Alendronate treatment of the postmenopausal osteoporotic woman: effect of multiple dosages on bone mass and bone remodeling

Association of lymphocyte subsets and cytokines with bone metabolism: a retrospective, cross-sectional study

BACKGROUND

Previous research has shown that lymphocytes and cytokines can mediate bone metabolism. This study explored the clinical association and predictive ability of lymphocytes and cytokines levels for bone metabolism.

METHODS

A total of 162 patients were enrolled in this study. The levels of N-terminal propeptide of type I procollagen (P1NP), β-collagen degradation product (β-CTX), total T lymphocytes, immature T lymphocytes, suppressor/cytotoxic T lymphocytes, helper/inducer T lymphocytes, B lymphocytes, natural killer (NK) cells, Interferon-gamma (IFN-γ), tumour necrosis factor-alpha (TNF-α), IFN-α, interleukin-1 beta (IL-1β), IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, and IL12p70 were evaluated. The relationship between these lymphocyte subsets and cytokines with bone metabolic status was examined and their predictive ability for bone metabolic status was assessed.

RESULTS

The principal component analysis (PCA) and correlation analysis results varied on differences in lymphocyte subsets and cytokines in various bone metabolism states. Differential analysis revealed significant differences in the absolute counts of B lymphocytes (P < 0.05), level of IL-12p70 (P < 0.05), and IL-8 (P < 0.001) at different P1NP levels. Significant differences were observed in the absolute counts of total T lymphocytes (P < 0.05), B lymphocytes (P < 0.05), the level of IL-6 (P < 0.05), the percentage of B lymphocytes (P < 0.01), and NK cells (P < 0.05) at different β-CTX levels. Furthermore, the receiver operating characteristic (ROC) curve showed that the absolute count of B lymphocytes and levels of IL-12p70 and IL-8 could be used to evaluate bone formation states, while the absolute counts of T and B lymphocytes, level of IL-6, and percentages of NK cells and B lymphocytes could be used to evaluate bone resorption states.

CONCLUSION

The bone metabolism status changed based on the lymphocyte subsets and cytokine levels. Differentially expressed lymphocytes and cytokines could be used to distinguish bone metabolism status.

Screening for the primary prevention of fragility fractures among adults aged 40 years and older in primary care: systematic reviews of the effects and acceptability of screening and treatment, and the accuracy of risk prediction tools

BACKGROUND

To inform recommendations by the Canadian Task Force on Preventive Health Care, we reviewed evidence on the benefits, harms, and acceptability of screening and treatment, and on the accuracy of risk prediction tools for the primary prevention of fragility fractures among adults aged 40 years and older in primary care.

METHODS

For screening effectiveness, accuracy of risk prediction tools, and treatment benefits, our search methods involved integrating studies published up to 2016 from an existing systematic review. Then, to locate more recent studies and any evidence relating to acceptability and treatment harms, we searched online databases (2016 to April 4, 2022 [screening] or to June 1, 2021 [predictive accuracy]; 1995 to June 1, 2021, for acceptability; 2016 to March 2, 2020, for treatment benefits; 2015 to June 24, 2020, for treatment harms), trial registries and gray literature, and hand-searched reviews, guidelines, and the included studies. Two reviewers selected studies, extracted results, and appraised risk of bias, with disagreements resolved by consensus or a third reviewer. The overview of reviews on treatment harms relied on one reviewer, with verification of data by another reviewer to correct errors and omissions. When appropriate, study results were pooled using random effects meta-analysis; otherwise, findings were described narratively. Evidence certainty was rated according to the GRADE approach.

