TNF Inhibitor Therapy Improves Body Composition, Muscle Function in RA Patients

Treatment with a tumor necrosis factor inhibitor (TNFi) for 1 year was associated with favorable changes in total lean mass, fat-free mass index, and skeletal muscle mass index as well as improvements in grip strength in patients with rheumatoid arthritis (RA) previously naive to biologic disease-modifying antirheumatic drugs (bDMARDs), according to study findings published in the Journal of Clinical Medicine.

This study included patients with active RA (age, 58.5±10.8 years; 75% women) who were biologically-naive but had started a treatment for their disease. All patients had at least 1 year of follow-up data available after starting therapy. Patients were classified by whether they received a TNFi (n=47), a non-TNFi-targeted biologic agent (n=18), or only a conventional DMARD (cDMARD; n=18).

Total body dual energy X-ray absorptiometry (DXA) scanning was performed at follow-up to evaluate changes in body composition, including changes in lean mass and fat-free mass. The researchers also measured changes in grip strength of the dominant hand.

The median duration of RA in this population was 3.7 years. In the TNFi group, patients received either etanercept (n=35), adalimumab (n=6), or golimumab (n=1). In the non-TNFi group, patients received rituximab (n=10), abatacept (n=6), and tocilizumab (n=2).

At 1 year following TNFi treatment, the investigators observed significant increases in total lean mass (P =.015), fat-free mass index (P =.013), and skeletal muscle mass index (P =.010). Body composition changes corresponded with an improvement in hand grip strength (P <.001) and walk test at 6 months (P =.006) and 12 months (P <.001).

In contrast to these findings, no significant changes in body composition were noted after 12 months among patients with RA receiving non-TNFI therapy. At 6 months, the participants in this group had an increase in body fat percentage (P =.016), a decrease in visceral fat (P =.024), and a decrease in total lean mass (P =.026). Patients treated with cDMARD alone experienced only a significant increase in visceral fat at 1 year (P =.033).

Limitations of this study included its nonrandomized design as well as the small number of patients in the control and non-TNFi groups.

The study investigators concluded that the findings suggest “a favorable metabolic profile of TNFi” when given to patients with RA.

Disclosure: Some authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

Reference

Vial G, Lambert C, Pereira B, et al. The effect of TNF and non-TNF-targeted biologics on body composition in rheumatoid arthritis. J Clin Med. 2021;10(3):487. doi:10.3390/jcm10030487