Overweight, Obesity, and the Likelihood of Achieving Sustained Remission in Early Rheumatoid Arthritis: Results From a Multicenter Prospective Cohort Study

Objective. Obesity is implicated in rheumatoid arthritis (RA) development, severity, outcomes, and treatment response. We estimated the independent effects of overweight and obesity on ability to achieve sustained remission (sREM) in the 3 years following RA diagnosis. Methods. Data were from the Canadian Early Arthritis Cohort, a multicenter observational trial of early RA patients treated by rheumatologists using guideline-based care. sREM was defined as Disease Activity Score in 28 joints (DAS28) <2.6 for 2 consecutive visits. Patients were stratified by body mass index (BMI) as healthy (18.5-24.9 kg/m(2)), overweight (25-29.9 kg/m(2)), and obese (>= 30 kg/m(2)). Cox regression was used to estimate the effect of the BMI category on the probability of achieving sREM over the first 3 years, controlling for age, sex, race, education, RA duration, smoking status, comorbidities, baseline DAS28, Health Assessment Questionnaire disability index, C-reactive protein level, and initial treatment. Results. Of 982 patients, 315 (32%) had a healthy BMI, 343 (35%) were overweight, and 324 (33%) were obese; 355 (36%) achieved sREM within 3 years. Initial treatment did not differ by BMI category. Compared to healthy BMI, overweight patients (hazard ratio [HR] 0.75 [95% confidence interval (95% CI) 0.58-0.98]) and obese patients (HR 0.53 [95% CI 0.39-0.71]) were significantly less likely to achieve sREM. Conclusion. Rates of overweight and obesity were high (69%) in this early RA cohort. Overweight patients were 25% less likely, and obese patients were 47% less likely, to achieve sREM in the first 3 years, despite similar initial disease-modifying antirheumatic drug treatment and subsequent biologic use. This is the largest study demonstrating the negative impact of excess weight on RA disease activity and supports a call to action to better identify and address this risk in RA patients.