RESULTS

We included 4 randomized controlled trials (RCTs) and 1 controlled clinical trial (CCT) for the benefits and harms of screening, 1 RCT for comparative benefits and harms of different screening strategies, 32 validation cohort studies for the calibration of risk prediction tools (26 of these reporting on the Fracture Risk Assessment Tool without [i.e., clinical FRAX], or with the inclusion of bone mineral density (BMD) results [i.e., FRAX + BMD]), 27 RCTs for the benefits of treatment, 10 systematic reviews for the harms of treatment, and 12 studies for the acceptability of screening or initiating treatment. In females aged 65 years and older who are willing to independently complete a mailed fracture risk questionnaire (referred to as "selected population"), 2-step screening using a risk assessment tool with or without measurement of BMD probably (moderate certainty) reduces the risk of hip fractures (3 RCTs and 1 CCT, n = 43,736, absolute risk reduction [ARD] = 6.2 fewer in 1000, 95% CI 9.0-2.8 fewer, number needed to screen [NNS] = 161) and clinical fragility fractures (3 RCTs, n = 42,009, ARD = 5.9 fewer in 1000, 95% CI 10.9-0.8 fewer, NNS = 169). It probably does not reduce all-cause mortality (2 RCTs and 1 CCT, n = 26,511, ARD = no difference in 1000, 95% CI 7.1 fewer to 5.3 more) and may (low certainty) not affect health-related quality of life. Benefits for fracture outcomes were not replicated in an offer-to-screen population where the rate of response to mailed screening questionnaires was low. For females aged 68-80 years, population screening may not reduce the risk of hip fractures (1 RCT, n = 34,229, ARD = 0.3 fewer in 1000, 95% CI 4.2 fewer to 3.9 more) or clinical fragility fractures (1 RCT, n = 34,229, ARD = 1.0 fewer in 1000, 95% CI 8.0 fewer to 6.0 more) over 5 years of follow-up. The evidence for serious adverse events among all patients and for all outcomes among males and younger females (<65 years) is very uncertain. We defined overdiagnosis as the identification of high risk in individuals who, if not screened, would never have known that they were at risk and would never have experienced a fragility fracture. This was not directly reported in any of the trials. Estimates using data available in the trials suggest that among "selected" females offered screening, 12% of those meeting age-specific treatment thresholds based on clinical FRAX 10-year hip fracture risk, and 19% of those meeting thresholds based on clinical FRAX 10-year major osteoporotic fracture risk, may be overdiagnosed as being at high risk of fracture. Of those identified as being at high clinical FRAX 10-year hip fracture risk and who were referred for BMD assessment, 24% may be overdiagnosed. One RCT (n = 9268) provided evidence comparing 1-step to 2-step screening among postmenopausal females, but the evidence from this trial was very uncertain. For the calibration of risk prediction tools, evidence from three Canadian studies (n = 67,611) without serious risk of bias concerns indicates that clinical FRAX-Canada may be well calibrated for the 10-year prediction of hip fractures (observed-to-expected fracture ratio [O:E] = 1.13, 95% CI 0.74-1.72, I² = 89.2%), and is probably well calibrated for the 10-year prediction of clinical fragility fractures (O:E = 1.10, 95% CI 1.01-1.20, I² = 50.4%), both leading to some underestimation of the observed risk. Data from these same studies (n = 61,156) showed that FRAX-Canada with BMD may perform poorly to estimate 10-year hip fracture risk (O:E = 1.31, 95% CI 0.91-2.13, I² = 92.7%), but is probably well calibrated for the 10-year prediction of clinical fragility fractures, with some underestimation of the observed risk (O:E 1.16, 95% CI 1.12-1.20, I² = 0%). The Canadian Association of Radiologists and Osteoporosis Canada Risk Assessment (CAROC) tool may be well calibrated to predict a category of risk for 10-year clinical fractures (low, moderate, or high risk; 1 study, n = 34,060). The evidence for most other tools was limited, or in the case of FRAX tools calibrated for countries other than Canada, very uncertain due to serious risk of bias concerns and large inconsistency in findings across studies. Postmenopausal females in a primary prevention population defined as <50% prevalence of prior fragility fracture (median 16.9%, range 0 to 48% when reported in the trials) and at risk of fragility fracture, treatment with bisphosphonates as a class (median 2 years, range 1-6 years) probably reduces the risk of clinical fragility fractures (19 RCTs, n = 22,482, ARD = 11.1 fewer in 1000, 95% CI 15.0-6.6 fewer, [number needed to treat for an additional beneficial outcome] NNT = 90), and may reduce the risk of hip fractures (14 RCTs, n = 21,038, ARD = 2.9 fewer in 1000, 95% CI 4.6-0.9 fewer, NNT = 345) and clinical vertebral fractures (11 RCTs, n = 8921, ARD = 10.0 fewer in 1000, 95% CI 14.0-3.9 fewer, NNT = 100); it may not reduce all-cause mortality. There is low certainty evidence of little-to-no reduction in hip fractures with any individual bisphosphonate, but all provided evidence of decreased risk of clinical fragility fractures (moderate certainty for alendronate [NNT=68] and zoledronic acid [NNT=50], low certainty for risedronate [NNT=128]) among postmenopausal females. Evidence for an impact on risk of clinical vertebral fractures is very uncertain for alendronate and risedronate; zoledronic acid may reduce the risk of this outcome (4 RCTs, n = 2367, ARD = 18.7 fewer in 1000, 95% CI 25.6-6.6 fewer, NNT = 54) for postmenopausal females. Denosumab probably reduces the risk of clinical fragility fractures (6 RCTs, n = 9473, ARD = 9.1 fewer in 1000, 95% CI 12.1-5.6 fewer, NNT = 110) and clinical vertebral fractures (4 RCTs, n = 8639, ARD = 16.0 fewer in 1000, 95% CI 18.6-12.1 fewer, NNT=62), but may make little-to-no difference in the risk of hip fractures among postmenopausal females. Denosumab probably makes little-to-no difference in the risk of all-cause mortality or health-related quality of life among postmenopausal females. Evidence in males is limited to two trials (1 zoledronic acid, 1 denosumab); in this population, zoledronic acid may make little-to-no difference in the risk of hip or clinical fragility fractures, and evidence for all-cause mortality is very uncertain. The evidence for treatment with denosumab in males is very uncertain for all fracture outcomes (hip, clinical fragility, clinical vertebral) and all-cause mortality. There is moderate certainty evidence that treatment causes a small number of patients to experience a non-serious adverse event, notably non-serious gastrointestinal events (e.g., abdominal pain, reflux) with alendronate (50 RCTs, n = 22,549, ARD = 16.3 more in 1000, 95% CI 2.4-31.3 more, [number needed to treat for an additional harmful outcome] NNH = 61) but not with risedronate; influenza-like symptoms with zoledronic acid (5 RCTs, n = 10,695, ARD = 142.5 more in 1000, 95% CI 105.5-188.5 more, NNH = 7); and non-serious gastrointestinal adverse events (3 RCTs, n = 8454, ARD = 64.5 more in 1000, 95% CI 26.4-13.3 more, NNH = 16), dermatologic adverse events (3 RCTs, n = 8454, ARD = 15.6 more in 1000, 95% CI 7.6-27.0 more, NNH = 64), and infections (any severity; 4 RCTs, n = 8691, ARD = 1.8 more in 1000, 95% CI 0.1-4.0 more, NNH = 556) with denosumab. For serious adverse events overall and specific to stroke and myocardial infarction, treatment with bisphosphonates probably makes little-to-no difference; evidence for other specific serious harms was less certain or not available. There was low certainty evidence for an increased risk for the rare occurrence of atypical femoral fractures (0.06 to 0.08 more in 1000) and osteonecrosis of the jaw (0.22 more in 1000) with bisphosphonates (most evidence for alendronate). The evidence for these rare outcomes and for rebound fractures with denosumab was very uncertain. Younger (lower risk) females have high willingness to be screened. A minority of postmenopausal females at increased risk for fracture may accept treatment. Further, there is large heterogeneity in the level of risk at which patients may be accepting of initiating treatment, and treatment effects appear to be overestimated.

