Bone Health in People Living with HIV/AIDS: An Update of Where We Are and Potential Future Strategies.

The developments in Human Immunodeficiency Virus (HIV) treatment and in the care of people living with HIV (PLWHIV) and Acquired Immunodeficiency Syndrome (AIDS) over the last three decades has led to a significant increase in life expectancy, on par with HIV-negative individuals. Aside from the fact that bone fractures tend to occur 10 years earlier than in HIV-negative individuals, HIV is, per se, an independent risk factor for bone fractures. A few available antiretroviral therapies (ARVs) are also linked with osteoporosis, particularly those involving tenofovir disoproxil fumarate (TDF). HIV and hepatitis C (HCV) coinfection is associated with a greater risk of osteoporosis and fracture than HIV monoinfection. Both the Fracture Risk Assessment Tool (FRAX) and measurement of bone mineral density (BMD) via a DEXA scan are routinely used in the assessment of fracture risk in individuals living with HIV, as bone loss is thought to start between the ages of 40 and 50 years old. The main treatment for established osteoporosis involves bisphosphonates. Supplementation with calcium and vitamin D is part of clinical practice of most HIV centers globally. Further research is needed to assess (i) the cut-off age for assessment of osteoporosis, (ii) the utility of anti-osteoporotic agents in PLWHIV and (iii) how concomitant viral infections and COVID-19 in PLWHIV can increase risk of osteoporosis.

Theaflavin-3,3'-Digallate Promotes the Formation of Osteoblasts Under Inflammatory Environment and Increases the Bone Mass of Ovariectomized Mice.

Postmenopausal osteoporosis is a disease of bone mass reduction and structural changes due to estrogen deficiency, which can eventually lead to increased pain and fracture risk. Chronic inflammatory microenvironment leading to the decreased activation of osteoblasts and inhibition of bone formation is an important pathological factor that leads to osteoporosis. Theaflavin-3,3'-digallate (TFDG) is an extract of black tea, which has potential anti-inflammatory and antiviral effects. In our study, we found that TFDG significantly increased the bone mass of ovariectomized (OVX) mice by micro-CT analysis. Compared with OVX mice, TFDG reduced the release of proinflammatory cytokines and increased the expression of osteogenic markers in vivo. In vitro experiments demonstrated that TFDG could promote the formation of osteoblasts in inflammatory environment and enhance their mineralization ability. In this process, TFDG activated MAPK, Wnt/ß-Catenin and BMP/Smad signaling pathways inhibited by TNF-α, and then promoted the transcription of osteogenic related factors including Runx2 and Osterix, promoting the differentiation and maturation of osteoblasts eventually. In general, our study confirmed that TFDG was able to promote osteoblast differentiation under inflammatory environment, enhance its mineralization ability, and ultimately increase bone mass in ovariectomized mice. These results suggested that TFDG might have the potential to be a more effective treatment of postmenopausal osteoporosis.

The effect of periodic dynamic mechanical load with different intensity on microgravity-induced osteoporosis / 医用生物力学

Objective To investigate the role and influence of physiological loading and overloading on microgravity-induced osteoporosis,so as to find a reliable way to prevent or treat related-orthopedic disorders in astronauts induced by long-time space activity.Metbods The microgravity environment in space was simulated by tail-suspension experiment,then the osteoporosis models of mice were built.A total of 32 C57BL/6J mice were randomly and evenly separated into four groups:normal group (normal),tail-suspension group (TS),physiological loading group (loading) and overloading group (overloading).Periodic dynamic mechanical load was applied on the left tibia in loading group and overloading group during tail-suspension test.After four weeks,tibial mechanical properties,micro-parameters of bone trabecular,biochemical indices and osteogenesis-related gene expression in each group were compared and analyzed.Results A great loss of tibial cancellous bone,significantly lower tibial biomechanical expression,serious damage of microstructure and weaker osteogenic activity were found in tail-suspended mice as compared with those of normal group.Physiological loading could clearly improve mechanical properties of bones,microstructure of bone trabecular,osteogenic activity and relative gene expression (P ＜ 0.05).Overloading could also improve the condition of microgravity-induced osteoporosis,but the effect was not obvious (P ＞ 0.05).Conclusions Tail-suspension can successfully simulate microgravity environment and duplicate osteoporosis model.Physiological loading can effectively prevent the emergence and development of microgravity-induced osteoporosis,while overloading can also counter microgravity-induced osteoporosis,but the results have no significant differences.

