Strontium ranelate for preventing and treating postmenopausal osteoporosis

Surface Pre-Reacted Glass-Ionomer Eluate Suppresses Osteoclastogenesis through Downregulation of the MAPK Signaling Pathway

Surface pre-reacted glass-ionomer (S-PRG) is a new bioactive filler utilized for the restoration of decayed teeth by its ability to release six bioactive ions that prevent the adhesion of dental plaque to the tooth surface. Since ionic liquids are reported to facilitate transepithelial penetration, we reasoned that S-PRG applied to root caries could impact the osteoclasts (OCs) in the proximal alveolar bone. Therefore, this study aimed to investigate the effect of S-PRG eluate solution on RANKL-induced OC-genesis and mineral dissolution in vitro. Using RAW264.7 cells as OC precursor cells (OPCs), TRAP staining and pit formation assays were conducted to monitor OC-genesis and mineral dissolution, respectively, while OC-genesis-associated gene expression was measured using quantitative real-time PCR (qPCR). Expression of NFATc1, a master regulator of OC differentiation, and the phosphorylation of MAPK signaling molecules were measured using Western blotting. S-PRG eluate dilutions at 1/200 and 1/400 showed no cytotoxicity to RAW264.7 cells but did significantly suppress both OC-genesis and mineral dissolution. The same concentrations of S-PRG eluate downregulated the RANKL-mediated induction of OCSTAMP and CATK mRNAs, as well as the expression of NFATc1 protein and the phosphorylation of ERK, JNK, and p38. These results demonstrate that S-PRG eluate can downregulate RANKL-induced OC-genesis and mineral dissolution, suggesting that its application to root caries might prevent alveolar bone resorption.

Osteoporosis treatment: current drugs and future developments

Osteoporosis is a common systemic metabolic disease characterized by a decrease in bone density and bone mass, destruction of bone tissue microstructure, and increased bone fragility leading to fracture susceptibility. Pharmacological treatment of osteoporosis is the focus of current research, and anti-osteoporosis drugs usually play a role in inhibiting bone resorption, promoting bone formation, and having a dual role. However, most of the drugs have the disadvantages of single target and high toxic and side effects. There are many types of traditional Chinese medicines (TCM), from a wide range of sources and mostly plants. Herbal plants have unique advantages in regulating the relationship between osteoporosis and the immune system, acupuncture therapy has significant therapeutic effects in combination with medicine for osteoporosis. The target cells and specific molecular mechanisms of TCM in preventing and treating osteoporosis have not been fully elucidated. At present, there is a lack of comprehensive understanding of the pathological mechanism of the disease. Therefore, a better understanding of the pathological signaling pathways and key molecules involved in the pathogenesis of osteoporosis is crucial for the design of therapeutic targets and drug development. In this paper, we review the development and current status of anti-osteoporosis drugs currently in clinical application and under development to provide relevant basis and reference for drug prevention and treatment of osteoporosis, with the aim of promoting pharmacological research and new drug development.

The unexplored role of alkali and alkaline earth elements (ALAEs) on the structure, processing, and biological effects of bioactive glasses

Bioactive glass has been employed in several medical applications since its inception in 1969. The compositions of these materials have been investigated extensively with emphasis on glass network formers, therapeutic transition metals, and glass network modifiers. Through these experiments, several commercial and experimental compositions have been developed with varying chemical durability, induced physiological responses, and hydroxyapatite forming abilities. In many of these studies, the concentrations of each alkali and alkaline earth element have been altered to monitor changes in structure and biological response. This review aims to discuss the impact of each alkali and alkaline earth element on the structure, processing, and biological effects of bioactive glass. We explore critical questions regarding these elements from both a glass science and biological perspective. Should elements with little biological impact be included? Are alkali free bioactive glasses more promising for greater biological responses? Does this mixed alkali effect show increased degradation rates and should it be employed for optimized dissolution? Each of these questions along with others are evaluated comprehensively and discussed in the final section where guidance for compositional design is provided.

