Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research
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J. Bone Miner. Res. · Feb 2012
Individual trabecula segmentation (ITS)-based morphological analyses and microfinite element analysis of HR-pQCT images discriminate postmenopausal fragility fractures independent of DXA measurements.
Osteoporosis is typically diagnosed by dual-energy X-ray absorptiometry (DXA) measurements of areal bone mineral density (aBMD). Emerging technologies, such as high-resolution peripheral quantitative computed tomography (HR-pQCT), may increase the diagnostic accuracy of DXA and enhance our mechanistic understanding of decreased bone strength in osteoporosis. Women with (n = 68) and without (n = 101) a history of postmenopausal fragility fracture had aBMD measured by DXA, trabecular plate and rod microarchitecture measured by HR-pQCT image-based individual trabecula segmentation (ITS) analysis, and whole bone and trabecular bone stiffness by microfinite element analysis (µFEA) of HR-pQCT images at the radius and tibia. ⋯ In summary, HR-pQCT-based ITS and µFEA measurements discriminate fracture status in postmenopausal women independent of DXA measurements. Moreover, these results suggest that preferential loss of plate-like trabeculae contribute to lower trabecular bone and whole bone stiffness in women with fractures. We conclude that HR-pQCT-based ITS and µFEA measurements increase our understanding of the microstructural pathogenesis of fragility fracture in postmenopausal women.
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J. Bone Miner. Res. · Jan 2012
Randomized Controlled TrialEffects of three-monthly oral 150,000 IU cholecalciferol supplementation on falls, mobility, and muscle strength in older postmenopausal women: a randomized controlled trial.
Daily vitamin D in addition to calcium supplementation reduces falls and fractures in older women. However, poor adherence to therapy is a common clinical problem. To examine the effects of supervised oral 3-monthly vitamin D therapy on falls, muscle strength, and mobility, we conducted a 9-month randomized, double-blind, placebo-controlled trial in 686 community-dwelling ambulant women aged over 70 years. ⋯ In conclusion, oral cholecalciferol 150,000 IU therapy administered 3-monthly had neither beneficial nor adverse effects on falls or physical function. These data together with previous findings confirm that intermittent large doses of vitamin D are ineffective or have a deleterious effect on falls. Thus despite adherence issues with daily vitamin D replacement, an intermittent, high-dose vitamin D regimen cannot be supported as a strategy to reduce falls and fractures.
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J. Bone Miner. Res. · Dec 2011
Randomized Controlled TrialExercise training in obese older adults prevents increase in bone turnover and attenuates decrease in hip bone mineral density induced by weight loss despite decline in bone-active hormones.
Weight loss therapy to improve health in obese older adults is controversial because it causes further bone loss. Therefore, it is recommended that weight loss therapy should include an intervention such as exercise training (ET) to minimize bone loss. The purpose of this study was to determine the independent and combined effects of weight loss and ET on bone metabolism in relation to bone mineral density (BMD) in obese older adults. ⋯ Serum leptin and estradiol concentrations decreased in the diet (-25% and -15%, respectively) and diet-exercise (-38% and -13%, respectively) groups, not in the exercise and control groups (between-group p = 0.001). Multivariate analyses revealed that changes in lean body mass (β = 0.33), serum osteocalcin (β = -0.24), and one-repetition maximum (1-RM) strength (β = 0.23) were independent predictors of changes in hip BMD (all p < 0.05). In conclusion, the addition of ET to weight loss therapy among obese older adults prevents weight loss-induced increase in bone turnover and attenuates weight loss-induced reduction in hip BMD despite weight loss-induced decrease in bone-active hormones.
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J. Bone Miner. Res. · Dec 2011
Case ReportsTeriparatide increases bone mineral density in a man with osteoporosis pseudoglioma.
Osteoporosis Pseudoglioma (OPPG) is characterized by severe juvenile-onset osteoporosis and ocular abnormalities. It is caused by one of several inactivating mutations in LRP5, a gene importantly involved in bone formation. The objective of this study was to evaluate the efficacy of teriparatide in a young man with OPPG. ⋯ The increase in CTX followed by P1NP is an unusual time course when teriparatide is used to treat osteoporosis but may be typical of low bone turnover states. There were no adverse events. In a patient with OPPG, teriparatide markedly increased BMD in the lumbar spine and femur hip.