CONCLUSION

An offer of 2-step screening with risk assessment and BMD measurement to selected postmenopausal females with low prevalence of prior fracture probably results in a small reduction in the risk of clinical fragility fracture and hip fracture compared to no screening. These findings were most applicable to the use of clinical FRAX for risk assessment and were not replicated in the offer-to-screen population where the rate of response to mailed screening questionnaires was low. Limited direct evidence on harms of screening were available; using study data to provide estimates, there may be a moderate degree of overdiagnosis of high risk for fracture to consider. The evidence for younger females and males is very limited. The benefits of screening and treatment need to be weighed against the potential for harm; patient views on the acceptability of treatment are highly variable.

SYSTEMATIC REVIEW REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO): CRD42019123767.

Normocalcemic primary hyperparathyroidism

Normocalcemic primary hyperparathyroidism (PHPT) is a newer phenotype of PHPT defined by elevated PTH concentrations in the setting of normal serum calcium levels. It is increasingly being diagnosed in the setting of evaluation for nephrolithiasis or metabolic bone diseases. It is important to demonstrate that PTH values remain consistently elevated and to measure ionized calcium levels to make the diagnosis. A diagnosis of normocalcemic disease is one of exclusion of secondary forms of hyperparathyroidism, including vitamin D deficiency, renal failure, medications, malabsorption, and hypercalciuria. Lack of rigorous diagnostic criteria and selection bias of the studied populations may explain the different rates of bone and renal complications. The natural history still remains unknown. Caution should be used in recommending surgery, unless clearly indicated. Here we will review the diagnostic features, epidemiology, clinical presentation, natural history, medical and surgical management of normocalcemic PHPT.

Osteoporosis and Fragility Fractures: currently available pharmacological options and future directions

Osteoporosis is a systemic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture. The average lifetime risk of a 50-year-old woman to suffer a fracture of the spine, hip, proximal humerus, or distal forearm has been estimated at close to 50%. In general, pharmacological treatment is recommended in patients who suffered a fragility fracture because their risk of suffering a subsequent fracture is increased dramatically. Therefore, many guidelines recommend pharmacological treatment in patients without a prevalent fracture if their fracture probability is comparable to or higher than that of a person of the same age with a prevalent fracture. The present review aims to highlight currently available pharmacological treatment options and their antifracture efficacy including safety aspects. Drug classes discussed comprise bisphosphonates, selective estrogen receptor modulators, parathyroid hormone peptides and derivatives, humanized monoclonal antibodies, and estrogens and gestagens and their combinations. Furthermore, a brief glimpse is provided into a potentially promising treatment option that involves mesenchymal stem cells.

The Rationale for Using Neridronate in Musculoskeletal Disorders: From Metabolic Bone Diseases to Musculoskeletal Pain

Neridronate or ((6-amino-1-hydroxy-1-phosphonohexyl) phosphonic acid) is an amino-bisphosphonate (BP) synthetized in Italy in 1986. Bisphosphonates are molecules with a P-C-P bond in their structure that allows strong and selectively binding to hydroxyapatite (HAP) as well as osteoclasts inhibition through different mechanisms of action. Neridronate was initially used to treat Paget disease of the bone, demonstrating effectiveness in reducing bone turnover markers as well as pain. The interesting molecular properties of neridronate foster its wide use in several other conditions, such as osteogenesis imperfecta, and osteoporosis. Thanks to the unique safety and efficacy profile, neridronate has been used in secondary osteoporosis due to genetic, rheumatic, and oncological diseases, including in pediatric patients. In the last decade, this drug has also been studied in chronic musculoskeletal pain conditions, such as algodystrophy, demonstrating effectiveness in improving extraskeletal outcomes. This review highlights historical and clinical insights about the use of neridronate for metabolic bone disorders and musculoskeletal pain conditions.