A Comparative Study on Physicochemical Properties and In Vitro Biocompatibility of Sr-Substituted and Sr Ranelate-Loaded Hydroxyapatite Nanoparticles

Synthetic hydroxyapatite nanoparticles (nHAp) possess compositional and structural similarities to those of bone minerals and play a key role in bone regenerative medicine. Functionalization of calcium phosphate biomaterials with Sr, i.e., bone extracellular matrix trace element, has been proven to be an effective biomaterial-based strategy for promoting osteogenesis in vitro and in vivo. Functionalizing nHAp with Sr2+ ions or strontium ranelate (SrRAN) can provide favorable bone tissue regeneration by locally delivering bioactive molecules to the bone defect microenvironment. Moreover, administering an antiosteoporotic drug, SrRAN, directly into site-specific bone defects could significantly reduce the necessary drug dosage and the risk of possible side effects. Our study evaluated the impact of the Sr source (Sr2+ ions and SrRAN) used to functionalize nHAp by wet precipitation on its in vitro cellular activities. The systematic comparison of physicochemical properties, in vitro Sr2+ and Ca2+ ion release, and their effect on in vitro cellular activities of the developed Sr-functionalized nHAp was performed. The ion release tests in TRIS-HCl demonstrated a 21-day slow and continuous release of the Sr2+ and Ca2+ ions from both Sr-substituted nHAp and SrRAN-loaded HAp. Also, SrRAN and Sr2+ ion release kinetics were evaluated in DMEM to understand their correlation with in vitro cellular effects in the same time frame. Relatively low concentration (up to 2 wt %) of Sr in the nHAp led to an increase in the alkaline phosphatase activity in preosteoblasts and expression of collagen I and osteocalcin in osteoblasts, demonstrating their ability to boost bone formation.

Bioactive Chitosan-Based Organometallic Scaffolds for Tissue Engineering and Regeneration

Captivating achievements in developing advanced hybrid biostructures through integrating natural biopolymers with inorganic materials (e.g., metals and metalloids) have paved the way towards the application of bioactive organometallic scaffolds (OMSs) in tissue engineering and regenerative medicine (TERM). Of various biopolymers, chitosan (CS) has been used widely for the development of bioactive OMSs, in large part due to its unique characteristics (e.g., biocompatibility, biodegradability, surface chemistry, and functionalization potential). In integration with inorganic elements, CS has been used to engineer advanced biomimetic matrices to accommodate both embedded cells and drug molecules and serve as scaffolds in TERM. The use of the CS-based OMSs is envisioned to provide a new pragmatic potential in TERM and even in precision medicine. In this review, we aim to elaborate on recent achievements in a variety of CS/metal, CS/metalloid hybrid scaffolds, and discuss their applications in TERM. We also provide comprehensive insights into the formulation, surface modification, characterization, biocompatibility, and cytotoxicity of different types of CS-based OMSs.

The Development of Molecular Biology of Osteoporosis

Osteoporosis is one of the major bone disorders that affects both women and men, and causes bone deterioration and bone strength. Bone remodeling maintains bone mass and mineral homeostasis through the balanced action of osteoblasts and osteoclasts, which are responsible for bone formation and bone resorption, respectively. The imbalance in bone remodeling is known to be the main cause of osteoporosis. The imbalance can be the result of the action of various molecules produced by one bone cell that acts on other bone cells and influence cell activity. The understanding of the effect of these molecules on bone can help identify new targets and therapeutics to prevent and treat bone disorders. In this article, we have focused on molecules that are produced by osteoblasts, osteocytes, and osteoclasts and their mechanism of action on these cells. We have also summarized the different pharmacological osteoporosis treatments that target different molecular aspects of these bone cells to minimize osteoporosis.

Antimicrobial Properties of Strontium Functionalized Titanium Surfaces for Oral Applications, A Systematic Review

