Body mass index and response to abatacept in rheumatoid arthritis

Background Previous studies suggested that obesity could negatively affect the response to antitumour necrosis factor‐α ( TNF α) agents in rheumatoid arthritis ( RA ). However, data are lacking on whether obesity affects the response to abatacept ( ABA ). We aimed to determine whether body mass index ( BMI ) affects the response to ABA in RA . Materials and methods In this multicenter retrospective study, we included RA patients who received ABA . BMI was calculated at the initiation of treatment. After 6 months of treatment, change from baseline in DAS 28, pain on a visual analog scale, erythrocyte sedimentation rate and C‐reactive protein level, tender and swollen joint count were analysed. The primary endpoint was decrease in DAS 28 ≥ 1·2. Secondary outcomes were good response and remission by EULAR criteria. Results At baseline, among 141 RA patients included, the median [interquartile range] BMI was 26·0 [22·9–30·8] kg/m². The number of patients with normal weight, overweight and obesity was 64 (45·4%), 38 (27%) and 39 (27·6%), respectively. Baseline characteristics did not differ among the three BMI subgroups. Univariate analysis revealed no difference in BMI between responders and nonresponders: DAS 28 decrease ≥ 1·2 (25·0 [23·4–31·3] vs. 26·3 [22·9–30·2], P = 0·95), EULAR good response (26·4 [23·5–30·9] vs. 26·0 [22·9–30·6], P = 0·96) and remission (26·7 [21·7–30·3] vs. 26·0 [23·0–30·1], P = 0·83). Conclusion In our real‐life study, BMI did not affect the response to ABA in RA . If confirmed, these results suggest that obesity is not a limitation of ABA use in RA .