Alfaleh M, H. Abdulaal W, Bakhaidar RB, Alselami MO, Zahrani MAL, Alqarni HM, F. Alghaith A, Alshehri S, Badr-Eldin SM, Aldawsari HM, Al-hejaili OD, Aldhabi BM, Mahdi WA. Wasp venom peptide improves the proapoptotic activity of alendronate sodium in A549 lung cancer cells

BACKGROUND

Lung cancer in men and women is considered the leading cause for cancer-related mortality worldwide. Anti-cancer peptides represent a potential untapped reservoir of effective cancer therapy.

METHODOLOGY

Box-Behnken response surface design was applied for formulating Alendronate sodium (ALS)-mastoparan peptide (MP) nanoconjugates using Design-Expert software. The optimization process aimed at minimizing the size of the prepared ALS-MP nanoconjugates. ALS-MP nanoconjugates' particle size, encapsulation efficiency and the release profile were determined. Cytotoxicity, cell cycle, annexin V staining and caspase 3 analyses on A549 cells were carried out for the optimized formula.

RESULTS

The results revealed that the optimized formula was of 134.91±5.1 nm particle size. The novel ALS-MP demonstrated the lowest IC50 (1.3 ± 0.34 μM) in comparison to ALS-Raw (37.6 ± 1.79 μM). Thus, the results indicated that when optimized ALS-MP nanoconjugate was used, the IC50 of ALS was also reduced by half. Cell cycle analysis demonstrated a significantly higher percentage of cells in the G2-M phase following the treatment with optimized ALS-MP nanoconjugates.

CONCLUSION

The optimized ALS-MP formula had significantly improved the parameters related to the cytotoxic activity towards A549 cells, compared to control, MP and ALS-Raw.

Efficacy of Antiresorptive Treatment in Osteoporotic Older Adults: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

OBJECTIVES

To investigate concerns surrounding the benefits of antiresorptive drugs in older adults, a systematic review was carried out to evaluate the efficacy of these treatments in the prevention of osteoporotic hip fractures in older adults.

DESIGN

a systematic review and meta-analysis of randomized clinical trials.

SETTING AND PARTICIPANTS

older adults ≥65 years with osteoporosis, with or without a previous fragility fracture. Studies with cancer-related and corticosteroid-induced osteoporosis, participants <65 years and no reported hip fracture were not included.

METHODS

MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, ISI Web of Science and Scopus databases were searched. The primary outcome was hip fracture, and subgroup analysis (≥75 years, with different drug types and secondary prevention) and sensitivity analysis was carried out using a GRADE evaluation. Secondary outcomes were any type of fractures, vertebral fracture, bone markers and adverse events. The risk of bias was assessment with the Cochrane risk of bias tool.

RESULTS

A total of 12 randomised controlled trials (RCTs) qualified for this meta-analysis, with 36,196 participants. Antiresorptive drugs have a statistically significant effect on the prevention of hip fracture (RR=0.70; 95%CI 0.60 to 0.81), but with a moderate GRADE quality of evidence and a high number needed to treat (NNT) of 186. For other outcomes, there is a statistically significant effect, but with a low to moderate quality of evidence. Antiresorptives showed no reduction in the risk of hip fracture in people ≥75 years. The results for different drug types, secondary prevention and sensitivity analysis are similar to the main analyses and have the same concerns.

CONCLUSIONS

Antiresorptive drugs have a statistically significant effect on preventing hip fracture but with a moderate quality (unclear/high risk of bias) and high NNT (186). This small benefit disappears in those ≥75 years, but increases in secondary prevention. More RCTs in very old osteoporotic adults are needed.

Advances in bone turnover markers

Bone fragility fractures remain an important worldwide health and economic problem due to increased morbidity and mortality. The current methods for predicting fractures are largely based on the measurement of bone mineral density and the utilization of mathematical risk calculators based on clinical risk factors for bone fragility. Despite these approaches, many bone fractures remain undiagnosed. Therefore, current research is focused on the identification of new factors such as bone turnover markers (BTM) for risk calculation. BTM are a group of proteins and peptides released during bone remodeling that can be found in serum or urine. They derive from bone resorptive and formative processes mediated by osteoclasts and osteoblasts, respectively. Potential use of BTM in monitoring these phenomenon and therefore bone fracture risk is limited by physiologic and pathophysiologic factors that influence BTM. These limitations in predicting fractures explain why their inclusion in clinical guidelines remains limited despite the large number of studies examining BTM.

Evaluation and Management of Elevated Parathyroid Hormone Levels in Normocalcemic Patients

Primary hyperparathyroidism is a common endocrine disorder. It used to present as a highly symptomatic disease before the advent of the multichannel autoanalyzer, now usually presenting as mild asymptomatic hypercalcemia. A newer presentation has been increasingly identified in the past two decades, normocalcemic primary hyperparathyroidism, presenting with elevated parathyroid hormone concentrations and consistently normal serum calcium. These patients are usually symptomatic, with parathyroid hormone levels measured in the evaluation for kidney stones or osteoporosis. It is important to exclude causes of secondary hyperparathyroidism. This review will focus on the evaluation and management of elevated parathyroid hormone levels in normocalcemic patients.

