bDMARDs More Effective than Methotrexate for Strength in PsA

A new cross-sectional study published in Arthritis Research & Therapy evaluated bone mass and strength levels in patients with psoriatic arthritis (PsA) based on whether they were treated with disease-modifying antirheumatic drugs (DMARDs). Specifically, the researchers concluded that biologic (b) DMARD-treated patients had better outcomes than those who received methotrexate or no DMARDs.

“In contrast to [rheumatoid arthritis], little is known about the effect of disease-modifying anti-rheumatic drugs (DMARDs) on bone structure in PsA,” the study authors reported. “In rheumatoid arthritis (RA), biological DMARDs (bDMARDs) have shown to inhibit bone loss and thus may prevent pathological fractures.”

Therefore, they assessed bone density, bone microstructure, and biomechanical properties in PsA patients.

The study included 165 PsA patients, of whom 79 received no DMARDs and 86 received DMARDs. In the DMARD group, 52 patients received bDMARDs, and 34 received methotrexate. Amon the bDMARD cohort, 31 patients used TNF inhibitors, including adalimumab (n = 13), etanercept (n = 9), infliximab (n = 6), certolizumab (n = 2), and golimumab (n = 1); 11 patients had a history of methotrexate treatment.

The bDMARD patients had the longest disease duration (7.6 years, P < 0.001 compared to no DMARDs); mean duration for the methotrexate group was 4.6 years, and for the no-DMARD group, 2.9 years.

Patients taking any DMARDs had higher total volumetric bone mineral density (vBMD) than the no-DMARD group (312 vs. 290, P = 0.004), as well as higher trabecular vBMD (171 vs. 156, P = 0.010). The DMARD group also had a higher number of trabeculae (2.09 vs. 1.99, P = 0.047), lower trabecular separation (0.43 vs. 0.47, P = 0.025), and higher cortical thickness (0.77 vs. 0.71, P = 0.0012). DMARD patients exhibited higher stiffness (50 vs. 45.2, P = 0.034) and failure load (2,385 vs. 2,154, P = 0.026).

The researchers further stratified the data by those treated with methotrexate versus bDMARDs and found that methotrexate had no impact on bone microstructure and functional properties, while the bDMARD group—compared to the no-DMARD group—had significantly higher total vBMD (320 vs. 290, P = 0.001) and trabecular vBMD (174 vs. 156, P = 0.005), as well as higher cortical thickness (0.80 vs. 0.71, P = 0.001) and better outcomes regarding stiffness (52.1 vs. 45.2, P = 0.012) and failure load (2,473 vs. 2,154; P = 0.012).

“In summary, this study shows that the use of bDMARDs is associated with better bone structure and function in PsA patients,” the authors concluded. “Given that PsA is associated with increased fracture risk, fast and adequate neutralization of the key pro-inflammatory and bone-destructive mediators seems to be important to restore bone health and to limit fracture risk in PsA patients.”