Background Several studies have suggested that obesity could have a negative influence on the response to anti-TNFα, including infliximab, in rheumatoid arthritis (RA) and spondyloarthritis. Little is known about the impact of body mass index (BMI) on other biologic agents.
Objectives The purpose of this study was to evaluate the influence of BMI on response to tocilizumab (TCZ) in RA.
Methods A total of 115 RA patients treated with TCZ were included in this multicenter retrospective study. BMI was calculated at the initiation of treatment. After six months of treatment, change from baseline in DAS28, pain on a visual analog scale, erythrocyte sedimentation rate and C-reactive protein level, tender and swollen joints, and consumption of corticosteroids were analyzed. The primary endpoint was decrease in DAS28 ≥1.2. Secondary outcomes were good EULAR response and EULAR remission.
Results At baseline, the median [interquartile range] BMI was 25.4 [22.0-28.8] kg/m2. The number of patients with normal weight, overweight and obesity was 53, 37 and 25, respectively. Baseline characteristics did not differ between the three subgroups of BMI. After six months, the number of RA patients with DAS28 decrease ≥1.2, EULAR good response and remission was 83 (72.2%), 44 (38.3%) and 37 (32.2%), respectively.
The median BMI did not differ between responders and non-responders for DAS28 decrease ≥1.2 (25.7 [22.1-29.9] vs. 24.9 [22.0-27.1], P=0.38), EULAR good response (25.9 [22.8-30.0] vs. 25.4 [22.0-28.4], P=0.61) and remission (25.1 [22.5-28.6] vs. 25.4 [22.0-28.9], P=0.76).
Conclusions In contrast to anti-TNFα agents, this study did not show any influence of BMI on response to TCZ in RA. However, prospective studies are needed to confirm these results that could be useful for the selection of biologics in obese RA patients.
Disclosure of Interest None declared