Dose-dependent effects of pharmaceutical treatments on bone matrix properties in ovariectomized rats

As both anabolic and anti-catabolic osteoporosis drugs affect bone formation and resorption processes, they may contribute to bone's overall mechanical behavior by altering the quality of the bone matrix. We used an ovariectomized rat model and a novel fracture mechanics approach to investigate whether treatment with an anabolic (parathyroid hormone) or anti-catabolic (alendronate) osteoporosis drugs will alter the organic and mineral matrix components and consequently cortical bone fracture toughness. Ovariectomized (at 5 months age) rats were treated with either parathyroid hormone or alendronate at low and high doses for 6 months (age 6–12 months). Specifically, treatment groups included untreated ovariectomized controls (n = 9), high-dose alendronate (n = 10), low-dose alendronate (n = 9), high-dose parathyroid hormone (n = 10), and low-dose parathyroid hormone (n = 9). After euthanasia, cortical microbeams from the lateral quadrant were extracted, notched, and tested in 3-point bending to measure fracture toughness. Portions of the bone were used to measure changes in the 1) organic matrix through quantification of advanced glycation end-products (AGEs) and non-collagenous proteins, and 2) mineral matrix through assessment of mineral crystallinity. Compared to the ovariectomized group, rats treated with high doses of parathyroid hormone and alendronate had significantly increased cortical bone fracture toughness, which corresponded primarily to increased non-collagenous proteins while there was no change in AGEs. Additionally, low-dose PTH treatment increased matrix crystallinity and decreased AGE levels. In summary, ovariectomized rats treated with pharmaceutical drugs had increased non-collagenous matrix proteins and improved fracture toughness compared to controls. Further investigation is required for different doses and longer treatment periods.

•

Alendronate increases non-collagenous proteins and improves fracture toughness.

•

Parathyroid hormone also increases collagen maturity and mineral crystallinity.

•

Both treatments minimize accumulation of advanced glycation end-products.

Denosumab, raloxifene, romosozumab and teriparatide to prevent osteoporotic fragility fractures: a systematic review and economic evaluation

BACKGROUND

Fragility fractures are fractures that result from mechanical forces that would not ordinarily result in fracture.

OBJECTIVES

The objectives were to evaluate the clinical effectiveness, safety and cost-effectiveness of non-bisphosphonates {denosumab [Prolia^®; Amgen Inc., Thousand Oaks, CA, USA], raloxifene [Evista^®; Daiichi Sankyo Company, Ltd, Tokyo, Japan], romosozumab [Evenity^®; Union Chimique Belge (UCB) S.A. (Brussels, Belgium) and Amgen Inc.] and teriparatide [Forsteo^®; Eli Lilly and Company, Indianapolis, IN, USA]}, compared with each other, bisphosphonates or no treatment, for the prevention of fragility fracture.

DATA SOURCES

For the clinical effectiveness review, nine electronic databases (including MEDLINE, EMBASE and the World Health Organization International Clinical Trials Registry Platform) were searched up to July 2018.

REVIEW METHODS

A systematic review and network meta-analysis of fracture and femoral neck bone mineral density were conducted. A review of published economic analyses was undertaken and a model previously used to evaluate bisphosphonates was adapted. Discrete event simulation was used to estimate lifetime costs and quality-adjusted life-years for a simulated cohort of patients with heterogeneous characteristics. This was done for each non-bisphosphonate treatment, a strategy of no treatment, and the five bisphosphonate treatments previously evaluated. The model was populated with effectiveness evidence from the systematic review and network meta-analysis. All other parameters were estimated from published sources. An NHS and Personal Social Services perspective was taken, and costs and benefits were discounted at 3.5% per annum. Fracture risk was estimated from patient characteristics using the QFracture^® (QFracture-2012 open source revision 38, Clinrisk Ltd, Leeds, UK) and FRAX^® (web version 3.9, University of Sheffield, Sheffield, UK) tools. The relationship between fracture risk and incremental net monetary benefit was estimated using non-parametric regression. A probabilistic sensitivity analysis and scenario analyses were used to assess uncertainty.

RESULTS

Fifty-two randomised controlled trials of non-bisphosphonates were included in the clinical effectiveness systematic review and an additional 51 randomised controlled trials of bisphosphonates were included in the network meta-analysis. All treatments had beneficial effects compared with placebo for vertebral, non-vertebral and hip fractures, with hazard ratios varying from 0.23 to 0.94, depending on treatment and fracture type. The effects on vertebral fractures and the percentage change in bone mineral density were statistically significant for all treatments. The rate of serious adverse events varied across trials (0-33%), with most between-group differences not being statistically significant for comparisons with placebo/no active treatment, non-bisphosphonates or bisphosphonates. The incremental cost-effectiveness ratios were > £20,000 per quality-adjusted life-year for all non-bisphosphonate interventions compared with no treatment across the range of QFracture and FRAX scores expected in the population eligible for fracture risk assessment. The incremental cost-effectiveness ratio for denosumab may fall below £30,000 per quality-adjusted life-year at very high levels of risk or for high-risk patients with specific characteristics. Raloxifene was dominated by no treatment (resulted in fewer quality-adjusted life-years) in most risk categories.