The aim of this systematic review was to assess the current scientific evidence of the antimicrobial potential of strontium (Sr) when used to functionalize titanium (Ti) for oral applications. Out of an initial list of 1081 potentially relevant publications identified in three electronic databases (MEDLINE via PubMed, Scopus, and Cochrane) up to 1 February 2021, nine publications based on in vitro studies met the inclusion criteria. The antimicrobial potential of Sr was investigated on different types of functionalized Ti substrates, employing different application methods. Nine studies reported on the early, i.e., 6–24 h, and two studies on the late, i.e., 7–28 days, antimicrobial effect of Sr, primarily against Staphylococcus aureus (S. aureus) and/or Escherichia coli (E. coli). Sr-modified samples demonstrated relevant early antimicrobial potential against S. aureus in three studies; only one of which presented statistical significance values, while the other two presented only the percentage of antimicrobial rate and biofilm inhibition. A relevant late biofilm inhibition potential against S. aureus of 40% and 10%—after 7 and 14 days, respectively—was reported in one study. Combining Sr with other metal ions, i.e., silver (Ag), zinc (Zn), and fluorine (F), demonstrated a significant antimicrobial effect and biofilm inhibition against both S. aureus and E. coli. Sr ion release within the first 24 h was generally low, i.e., below 50 µg/L and 0.6 ppm; however, sustained Sr ion release for up to 30 days, while maintaining up to 90% of its original content, was also demonstrated. Thus, in most studies included herein, Sr-functionalized Ti showed a limited immediate (i.e., 24 h) antimicrobial effect, likely due to a low Sr ion release; however, with an adequate Sr ion release, a relevant antimicrobial effect, as well as a biofilm inhibition potential against S. aureus—but not E. coli—was observed at both early and late timepoints. Future studies should assess the antimicrobial potential of Ti functionalized with Sr against multispecies biofilms associated with peri-implantitis.

Effects of strontium ions with potential antibacterial activity on in vivo bone regeneration

Bioactive glasses (BGs) have attracted added attention in the structure of the scaffolds for bone repair applications. Different metal ions could be doped in BGs to induce specific biological responses. Among these ions, strontium (Sr) is considered as an effective and safe doping element with promising effects on bone formation and regeneration. In this experiment, we evaluated the antibacterial activities of the gelatin-BG (Gel-BG) and Gel-BG/Sr scaffolds in vitro. The osteogenic properties of the prepared scaffolds were also assessed in rabbit calvarial bone defects for 12 weeks. Both scaffolds showed in vivo bone formation during 12 weeks with the newly formed bone area in Gel-BG/Sr scaffold was higher than that in Gel-BG scaffolds after the whole period. Based on the histological results, Gel-BG/Sr exhibited acceleration of early-stage bone formation in vivo. The results of antibacterial investigation for both scaffolds showed complete growth inhibition against Escherichia coli (E. coli). Although Gel-BG revealed no antibacterial effect on Staphylococcus aureus (S. aureus), the Gel-BG/Sr was able to partially inhibit the growth of S. aureus, as detected by threefold reduction in growth index. Our results confirmed that Sr doped BG is a favorable candidate for bone tissue engineering with superior antibacterial activity and bone regeneration capacity compared with similar counterparts having no Sr ion.

Osseointegration effects of local release of strontium ranelate from implant surfaces in rats

BACKGROUND

Numerous studies have reported the beneficial effects of strontium on bone growth, particularly by stimulating osteoblast proliferation and differentiation. Thus, strontium release around implants has been suggested as one possible strategy to enhance implant osseointegration.

AIM

This study aimed to evaluate whether the local release of strontium ranelate (Sr-ranelate) from implants coated with mesoporous titania could improve bone formation around implants in an animal model.

MATERIALS AND METHODS

Mesoporous titania (MT) thin coatings were formed utilizing the evaporation induced self-assembly (EISA) method using Pluronic (P123) with or without the addition of poly propylene glycol (PPG) to create materials with two different pore sizes. The MT was deposited on disks and mini-screws, both made of cp Ti grade IV. Scanning electron microscopy (SEM) was performed to characterize the MT using a Leo Ultra55 FEG instrument (Zeiss, Oberkochen, Germany). The MT was loaded with Sr-ranelate using soaking and the drug uptake and release kinetics to and from the surfaces were evaluated using quartz crystal microbalance with dissipation monitoring (QCM-D) utilizing a Q-sense E4 instrument. For the in vivo experiment, 24 adult rats were analyzed at two time points of implant healing (2 and 6 weeks). Titanium implants shaped as mini screws were coated with MT films and divided into two groups; supplied with Sr-ranelate (test group) and without Sr-ranelate (control group). Four implants (both test and control) were inserted in the tibia of each rat. The in vivo study was evaluated using histomorphometric analyses of the implant/bone interphase using optical microscopy.

