Special Theme Articles: Obesity and the Rheumatic Diseases
Sex differences in assessment of obesity in rheumatoid arthritis
Article first published online: 27 DEC 2012
Copyright © 2013 by the American College of Rheumatology
Arthritis Care & Research
Volume 65, Issue 1, pages 62–70, January 2013
How to Cite
Katz, P. P., Yazdany, J., Trupin, L., Schmajuk, G., Margaretten, M., Barton, J., Criswell, L. A. and Yelin, E. H. (2013), Sex differences in assessment of obesity in rheumatoid arthritis. Arthritis Care Res, 65: 62–70. doi: 10.1002/acr.21810
- Issue published online: 27 DEC 2012
- Article first published online: 27 DEC 2012
- Accepted manuscript online: 25 JUL 2012 09:56AM EST
- Manuscript Accepted: 10 JUL 2012
- Manuscript Received: 26 FEB 2012
- NIH/National Institute of Arthritis and Musculoskeletal and Skin Diseases. Grant Number: P60-AR053308
- National Center for Research Resources
- National Center for Advancing Translational Sciences/NIH through a University of California
- San Francisco Clinical and Translational Science Institute. Grant Number: UL1-RR024131
To determine the prevalence of obesity and how accurately standard anthropometric measures identify obesity among men and women with rheumatoid arthritis (RA).
Dual x-ray absorptiometry (DXA) was performed for 141 persons with RA (56 men and 85 women). Two anthropometric proxies of obesity (body mass index [BMI] and waist circumference [WC]) were compared to a DXA-based obesity criterion. Receiver operating characteristic curves determined optimal cut points for each anthropometric measure, relative to DXA. The association of body fat and anthropometric obesity measures with disease status and cardiovascular risk was assessed in multiple regression analyses, controlling for age and glucocorticoid use. All analyses were performed separately for men and women.
A total of 20%, 32%, and 44% of women and 41%, 36%, and 80% of men were classified as obese by BMI, WC, and DXA, respectively. Cut points were identified for anthropometric measures to better approximate DXA estimates of percent body fat (BMI ≥26.1 kg/m2 for women and ≥24.7 kg/m2 for men; WC ≥83 cm for women and ≥96 cm for men). For women and men, higher percent fat was associated with poorer RA status. Anthropometric measures were more closely linked to RA status for women, but identified cardiovascular risk for both women and men.
A large percentage of this RA sample was overfat; DXA-defined obesity was twice as common in men as in women. Utility of revised BMI and WC cut points compared to traditional cut points remains to be examined in prospective studies, but results suggest that lower, sex-specific cut points may be warranted to better identify individuals at risk for poor RA and/or cardiovascular outcomes.