LIMITATIONS

The incremental cost-effectiveness ratios are uncertain for very high-risk patients.

CONCLUSIONS

Non-bisphosphonates are effective in preventing fragility fractures, but the incremental cost-effectiveness ratios are generally greater than the commonly applied threshold of £20,000-30,000 per quality-adjusted life-year.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42018107651.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 29. See the NIHR Journals Library website for further project information.

Effects of anti-osteoporosis therapy on plasma aldosterone and renin

OBJECTIVE

This study aimed to investigate the effect of anti-osteoporosis therapy on plasma aldosterone concentration (PAC), plasma renin concentration (PRC) and the aldosterone/renin ratio (ARR) in patients with postmenopausal osteoporosis.

METHODS

In 60 patients with postmenopausal osteoporosis, bone mineral density (BMD), PAC and PRC were measured before and after treatment with alendronate (70 mg/week, n=22) or recombinant human parathyroid hormone (20 μg/day, n=35) for 48 weeks.

RESULTS

PAC was negatively correlated with the T-score of lumbar spine BMD and femoral neck BMD (lumbar r=-0.386, p<0.01; femoral neck r=-0.262, p<0.05). With the improvement in lumbar BMD after anti-osteoporosis treatment (T-score -3.4±0.5 vs. -3.1 ±0.4, p<0.0001), PAC decreased from 182.8±53.2 to 143.7±68.6 pg/mL (p<0.0001), PRC increased from 7.8±11.6 to 39.2±50.0 μIU/mL (p<0.0001) and the ARR decreased from 74.8±75.2 to 13.1±17.1 pg/μIU (p<0.0001). At baseline, 58% (35/60) of the patients had an ARR >37 pg/μIU, and the proportion decreased to 8% (5/57) after treatment.

CONCLUSION

Treatment with alendronate or parathyroid hormone causes decreased PAC and increased PRC, resulting in a decreased ARR in postmenopausal women with osteoporosis.

The Use of Standard Cemented Femoral Stems in Total Hip Replacement After Failed Internal Fixation of Intertrochanteric Femoral Fractures

BACKGROUND

Total hip replacement (THR) after failed internal fixation of intertrochanteric femoral fractures is challenging. The aim of this study is to show the reliability of using standard cemented femoral stems in this operation.

METHODS

This work included 107 THRs performed in 107 patients after failed treatment of intertrochanteric femoral fractures. The etiology of failure included 67 cases of failure of fixation, 16 cases of nonunion, 15 cases of avascular necrosis, and 9 cases of post-traumatic osteoarthritis. There were 48 males and 59 females. The mean age was 66 years (range 58-81). Failed dynamic hip screws were removed at the time of THR, and the screw holes were blocked with cement. All cases had cemented standard stem femoral prostheses.

RESULTS

At an average 7.4 years with a minimum of 5 years of follow-up, 102 cases had good clinical and radiological outcomes and 5 cases had fair outcomes. One patient was infected and required 2 stages of revision arthroplasty. Two cases had intraoperative proximal femoral crack, and were treated by cerclage wires. Two patients had early postoperative dislocations. No patients had late periprosthetic femoral fractures or implant loosening.

CONCLUSION

Standard cemented femoral stems are reliable and cost-effective prostheses in such cases. It is not necessary to bypass the distal screw hole by doubling the femoral canal diameter as long as the bone holes are covered by cement.

History of alendronate

Alendronate was synthesized in 1970s in a search for inhibitors of calcification. Istituto Gentili investigators identified it as a potent inhibitor of bone resorption and obtained a patent covering its use in the treatment of osteoporosis and other disorders of excessive bone resorption in the 1980s. Merck licensed alendronate in 1988 and its pharmaceutical chemists reformulated it as a sodium salt with good solubility in a tablet that reduced its potential for esophageal irritation. Clinical trials proved that it reduced bone turnover, increased BMD and reduced the risk of vertebral fractures in postmenopausal osteoporotic women. Merck sponsored a large clinical trials that won FDA approval for treatment of osteoporosis in postmenopausal women and showed that it reduced the risk of spine and hip fractures. Its approval in the US in 1995 spurred sales of bone densitometers and BMD testing to screen for low bone mineral density and identify osteoporosis. Bone mass measurement was supported by medical society guidelines and reimbursement by Medicare and other insurers in the USA. A 70 mg weekly instead of 10 mg daily dose of alendronate produced the same effect on BMD and biochemical markers of bone remodelling with greater convenience and reduced potential for upper GI adverse events. Consequently, by 2006, about 30 million prescriptions for alendronate were written annually in the U.S. for about 15% of postmenopausal women in the U.S. Thereafter, publicity about rare but concerning atypical femoral fractures (AFF) and osteonecrosis of the jaw (ONJ) along with the expiry of Merck's patent (in 2008) and cessation of their promotion of alendronate, and a decline in use of densitometry led to a steady slide in its use even among patients for whom the benefits of alendronate far outweigh its potential risks. Nevertheless, in 25 years since its regulatory approval, alendronate has undoubtedly prevented millions of fractures world-wide.