Analysis on microstructure and biomechanical properties in different regions of osteoporotic femoral head / 医用生物力学

Objective To investigate the structure and biomechanical property differences in different regions of the femoral head for elderly patients with femoral neck fractures,and to study its influence on internal fixation for fracture.Methods Twenty femoral head specimens were collected from elderly patients with femoral neck fracture after joint replacement.The femoral head was divided into 3 parts (lateral,inferior and medial region) with reference to anatomical markers on surface of the femoral head.After the position and drilling direction of the ring drill were determined,a circular drill was used to obtain the cylindrical cancellous bone columns with 10 mm in diameter and 10 mm in height.The data of cancellous bone columns in different regions were analyzed by Micro-CT scanning system,including bone volume fraction (BVF),trabecular space (Tb.Sp),trabecular thickness (Tb.Th),the number of trabecular number (Tb.N),the bone surface volume ratio (bone surface/bone volume,BS/BV),structural model index (SMI).Mechanical property differences of bone tissues in different regions were calculated by micro-finite element analysis.Results Bone mass in the elderly osteoporotic femoral head decreased,and there were significant differences in bone microstructure and mechanical properties in different regions of the femoral head.Bone microstructure and mechanical properties in medial region were obviously superior to those in lateral and interior region.Conclusions The bone structure and mechanical strength in medial region of the femoral head are obvious superior to those in lateral and inferior regions.The position for internal fixation should be fully considered during treatment of osteoporotic femoral neck fracture in clinic.

The effect of periodic dynamic mechanical load with different intensity on microgravity-induced osteoporosis / 医用生物力学

Objective To investigate the role and influence of physiological loading and overloading on microgravity-induced osteoporosis,so as to find a reliable way to prevent or treat related-orthopedic disorders in astronauts induced by long-time space activity.Metbods The microgravity environment in space was simulated by tail-suspension experiment,then the osteoporosis models of mice were built.A total of 32 C57BL/6J mice were randomly and evenly separated into four groups:normal group (normal),tail-suspension group (TS),physiological loading group (loading) and overloading group (overloading).Periodic dynamic mechanical load was applied on the left tibia in loading group and overloading group during tail-suspension test.After four weeks,tibial mechanical properties,micro-parameters of bone trabecular,biochemical indices and osteogenesis-related gene expression in each group were compared and analyzed.Results A great loss of tibial cancellous bone,significantly lower tibial biomechanical expression,serious damage of microstructure and weaker osteogenic activity were found in tail-suspended mice as compared with those of normal group.Physiological loading could clearly improve mechanical properties of bones,microstructure of bone trabecular,osteogenic activity and relative gene expression (P ＜ 0.05).Overloading could also improve the condition of microgravity-induced osteoporosis,but the effect was not obvious (P ＞ 0.05).Conclusions Tail-suspension can successfully simulate microgravity environment and duplicate osteoporosis model.Physiological loading can effectively prevent the emergence and development of microgravity-induced osteoporosis,while overloading can also counter microgravity-induced osteoporosis,but the results have no significant differences.

Analysis on microstructure and biomechanical properties in different regions of osteoporotic femoral head / 医用生物力学

Objective To investigate the structure and biomechanical property differences in different regions of the femoral head for elderly patients with femoral neck fractures,and to study its influence on internal fixation for fracture.Methods Twenty femoral head specimens were collected from elderly patients with femoral neck fracture after joint replacement.The femoral head was divided into 3 parts (lateral,inferior and medial region) with reference to anatomical markers on surface of the femoral head.After the position and drilling direction of the ring drill were determined,a circular drill was used to obtain the cylindrical cancellous bone columns with 10 mm in diameter and 10 mm in height.The data of cancellous bone columns in different regions were analyzed by Micro-CT scanning system,including bone volume fraction (BVF),trabecular space (Tb.Sp),trabecular thickness (Tb.Th),the number of trabecular number (Tb.N),the bone surface volume ratio (bone surface/bone volume,BS/BV),structural model index (SMI).Mechanical property differences of bone tissues in different regions were calculated by micro-finite element analysis.Results Bone mass in the elderly osteoporotic femoral head decreased,and there were significant differences in bone microstructure and mechanical properties in different regions of the femoral head.Bone microstructure and mechanical properties in medial region were obviously superior to those in lateral and interior region.Conclusions The bone structure and mechanical strength in medial region of the femoral head are obvious superior to those in lateral and inferior regions.The position for internal fixation should be fully considered during treatment of osteoporotic femoral neck fracture in clinic.

