Comparative effects of teriparatide and ibandronate on spine bone mineral density (BMD) and microarchitecture (TBS) in postmenopausal women with osteoporosis: a 2-year open-label study.
Treatment effects over 2 years of teriparatide vs. ibandronate in postmenopausal women with osteoporosis were compared using lumbar spine bone mineral density (BMD) and trabecular bone score (TBS). Teriparatide induced larger increases in BMD and TBS compared to ibandronate, suggesting a more pronounced effect on bone microarchitecture of the bone anabolic drug.


BACKGROUND
The trabecular bone score (TBS) is an index of bone microarchitecture, independent of bone mineral density (BMD), calculated from anteroposterior spine dual X-ray absorptiometry (DXA) scans. The potential role of TBS for monitoring treatment response with bone-active substances is not established. The aim of this study was to compare the effects of recombinant human 1-34 parathyroid hormone (teriparatide) and the bisphosphonate ibandronate (IBN), on lumbar spine (LS) BMD and TBS in postmenopausal women with osteoporosis.


METHODS
Two patient groups with matched age, body mass index (BMI), and baseline LS BMD, treated with either daily subcutaneous teriparatide (N = 65) or quarterly intravenous IBN (N = 122) during 2 years and with available LS BMD measurements at baseline and 2 years after treatment initiation were compared.


RESULTS
Baseline characteristics (overall mean ± SD) were similar between groups in terms of age 67.9 ± 7.4 years, body mass index 23.8 ± 3.8 kg/m(2), BMD L1-L4 0.741 ± 0.100 g/cm(2), and TBS 1.208 ± 0.100. Over 24 months, teriparatide induced a significantly larger increase in LS BMD and TBS than IBN (+7.6 % ± 6.3 vs. +2.9 % ± 3.3 and +4.3 % ± 6.6 vs. +0.3 % ± 4.1, respectively; P < 0.0001 for both). LS BMD and TBS were only weakly correlated at baseline (r (2) = 0.04) with no correlation between the changes in BMD and TBS over 24 months.


CONCLUSIONS
In postmenopausal women with osteoporosis, a 2-year treatment with teriparatide led to a significantly larger increase in LS BMD and TBS than IBN, suggesting that teriparatide had more pronounced effects on bone microarchitecture than IBN.
Department of Osteoporosis, Inselspital, Berne University Hospital and University of Berne, CH-3010, Berne, Switzerland.
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Senn
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Günther
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Popp
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Perrelet
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Hans
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Lippuner
D015502:Absorptiometry, Photon / Q000379:methods; D000368:Aged; D015519:Bone Density / Q000187:drug effects*; D050071:Bone Density Conservation Agents / Q000494:pharmacology / Q000627:therapeutic use*; D004164:Diphosphonates / Q000494:pharmacology / Q000627:therapeutic use*; D004341:Drug Evaluation / Q000379:methods; D005260:Female; D006801:Humans; D000077557:Ibandronic Acid; D007275:Injections, Intravenous; D007279:Injections, Subcutaneous; D008159:Lumbar Vertebrae / Q000503:physiopathology; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000188:drug therapy* / Q000503:physiopathology; D012189:Retrospective Studies; D019379:Teriparatide / Q000494:pharmacology / Q000627:therapeutic use*; D016896:Treatment Outcome
D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D019379:Teriparatide; D000077557:Ibandronic Acid