Hip fracture protection by alendronate treatment in postmenopausal women with osteoporosis: a review of the literature

Engineering a targeted and safe bone anabolic gene therapy to treat osteoporosis in alveolar bone loss

Alveolar bone loss in elderly populations is highly prevalent and increases the risk of tooth loss, gum disease susceptibility, and facial deformity. Unfortunately, there are very limited treatment options available. Here, we developed a bone-targeted gene therapy that reverses alveolar bone loss in patients with osteoporosis by targeting the adaptor protein Schnurri-3 (SHN3). SHN3 is a promising therapeutic target for alveolar bone regeneration, because SHN3 expression is elevated in the mandible tissues of humans and mice with osteoporosis while deletion of SHN3 in mice greatly increases alveolar bone and tooth dentin mass. We used a bone-targeted recombinant adeno-associated virus (rAAV) carrying an artificial microRNA (miRNA) that silences SHN3 expression to restore alveolar bone loss in mouse models of both postmenopausal and senile osteoporosis by enhancing WNT signaling and osteoblast function. In addition, rAAV-mediated silencing of SHN3 enhanced bone formation and collagen production of human skeletal organoids in xenograft mice. Finally, rAAV expression in the mandible was tightly controlled via liver- and heart-specific miRNA-mediated repression or via a vibration-inducible mechanism. Collectively, our results demonstrate that AAV-based bone anabolic gene therapy is a promising strategy to treat alveolar bone loss in osteoporosis.

Circular RNA atlas in osteoclast differentiation with and without alendronate treatment

BACKGROUND

Alendronate (AL) is the most widely used bisphosphonate in the treatment of osteoporosis (OP). However, the role of circular RNAs (circRNAs) in the treatment of OP with AL remains unclear.

METHODS

In this study, we showed that osteoclast (OC) precursors (OPCSs) could be induced into OCs with macrophage colony-stimulating factor (MCSF) and receptor activator of nuclear factor-κB ligand (RANKL) treatment. Subsequently, the OCs were treated with AL. OC differentiation-related biomarkers including RANK, tartrate-resistant acid phosphatase (TRAP), and cathepsin K (CTSK) were analyzed with TRAP staining, quantitative real-time (qPCR), and western blotting. Differentially expressed circRNAs (DECs) were identified among the OPCS, OC, and OC + AL groups. In addition, the expression levels of 10 DECs related to OC differentiation were verified by qPCR.

RESULTS

TRAP staining showed that MCSF and RANKL treatment effectively induced OPCSs to differentiate into OCs. In addition, qPCR and western blot analysis revealed that the three biomarkers of OC (RANK, TRAP, and CTSK) were expressed significantly more in the OC group than those in the OPCS group. In contrast, the mRNA and protein expression levels of these three biomarkers decreased significantly in OCs treated with AL compared with those non-treated OCs. GO analysis of the DECs in the OPCS group vs. the OC group revealed that their functions were mainly related to cell, cell part, binding, and single-organism terms. KEGG analysis of the top 20 DECs in a comparison between the OPCS and OC groups showed that genes involved in mitogen-activated protein kinase signaling were the most common. Results of functional analyses of DECs in an OC vs. OC + AL comparison were similar to those in the OPCS vs. OC comparison. Finally, qPCR showed that, in the OC + AL vs. OC group comparison, the expression levels of seven and three DECs significantly decreased and increased, respectively.

CONCLUSIONS

Having successfully induced OPCSs to differentiate into OCs, we showed that AL suppresses the differentiation of OPCS into OC and that 10 DECs were involved in the regulation of this process. This indicates that these DECs might be important to the treatment of OP.

Treatment Effects of Bisphosphonates and Denosumab on Survival and Refracture from Real-World Data of Hip-Fractured Patients

We examined differences in patients' survival after hip fracture (HF) and risk for subsequent HF among patients treated with oral and intravenous bisphosphonates (oBPs, iBPs), denosumab (DMAB), and patients without therapy. We used data from all patients in Austria aged ≥ 50 who sustained a HF between 2012 and 2017 and were followed for a subsequent HF and all-cause mortality until 2017. Antiosteoporotic treatment-naïve patients, who were incident users of BPs and DMAB, were eligible for propensity score matching 1:1 to obtain comparable user groups. We applied competing risk approach and calculated cumulative incidence functions and subdistribution-hazards for refracture. Cox regression models were applied for mortality risk. A total of 54,145 hip-fractured patients were observed (1919 oBPs; 1870 iBPs; 555 DMAB users; and 42,795 untreated patients were included in the matched sets) and followed up for a median (interquartile range) of 22.6 months (26.2). Patients treated with antiresorptive medications had significantly longer survival time than patients without treatment. Receiving treatment significantly decreased a hazard of dying only for women by 17% for iBPs (HR 0.83, 95% CI 0.71-0.98, p = 0.023). For DMAB and oBPs, the results were not statistically significant. Higher risk of a subsequent HF was observed in women on DMAB (SHR 1.77, 95% CI 1.08-2.91) and on iBP (SHR 1.81, 95% CI 1.35-2.41), and in men on oBPs (SHR 2.89, 95% CI 1.58-5.30). Patients who were treated with antiresorptive medications after HF had longer survival than patients without treatment, highlighting the importance of initiation of antiresorptive treatment after HF.

