Background Although medication of rheumatoid arthritis (RA) has been improved by early intensive treatment using MTX and biological agents (BIO) for decades, treatment of concomitant disease in RA patients, such as osteoporosis (OP), will be more important to improve activity of daily living of RA patients. OP of RA patients is composed from multifactorial pathogenesis, such as excess of inflammatory cytokines, excess of rest due to joint pain and drugs used for treatment of RA. Although we reported one-year outcome of daily teriparatide (TPTD) on OP in RA patients in EULAR 2013 1), the additional results for 2 years are reported in this study.
Objectives This prospective study investigated (1) the efficacy of TPTD for 2 years on OP in RA patients, (2) the predictors of efficacy at 2 year in TPTD treatment and (3) the outcome of combination of TPTD and BIO.
Methods 24 months (m) passed after initiation of TPTD in 33 RA patents. 28 cases (27 females and a male) among them completed 2-year TPTD treatment and were used for analysis. Bone mineral density (BMD) of lumbar spine (LS) and proximal femur (PF) by DEXA and bone turnover markers (BTMs), that is BAP, P1NP, NTX and TRACP-5b, were measured at every 6m.
Results Mean age was 72 years old. Mean RA duration was 20.2 years. 23 cases (69.7%) were concomitant with oral PSL. 14 cases (42.4%) were concomitant with BIO. 27 cases (81.8%) have the past history of fracture. %increase of LS-BMD was 6.9% at 6m, 11.2% at 12m, 11.8% at 18m and 12.5% at 24m. %increase of PF-BMD was 2.1% at 6m, 4.0% at 12m, 4.9% at 18m and 5.8% at 24m. BTMs were significantly increases and %increase of P1NP at 6m was maximum among them (384.0%). Next, all cases were divided into two group, good outcome group (GO group) and non-good outcome group (non-GO group), by mean LS-BMD and PF-BMD. %increase of LS-BMD at 6m in LS-GO group (n=14) was significantly larger than that in LS-non-GO group (n=12) (10.4% vs. 4.0%). %increase of PF-BMD at 6m in PF-GO group (n=14) was also significantly larger than that in LS-non-GO group (n=11) (4.7% vs. -1.1%). Baseline CRP in PF-non-GO group was also larger than that in PF-GO group (0.51mg/dl vs. 0.25mg/dl). There were no significant differences in changes of BTMs between groups. At last, all cases were divided into two groups, that is the BIO-concomitant (n=11) and the non-BIO-concomitant (n=17). LS-BMD in the non-BIO-concomitant was better than that in the BIO-concomitant and there was a significant difference between groups at 18m (7.8% vs. 14.0%). Similar findings were seen in analysis of PF-BMD and there was a significant difference between groups at 24m (3.6% vs. 7.4%). %increase of BTMs in the BIO-concomitant was high compared with that in the non-BIO-concomitant.
Conclusions TPTD was effective in OP of RA patients. Early response in BMD was one of the predictors of outcomes at 24m. BTMs were not the predictors of efficacy of TPTD. The results in the BIO-concomitant showed different trend from that in whole cases and these paradoxical results suggested that medicinal action of TPTD might be interfere with that of BIO.
Y. Hirano et al. efficacy of teriparatide on osteoporosis in patients with rheumatoid arthritis. Ann Rheum Dis 2013;72(Suppl3):304.
Disclosure of Interest None declared