The effect of periodic dynamic mechanical load with different intensity on microgravity-induced osteoporosis / 医用生物力学

Objective To investigate the role and influence of physiological loading and overloading on microgravity-induced osteoporosis, so as to find a reliable way to prevent or treat related-orthopedic disorders in astronauts induced by long-time space activity. Methods The microgravity environment in space was simulated by tail-suspension experiment, then the osteoporosis models of mice were built. A total of 32 C57BL/6J mice were randomly and evenly separated into four groups: normal group (normal), tail-suspension group (TS), physiological loading group (loading) and overloading group (overloading). Periodic dynamic mechanical load was applied on the left tibia in loading group and overloading group during tail-suspension test. After four weeks, tibial mechanical properties, micro-parameters of bone trabecular, biochemical indices and osteogenesis-related gene expression in each group were compared and analyzed. Results A great loss of tibial cancellous bone, significantly lower tibial biomechanical expression, serious damage of microstructure and weaker osteogenic activity were found in tail-suspended mice as compared with those of normal group. Physiological loading could clearly improve mechanical properties of bones, microstructure of bone trabecular, osteogenic activity and relative gene expression (P＜0.05). Overloading could also improve the condition of microgravity-induced osteoporosis, but the effect was not obvious (P＞0.05). Conclusions Tail-suspension can successfully simulate microgravity environment and duplicate osteoporosis model. Physiological loading can effectively prevent the emergence and development of microgravity-induced osteoporosis, while overloading can also counter microgravity-induced osteoporosis, but the results have no significant differences.

Analysis on microstructure and biomechanical properties in different regions of osteoporotic femoral head / 医用生物力学

Objective To investigate the structure and biomechanical property differences in different regions of the femoral head for elderly patients with femoral neck fractures, and to study its influence on internal fixation for fracture. Methods Twenty femoral head specimens were collected from elderly patients with femoral neck fracture after joint replacement. The femoral head was divided into 3 parts (lateral, inferior and medial region) with reference to anatomical markers on surface of the femoral head. After the position and drilling direction of the ring drill were determined, a circular drill was used to obtain the cylindrical cancellous bone columns with 10 mm in diameter and 10 mm in height. The data of cancellous bone columns in different regions were analyzed by Micro-CT scanning system, including bone volume fraction (BVF), trabecular space (Tb.Sp), trabecular thickness (Tb.Th), the number of trabecular number (Tb.N), the bone surface volume ratio (bone surface/bone volume, BS/BV), structural model index (SMI). Mechanical property differences of bone tissues in different regions were calculated by micro-finite element analysis. ResultsBone mass in the elderly osteoporotic femoral head decreased, and there were significant differences in bone microstructure and mechanical properties in different regions of the femoral head. Bone microstructure and mechanical properties in medial region were obviously superior to those in lateral and interior region. Conclusions The bone structure and mechanical strength in medial region of the femoral head are obvious superior to those in lateral and inferior regions. The position for internal fixation should be fully considered during treatment of osteoporotic femoral neck fracture in clinic.

Analysis on microstructure and biomechanical properties in different regions of osteoporotic femoral head / 医用生物力学

Objective To investigate the structure and biomechanical property differences in different regions of the femoral head for elderly patients with femoral neck fractures,and to study its influence on internal fixation for fracture.Methods Twenty femoral head specimens were collected from elderly patients with femoral neck fracture after joint replacement.The femoral head was divided into 3 parts (lateral,inferior and medial region) with reference to anatomical markers on surface of the femoral head.After the position and drilling direction of the ring drill were determined,a circular drill was used to obtain the cylindrical cancellous bone columns with 10 mm in diameter and 10 mm in height.The data of cancellous bone columns in different regions were analyzed by Micro-CT scanning system,including bone volume fraction (BVF),trabecular space (Tb.Sp),trabecular thickness (Tb.Th),the number of trabecular number (Tb.N),the bone surface volume ratio (bone surface/bone volume,BS/BV),structural model index (SMI).Mechanical property differences of bone tissues in different regions were calculated by micro-finite element analysis.Results Bone mass in the elderly osteoporotic femoral head decreased,and there were significant differences in bone microstructure and mechanical properties in different regions of the femoral head.Bone microstructure and mechanical properties in medial region were obviously superior to those in lateral and interior region.Conclusions The bone structure and mechanical strength in medial region of the femoral head are obvious superior to those in lateral and inferior regions.The position for internal fixation should be fully considered during treatment of osteoporotic femoral neck fracture in clinic.