Significant improvement of bone mineral density and bone turnover markers by denosumab therapy in bisphosphonate-unresponsive patients

Bone mineral density (BMD) sometimes cannot be improved by long-term bisphosphonate (BP) therapy in osteoporosis (OP). This study showed that lumbar as well as hip BMD significantly increased after denosumab treatment in patients not responsive to BPs. Thus, denosumab may be a strong OP treatment option for BP-unresponsive patients.

INTRODUCTION

BMD sometimes cannot be improved by long-term BP therapy.

METHODS

We administered denosumab to osteoporotic patients with a poor response to BPs who had been taking them for 2 years or longer. Ninety-eight women with BP-poor responsive OP were enrolled in this study. Mean (standard deviation [SD]) age was 71.2 (6.9) years and mean (SD) duration of BP treatment was 59.9 (34.3) months. We distinguished BP responders from non-responders based on changes in BMD values at denosumab commencement (baseline) from 2 years beforehand.

RESULTS

There were no significant differences in age, duration of BP use, bone turnover markers, or BMD at baseline between the groups. Prior to denosumab, BMD had increased significantly in responders and decreased significantly in non-responders. Bone turnover markers had decreased significantly at 4 months of denosumab treatment (P < 0.001) and lumbar and hip BMD were significantly increased at 1 year of therapy in both groups (P < 0.001). Simple correlation coefficients were -0.337 for lumbar and -0.339 for hip BMD changes (both P = 0.001) before and after denosumab treatment. Both at the lumbar spine and hips, decreased BMD before denosumab therapy was significantly associated with an increase in BMD at 1 year of treatment (spine, t value = -3.502, P = 0.001, R = 0.113; hip, t value = -3.526, P = 0.001, R = 0.115).

CONCLUSIONS

These results suggest that denosumab may be a strong OP treatment option for BP-unresponsive patients.

Bone cross-sectional geometry is not associated with atypical femoral fractures in Asian female chronic bisphosphonate users

INTRODUCTION

Atypical femoral fractures (AFF) tend to occur in Asian women with prolonged bisphosphonate exposure. Hip geometry is thought to contribute to the risk of AFF formation. We examined the hip structural geometry parameters in Asian female chronic bisphosphonate users who sustained an AFF and compared them to chronic bisphosphonate users who did not sustain any femoral fracture (NFF) and bisphosphonate-naïve patients who sustained an osteoporotic femoral fracture (OFF).

MATERIALS & METHODS

Thirty-one patients with AFFs were gender and age-matched to 31 patients with NFFs and 49 patients with OFFs. The Hip Structural Analysis parameters analyzed were bone mineral density (BMD), cross-sectional area (CSA; a metric of resistance to axial compression), section modulus (SM; a metric of resistance to tensile loads), average cortical thickness (ACT; mean thickness of the femoral cortices), buckling ratio (BR; an index of likelihood of local buckling), and neck shaft angle (NSA; the angle between the neck and shaft axes). The regions analyzed were three cross-sections measured at the narrowest femoral neck diameter, the intertrochanteric area, and the proximal femoral shaft. One-way ANOVA with Bonferroni adjustment for multiple comparisons was used to compare parameters between the three patient groups, with statistical significance defined as p<0.05.

RESULTS

There were no statistical differences in parameters between patients with AFFs and patients with NFFs at all measured regions. Patients with AFFs and NFFs had statistically higher BMD, CSA, ACT, SM values and lower BR values at the NN and IT regions than patients with OFFs. Additionally, patients with NFFs had statistically higher SM values at the IT region than patients with OFFs, while patients with AFFs had statistically higher BMD, CSA, and ACT values at the FS region. All other measured parameters were not statistically different between the groups.

CONCLUSIONS

Chronic bisphosphonate users with and without AFFs had similar femoral structural geometries. Unlike in other populations, varus neck shaft angles were not found to be associated with AFFs in Asian female chronic bisphosphonate users. Thus, bone cross-sectional geometry is not likely to be associated with AFFs in Asian female chronic bisphosphonate users. Hip Structural Analysis does not show an increased predilection for tensile failure in AFFs.

