Comparison of the effect of 18-month daily teriparatide administration on patients with rheumatoid arthritis and postmenopausal osteoporosis patients.

UNLABELLED: Patients with rheumatoid arthritis showed greater response to 18-month administration of daily teriparatide especially in the increase of bone formation markers at 1 month and femoral neck bone mineral density at 18 months compared to postmenopausal osteoporosis patients.

INTRODUCTION

The aim of this study was to evaluate the effects of 18-month administration of daily teriparatide (TPTD) in osteoporosis patients with rheumatoid arthritis (RA) by comparing that of postmenopausal osteoporosis patients (Porosis).

METHODS

The effects of TPTD were examined between RA (n = 70; age 68.4 years; disease activity score assessing 28 joints with CRP [DAS28-CRP] 2.8; rheumatoid factor [RF] positivity 75.5 %) with 77.1 % of prior bisphosphonate (BP), 84.3 % of oral prednisolone (PSL) (4.4 mg/day at baseline), 25.7 % of biologics, and Porosis (n = 62; age 71.3 years) with 77.4 % of prior BP.

RESULTS

Femoral neck (FN) bone mineral density (BMD) increase at 18 months was significantly greater in RA compared to Porosis (4.7 vs. 0.7 %, P = 0.038), whereas it was 9.7 versus 7.9 % (P = 0.736) in the lumbar spine (LS). The increase of bone formation markers (bone alkaline phosphatase [bone ALP] and N-terminal type I procollagen propeptide [PINP]) at 1 month were all significantly greater in RA compared to Porosis. A multivariate logistic regression analysis revealed that the significant indicator of 18-month BMD increase in RA was a 3-month increase of under-carboxylated osteocalcin (ucOC) for LS (β = 0.446, P = 0.005) and baseline ucOC for FN (β = 0.554, P = 0.001), in which both showed significant negative correlation with baseline PSL dose.

CONCLUSIONS

RA showed greater response to daily TPTD administration, especially in the increase of bone formation markers at 1 month and FN BMD increase at 18 months compared to Porosis.