History of risedronate

Herein we review the discovery, development, commercial history and legacy of risedronate or NE-58095, a potent N-containing bisphosphonate developed by scientists at the Cincinnati Miami Valley Laboratories and the Norwich Eaton Laboratories of Procter and Gamble. It is characterized by a hydroxyl substituent (R₁) and a pyridyl-methylene substituent (R₂) at the carbon bridging two phosphonate moieties. It was shown to have greater potency than alendronate in cell-based systems while binding affinity to bone matrix was lower than alendronate, accounting for the relatively rapid offset of bone turnover inhibition when therapy is discontinued. Risedronate was shown to significantly reduce serum alkaline phosphatase and clinical features in patients with Paget's disease and was approved for this indication, at a dose of 30 mg daily for 2 months, in 1998. Formal dose response testing for treatment of osteoporosis was not performed. In large Phase 3 studies, 5 mg risedronate daily increased bone mineral density more than did the 2.5 mg dose. As a result, the 2.5 mg dose was dropped from most of the Phase 3 studies after 12 months. The 5 mg daily dose was approved for treating and preventing postmenopausal osteoporosis and glucocorticoid-induced osteoporosis in 2000. The drug was subsequently approved for treating men with osteoporosis. Following the leads of other companies, weekly and monthly preparations were developed and approved, based on non-inferiority BMD studies vs the 5 mg daily oral dose as was a unique dosing regimen of 75 mg given on 2 consecutive days each month. Finally, to overcome the effect of food on limiting the already poor gastrointestinal absorption of the drug, a once-weekly oral preparation containing the chelating agent EDTA and with an enteric coating delaying dissolution until the tablet was in the small intestine was approved in 2010 to be administered after breakfast. The Alliance for Better Bone Health, a collaboration between Procter & Gamble Pharmaceuticals and sanofi-aventis U.S. was formed to market risedronate as Actonel® and, subsequently, Actonel-EC® or Atelvia®. These drugs are still marketed by sanofi-aventis in some countries. The sale of the pharmaceutical division of Procter & Gamble to Warner Chilcott (US) was based, in large part, on the perceived value and marketability of the risedronate drugs. When marketing targets of Warner-Chilcott were not met, the rights of risedronate were sold to Allergan USA, Inc. which never actively promoted the drug. Generic forms of risedronate were introduced into the United States in 2015 but are rarely used, although several generic forms are actively marketed in other countries.

Effects of corn syrup solids containing maltobionic acid (maltobionic acid calcium salt) on bone resorption in healthy Japanese adult women: A randomized double-blind placebo-controlled crossover study

Maltobionic acid is known to have an inhibitory effect on the differentiation of osteoclasts, and it has also been reported in an intervention trial that ingestion of corn syrup solids containing maltobionic acid maintained and increased the bone density of postmenopausal women. However, there is no information on whether maltobionic acid improves bone metabolism in humans. Therefore, we evaluated the influence of corn syrup solids containing maltobionic acid (maltobionic acid calcium salt) on bone resorption markers in healthy Japanese women. Forty-one individuals were selected from 68 participants and assigned to two groups: 21 individuals in the test food antecedent group and 20 individuals in the placebo food antecedent group; individuals in the first group ingested 4 g of corn syrup solids containing maltobionic acid, and subjects in the second group ingested 4 g of placebo (hydrous crystalline maltose and calcium carbonate) for 4 weeks. Bone resorption marker levels (DPD and u-NTx) were evaluated by urinalysis. Forty subjects completed the study, and no adverse events related to the test food were observed. Fourteen subjects were excluded prior to the efficacy analysis because of conflict with the control criteria; the remaining 33 subjects were analyzed. Consumption of corn syrup solids containing maltobionic acid was maintained; DPD and u-NTx values were improved (p < .05). These results indicate that corn syrup solids containing maltobionic acid might contribute to suppress bone resorption and improve bone metabolism in postmenstrual women. (UMIN-CTR ID: UMIN000034257; Foundation: San-ei Sucrochemical Co., Ltd.).

Bisphosphonates reduce biomaterial turnover in healing of critical-size rat femoral defects

Treatment of osteoporotic patients with bisphosphonates (BPs) preserves bone mass and microarchitecture. The high prescription rate of the drugs brings about increases in the numbers of fractures and bone defects requiring surgical interventions in these patients. Currently, critical-size defects are filled with biomaterials and healing is supported with bone morphogenetic proteins (BMP). It is hypothesized that BPs interfere with biomaterial turnover during BMP-supported repair of defects filled with β-tricalcium phosphate (βTCP) ceramics. To test this hypothesis, retired breeder rats were ovariectomized ( OVX). After 8 weeks, treatment with alendronate (ALN) commenced. Five weeks later, 6 mm diaphyseal femoral defects were applied and stabilized with locking plates. βTCP cylinders loaded with 1 μg and 10 μg BMP2, 10 μg L51P, an inhibitor of BMP antagonists and 1 μg BMP2/10 μg L51P were fitted into the defects. Femora were collected 16 weeks post-implantation. In groups receiving calcium phosphate implants loaded with 10 μg BMP2 and 1 μg BMP2/10 μg L51P, the volume of bone was increased and βTCP was decreased compared to groups receiving implants with 1 μg BMP2 and 10 μg L51P. Treatment of animals with ALN caused a decrease in βTCP turnover. The results corroborate the synergistic effects of BMP2 and L51P on bone augmentation. Administration of ALN caused a reduction in implant turnover, demonstrating the dependence of βTCP removal on osteoclast activity, rather than on chemical solubility. Based on these data, it is suggested that in patients treated with BPs, healing of biomaterial-filled bone defects may be impaired because of the failure to remove the implant and its replacement by authentic bone.