RESULTS

SEM images showed the successful formation of evenly distributed MT films covering the entire surface with pore sizes of 6 and 7.2 nm, respectively. The QCM-D analysis revealed an absorption of 3300 ng/cm² of Sr-ranelate on the 7.2 nm MT, which was about 3 times more than the observed amount on the 6 nm MT (1200 ng/cm²). Both groups showed sustained release of Sr-ranelate from MT coated disks. The histomorphometric analysis revealed no significant differences in bone implant contact (BIC) and bone area (BA) between the implants with Sr-ranelate and implants in the control groups after 2 and 6 weeks of healing (BIC with a p-value of 0.43 after 2 weeks and 0.172 after 6 weeks; BA with a p-value of 0.503 after 2 weeks, and 0.088 after 6 weeks). The mean BIC and BA values within the same group showed significant increase among all groups between 2 and 6 weeks.

CONCLUSION

This study could not confirm any positive effects of Sr-ranelate on implant osseointegration.

Pharmacological Therapy of Osteoporosis: A Systematic Current Review of Literature

Osteoporosis is the most common bone disease affecting millions of people worldwide, particularly in elderly or in post-menopausal women. The pathogenesis is useful to understand the possible mechanism of action of anti-osteoporotic drugs. Early diagnosis, possible with several laboratory and instrumental tests, allows a major accuracy in the choice of anti-osteoporosis drugs. Treatment of osteoporosis is strictly related to severity of pathology and consists on prevention of fragility fractures with a correct lifestyle and adequate nutritional supplements, and use of pharmacological therapy, started in patients with osteopenia and history of fragility fracture of the hip or spine. The purpose of this review is to focus on main current pharmacological products to treat osteoporotic patients.

New horizons in treatment of osteoporosis

BACKGROUND

Prevalence of osteoporosis is increasing both in developed and developing countries. Due to rapid growth in the burden and cost of osteoporosis, worldwide, it seems reasonable to focus on the reduction of fractures as the main goal of treatment. Although, efficient pharmacological agents are available for the treatment of osteoporosis, there still remains a need to more specific drugs with less adverse effects.

MAIN BODY

This review article provides a brief update on the pathogenesis, presenting current pharmacological products approved by the US Food and Drug Administration (FDA) or Europe, and also newer therapeutic agents to treat osteoporosis according to the clinical trial data available at PubMed, UpToDate, International Osteoporosis Foundation (IOF), and clinical practice guidelines. As well, the effect of combination therapy and recommendations for future research will be further discussed.

SHORT CONCLUSION

The use of current antiresorptive and anabolic agents alone or in combinations for the treatment of osteoporosis entails several limitations. Mainly, their efficacy on non-vertebral fracture reduction is lower than that observed on vertebral fracture. In addition, they have potential adverse events on long time usage. Development of newer agents such as cathepsin k inhibitor and strontium ranelate not only have increased the available options for treating osteoporosis, but also have opened doors of opportunity to improvements in the effective treatment. However, the high cost of new agents have restricted their usage in selective patients who are at high risk of fracture or whom failed response to first line treatment options. Thus, personalized medicine should be considered for future evaluation of genetic risk score and also for environmental exposure assessment. In addition to permanent attention to early diagnosis of osteoporosis and understanding of the pathophysiology of osteoporosis for novel approach in drug discovery, there seems a need to more well-designed clinical trials with larger sample sizes and longer duration on current as well as on newer agents. Also, continuous research on plant-derived components as the source of discovering new agents, and conducting more clinical trials with combination of two or more synthetic drugs, plants, or drug-plant for the treatment of osteoporosis are recommended. Summary of treatment modalities for osteoporosis.

Optimizing literature search in systematic reviews - are MEDLINE, EMBASE and CENTRAL enough for identifying effect studies within the area of musculoskeletal disorders?

BACKGROUND

When conducting systematic reviews, it is essential to perform a comprehensive literature search to identify all published studies relevant to the specific research question. The Cochrane Collaborations Methodological Expectations of Cochrane Intervention Reviews (MECIR) guidelines state that searching MEDLINE, EMBASE and CENTRAL should be considered mandatory. The aim of this study was to evaluate the MECIR recommendations to use MEDLINE, EMBASE and CENTRAL combined, and examine the yield of using these to find randomized controlled trials (RCTs) within the area of musculoskeletal disorders.

