1.
Comprehensive Interventions Including Vitamin D Effectively Reduce the Risk of Falls in Elderly Osteoporotic Patients.
Feng, F, Shi, G, Chen, H, Jia, P, Bao, L, Xu, F, Sun, QC, Tang, H
Orthopaedic surgery. 2021;(4):1262-1268
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Abstract
OBJECTIVE To evaluate the effects of different intervention measures to prevent falls in elderly osteoporotic patients. METHODS A randomized controlled trial was conducted in our outpatient ward from August 2014 to September 2015. A total of 420 patients over 60 years of age were assigned to four groups. NA VitD group took 800 mg calcium and 800 IU non-active vitamin D. P-NA VitD group took 800 mg calcium, 800 IU non-active vitamin D, and received physical exercise. A VitD group took 800 mg calcium and 0.5 μg active vitamin D. P-A VitD took 800 mg calcium, 0.5 μg active vitamin D, and received physical exercise. Physical exercise includes guidance in improving muscle strength and balance ability. Short physical performance battery (SPPB), grip strength, modified falls efficacy scale (MFES), blood calcium, and 25-hydroxyl vitamin D were measured before interventions and at 3, 6, and 12 months after interventions. Bone mineral density (BMD) was detected before interventions and at 12 months after interventions. The incidence of falls and fractures, adverse events, and drug reactions were recorded for 12 months. RESULTS A total of 420 patients were allocated in the four groups: 98 cases into the NA VitD group (11 males, 87 females), 97 cases into the P-NA VitD group (13 males, 84 females), 99 cases in the A VitD group (15 males, 84 females), and 98 cases into the P-A VitD group (11 males, 87 females). At 6 months after interventions, the SPPB of A VitD group significantly increased from 6.9 ± 1.9 to 8.0 ± 2.4 (P < 0.05), and the SPPB of A VitD group significantly increased from 7.2 ± 2.1 to 8.6 ± 1.7 (P < 0.05). At 6 months after interventions, MFES of P-NA VitD group 7.0 ± 1.6 to 7.6 ± 1.6 (P < 0.05), and MFES of P-A VitD group significantly increased from 6.7 ± 1.6 to 7.5 ± 1.6 (P < 0.05). At 12 months after interventions, SPPB of all groups, grip strength, and MFES of P-NA VitD group, A VitD group, P-A VitD group were significantly improved (P < 0.05). The BMD of lumbar vertebrae of A VitD group significantly increased from 0.742 ± 0.042 to 0.776 ± 0.039, and P-A VitD group significantly increased from 0.743 ± 0.048 to 0.783 ± 0.042 (P < 0.05). No serious adverse events occurred during the 12 months of follow-up. CONCLUSION Active vitamin D is better than non-active vitamin D to improve physical ability and the BMD of lumbar vertebrae and reduce the risk of falls.
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Fluid flow induced calcium response in osteoblasts: mathematical modeling.
Su, JH, Xu, F, Lu, XL, Lu, TJ
Journal of biomechanics. 2011;(11):2040-6
Abstract
Fluid flow in the bone lacuno-canalicular network can induce dynamic fluctuation of intracellular calcium concentration ([Ca(2+)](i)) in osteoblasts, which plays an important role in bone remodeling. There has been limited progress in the mathematical modeling of this process probably due to its complexity, which is controlled by various factors such as Ca(2+) channels and extracellular messengers. In this study we developed a mathematical model to describe [Ca(2+)](i) response induced by fluid shear stress (SS) by integrating the major factors involved and analyzed the effects of different experimental setups (e.g. [Ca(2+)](i) baseline, pretreatment with ATP). In this model we considered the ATP release process and the activities of multiple ion channels and purinergic receptors. The model was further verified quantitatively by comparing the simulation results with experimental data reported in literature. The results showed that: (i) extracellular ATP concentration has more significant effect on [Ca(2+)](i) baseline (73% increase in [Ca(2+)](i) with extracellular ATP concentration varying between 0 and 10 μM), as compared to that induced by SS (25% variation in [Ca(2+)](i) with SS varying from 0 to 3.5 Pa); (ii) Pretreatment with ATP-medium results in different [Ca(2+)](i) response as compared to the control group (ATP-free medium) under SS; (iii) Relative [Ca(2+)](i) fluctuation over baseline is more reliable to show the [Ca(2+)](i) response process than the absolute [Ca(2+)](i) response peak. The developed model may improve the experimental design and facilitate our understanding of the mechanotransduction process in osteoblasts.