Clinical research study
Obesity Is Not Protective against Fracture in Postmenopausal Women: GLOW

https://doi.org/10.1016/j.amjmed.2011.06.013Get rights and content

Abstract

Objective

To investigate the prevalence and incidence of clinical fractures in obese, postmenopausal women enrolled in the Global Longitudinal study of Osteoporosis in Women (GLOW).

Methods

This was a multinational, prospective, observational, population-based study carried out by 723 physician practices at 17 sites in 10 countries. A total of 60,393 women aged ≥55 years were included. Data were collected using self-administered questionnaires that covered domains that included patient characteristics, fracture history, risk factors for fracture, and anti-osteoporosis medications.

Results

Body mass index (BMI) and fracture history were available at baseline and at 1 and 2 years in 44,534 women, 23.4% of whom were obese (BMI ≥30 kg/m2). Fracture prevalence in obese women at baseline was 222 per 1000 and incidence at 2 years was 61.7 per 1000, similar to rates in nonobese women (227 and 66.0 per 1000, respectively). Fractures in obese women accounted for 23% and 22% of all previous and incident fractures, respectively. The risk of incident ankle and upper leg fractures was significantly higher in obese than in nonobese women, while the risk of wrist fracture was significantly lower. Obese women with fracture were more likely to have experienced early menopause and to report 2 or more falls in the past year. Self-reported asthma, emphysema, and type 1 diabetes were all significantly more common in obese than nonobese women with incident fracture. At 2 years, 27% of obese women with incident fracture were receiving bone protective therapy, compared with 41% of nonobese and 57% of underweight women.

Conclusions

Our results demonstrate that obesity is not protective against fracture in postmenopausal women and is associated with increased risk of ankle and upper leg fractures.

Section snippets

Methods

GLOW is a prospective cohort study involving 723 physician practices at 17 sites in 10 countries (Australia, Belgium, Canada, France, Germany, Italy, Netherlands, Spain, UK, and US). The study methods have been described previously.9 In brief, practices typical of each region were recruited through primary care networks organized for administrative, research, or educational purposes, or by identifying all physicians in a geographic area. Each site obtained local ethics committee approval to

Results

Of 60,393 women enrolled at baseline, 46,443 (76.9%) completed both 1- and 2-year surveys. We further excluded one woman with a BMI of 130 kg/m2 and 1908 women with incomplete information on BMI or fracture history, leaving 44,534 women for further analysis. Among the 57,556 women enrolled at baseline with BMI data, 23.8% were obese, 74.4% were nonobese, and 1.9% were underweight. Of the 44,534 women analyzed, the corresponding figures were 23.4%, 74.9%, and 1.7%, respectively. Average ages

Discussion

Our results challenge the widespread belief that obesity is protective against fracture, and indeed suggest that obesity is a risk factor for certain fractures, particularly those of the ankle and upper leg. In this large, population-based cohort of postmenopausal women, the rates of both previous and incident fracture in obese women were similar to those observed in nonobese women. Although the highest fracture rates occurred in underweight women, the small proportion of women in the

Conclusions

The finding that obesity is not protective against fracture in postmenopausal women and is associated with increased risk of incident upper leg and ankle fractures has major public health implications. The morbidity and economic costs associated with fractures in the obese population are likely to be higher than in nonobese women because of a greater risk of nonunion, postoperative complications, comorbidities, and slower rehabilitation.54, 55 Furthermore, in view of the rapidly rising

Acknowledgment

We thank the physicians and study coordinators participating in GLOW, the staff at the Center for Outcomes Research, and Linda Chase for secretarial support. Sophie Rushton-Smith coordinated revisions and provided editorial assistance including editing, checking content and language, formatting and referencing.

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  • Funding: Financial support for the GLOW study is provided by Warner Chilcott Company, LLC and sanofi-aventis to the Center for Outcomes Research, University of Massachusetts Medical School. JEC acknowledges support from the Cambridge Biomedical Research Centre and National Institute for Health Research (NIHR).

    Conflict of Interest: None.

    Authorship: All authors conceived and designed the study, critically revised the draft for important intellectual content, and gave final approval of the version to be published. All authors had full access to all of the data (including statistical reports and tables) in the study and can take responsibility for the integrity of the data and the accuracy of the data analysis.

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