Patients with obesity and rheumatoid arthritis (RA) experienced worse clinical and ultrasonographic outcomes compared with patients without obesity, according to study results published in The Journal of Rheumatology.
Investigators performed a post hoc analysis of the MUSICA trial (ClinicalTrials.gov identifier: NCT01185288), which assessed clinical outcomes in patients with RA who initiated adalimumab in combination with low- (7.5 mg per week) or high-dose (20 mg per week) methotrexate (MTX) following inadequate response to MTX alone. Musculoskeletal ultrasound was used to capture synovial hypertrophy and vascularity improvements from baseline to 12 and 24 weeks of treatment. Additional treatment outcomes included swollen joint count, tender joint count, 28-joint count Disease Activity Score using C-reactive protein (DAS28-CRP), and number of patients achieving 20% or 50% improvement in the American College of Rheumatology criteria (ACR20/50).
According to BMI data, 137 people (44.5%) participating in the MUSICA trial were classified as obese at baseline. Compared with patients in the normal and overweight categories, fewer patients with obesity achieved ACR20 and ACR50 at 12 and 24 weeks. Additionally, fewer patients with obesity achieved low disease activity at 12 weeks as defined by Clinical Disease Activity Index, an effect that was particularly pronounced for patients with obesity receiving low-dose MTX. Patients with obesity in the low-dose MTX group also had significantly less improvement from baseline to 12 weeks (P =.002) and 24 weeks (P =.03) in synovial hypertrophy compared with overweight or normal-weight patients. Patients with obesity also experienced numerically smaller changes from baseline to 12 and 24 weeks in synovial vascularity, sore joint count, tender joint count, and DAS28-CRP compared with patients in other weight categories.
These data emphasize the need for targeted treatment to improve RA symptoms in patients with obesity. Researchers suggested that adalimumab initiated with high-dose MTX may be more effective than low-dose MTX in achieving RA symptom improvements for patients with obesity. Further research is necessary to confirm this conclusion and to identify other modes of treatment for reducing the burden of RA symptoms in patients with obesity.
Kaeley GS, MacCarter DK, Pangan AL, Wang X, Kalabic J, Ranganath VK. Clinical response and synovial vascularity in obese rheumatoid arthritis patients treated with adalimumab and methotrexate [published online September 1, 2018]. J Rhematol. doi:10.3899/jrheum.171232