Symptomatic atypical femoral fractures are related to underlying hip geometry

The benefits of bisphosphonates are well documented, but prolonged use has been associated with atypical femur fractures. Radiographic markers for fracture predisposition could potentially aid in safer medication use. In this case-control designed study, we compared hip radiographic parameters and the demographic characteristics of chronic bisphosphonate users who sustained an atypical femoral fracture with a group of chronic bisphosphonate users who did not sustain an atypical femur fracture and also a group who sustained an intertrochanteric hip fracture. Radiographic parameters included were neck-shaft angle (NSA), hip-axis length (HAL) and center-edge angle (CE). Multivariate regression was used to evaluate the relationship between radiographic measures and femur fracture. Receiver-operating characteristic analysis determined cut-off points for neck-shaft angle and risk of atypical femur fracture. Ultimately, pre-fracture radiographs of 53 bisphosphonate users who developed atypical fracture were compared with 43 asymptomatic chronic bisphosphonate users and 64 intertrochanteric fracture patients. Duration of bisphosphonate use did not statistically differ between users sustaining atypical fracture and those without fracture (7.9 [±3.5] vs. 7.7 [±3.3] years, p=0.7). Bisphosphonate users who fractured had acute/varus pre-fracture neck-shaft angles (p<0.001), shorter hip-axis length (p<0.01), and narrower center-edge angles (p<0.01). Regression analysis revealed associations between neck-shaft angle (OR=0.89 [95% CI=0.81-0.97; p=0.01), center edge angle (OR=0.89 [95% CI=0.80-0.99]; p=0.03), and BMI (OR=1.15 [95% CI=1.02-1.31; p=0.03) with fracture development. ROC curve analysis (AUC=0.67 [95% CI=0.56-0.79]) determined that a cut-off point for neck-shaft angle <128.3° yielded 69% sensitivity and 63% specificity for development of atypical femoral fracture. Ultimately, an acute/varus angle of the femoral neck, high BMI, and narrow center-edge angle were associated with development of atypical femur fracture in long-term bisphosphonate users. Patients on long-term bisphosphonates should be regularly radiographically evaluated in order to assess for potential risk of atypical fracture.

SC, Li ZQ, Deng WM. Effect of whole body vibration therapy on circulating serotonin levels in an ovariectomized rat model of osteoporosis

OBJECTIVE(S)

Studies have reported that whole body vibration (WBV) played a vital role in bone remodeling. Circulating serotonin is also involved in negative regulating bone mass in rodents and humans. However, both WBV and inhibition of serotonin biosynthesis may suppress receptor activator of nuclear factor-kappaB ligand (RANKL)-induced osteoclastogenesis in vitro. The purpose of the current study was to investigate the effect of WBV therapy on the levels of serum serotonin in ovariectomized rats.

MATERIALS AND METHODS

Thirty-six-month-old female Sprague Dawley rats weighing 276.15±37.75 g were ovariectomized to induce osteoporosis, and another ten rats underwent sham operation to establish sham control (SHAM) group. After 3 months, ovariectomized rats were divided into three subgroups and then separately treated with WBV, Alendronate (ALN) and normal saline (OVX), SHAM group was given normal saline. After 6 weeks of treatment, rats were sacrificed. Serum serotonin, RANKL, bone turnover markers, and bone mineral density (BMD), bone strength were evaluated.

RESULTS

The serum serotonin level was significantly lower in WBV group than OVX and ALN groups (P<0.05 and P<0.001). RANKL levels significantly decreased in WBV and ALN groups compared to OVX group (P<0.001 for both). BMD and biomechanical parameters of femur significantly increased (P<0.05 for both) and bone turnover levels decreased (P<0.001 for both) in WBV group compared to OVX group.

CONCLUSION

These data indicated that WBV enhanced the bone strength and BMD in ovariectomized rats most likely by reducing the levels of circulating serotonin.

Treating osteoporosis by targeting parathyroid hormone to bone

Osteoporosis is a major public health problem despite widespread use of bisphosphonate therapy. PTH(1-34) is a more effective treatment; but its use has been limited by side effects (hypercalcemia, tumor risk) and inconvenient dosing (daily injection). Long-acting forms of PTH are also effective but cause severe hypercalcemia, presumably from effects in kidney. We hypothesized that targeted delivery of PTH to bone using a collagen binding domain (PTH-CBD) could reduce hypercalcemia. PTH-CBD is cleared from serum within 12hours after subcutaneous administration. In ovariectomized rats, monthly administration of PTH-CBD increased spinal BMD by 14.2% with no associated hypercalcemia. Such bone-targeted anabolic agents may ultimately allow the superior efficacy of anabolic therapy to be obtained with the dosing convenience of bisphosphonates.

Surgical treatment improves clinical and functional outcomes for patients who sustain incomplete bisphosphonate-related femur fractures

OBJECTIVE

To describe the outcomes for patients treated at a single institution, who sustained incomplete bisphosphonate-induced femoral fractures.

DESIGN

Retrospective review.

SETTING

University-based academic medical center.

PATIENTS

Thirty-one patients with 43 incomplete fractures met the inclusion criteria.

INTERVENTION

Nonoperative management or surgical intervention for fractures with refractory symptoms or progression of fracture lucency on radiographs.

