Effects of strontium ranelate and alendronate on bone microstructure in women with osteoporosis
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Strontium ranelate appears to influence more than alendronate distal tibia bone microstructure as assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT), and biomechanically relevant parameters as assessed by micro-finite element analysis (μFEA), over 2 years, in postmenopausal osteoporotic women.
Bone microstructure changes are a target in osteoporosis treatment to increase bone strength and reduce fracture risk.
Using HR-pQCT, we investigated the effects on distal tibia and radius microstructure of strontium ranelate (SrRan; 2 g/day) or alendronate (70 mg/week) for 2 years in postmenopausal osteoporotic women. This exploratory randomized, double-blind trial evaluated HR-pQCT and FEA parameters, areal bone mineral density (BMD), and bone turnover markers.
In the intention-to-treat population (n = 83, age: 64 ± 8 years; lumbar T-score: −2.8 ± 0.8 [DXA]), distal tibia Cortical Thickness (CTh) and Density (DCort), and cancellous BV/TV increased by 6.3%, 1.4%, and 2.5%, respectively (all P < 0.005), with SrRan, but not with alendronate (0.9%, 0.4%, and 0.8%, NS) (P < 0.05 for all above between-group differences). Difference for CTh evaluated with a distance transformation method was close to significance (P = 0.06). The estimated failure load increased with SrRan (+2.1%, P < 0.005), not with alendronate (−0.6%, NS) (between-group difference, P < 0.01). Cortical stress was lower with SrRan (P < 0.05); both treatments decreased trabecular stress. At distal radius, there was no between-group difference other than DCort (P < 0.05). Bone turnover markers decreased with alendronate; bALP increased (+21%) and serum-CTX-I decreased (−1%) after 2 years of SrRan (between-group difference at each time point for both markers, P < 0.0001). Both treatments were well tolerated.
Within the constraints of HR-pQCT method, and while a possible artefactual contribution of strontium cannot be quantified, SrRan appeared to influence distal tibia bone microstructure and FEA-determined biomechanical parameters more than alendronate. However, the magnitude of the differences is unclear and requires confirmation with another method.
KeywordsAlendronate Finite elements analysis HR-pQCT Microstructure Osteoporosis Strontium ranelate
The study was sponsored by Servier.
Conflicts of interest
All authors are investigators in the study, except A. Laib, who was responsible for central reading of HR-pQCT parameters, and S. Boutroy, who was responsible for central reading of FEA parameters.
- 16.Reginster JY, Seeman E, De Vernejoul MC, Adami S, Compston J, Phenekos C et al (2005) Strontium ranelate reduces the risk of nonvertebral fractures in postmenopausal women with osteoporosis: Treatment of Peripheral Osteoporosis (TROPOS) study. J Clin Endocrinol Metab 90(5):2816–2822PubMedCrossRefGoogle Scholar
- 22.Parfitt AM, Mathews CH, Villanueva AR, Kleerekoper M, Frame B, Rao DS (1983) Relationships between surface, volume, and thickness of iliac trabecular bone in aging and in osteoporosis. Implications for the microanatomic and cellular mechanisms of bone loss. J Clin Invest 72(4):1396–1409PubMedCrossRefGoogle Scholar
- 30.Boivin G, Farlay D, Khebbab MT, Jaurand X, Delmas PD, Meunier PJ. (2010) In osteoporotic women treated with strontium ranelate, strontium is located in bone formed during treatment with a maintained degree of mineralization. Osteoporos Int 21(4):667–677Google Scholar
- 32.Busse B, Jobke B, Hahn M, Priemel M, Niecke M, Seitz S et al (2010) Effects of strontium ranelate administration on bisphosphonate-altered hydroxyapatite: matrix incorporation of strontium is accompanied by changes in mineralization and microstructure. Acta Biomater 6(12):4513–4521PubMedCrossRefGoogle Scholar
- 33.Burghardt AJ, Kazakia GJ, Sode M, de Papp AE, Link TM, Majumdar S (2010) A longitudinal HR-pQCT study of alendronate treatment in postmenopausal women with low bone density: relations among density, cortical and trabecular microarchitecture, biomechanics, and bone turnover. J Bone Miner Res 25(12):2558–2571PubMedCrossRefGoogle Scholar