practitioners in Catalonia (northeastern Spain), with information on a representative 80% of the population (>5 million people). In 2009, 1,039,878 women aged ≥50 years were eligible, of whom 832,775 (80.1%) had a BMI measurement. These were categorized into underweight/normal (302,414 women), overweight (266,798), and obese (263,563). Fractures were ascertained using the International Classification of Diseases, 10th revision (ICD-10) codes. Multivariate Poisson regression models were fitted to adjust for age, smoking, high alcohol intake, type 2 diabetes, and oral corticosteroid use. Hip fractures were significantly less common in overweight and obese women than in normal/underweight women (rate ratio [RR] 0.77 [95% confidence interval (CI) 0.68 to 0.88], RR 0.63 [95% CI 0.64 to 0.79], p < 0.001, respectively). Pelvis fracture rates were lower in the overweight (RR 0.78 [95% CI 0.63 to 0.96], p = 0.017) and obese (RR 0.58 [95% CI 0.47 to 0.73], p < 0.001) groups. Conversely, obese women were at significantly higher risk of proximal humerus fracture than the normal/underweight group (RR 1.28 [95% CI 1.04 to 1.58], p = 0.018). Clinical spine, wrist, tibial, and multiple rib fracture rates were not significantly different between groups. An age-related increase in incidence was seen for all BMI groups at all fracture sites; obese women with hip, clinical spine, and pelvis fracture were significantly younger at the time of fracture than normal/underweight women, whereas those with wrist fracture were significantly older. The association between obesity and fracture in postmenopausal women is site-dependent, obesity being protective against hip and pelvis fractures but associated with an almost 30% increase in risk for proximal humerus fractures when compared with normal/underweight women. The reasons for these site-specific variations are unknown but may be related to different patterns of falls and attenuation of their impact by adipose tissue. © 2012 American Society for Bone and Mineral Research

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