Investigation of the association between metabolic syndrome and disease activity in rheumatoid arthritis.

Rheumatoid arthritis (RA) is the most common form of autoimmune arthritis. Increased prevalence of metabolic syndrome (MetS) in RA may occur secondary to specific drug treatment and reduced physical activity associated with this condition. However, some recent studies suggest contradictory theories about the association of RA with MetS. This study was designed to evaluate the frequency of MetS in RA patients and the relationship between MetS with RA disease activity and body mass index (BMI). The study was conducted on 120 RA patients and 431 age- and sex-matched apparently healthy controls. A considerable proportion of patients were being treated with prednisolone and/or methotrexate and/or hydroxychloroquine. Disease activity was measured by the 28 joint count of disease activity score-Cerythrocyte sedimentation rate (DAS28ESR). MetS was evaluated according to International Diabetic Federation (IDF) and Adult Treatment Panel III (ATP III) criteria. The prevalence of MetS was significantly higher in the control group (p = 0.005). We did not find any difference in the prevalence of MetS between the patients with DAS < 3.2 and DAS ≥ 3.2. There was no association between the DAS28 score and the presence of MetS components by either definition. Multiple logistic regression analysis showed that the odds of a DAS > 3.2 in patients with BMI between 25 and 30 kg/m2 (OR = 0.1, p = 0.01) and BMI > 30 kg/m2 (OR = 0.3, p = 0.1), in comparison to BMI < 25 kg/m2, was 1/5 and 1/3, respectively. RA was not found to increase the risk of MetS. In addition, disease activity in RA patients was not influenced by the presence of MetS.