Dr. Bathon has received consulting fees, speaking fees, and/or honoraria from Abbott, Amgen, and Centocor (less than $10,000 each) and research support from Amgen, Biogen Idec, and Bristol-Myers Squibb.
Rheumatoid Arthritis Clinical Studies
Association of body fat with C-reactive protein in rheumatoid arthritis
Article first published online: 29 AUG 2008
Copyright © 2008 by the American College of Rheumatology
Arthritis & Rheumatism
Volume 58, Issue 9, pages 2632–2641, September 2008
How to Cite
Giles, J. T., Bartlett, S. J., Andersen, R., Thompson, R., Fontaine, K. R. and Bathon, J. M. (2008), Association of body fat with C-reactive protein in rheumatoid arthritis. Arthritis & Rheumatism, 58: 2632–2641. doi: 10.1002/art.23766
- Issue published online: 29 AUG 2008
- Article first published online: 29 AUG 2008
- Manuscript Accepted: 16 MAY 2008
- Manuscript Received: 4 SEP 2007
- NIH grants (National Institute of Arthritis and Musculoskeletal and Skin Diseases. Grant Numbers: AR-050026-01, 1K23-AR-054112-01
- Johns Hopkins Bayview Medical Center General Clinical Research Center
- Clinical Investigator Fellowship award from the Research and Education Foundation of the American College of Rheumatology
The serum C-reactive protein (CRP) concentration is commonly used in rheumatoid arthritis (RA) as a surrogate marker of systemic inflammation, presumably induced by synovitis. However, other tissues, such as adipose tissue, can induce CRP production. This study was undertaken to explore the associations between measures of adiposity and CRP levels in RA.
One hundred ninety-six men and women with RA underwent anthropometric assessment and total body dual-energy x-ray absorptiometry for measurement of total and regional body fat and lean mass. The associations between measures of fat and lean mass and serum levels of CRP and interleukin-6 (IL-6) were determined in analyses stratified by sex, with adjustment for pertinent demographic, lifestyle, and RA disease and treatment covariates as well as for the potential modifying effects of articular activity and biologic pharmacotherapeutic agents.
All measures of adiposity were significantly associated with the level of CRP in women, but not in men. In women, the measure of adiposity that showed the strongest association with the CRP level was truncal fat, in which, in adjusted analyses, each kilogram increase was associated with a 0.101-unit increase in the logarithmically transformed CRP level (P < 0.001). Neither the level of articular activity nor the use of biologic agents significantly modified this association in women. However, in men, elevated articular involvement was associated with a decreasing CRP level as truncal fat increased. For all analyses, substitution of IL-6 for CRP produced similar findings.
Adiposity is independently associated with CRP levels in women with RA, and thus may confound the estimation of RA disease activity when serum CRP concentration is used as a surrogate for systemic inflammation.