MAIN OUTCOME MEASUREMENTS

Radiographic assessments and the Short Musculoskeletal Functional Assessment to gauge functional status.

RESULTS

The cohort was all women with an average age of 69.2 (range: 46-92) years and had been treated with bisphosphonate therapy for an average of 9.1 (range: 5-20) years. The average healing time for all incomplete fractures was 9.4 (range: 1.5-36) months. Forty-nine percent of the fractures (21 of 43 fractures) were ultimately treated with surgery for impending complete fracture or failure of nonsurgical management. Of the incomplete fractures treated with surgery, 81% became pain free and 100% were radiographically healed at a mean of 7.1 (range: 1.5-12) months. In contrast, of the nonoperatively treated incomplete fractures, only 64% were pain free at latest follow-up, with only 18% of fractures demonstrating radiographic evidence of healing at an average of 11 (range: 6-24) months. Standardized dysfunction index from the Short Musculoskeletal Functional Assessment was better (19.7) in the surgical group than in the nonsurgical group (19.7 vs. 25.7, P = 0.0017).

CONCLUSIONS

A higher percentage of patients treated surgically became asymptomatic and demonstrated radiographic evidence of healing earlier than those treated nonsurgically. Surgical intervention is effective for relief of symptoms when treating incomplete bisphosphonate-related femur fractures, and patients should be counseled to the potential benefits of prophylactic surgery.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Risk factors associated with the occurrence of hip fracture in Japanese patients with rheumatoid arthritis: a prospective observational cohort study

Risk factors associated with the occurrence of hip fracture in Japanese patients with rheumatoid arthritis (RA) were evaluated in a prospective, observational cohort study. Physical disability, advanced age, history of total knee replacement (TKR), and low body mass index (BMI) appear to be associated with the occurrence of hip fracture.

INTRODUCTION

This study seeks to evaluate the association between potential risk factors and the occurrence of hip fractures in Japanese RA patients.

METHODS

A total of 9,720 patients (82.1% female; mean age, 55.7 years) with RA were enrolled in a prospective observational study from 2000 to 2010. Self-reported hip fractures were verified using patient medical records. Cox proportional hazards models were used to analyze independent contributions of various risk factors to hip fracture occurrence.

RESULTS

During a mean follow-up of 5.2 years, 152 patients reported 152 hip fractures. Among these patients, 97 hip fractures in 97 patients (15 males, 82 females) were verified with medical records. Japanese version of the Health Assessment Questionnaire (J-HAQ) disability score [per 1 score, hazard ratio (HR), 2.64; 95% confidence interval (CI), 1.94-3.58], age (per 10 years; HR, 1.53; 95% CI, 1.25-1.87), history of TKR (HR, 3.75; 95% CI, 1.57-8.96), and BMI (per 1 kg/m2, HR, 0.92; 95% CI, 0.86-0.99) were significantly associated with hip fractures. Among the scores on the eight domains of the J-HAQ, J-HAQ (arising) (HR, 1.74; 95% CI, 1.28-2.36) and J-HAQ (hygiene) (HR, 1.58; 95% CI, 1.11-2.24) were significantly correlated with the occurrence of hip fracture.

CONCLUSIONS

High J-HAQ disability score, advanced age, history of TKR, and low BMI appear to be associated with the occurrence of hip fractures in Japanese RA patients. Among the eight domains of the J-HAQ, arising and hygiene disabilities appear to be correlated with the occurrence of hip fractures in this patient population.

Strategy for prevention of hip fractures in patients with Parkinson's disease

Hypovitaminosis D and K due to malnutrition or sunlight deprivation, increased bone resorption due to immobilization, low bone mineral density (BMD) and an increased risk of falls may contribute to an increased risk of hip fractures in patients with Parkinson's disease. The purpose of the present study was to clarify the efficacy of interventions intended to prevent hip fractures in elderly patients with Parkinson's disease. PubMed was used to search the literature for randomized controlled trials (RCTs) regarding Parkinson's disease and hip fractures. The inclusion criteria were 50 or more subjects per group and a study period of 1 year or longer. Five RCTs were identified and the relative risk and 95% confidence interval were calculated for individual RCTs. Sunlight exposure increased serum hydroxyvitamin D [25(OH)D] concentration, improved motor function, decreased bone resorption and increased BMD. Alendronate or risedronate with vitamin D supplementation increased serum 25(OH)D concentration, strongly decreased bone resorption and increased BMD. Menatetrenone (vitamin K(2)) decreased serum undercarboxylated osteocalcin concentration, decreased bone resorption and increased BMD. Sunlight exposure (men and women), menatetrenone (women), alendronate and risedronate with vitamin D supplementation (women) significantly reduced the incidence of hip fractures. The respective RRs (95% confidence intervals) according to the intention-to-treat analysis were 0.27 (0.08, 0.96), 0.13 (0.02, 0.97), 0.29 (0.10, 0.85) and 0.20 (0.06, 0.68). Interventions, including sunlight exposure, menatetrenone and oral bisphosphonates with vitamin D supplementation, have a protective effect against hip fractures elderly patients with Parkinson's disease.

