Biologic treatment in comparison to methotrexate has positive effect on trabecular bone score in rheumatoid arthritis patients: 1-year follow-up

Introduction: Biologic treatment may influence activity of rheumatoid arthritis (RA), as well as areal bone mineral density (aBMD). Decreased aBMD explains the fracture risk in RA patients only partially. The trabecular bone score (TBS), novel texture parameter reflects degradation of trabecular bone and therefore could be used as a further parameter to predict the risk of fragility fracture.

Objective: To compare the effects of biological disease-modifying antirheumatic drugs (bDMARDs) and conventional synthetic (cs) DMARDs (methotrexate) on aBMD and TBS in patients suffering from active RA.

Methods: A 12 month prospective trial was performed in 105 active RA patients. The cohort was divided into two groups: group 1 (n = 84, mean age 54 yrs) treated with bDMARDs and group 2 (n = 21, mean age 53 yrs) treated with csDMARDs. The mean daily dose of prednisone at baseline was 6.2 and 6.6 mg (NS) between group 1 and 2, respectively. Patients with anti-osteoporotic treatment were not included. All patients received calcium (600 mg) and cholecalciferol (800IU). Lumbar spine (LS) and FN aBMD (by DXA, Hologic) were measured at baseline and after 1 year of treatment. TBS was generated using TBS Insight software (Medimaps, Switzerland).

Results: Treatment with bDMARDS led to decrease in mean prednisone dose and to increase of 1.7% (p < 0.05) in TBS and OC levels of 26% (p < 0.001) but not on aBMD and CTX after treatment. The greatest TBS increase (2.7%, p < 0.05) was observed in premenopausal females within group 1. No effect of csDMARDS on measured parameters was observed.

Conclusion: Treatment of patients suffering from active RA with bDMARDs in comparison to csDMARDS led to increase of TBS, with greater increment of TBS in premenopausal women, despite no change in aBMD.

Rheumatoid arthritis; biologic treatment; bone mineral density; bone turnover markers; trabecular bone score.