METHODS

Data sources were systematic reviews published by the Cochrane Musculoskeletal Review Group, including at least five RCTs, reporting a search history, searching MEDLINE, EMBASE, CENTRAL, and adding reference- and hand-searching. Additional databases were deemed eligible if they indexed RCTs, were in English and used in more than three of the systematic reviews. Relative recall was calculated as the number of studies identified by the literature search divided by the number of eligible studies i.e. included studies in the individual systematic reviews. Finally, cumulative median recall was calculated for MEDLINE, EMBASE and CENTRAL combined followed by the databases yielding additional studies.

RESULTS

Deemed eligible was twenty-three systematic reviews and the databases included other than MEDLINE, EMBASE and CENTRAL was AMED, CINAHL, HealthSTAR, MANTIS, OT-Seeker, PEDro, PsychINFO, SCOPUS, SportDISCUS and Web of Science. Cumulative median recall for combined searching in MEDLINE, EMBASE and CENTRAL was 88.9% and increased to 90.9% when adding 10 additional databases.

CONCLUSION

Searching MEDLINE, EMBASE and CENTRAL was not sufficient for identifying all effect studies on musculoskeletal disorders, but additional ten databases did only increase the median recall by 2%. It is possible that searching databases is not sufficient to identify all relevant references, and that reviewers must rely upon additional sources in their literature search. However further research is needed.

The future of osteoarthritis therapeutics: targeted pharmacological therapy

Osteoarthritis (OA) is one of the most common forms of degenerative joint disease and a major cause of pain and disability affecting the aging population. It is estimated that more than 20 million Americans and 35 to 40 million Europeans suffer from OA. Analgesics and non-steroidal anti-inflammatory drugs (NSAIDs) are the only therapeutic treatment options for OA. Effective pharmacotherapy for OA, capable of restoring the original structure and function of damaged cartilage and other synovial tissue, is urgently needed, and research into such disease-modifying osteoarthritis drugs (DMOADs) is in progress. This is the first of three reviews focusing on OA therapeutics. This paper provides an overview of current research into potential structure-modifying drugs and more appropriately targeted pharmacological therapy. The challenges and opportunities in this area of research and development are reviewed, covering the most up-to-date initiatives, trends, and topics.

Digital X-ray radiogrammetry of hand or wrist radiographs can predict hip fracture risk--a study in 5,420 women and 2,837 men

OBJECTIVES

To assess whether digital X-ray radiogrammetry (DXR) analysis of standard clinical hand or wrist radiographs obtained at emergency hospitals can predict hip fracture risk.

METHODS

A total of 45,538 radiographs depicting the left hand were gathered from three emergency hospitals in Stockholm, Sweden. Radiographs with insufficiently included metacarpal bone, fractures in measurement regions, foreign material or unacceptable positioning were manually excluded. A total of 18,824 radiographs from 15,072 patients were analysed with DXR, yielding a calculated BMD equivalent (DXR-BMD). Patients were matched with the national death and inpatient registers. Inclusion criteria were age ≥ 40 years, no prior hip fracture and observation time > 7 days. Hip fractures were identified via ICD-10 codes. Age-adjusted hazard ratio per standard deviation (HR/SD) was calculated using Cox regression.

RESULTS

8,257 patients (65.6 % female, 34.4 % male) met the inclusion criteria. One hundred twenty-two patients suffered a hip fracture after their radiograph. The fracture group had a significantly lower DXR-BMD than the non-fracture group when adjusted for age. The HR/SD for hip fracture was 2.52 and 2.08 in women and men respectively. The area under the curve was 0.89 in women and 0.84 in men.

CONCLUSIONS

DXR analysis of wrist and hand radiographs obtained at emergency hospitals predicts hip fracture risk in women and men.

KEY POINTS

• Digital X-ray radiogrammetry of emergency hand/wrist radiographs predicts hip fracture risk. • Digital X-ray radiogrammetry (DXR) predicts hip fracture risk in both women and men. • Osteoporosis can potentially be identified in patients with suspected wrist fractures. • DXR can potentially be used for selective osteoporosis screening.

