Background Although medication of rheumatoid arthritis (RA) has been improved by positive administration of methotrexate and biological agents (BIO) for decades, treatment of concomitant disease in RA patients, such as osteoporosis, will be more important for better outcome in RA patients. Osteoporosis 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.
Objectives This retrospective study investigated the efficacy of teriparatide (TPTD) on osteoporosis in RA patients and focused on relationship the efficacy of TPTD and concomitant drugs, such as oral prednisolone (PSL), activated vitamin D (actVitD) and BIO.
Methods 45 cases (44 female and one male) were used in this study. Patients’ characteristics, bone mineral density (BMD) of lumbar spine (LS) and proximal femur (PF) measured by DEXA and bone turnover markers (BAP, P1NP, NTX, TRACP-5b) were investigated. (1)Factors that affect efficacy of TPTD, (2)the comparison between the BIO-concomitant and the non BIO-concomitant and (3)the comparison between the actVitD-concomitant and the non actVitD concomitant were analyzed.
Results Mean age was 70.8 years old. Mean RA duration was 19.5 years. 31 case (68.9%) were concomitant with oral PSL. 15 cases (33.3%) were concomitant with BIO. 33 cases (73.3%) were concomitant with actVitD. 32 cases (71.1%) have the past history of fracture. %increase of LS-BMD in all cases was 7.6% at 6month and 11.9% at 12month. %increase of PF-BMD in all cases was 1.6% at 6month and 3.9% at 12month. Four bone turnover markers were significantly increased and %increase of P1NP was maximum among them. Significant low body mass index (BMI) and significant low oral PSL usage were seen in the good outcome group of LS-BMD. P1NP in good outcome group of LS-BMD was increased more than that in non good outcome group. Although %increase of BMD in the BIO-concomitant was low compared with that in the non BIO-concomitant, %increase of bone turnover markers in the BIO-concomitant was high compared with that in the non BIO-concomitant. This results was paradoxical from that in whole cases. %increase of PF-BMD in the actVitD-concomitant was better than that in the non actVitD-concomitant. Hypercalcemia occurred in 18.2% of the actVitD-concomitant and 8.3% of non actVitD concomitant (p=0.65).
Conclusions TPTD was effective in osteoporosis of RA patients. Efficacy of TPTD in RA patients was affected with BMI, response of bone turnover markers and drugs concomitantly used. 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. PF-BMD in the actVitD-concomitant was better than the non-concomitant and this result suggested that some patients needed actVitD when treated with TPTD.
Disclosure of Interest None Declared