The effect of periodic dynamic mechanical load with different intensity on microgravity-induced osteoporosis / 医用生物力学

Objective To investigate the role and influence of physiological loading and overloading on microgravity-induced osteoporosis,so as to find a reliable way to prevent or treat related-orthopedic disorders in astronauts induced by long-time space activity.Metbods The microgravity environment in space was simulated by tail-suspension experiment,then the osteoporosis models of mice were built.A total of 32 C57BL/6J mice were randomly and evenly separated into four groups:normal group (normal),tail-suspension group (TS),physiological loading group (loading) and overloading group (overloading).Periodic dynamic mechanical load was applied on the left tibia in loading group and overloading group during tail-suspension test.After four weeks,tibial mechanical properties,micro-parameters of bone trabecular,biochemical indices and osteogenesis-related gene expression in each group were compared and analyzed.Results A great loss of tibial cancellous bone,significantly lower tibial biomechanical expression,serious damage of microstructure and weaker osteogenic activity were found in tail-suspended mice as compared with those of normal group.Physiological loading could clearly improve mechanical properties of bones,microstructure of bone trabecular,osteogenic activity and relative gene expression (P ＜ 0.05).Overloading could also improve the condition of microgravity-induced osteoporosis,but the effect was not obvious (P ＞ 0.05).Conclusions Tail-suspension can successfully simulate microgravity environment and duplicate osteoporosis model.Physiological loading can effectively prevent the emergence and development of microgravity-induced osteoporosis,while overloading can also counter microgravity-induced osteoporosis,but the results have no significant differences.

Relationship between Helicobacter pylori infection (HP) and bone mineral density (BMD) in elderly people.

BACKGROUND: Low bone mass is a frequent complication of chronic inflammatory disease. The pathogenesis of osteoporosis in chronic inflammatory disease may be secondary to releases of cytokines such as TNF- and IL6. Chronic gastritis due to helicobacter pylori (HP) infection may lead to decreased bone mineral density (BMD) and predispose patients to osteoporosis. The objective of this study was to determine the BMD status in HP positive patients with gastritis versus HP negative cases. METHODS: In this cross-sectional study, we enrolled 967 participants aged 60 years old and more from Amirkola Health Study Ageing Project. Seven-hundred and fifty eight HP positive and 209 HP negative patients were analyzed. BMD was measured by dual-energy x-ray absorptiometry (DXA) method in the spine and femoral neck in all participants. RESULTS: The mean age in HP+ and HP- negative patients was 68.3±6.8 and 69.3±7.4 years, respectively. BMD g/cm2 in the spine and femoral neck did not differ between the two groups (P=0.19 and 0.22 respectively). The prevalence of osteoporosis did not also differ across the two groups as well. There was no relationship between the level of antibodies against HP and BMD. CONCLUSION: According to the findings of this study, H. pylori infection is not associated with BMD changes in the elderly population.

The preliminary clinical application of percutaneous vertebroplasty / 介入放射学杂志

Objective To study the method of percutaneous vertebroplasty (PVP) and investigate its clinical efficacy. Methods Tweenty five cases (13 patients with painful osteoporotic vertebral fractures, 8 cases with metastatic neoplasms and 4 cases with hemangionmas) were treated by the injection of polymethyl methacrykate (PMMA) under DSA fluoroscopic guidance. the time of follow up ranged from 1 15 months. Results The procedure was successful in all patients. Among 25 patients, 18 experinced with complete relief of pain, 6 with conspicuous relief, 1 with no significant change. Two patients showed transient symptom of radiculopathy and no clinical complication in others. Conclusions PVP is a safe and feasible treatment for patients with hemangiomas and vertebral fractures caused by malignancies and osteoporosis.