Models of care for the secondary prevention of osteoporotic fractures: a systematic review and meta-analysis

Most people presenting with incident osteoporotic fractures are neither assessed nor treated for osteoporosis to reduce their risk of further fractures, despite the availability of effective treatments. We evaluated the effectiveness of published models of care for the secondary prevention of osteoporotic fractures. We searched eight medical literature databases to identify reports published between 1996 and 2011, describing models of care for secondary fracture prevention. Information extracted from each publication included study design, patient characteristics, identification strategies, assessment and treatment initiation strategies, as well as outcome measures (rates of bone mineral density (BMD) testing, osteoporosis treatment initiation, adherence, re-fractures and cost-effectiveness). Meta-analyses of studies with valid control groups were conducted for two outcome measures: BMD testing and osteoporosis treatment initiation. Out of 574 references, 42 articles were identified as analysable. These studies were grouped into four general models of care-type A: identification, assessment and treatment of patients as part of the service; type B: similar to A, without treatment initiation; type C: alerting patients plus primary care physicians; and type D: patient education only. Meta-regressions revealed a trend towards increased BMD testing (p = 0.06) and treatment initiation (p = 0.03) with increasing intensity of intervention. One type A service with a valid control group showed a significant decrease in re-fractures. Types A and B services were cost-effective, although definition of cost-effectiveness varied between studies. Fully coordinated, intensive models of care for secondary fracture prevention are more effective in improving patient outcomes than approaches involving alerts and/or education only.

Influence of strontium for calcium substitution in bioactive glasses on degradation, ion release and apatite formation

Bioactive glasses are able to bond to bone through the formation of hydroxy-carbonate apatite in body fluids while strontium (Sr)-releasing bioactive glasses are of interest for patients suffering from osteoporosis, as Sr was shown to increase bone formation both in vitro and in vivo. A melt-derived glass series (SiO(2)-P(2)O(5)-CaO-Na(2)O) with 0-100% of calcium (Ca) replaced by Sr on a molar base was prepared. pH change, ion release and apatite formation during immersion of glass powder in simulated body fluid and Tris buffer at 37°C over up to 8 h were investigated and showed that substituting Sr for Ca increased glass dissolution and ion release, an effect owing to an expansion of the glass network caused by the larger ionic radius of Sr ions compared with Ca. Sr release increased linearly with Sr substitution, and apatite formation was enhanced significantly in the fully Sr-substituted glass, which allowed for enhanced osteoblast attachment as well as proliferation and control of osteoblast and osteoclast activity as shown previously. Studying the composition-structure-property relationship in bioactive glasses enables us to successfully design next-generation biomaterials that combine the bone regenerative properties of bioactive glasses with the release of therapeutically active Sr ions.

The impact of pharmacist interventions on osteoporosis management: a systematic review

We completed a systematic review of the literature to examine the impact of pharmacist interventions in improving osteoporosis management. Results from randomized controlled trials suggest that pharmacist interventions may improve bone mineral density testing and calcium intake among patients at high risk for osteoporosis.

INTRODUCTION

Pharmacists play a key role in many healthcare systems by helping patients manage chronic diseases. We completed a systematic review of the literature to identify randomized controlled trials (RCTs) that have examined the impact of pharmacy interventions in narrowing two gaps in osteoporosis management: identifying at-risk individuals and improving adherence to therapy.

METHODS

We searched the electronic databases of EMBASE, HealthStar, International Pharmaceutical Abstracts, MEDLINE, and PubMed from database development to April 2010, examined grey literature, and completed manual searches of reference lists to identify English-language research that examined osteoporosis management interventions within pharmacy practice. Results from RCTs were abstracted and assessed for bias.

RESULTS

We identified 25 studies that examined pharmacist interventions in osteoporosis management: 16 cohort, 5 cross-sectional, 1 historical/ecological control, and 3 RCTs. RCT interventions included osteoporosis educational and counseling programs, screening by pharmacists based on risk factor assessment or bone mineral density testing, and physician contact or recommendations for patients to follow-up with a general practitioner. Results from the three RCTs suggest that pharmacist interventions may improve bone mineral density testing (targeted screening) and calcium intake among patients at high risk for osteoporosis. However, two of the three RCTs had high risk of bias, and no study examined the impact of pharmacist intervention on osteoporosis treatment adherence.