A single injection of the anabolic bone agent, parathyroid hormone-collagen binding domain (PTH-CBD), results in sustained increases in bone mineral density for up to 12 months in normal female mice

Parathyroid hormone (PTH) is the most effective osteoporosis treatment, but it is only effective if administered by daily injections. We fused PTH(1-33) to a collagen binding domain (PTH-CBD) to extend its activity, and have shown an anabolic bone effect with monthly dosing. We tested the duration of action of this compound with different routes of administration. Normal young C57BL/6J mice received a single intraperitoneal injection of PTH-CBD (320 μg/kg). PTH-CBD treated mice showed a 22.2 % increase in bone mineral density (BMD) at 6 months and 12.8 % increase at 12 months. When administered by subcutaneous injection, PTH-CBD again caused increases in BMD, 15.2 % at 6 months and 14.3 % at 12 months. Radiolabeled PTH-CBD was concentrated in bone and skin after either route of administration. We further investigated skin effects of PTH-CBD, and histological analysis revealed an apparent increase in anagen VI hair follicles. A single dose of PTH-CBD caused sustained increases in BMD by >10 % for 1 year in normal mice, regardless of the route of administration, thus showing promise as a potential osteoporosis therapy.

Sunlight exposure is important for preventing hip fractures in patients with Alzheimer's disease, Parkinson's disease, or stroke

OBJECTIVES

Hypovitaminosis D as a result of malnutrition or sunlight deprivation, increased bone resorption, low bone mineral density (BMD), or an increased risk of falls may contribute to an increased risk of hip fractures in patients with neurological diseases, including Alzheimer's disease, Parkinson's disease, and stroke. The purpose of this study was to clarify the efficacy of sunlight exposure for reducing the risk of hip fractures in patients with such neurological diseases.

METHODS

The English literature was searched using PubMed, and randomized controlled trials evaluating the efficacy of sunlight exposure for reducing the risk of hip fractures in patients with Alzheimer's disease, Parkinson's disease, and stroke were identified. The relative risk and the 95% confidence interval were calculated for individual randomized controlled trials, and a pooled data analysis (meta-analysis) was performed.

RESULTS

Three randomized controlled trials were identified. Sunlight exposure improved hypovitaminosis D and increased the BMD. The relative risk (95% confidence interval) of hip fractures was 0.22 (0.05, 1.01) for Alzheimer's disease, 0.27 (0.08, 0.96) for Parkinson's disease, and 0.17 (0.02, 1.36) for stroke. The relative risk (95% confidence interval) calculated for the pooled data analysis was 0.23 (0.10, 0.56) (P = 0.0012), suggesting a significant risk reduction rate of 77%.

CONCLUSION

The present meta-analysis added additional evidence indicating the efficacy of sunlight exposure for reducing the risk of hip fractures in patients with Alzheimer's disease, Parkinson's disease, and stroke.

Three-year experience with risedronate therapy for patients with an increased fracture risk: assessment of proximal femoral bone density and geometry by DXA

BACKGROUND AND OBJECTIVE

We previously reported that risedronate improved the structural parameters of the proximal femur, as well as lumbar spine and proximal femoral bone mineral density (BMD), after 1 year of therapy by suppressing bone resorption in patients with an increased risk of fracture. Our practice-based observational study was subsequently extended to determine whether these effects were enhanced, maintained or attenuated after 3 years.

METHODS

A total of 174 patients (nine men and 165 postmenopausal women) with a mean age of 67.8 years who had osteoporosis or osteopenia and clinical risk factors for fracture started risedronate therapy. The BMD of the lumbar spine and proximal femur, as well as proximal femoral structural parameters, were evaluated by dual-energy x-ray absorptiometry with advanced hip assessment (AHA) software at baseline and every year for 3 years.

RESULTS

Data were available for 107 patients at 1 year, 80 patients at 2 years and 74 patients at 3 years. Lumbar spine, total hip and femoral neck BMD and the cross-sectional area (CSA) of the proximal femur increased from baseline after 1 year with levels being maintained after 2-3 years. The cross-sectional moment of inertia (CSMI) of the proximal femur increased from baseline after 1 year and the increase was enhanced after 2 years with levels being maintained after 3 years. The femoral strength index (FSI) increased from baseline after 1 and 2 years and the increase was enhanced after 3 years. The increases in proximal femoral CSMI and FSI were greater than those of total hip and femoral neck BMD after 3 years of therapy.

CONCLUSION

The present study showed the effects of risedronate therapy for 3 years on the BMD of the lumbar spine and proximal femur, as well as on proximal femoral structure, in patients with an increased risk for fracture.

