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. · Aug 2018
Differential Mortality and the Excess Rates of Hip Fracture Associated With Type 2 Diabetes: Accounting for Competing Risks in Fracture Prediction Matters.
Type 2 diabetes (T2DM) is associated with a reduced life expectancy. The latest published evidence suggests an increased risk of fractures among T2DM patients. We conducted a population-based cohort study to determine the impact of mortality as a competing risk in the study of the association between T2DM and hip fracture rates. ⋯ Accounting for death as a competing event (Fine-Gray models), the association between T2DM and hip fracture risk remained statistically significant (SHR 1.15; 95% CI, 1.09 to 1.21) and the probability of a hip fracture within 5 years was 2.3% for TD2M and 1.9% for non-TD2M patients compared to 2.6% and 2.1% respectively using Kaplan-Meier (KM) estimates. T2DM patients have a 50% increased mortality and, after adjusting for differential survival at 5 years, a 21% increased incidence of hip fracture when compared to matched non-T2DM. Failing to account for differential mortality leads to an overestimation of fracture risk. © 2018 American Society for Bone and Mineral Research.
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J. Bone Miner. Res. · May 2018
Clinical TrialFuture Osteoporotic Fracture Risk Related to Lumbar Vertebral Trabecular Attenuation Measured at Routine Body CT.
We sought to determine if vertebral trabecular attenuation values measured on routine body computed tomography (CT) scans obtained for a variety of unrelated indications can predict future osteoporotic fractures at multiple skeletal sites. For this Health Insurance Portability and Accountability Act (HIPAA)-compliant and Institutional Review Board (IRB)-approved retrospective cohort study, trabecular attenuation of the first lumbar vertebra was measured in 1966 consecutive older adults who underwent chest and/or abdominal CT at a single institution over the course of 1 year. New pathologic fragility fractures that occurred after a patient's CT study date were identified through an electronic health record database query using International Classification of Diseases (ICD)-9 codes for vertebral, hip, and extremity fractures. ⋯ The model concordance index was 0.700. Ten-year probabilities for major osteoporosis-related fractures straddled the treatment threshold for most subcohorts over the observed L1 HU range. In conclusion, for patients undergoing body CT scanning for any indication, L1 vertebral trabecular attenuation is a simple measure that, when ≤90 HU, identifies patients with a significant decrease in fracture-free survival. © 2018 American Society for Bone and Mineral Research.
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J. Bone Miner. Res. · Mar 2018
Osteoblast-Derived Extracellular Vesicles Are Biological Tools for the Delivery of Active Molecules to Bone.
Extracellular vesicles (EVs) are newly appreciated regulators of tissue homeostasis and a means of intercellular communication. Reports have investigated the role of EVs and their cargoes in cellular regulation and have tried to fine-tune their biotechnological use, but to date very little is known on their function in bone biology. To investigate the relevance of EV-mediated communication between bone cells, we isolated EVs from primary mouse osteoblasts and assessed membrane integrity, size, and structure by transmission electron microscopy (TEM) and fluorescence-activated cell sorting (FACS). ⋯ Finally, osteoblast EVs internalized and shuttled anti-osteoclast drugs (zoledronate and dasatinib), inhibiting osteoclast activity in vitro and in vivo. We conclude that osteoblast EVs are involved in intercellular communication between bone cells, contribute to the Rankl pro-osteoclastic effect, and shuttle anti-osteoclast drugs, representing a potential means of targeted therapeutic delivery. © 2017 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.
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J. Bone Miner. Res. · Feb 2018
Randomized Controlled Trial Comparative StudySerum Sclerostin Levels in Adults With Osteogenesis Imperfecta: Comparison With Normal Individuals and Response to Teriparatide Therapy.
Sclerostin (SOST), a glycoprotein primarily derived from osteocytes, is an important regulator of bone remodeling. Osteogenesis imperfecta (OI) is a heritable disorder of bone characterized by low bone mass, bone fragility, recurrent fractures, and bone deformities. Altered SOST-mediated signaling may have a role in pathogenesis of type I collagen-related OI; however, this has not been evaluated in humans. ⋯ The increase was significant at 6, 12, and 24 months of therapy (p ≤ 0.02) and was apparent as early as 3 months (p = 0.06). The magnitude of increases in SOST levels during therapy was inversely correlated with increases in vertebral volumetric bone mineral density (vBMD). Overall, these results suggest that: 1) SOST regulation is fundamentally altered in osteogenesis imperfecta; 2) serum SOST levels could be a biomarker of OI in adults; and 3) alterations in SOST may help predict the response to anabolic therapies in OI. © 2017 American Society for Bone and Mineral Research.
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J. Bone Miner. Res. · Dec 2017
Long-Term Effects of Severe Burn Injury on Bone Turnover and Microarchitecture.
Severe burn injury triggers massive alterations in stress hormone levels with a dose-dependent hypermetabolic status including increased bone resorption. This study evaluated bone microarchitecture measured by noninvasive high-resolution peripheral quantitative computed tomography (HR-pQCT). Changes of serum bone turnover markers (BTM) as well as regulators of bone signaling pathways involved in skeletal health were assessed. ⋯ In adult male patients, early and sustained changes of markers of bone resorption, formation and regulators of bone signaling pathways, prolonged inflammatory cytokine activities in conjunction with muscle catabolism, and vitamin D insufficiency were observed. These alterations are directly linked to a prolonged deterioration of bone microstructure. The probably increased risk of fragility fractures should be of clinical concern and subject to future interventional studies with bone-protective agents. © 2017 American Society for Bone and Mineral Research.