CONCLUSIONS

Data support the potential role for pharmacists to help reduce gaps in osteoporosis management through improved identification of high-risk patients. More research is needed to examine pharmacist interventions on osteoporosis treatment adherence.

Exercise for preventing and treating osteoporosis in postmenopausal women

BACKGROUND

Osteoporosis is a condition resulting in an increased risk of skeletal fractures due to a reduction in the density of bone tissue. Treatment of osteoporosis typically involves the use of pharmacological agents. In general it is thought that disuse (prolonged periods of inactivity) and unloading of the skeleton promotes reduced bone mass, whereas mechanical loading through exercise increases bone mass.

OBJECTIVES

To examine the effectiveness of exercise interventions in preventing bone loss and fractures in postmenopausal women.

SEARCH STRATEGY

During the update of this review we updated the original search strategy by searching up to December 2010 the following electronic databases: the Cochrane Musculoskeletal Group's Trials Register; the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2010 Issue 12); MEDLINE; EMBASE; HealthSTAR; Sports Discus; CINAHL; PEDro; Web of Science; Controlled Clinical Trials; and AMED. We attempted to identify other studies by contacting experts, searching reference lists and searching trial registers.

SELECTION CRITERIA

All randomised controlled trials (RCTs) that met our predetermined inclusion criteria.

DATA COLLECTION AND ANALYSIS

Pairs of members of the review team extracted the data and assessed trial quality using predetermined forms. For dichotomous outcomes (fractures), we calculated risk ratios (RRs) using a fixed-effect model. For continuous data, we calculated mean differences (MDs) of the percentage change from baseline. Where heterogeneity existed (determined by the I(2) statistic), we used a random-effects model.

MAIN RESULTS

Forty-three RCTs (27 new in this update) with 4320 participants met the inclusion criteria. The most effective type of exercise intervention on bone mineral density (BMD) for the neck of femur appears to be non-weight bearing high force exercise such as progressive resistance strength training for the lower limbs (MD 1.03; 95% confidence interval (CI) 0.24 to 1.82). The most effective intervention for BMD at the spine was combination exercise programmes (MD 3.22; 95% CI 1.80 to 4.64) compared with control groups. Fractures and falls were reported as adverse events in some studies. There was no effect on numbers of fractures (odds ratio (OR) 0.61; 95% CI 0.23 to 1.64). Overall, the quality of the reporting of studies in the meta-analyses was low, in particular in the areas of sequence generation, allocation concealment, blinding and loss to follow-up.

AUTHORS' CONCLUSIONS

Our results suggest a relatively small statistically significant, but possibly important, effect of exercise on bone density compared with control groups. Exercise has the potential to be a safe and effective way to avert bone loss in postmenopausal women.

Impact of treatments for postmenopausal osteoporosis (bisphosphonates, parathyroid hormone, strontium ranelate, and denosumab) on bone quality: a systematic review

The objective of this systematic review was to examine the influence of treatments for postmenopausal osteoporosis (parathyroid hormone [PTH], bisphosphonates, strontium ranelate, and denosumab) on bone quality and discuss the clinical implications. Most bone-quality data for PTH is from teriparatide. Teriparatide results in a rapid increase in bone-formation markers, followed by increases in bone-resorption markers, opening an "anabolic window," a period of time when PTH is maximally anabolic. Teriparatide reverses the structural damage seen in osteoporosis and restores the structure of trabecular bone. It has a positive effect on cortical bone, and any early increases in cortical porosity appear to be offset by increases in cortical thickness and diameter. Bisphosphonates are antiresorptive agents which reduce bone turnover, improve trabecular microarchitecture, and mineralization. Concerns have been raised that the prolonged antiresorptive action of bisphosphonates may lead to failure to repair microdamage, resulting in microcracks and atypical fragility. Strontium ranelate is thought to have a mixed mode of action, increasing bone formation and decreasing bone resorption. Strontium ranelate improves cortical thickness, trabecular number, and connectivity, with no change in cortical porosity. Denosumab exerts rapid, marked, and sustained effects on bone resorption, resulting in falls in the markers of bone turnover. Evidence from bone-quality studies suggests that treatment-naive women, aged 60-65 years, with very low BMD T scores may benefit from PTH as primary therapy to improve bone substrate and build bone. Post-PTH treatment with bisphosphonates will maintain improvements in bone quality and reduce the risk of fracture.