Alendronate is more effective than elcatonin in improving pain and quality of life in postmenopausal women with osteoporosis

A randomized controlled trial was performed to compare the short-term effects of alendronate (ALN) and ECT on pain and quality of life (QOL) in postmenopausal women with osteoporosis. Back pain and QOL [Short-Form Health Survey (SF-8)] significantly improved at 1, 3, and 6 months in both groups, with greater improvements in the ALN group than in the ECT group. These results suggested that ALN reduced back pain and improved QOL more markedly than ECT in postmenopausal osteoporotic women with back pain.

INTRODUCTION

Intramuscular ECT is known to reduce pain via the central nervous system. A multicenter randomized controlled trial was performed to compare the short-term effects of ALN and ECT on pain and QOL in postmenopausal women with osteoporosis.

METHODS

One hundred and 94 postmenopausal osteoporotic women with back pain (mean age 79.8 years, range 60-96 years) were randomly divided into two groups: the ALN group (35 mg weekly) and the ECT group (intramuscular 20 units a week). The duration of the study was 6 months. The trial was completed in 97 (100%) women of the ALN group and 96 (99.0%) women of the ECT group. Urinary levels of cross-linked N-terminal telopeptide of type I collagen (NTX), serum alkaline phosphatase (ALP), face scale score (FSS, back pain), and SF-8 (QOL) were monitored.

RESULTS

Urinary NTX levels significantly decreased at 3 months in the ALN group, but not in the ECT group. Serum ALP levels significantly decreased at 6 months in the both groups, with a greater reduction in the ALN group. The FSS and SF-8 significantly improved at 1, 3, and 6 months in both groups, with greater improvements in the ALN group than in the ECT group.

CONCLUSIONS

ALN suppressed bone turnover, reduced back pain, and improved QOL more markedly than ECT in postmenopausal osteoporotic women with back pain.

Efficacy of oral bisphosphonates for preventing hip fracture in disabled patients with neurological diseases: a meta-analysis of randomized controlled trials among the Japanese population

OBJECTIVE

Neurological diseases such as amyotrophic lateral sclerosis (ALS), stroke, and Parkinson's disease cause disability and immobilization that increases the risk of hip fracture. The purpose of the present study was to clarify the efficacy of oral bisphosphonates for preventing hip fracture in disabled patients with such neurological diseases.

METHODS

A literature search (PubMed) was done from 1995 to the present for randomized controlled trials (RCTs), and a meta-analysis was conducted.

RESULTS

Seven RCTs met the criteria, including two of etidronate (ALS and stroke), two of alendronate (stroke and Parkinson's disease), and three of risedronate (stroke and Parkinson's disease). All of the RCTs were performed on Japanese patients. According to the results of pooled data analysis, the relative risk (95% confidence interval) of hip fracture in patients receiving etidronate, alendronate, and risedronate treatment compared with placebo or active control treatment was 0.16 (0.03-0.87), 0.29 (0.10-0.80), and 0.24 (0.10-0.58), respectively, suggesting a reduction of risk by more than 70% with oral bisphosphonates. There was no statistical evidence of heterogeneity among RCTs, and publication bias was not identified by the funnel plot and Begg's rank correlation test. No severe adverse events due to oral bisphosphonate treatment were reported.

LIMITATION

It remains uncertain whether the findings are relevant for Western patients with an increased risk of hip fracture due to neurological diseases.

CONCLUSION

A meta-analysis of RCTs suggested that oral bisphosphonate treatment prevents hip fracture in disabled Japanese patients with neurological diseases, including ALS, stroke, and Parkinson's disease. Oral bisphosphonate treatment was well tolerated by such patients.

Monthly administration of a novel PTH-collagen binding domain fusion protein is anabolic in mice

We synthesized fusion proteins of parathyroid hormone (PTH) (1-33) and the collagen binding domain of ColH (CBD) and tested them for anabolic bone activity in mice. Two fusion proteins were synthesized, linking the carboxy terminus of PTH(1-33) either directly to the amino terminal of the CBD or to the CBD through an adjacent ColH domain (PTH-PKD-CBD). Both PTH-CBD and PTH-PKD-CBD increased cAMP accumulation in cells stably transfected with the PTH/PTHrP receptor, and both peptides bound to type 1 collagen in flow-through assays. Distribution studies indicated that the PTH-CBD was concentrated in the bone and skin, tissues with abundant collagen and blood flow. Administration of 320 μg/kg PTH-CBD either weekly (for 8 weeks) or monthly (for 6 months) to 7-week-old C57BL/6J mice resulted in a sustained increase in bone mineral density (BMD) (15% for weekly studies, 13% for monthly studies; P < 0.05). PTH-PKD-CBD showed only 5% increases in BMD after weekly administration, and, as expected, neither weekly nor monthly PTH(1-34) affected BMD. PTH-CBD increased serum alkaline phosphatase levels. Importantly, there were no significant increases in serum calcium observed. Collectively, the data suggest that PTH-CBD has a sustained anabolic effect in bone with either weekly or monthly administration. This approach of targeted delivery of PTH to bone may show promise for the treatment of disorders of low bone mass, such as postmenopausal osteoporosis.

