Body Mass Index and Clinical Response to Tocilizumab in Patients With Rheumatoid Arthritis

Abstract

Objectives: This study aims to determine whether baseline body mass index (BMI) affects clinical response to tocilizumab (TCZ) after six months of treatment in rheumatoid arthritis (RA) patients. Patients and methods: In this prospective study, a total of 52 RA patients (10 males, 42 females; mean age 50.6±12.2 years; range, 23 to 73 years) receiving intravenous TCZ were consecutively recruited and followed-up for six months. BMI was calculated before initiation of TCZ treatment. The primary clinical response criterion was clinical disease activity index (CDAI) low disease activity (LDA) and the secondary clinical response criteria included CDAI remission, disease activity score based on 28 joints (DAS28)-erythrocyte sedimentation rate (ESR) LDA, DAS28-ESR remission, European League Against Rheumatism (EULAR) good response, and decreased DAS28-ESR (ΔDAS28-ESR)≥1.2. Results: The number of RA patients classified as normal weight, overweight, and obese according to baseline BMI was 38 (73.1%), eight (15.4%), and six (11.5%), respectively. Similar baseline BMI median levels were found between RA patients reaching CDAI LDA and non-LDA: 21.11 (18.94-23.72) versus 20.78 (20.03-22.29) (p=0.98), and non-significant difference in the proportion of responders between normal weight and overweight/obese RA patients was found (p=0.47). No significant difference was found when the secondary clinical response criteria were applied. Conclusion: Our study demonstrates that BMI is not associated with clinical response to TCZ among RA patients and TCZ may be used to treat RA patients regardless of BMI levels.

Obesity in rheumatoid arthritis: impact on response to biologic therapies

“…Obesity was associated with less frequent remission defined by SDAI and CDAI (hazard ratios, HR of 0.80 and 0.77 respectively). The remaining six studies did not show an influence of BMI on EULAR responses, mean change in CDAI, or achievement of remission [38,39,[57][58][59][60]. One study noted lower tocilizumab drug levels in patients with obesity, but this did not result in a poorer clinical response than in non-obese patients [57].…”

“…For most studies, obesity was defined using standard WHO cut-offs [25], however, some reports in non-Caucasian populations used lower BMI cut-offs, for example, Kim et al [36], Hirai et al [37], and Inanc et al [38] defined obesity as BMI greater than 25. Huang et al [39] allocated anyone with a BMI greater than 23 in a combined overweight and obese category.…”