Current, new and future treatments of osteoporosis

Osteoporosis as a common chronic disease is challenging human health. Although different therapeutic options are routinely used for prevention/treatment of osteoporosis, their side effects and benefits are under question. Increasing our knowledge about signaling pathways in bone and osteocytes as well as osteoblasts and osteoclasts will help us in designing new therapeutic modalities for osteoporosis. In the present study, all new therapeutic measures of osteoporosis have been reviewed. For this purpose, search engines like Pubmed, Web of Science, Scopus, Google Scholar were searched and all relevant articles were found. The study was limited to the year 1998-2010. Bisphosphonates are the cornerstone of osteoporosis treatment, but there are not enough relevant studies that investigated their equivalencies in comparison with each other or the other medications. Therefore, medication selection is empirical and subjective. Furthermore, no eminent study has compared certain combinations. There are new hopes for treatment of osteoporosis, which are more specific with less harm. Our results show that new and emerging therapies are more potent and target specified which more individualize osteoporosis treatment; however, more investigations on their safety and efficacy in comparison with current medications are highly recommended.

Prevalent and Emerging Therapies for Osteoporosis

Osteoporosis and fractures associated with it constitute a real and serious socio-medical problem, which only recently has come to the forefront of social consciousness. With increasing number of exservicemen and their dependents, osteoporosis management has become very important in our setup. Currently available pharmacological therapies for prevention of fragility fractures are limited in scope, efficacy and acceptability to patients. Oral bisphosphonates are the standard treatment for osteoporosis which are associated with significant gastrointestinal side effects and thus poor patient compliance. Newer regimens, including intravenous (IV) formulations of bisphosphonates, have successfully come in vogue with greater patient compliance and equal or better benefits. The real need in osteoporosis treatment is for additional anabolic drugs. The only currently approved anabolic agent for treating osteoporosis is teriparatide (recombinant human parathyroid hormone 1-34), which stimulates new bone formation. Considerable efforts are being made to develop new, more effective treatment for osteoporosis. These novel drugs under trial include those primarily inhibiting osteoclastic bone resorption (like bisphosphonates) such as inhibitors of receptor activator of nuclear factor-kappa B ligand (RANKL) signalling, cathepsin K inhibitors, c-Src kinase inhibitors, integrin inhibitors, chloride channel inhibitors and the drugs with osteo-anabolic actions such as orally active parathyroid hormone (PTH) analogues, calcium sensing receptor antagonists, PTH-related peptide analogues and agents that induce osteoblast anabolism via pathways involving key, recently identified, molecular targets (wnt low-density lipoprotein receptor-related protein-5 signalling; sclerostin antibodies).

Clinical challenges in the management of osteoporosis

While knowledge regarding the diagnosis and treatment of osteoporosis has expanded dramatically over the last few years, gaps in knowledge still exist with guidance lacking on the appropriate management of several common clinical scenarios. This article uses fictional clinical scenarios to help answer three challenging questions commonly encountered in clinical practice. The first clinical challenge is when to initiate drug therapy in a patient with low bone density. It is estimated that 34 million America have low bone density and are at a higher risk for low trauma fractures. Limitations of using bone mineral density alone for drug therapy decisions, absolute risk assessment and evidence for the cost-effectiveness of therapy in this population are presented. The second clinical challenge is the prevention and treatment of vitamin D deficiency. Appropriate definitions for vitamin D insufficiency and deficiency, the populations at risk for low vitamin, potential consequences of low vitamin D, and how to manage a patient with low vitamin D are reviewed. The third clinical challenge is how to manage a patient receiving drug therapy for osteoporosis who has been deemed a potential treatment failure. How to define treatment failure, common causes of treatment failure, and the approach to the management of a patient who is not responding to appropriate osteoporosis therapy are discussed.