Evaluation of bone remodelling parameters after one year treatment with alendronate in postmenopausal women with osteoporosis

Antiresorptive agents are widely used to treat osteoporosis. Both reduction in bone turnover and increase in BMD may be necessary to decrease the fracture risk. The aim of the study was to evaluate the effects of aledronate on bone turnover markers and bone mineral density in postmenopausal women with osteoporosis. The study involved a group of 56 postmenopausal women with osteoporosis treated with alendronate (70 mg) weekly at the Institute of Nuclear Medicine Clinical Center University of Sarajevo during a 12-months period. Bone mineral density (BMD) at lumbar spine and proximal femur and bone turnover markers (serum β-CrossLaps, urinary N-telopeptides of type I collagen (NTx), total serum alkaline phosphatase (AP) and serum osteocalcin) were measured at baseline and after 12 months of the treatment with aledronate. BMD values significantly increased both at lumbar spine by 13.46% and proximal femur by 21.96% during the study period (-3.12±0.24 vs. -2.7±0.19 and -2.55±0.2 vs. -1.99±0.19 respectively; p<0.001). Bone turnover markers significantly decreased during the study period; C-terminal telopeptides of type I collagen fragment (β-CrossLaps) 49.0% (0.51±0.05 vs.0.26±0.028 ng/mL), NTX 33.4% (48.3±4.9 vs.32.15±3.25 nMBCE/mM Cr), AP 24.3% (81.1±5.2 to 61.43±5.2 IU/L) and serum osteocalcin by 29.7% (34.3±2.65 to 24.1±1.36 ng/mL)(p<0.001). Alendronate treatment increased BMD and reduced the level of bone turnover markers. Therefore, the treatment with aledronate during 12 months period can be recommended in postmenopausal women with osteoporosis.

Risedronate improves proximal femur bone density and geometry in patients with osteoporosis or osteopenia and clinical risk factors of fractures: a practice-based observational study

The purpose of this practice-based observational study was to clarify the acute effect of risedronate on proximal femur bone mineral density (BMD) and structural geometry in patients with an increased risk of fractures. One hundred sixty-four patients (7 men and 157 postmenopausal women; mean age, 69.2 years) with osteoporosis or osteopenia and clinical risk factors of fractures were analyzed. All these patients were treated with risedronate for 1 year. Urinary levels of cross-linked N-terminal telopeptide of type I collagen (NTX) were measured at baseline and 4 months after the start of treatment. BMD of the lumbar spine and proximal femur and structural geometric parameters of the proximal femur were evaluated by dual-energy X-ray absorptiometry with advanced hip assessment (AHA) software at baseline and every 4 months. Urinary NTX levels significantly decreased after 4 months of treatment. BMD of the femoral neck and total hip significantly increased after 4, 8, and 12 months of treatment. Cross-sectional moment of inertia (CSMI) and cross-sectional area significantly increased after 4, 8, and 12 months of treatment. An increase in CSMI was apparently greater than those of proximal femur BMD after 4 months of treatment. These results suggest the acute (4 months) and sustained (12 months) effect of risedronate on proximal femur structural geometry as well as BMD as a result of suppression of bone resorption in patients with an increased risk of fractures.

One year of alendronate treatment lowers microstructural stresses associated with trabecular microdamage initiation

Alendronate, an anti-remodeling agent, is commonly used to treat patients suffering from osteoporosis by increasing bone mineral density. Though fracture risk is lowered, an increase in microdamage accumulation has been documented in patients receiving alendronate, leading to questions about the potentially detrimental effects of remodeling suppression on the local tissue (material) properties. In this study, trabecular bone cores from the distal femur of beagle dogs treated for one year with alendronate, at doses scaled by weight to approximate osteoporotic and Paget's disease treatment doses in humans, were subjected to uniaxial compression to induce microdamage. Tissue level von Mises stresses were computed for alendronate-treated and non-treated controls using finite element analysis and correlated to microdamage morphology. Using a modified version of the Moore and Gibson classification for damage morphology, we determined that the von Mises stress for trabeculae exhibiting severe and linear microcrack patterns was decreased by approximately 25% in samples treated with alendronate compared with non-treated controls (p<0.01), whereas there was no reduction in the von Mises stress state for diffuse microdamage formation. Furthermore, an examination of the architectural and structural characteristics of damaged trabeculae demonstrated that severely damaged trabeculae were thinner, more aligned with the loading axis, and less mineralized than undamaged trabeculae in alendronate-treated samples (p<0.01). Similar relationships with damage morphology were found only with trabecular orientation in vehicle-treated control dogs. These results indicate that changes in bone's architecture and matrix properties associated with one year of alendronate administration reduce trabecular bone's ability to resist the formation of loading-induced severe and linear microcracks, both of which dissipate less energy prior to fracture than does diffuse damage.

