A high body mass index is protective on the amount of joint destruction in small joints in early rheumatoid arthritis
- C F Allaart ( )
- R EM Toes ( )
- T WJ Huizinga ( )
- Published Online First 26 October 2007
Objectives: Obesity is a state of chronic low-grade inflammation that predisposes individuals to several diseases and that is increasingly prevalent. Rheumatoid arthritis (RA) is marked by the presence of pro-inflammatory cytokines and in general the presence of high levels of inflammatory markers is associated with a severe disease course and joint damage. We evaluated prospectively (1) whether obesity is a risk factor to develop RA and (2) whether the body mass index (BMI) is associated with the amount of joint destruction in early RA after three years follow-up.
Methods: In a cohort of 570 patients with undifferentiated arthritis, the relation between the BMI and the development of RA during 1 year of follow-up was assessed. In a cohort of 488 early RA-patients the correlation between the BMI and degree of radiological joint destruction (Sharp-van der Heijde score) after three years of follow-up was determined. The findings were replicated in an independent cohort of 247 early RA-patients.
Results: Obesity did not influence the chance to develop RA. In both RA cohorts, the BMI was inversely correlated with the Sharp-van der Heijde score after 3 years follow-up (correlation coefficient -0.15, p=0.025 for the Leiden EAC and correlation coefficient -0.27, p<0.001 for the replication cohort). Linear regression analyses in both cohorts revealed that the BMI was independently and inversely associated with the level of joint destruction in the anti-CCP positive RA-patients, but not in anti-CCP negative RA-patients.
Conclusions: A high BMI is associated with a less severe disease outcome in anti-CCP positive RA-patients.