Pos0648 effect of obesity on disease activity of patients with early rheumatoid arthritis: data from a nationwide cohort

Background Rheumatoid arthritis (RA) is a chronic, multifactorial, inflammatory disease, and obesity is one of the risk factors implicated in RA development. Although obesity has been recently reported to be related to disease activity and clinical response of RA, the association between obesity and disease activity of RA is still controversial. Objectives This study aimed to investigate the effect of obesity on baseline disease activity and clinical response of patients with early RA. Methods Of 5,077 patients with RA enrolled in the Korean observational study network for arthritis (KORONA) registry, a nationwide RA-specific cohort, we identified 1,178 patients with disease duration of <2 years who had both baseline and 2-year follow-up data. Patients were grouped according to their body mass index (BMI): obese (BMI ≥25) and non-obese (BMI <25). Baseline and 2-year follow-up disease activity markers including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), swollen and tender joints, patient global assessment (PGA), evaluator global assessment (EGA), clinical disease activity index (CDAI), and health assessment questionnaire-disability index (HAQ-DI) were compared between two groups. Results Among early RA patients, 282 (23.9%) obese and 896 (76.1%) non-obese patients were identified. The non-obese group showed higher ESR than the obese group at baseline (29.9±0.9 vs 25.6±1.6, p=0.019), and other disease activity variables showed no difference according to the obesity status. When comparing the group who maintained obese (n=176) and non-obese (n=660) for two years, the obese group had higher CRP positivity (37.4% vs 26.9%, p=0.009) while other variables including CDAI showed no significant difference between the two groups. Conclusion Obesity was not associated with baseline disease activity and treatment response of patients with early RA. As obesity was related to CRP positivity in 2-year follow-up measurements, the use of disease activity tools containing CRP requires careful attention. References [1]Sandberg ME, Bengtsson C, Källberg H, et al. Overweight decreases the chance of achieving good response and low disease activity in early rheumatoid arthritis. Ann Rheum Dis 2014;73:2029-2033. [2]Mirpourian M, Salesi M, Abdolahi H, Farajzadegan Z, Karimzadeh H. The association of body mass index with disease activity and clinical response to combination therapy in patients with rheumatoid arthritis. J Res Med Sci 2014;19:509-514. Table 1. 2-year follow-up disease activity variables of obese and non-obese patients with RA Obese (n=176) Non-obese (n=660) p-value ESR, mm/hr 22.5±1.7 23.5±0.8 0.606 CRP positivity 61 (37.4) 166 (26.9) 0.009 Tender joint count 2.15±0.25 1.86±0.18 0.305 Swollen joint count 1.79±0.15 1.50±0.08 0.100 PGA (0-100) 16.7±1.1 16.0±0.6 0.584 EGA (0-100) 33.1±1.8 33.0±0.9 0.975 CDAI score (0-76) 8.9±0.5 8.2±0.3 0.249 CDAI status 0.273 LDA 123 (70.3) 460 (70.4) MDA 42 (24.0) 172 (26.3) HDA 10 (5.7) 21 (3.2) CDAI remission, n (%) 19 (10.9) 65 (9.9) 0.716 HAQ-DI 0.42±0.04 0.41±0.02 0.840 Newly start of biologics 6 (3.4) 37 (5.6%) 0.241 Data are presented as number (%) or mean ± standard deviation, adjusted for gender, age, smoking status, income status, education levels, diabetes mellitus, and hypertension Acknowledgements: NIL. Disclosure of Interests None Declared.