Effect of alendronate on bone mineral density and bone turnover markers in post-gastrectomy osteoporotic patients

Alendronate decreases the urinary levels of cross-linked N-terminal telopeptides of type I collagen (NTX; about 45% at 3 months) and serum levels of alkaline phosphatase (ALP; about 27% at 24 months), leading to an increase in lumbar spine bone mineral density (BMD; about 9% at 24 months) in postmenopausal Japanese women with osteoporosis. However, the effectiveness of oral bisphosphonates on osteoporosis remains to be established in patients who have undergone a gastrectomy. The objective of the present case series study was to examine the effect of alendronate on BMD and bone turnover markers in post-gastrectomy osteoporotic patients. Sixteen patients (3 men and 13 postmenopausal women) with osteoporosis, who had undergone a gastrectomy (mean age: 69.1 years), were recruited in our outpatient clinic. All the patients were treated with alendronate (5 mg daily or 35 mg weekly) for 24 months. The effects of alendronate on lumbar spine (women) or total hip (men) BMD and urinary NTX and serum ALP levels were examined. A total or partial gastrectomy had been performed for eight patients each. The mean duration after surgery was 16.0 years. With alendronate therapy, urinary NTX levels significantly decreased at 3 months (-27.0%). Serum ALP levels decreased (-12.1%) and lumbar spine BMD increased (+5.2%), but total hip BMD did not significantly change (+0.6%) at 24 months. No severe adverse events were observed, and alendronate therapy was well tolerated. These results suggest that alendronate mildly increases lumbar spine BMD by mildly reducing bone turnover in osteoporotic patients after a gastrectomy.

In vivo evaluation of the presence of bone marrow in cortical porosity in postmenopausal osteopenic women

This is the first observational study examining cortical porosity in vivo in postmenopausal osteopenic women and to incorporate data from two different imaging modalities to further examine the nature of cortical porosity. The goal of this study was to combine high-resolution peripheral computed tomography (HR-pQCT) images, which contain high spatial resolution information of the cortical structure, and magnetic resonance (MR) images, which allow the visualization of soft tissues such as bone marrow, to observe the amount of cortical porosity that contains bone marrow in postmenopausal osteopenic women. The radius of 49 and the tibia of 51 postmenopausal osteopenic women (age 56 ± 3.7) were scanned using both HR-pQCT and MR imaging. A normalized mutual information registration algorithm was used to obtain a three-dimensional rigid transform which aligned the MR image to the HR-pQCT image. The aligned images allowed for the visualization of bone marrow in cortical pores. From the HR-pQCT image, the percent cortical porosity, the number of cortical pores, and the size of each cortical pore was determined. By overlaying the aligned MR and HR-pQCT images, the percent of cortical pores containing marrow, the number of cortical pores containing marrow, and the size of each cortical pore containing marrow were measured. While the amount of cortical porosity did not vary greatly between subjects, the type of cortical pore, containing marrow vs. not containing marrow, varied highly between subjects. The results suggest that cortical pore spaces contain components of varying composition, and that there may be more than one mechanism for the development of cortical porosity.

Effects of short-term combined treatment with alendronate and elcatonin on bone mineral density and bone turnover in postmenopausal women with osteoporosis

The antiresorptive drug elcatonin (ECT) is known to relieve pain in postmenopausal women with osteoporosis. A prospective open-labeled trial was conducted to compare the effects of short-term combined treatment with alendronate (ALN) and ECT on bone mineral density (BMD) and bone turnover with those of single treatment with ALN in postmenopausal women with osteoporosis. Two hundred and five postmenopausal osteoporotic women (mean age: 70 years) were recruited in our outpatient clinic. Forty-six women with back pain were treated with ALN and ECT (intramuscular, 20 units a week), and 159 women without obvious back pain were treated with ALN alone. The lumbar BMD, urinary levels of cross-linked N-terminal telopeptides of type I collagen (NTX), and serum levels of alkaline phosphatase (ALP) were measured during the six-month treatment period. The baseline characteristics, except for age, body weight and number of patients with prevalent vertebral fractures, were not significantly different between the two groups. The mean increase rate in the lumbar BMD at six months was similar in the ALN (+4.41%) and ALN+ECT (+5.15%) groups, following similar reduction rates in urinary NTX levels (-40.2% and -43.0%, respectively, at three months) and serum ALP levels (-19.0% and -19.7%, respectively, at six months). These results were consistent even after adjustments for age, body weight, and number of patients with prevalent vertebral fractures. The present study in postmenopausal osteoporotic women confirmed that the effects of short-term combined treatment with ALN and ECT on lumbar BMD and bone turnover in patients with back pain appeared to be comparable to those of single treatment with ALN in patients without obvious back pain.