medwireNews: Psoriatic arthritis (PsA) patients treated with biologic (b)DMARDs have higher bone mass and strength than those not receiving DMARD treatment, suggest findings from a cross-sectional study.
However, no such differences were observed among patients treated with methotrexate versus no DMARDs, “suggesting that the beneficial bone effect of DMARD treatment in PsA is confined to the use of bDMARDs,” note the researchers.
The study included 165 individuals with PsA, of whom 52 had been receiving biologics for at least 6 months, 34 were undergoing methotrexate treatment, and 79 were not receiving any DMARDs. The most commonly used biologic agents were tumor necrosis factor inhibitors (60%), followed by secukinumab (31%) and ustekinumab (10%), and the average duration of biologic treatment was 3.9 years.
Georg Schett (Universitätsklinikum Erlangen, Germany) and fellow researchers found that patients taking any DMARD – either methotrexate or a biologic agent – had significantly higher total volumetric bone mineral density (vBMD) and trabecular vBMD measured by high-resolution peripheral quantitative computed tomography than those not receiving DMARDs, at 312 versus 290 HA/cm3 and 171 versus 156 HA/cm3, respectively.
Moreover, individuals taking DMARDs had better bone microstructure as indicated by a significantly higher number of trabeculae, lower trabecular separation, and greater cortical thickness, as well as better biomechanical properties as shown by higher stiffness and failure load, than those not taking DMARDs.
When DMARD-treated patients were categorized into those treated with biologics and those given methotrexate, biologics, but not methotrexate, were associated with significantly higher total vBMD, trabecular vBMD, and cortical thickness relative to no DMARD treatment.
Methotrexate “had no influence on bone microstructure and functional properties,” report Schett and colleagues in Arthritis Research & Therapy.
“This finding is interesting since the control of signs and symptoms of PsA was similar in the [methotrexate]- and bDMARD-treated groups,” and therefore “indirect effects such as better control of inflammation by bDMARDs are less likely to attribute for these differences,” they write.
The study authors note that the beneficial association between biologic use and bone structure occurred despite longer average disease duration among patients treated with biologics compared with those given methotrexate or no DMARDs (7.8, 4.6, and 2.9 years, respectively).
medwireNews is an independent medical news service provided by Springer Healthcare. © 2019 Springer Healthcare part of the Springer Nature group
Arthritis Res Ther 2019; 21: 162
See also: