Basal metabolic rate and Charlson comorbidity index are independent predictors of metabolic syndrome in patients with rheumatoid arthritis.

ABSTRACT Objective: To prospectively analyze predictors of metabolic syndrome (MetS) in patients with rheumatoid arthritis (RA) during 2 years of follow-up. Methods: We recruited 319 consecutive patients with RA who did not have MetS. MetS was defined in accordance with the modified National Cholesterol Education Program/Adult Treatment Panel III 2005 for Asian populations. Sociodemographic data, laboratory findings, disease activity data, and medication history were collected during face-to-face interviews at baseline and follow-up. Independent predictors of MetS were assessed by univariate and multivariate logistic regression analyses. Results: Of the 247 patients with RA who completed the 2-year follow-up, 37 (15.0%) developed MetS. At baseline, these patients were older and had higher body mass index, waist circumference, waist-hip ratio, skeletal muscle mass, body fat mass, percent body fat, and Charlson comorbidity index scores, as well as lower basal metabolic rate (BMR). Moreover, these patients with MetS took less hydroxychloroquine and more oral hypoglycemic agents; they also had lower European Quality of Life Health-state Questionnaire scores. After exclusion of variables associated with MetS composition, multivariate analysis identified BMR (odds ratio [OR] = 0.205, 95% confidence interval [CI]: 0.078–0.541, P = 0.001) and Charlson comorbidity index score (OR = 2.191, 95% CI: 1.280–3.751, P = 0.004) as significant predictors of MetS. Conclusions: Our study showed that the annual incidence rate of MetS was 11.5% in patients with RA. Moreover, the development of MetS was associated with BMR and Charlson comorbidity index score at baseline. Abbreviations: Group 1, patients with new-onset metabolic syndrome; Group 2, patients without metabolic syndrome.