Rheumatoid Arthritis Clinical Studies
Radiographic joint damage in early rheumatoid arthritis is highly dependent on body mass index
Article first published online: 29 OCT 2007
Copyright © 2007 by the American College of Rheumatology
Arthritis & Rheumatism
Volume 56, Issue 11, pages 3575–3582, November 2007
How to Cite
Westhoff, G., Rau, R. and Zink, A. (2007), Radiographic joint damage in early rheumatoid arthritis is highly dependent on body mass index. Arthritis & Rheumatism, 56: 3575–3582. doi: 10.1002/art.23033
- Issue published online: 29 OCT 2007
- Article first published online: 29 OCT 2007
- Manuscript Accepted: 3 AUG 2007
- Manuscript Received: 24 JAN 2007
- German Federal Ministry of Research within the Competence Network Rheumatology (1999–2005)
To investigate the association between body mass index (BMI) and radiographic joint damage (using the Ratingen Score [RS]) in early rheumatoid arthritis (RA).
The study was carried out in 767 patients with early RA. Standard clinical data, RS, and BMI were evaluated at baseline and after 3 years. Multivariate logistic regression analyses were performed in rheumatoid factor (RF)–positive and RF-negative patients to determine the influence of BMI (<25 versus ≥30 kg/m2) on considerable joint damage (RS ≥7) after 3 years, adjusting for sex, age, disease duration, and disease activity (using the Disease Activity Scale in 28 joints [DAS28]).
Patients of normal weight already had significantly more joint damage at study entry than obese patients (mean RS 4.5 versus 2.4; P = 0.004) and experienced significantly more progression than obese patients (RS 3.4 versus 1.3; P = 0.011). At 3 years, their RS score was twice as high as that of the obese patients (7.5 versus 3.7; P < 0.001). Multivariate regression analyses in both serologic groups revealed significantly higher odds of RS ≥7 in RF-positive patients of normal weight than in RF-positive obese patients (odds ratio [OR] 3.3), but not in RF-negative patients. Male sex (OR 1.6), osteoporosis (OR 2.0), C-reactive protein levels >15 mg/liter versus <5 mg/liter (OR 2.6), and disease activity (DAS28 ≥5.1 versus <3.2; OR 1.9) were independently associated with RS ≥7.
BMI provides a risk estimate of joint damage in RA patients. Further studies are needed to elucidate the association between BMI, RF, and joint damage in RA and the possible role of adipose tissue.