The comparison of the efficacy of switching bisphosphonates to either denosumab or daily teriparatide in treating osteoporosis in patients with rheumatoid arthritis

Abstract

  Objectives: We report the comparison of the efficacy of switching bisphosphonates（BPs）to either denosumab（DMB）or daily teriparatide（dTPTD）at 24 months in treating osteoporosis in patients with rheumatoid arthritis（RAOP）.

  Methods: Fifty-four RAOP females treated by switching BPs to DMB（DMB group; n=18）or dTPTD（dTPTD group; n=36）were used for this retrospective study. We compared baseline data, percent change of（%-）bone mineral density（BMD）in lumbar spine（LS-）and total hip（TH-）, absolute values of N-terminal propeptide of type 1 collagen（P1NP）and tartrate-resistant acid phosphatase（TRACP）-5b, %P1NP and %TRACP-5b every 6 months.

  Results: Types of prior BP treatment were significantly different between two groups. Baseline P1NP were significantly greater in the dTPTD group than in the DMB group. In the DMB group and the dTPTD group at 24 months, %LS-BMD were 6.4% and 11.0%（p=0.069）, %TH-BMD were 3.9% and 3.9%（n. s.）, the absolute values of P1NP and TRACP-5b were 28.5μg/L and 76.3μg/L（p<0.001）and 338.5mU/dL and 563.9mU/dL（p<0.001）, and %P1NP and %TRACP-5b were 36.4% and 144.6%（p<0.05）and 13.4% and 61.8%（p<0.05）, respectively. There were 3 fragility fractures in the DMB group and 2 fragility fractures in the dTPTD group（p=0.3193）. Hypercalcemia was obtained more frequently in the dTPTD group than in the DMB group（12 cases vs. 1 case, p=0.040）.

  Conclusions: Both switching BPs to DMB and dTPTD were effective to increase LS- and TH-BMD in RA-OP. LS-BMD tended to increase greatly with dTPTD than with DMB, while TH-BMD similarly increased both with DMB and dTPTD.