Pharmacogenomics of osteonecrosis of the jaw

Osteonecrosis of the jaw (ONJ) is a rare but serious drug induced adverse event, mainly associated with the use of antiresorptive medications, such as intravenous (IV) bisphosphonates (BPs) in cancer patients. In this review, we evaluated all the pharmacogenomic association studies for ONJ published up to December 2018. To date, two SNPs (CYP2C8 rs1934951 and RBMS3 rs17024608) were identified to be associated with ONJ by two genome-wide association studies (GWAS). However, all six subsequent candidate gene studies failed to replicate these results. In addition, six discovery candidate gene studies tried to identify the genetic markers in several genes associated with bone remodeling, bone mineral density, or osteoporosis. After evaluating the results of these 6 studies, none of the SNPs was significantly associated with ONJ. Recently, two whole-exome sequencing (WES) analysis (including one from our group) were performed to identify variants associated with ONJ. So far, only our study successfully replicated discovery result indicating SIRT1 SNP rs7896005 to be associated with ONJ. However, this SNP also did not reach genome-wide significance. The major limitations of these studies include lack of replication phases and limited sample sizes. Even though some studies had larger sample sizes, they recruited healthy individuals as controls, not subjects treated with BPs. We conclude that a GWAS with a larger sample size followed by replication phase will be needed to fully investigate the pharmacogenomic markers of ONJ.

Management of normocalcemic primary hyperparathyroidism

Traditional hypercalcemic primary hyperparathyroidism is a common endocrine disease. Patients with a history of nephrolithiasis or a suspected metabolic bone disease are increasingly being identified with elevated PTH concentrations in the setting of consistently normal serum and ionized calcium concentrations. In the absence of secondary causes of hyperparathyroidism, a diagnosis of normocalcemic primary hyperparathyroidism is reasonable. As most cohorts described in the literature are from referral populations, involvement of the skeleton and the kidneys is common, two traditional target organs of primary hyperparathyroidism. Data from small cohorts show patients with normocalcemic disease respond similarly to hypercalcemic primary hyperparathyroidism with regard to medical and surgical approaches. In normocalcemic patients, multiglandular disease may be more common. In this article, we review the available literature on the epidemiology, diagnosis, clinical features, medical and surgical management of this newer phenotype of primary hyperparathyroidism.

Healing of fractures in osteoporotic bones in mice treated with bisphosphonates - A transcriptome analysis

Bisphosphonates (BP) are inhibitors of bone resorption and are used to treat postmenopausal osteoporosis. Long-term treatment with BP attenuates bone remodeling, possibly leading to detrimental consequences for the bones' ability to repair defects. To test this hypothesis, an animal model was established. Twelve week old mice were ovariectomized (OVX). Following confirmation of bone loss 8 weeks after OVX, the animals were treated with Alendronate (ALN) until sacrifice. After 5 weeks of ALN injections, the femoral bones were osteotomized and the osteotomies were either rigidly or non-rigidly stabilized. In rigidly fixed defects, no callus developed between 1 and 5 weeks after osteotomy, whereas after non-rigid fixation, callus development occurred. The administration of ALN resulted in an increase in newly formed bone at the defect site 5 weeks after osteotomy, irrespective of the estrogen status or fixation system. Transcriptome analysis demonstrated that both rigid and non-rigid fixation affected gene expression primarily during the middle phase of bone repair. Furthermore, the number of differentially expressed genes in tissues from non-rigidly fixed defect sites increased in animals treated with ALN over the course of bone repair. This indicates that ALN-dependent repair processes become increasingly dominant in the late phases of the healing process. Ranking of the factors affecting the composition of the transcriptome and their impact on the healing process revealed fixation at the defect site to be the strongest causative factor, followed by bisphosphonate treatment and estrogen deficiency. The present study suggests that the continuous administration of ALN is detrimental to bone repair, eventually causing a delay in healing in mechanically compromised situations. Consequently, rigid fixation may prove essential for a successful intervention.

Screening to Prevent Osteoporotic Fractures: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Osteoporotic fractures cause significant morbidity and mortality.

OBJECTIVE

To update the evidence on screening and treatment to prevent osteoporotic fractures for the US Preventive Services Task Force.

DATA SOURCES

PubMed, the Cochrane Library, EMBASE, and trial registries (November 1, 2009, through October 1, 2016) and surveillance of the literature (through March 23, 2018); bibliographies from articles.

STUDY SELECTION

Adults 40 years and older; screening cohorts without prevalent low-trauma fractures or treatment cohorts with increased fracture risk; studies assessing screening, bone measurement tests or clinical risk assessments, pharmacologic treatment.

DATA EXTRACTION AND SYNTHESIS

Dual, independent review of titles/abstracts and full-text articles; study quality rating; random-effects meta-analysis.

MAIN OUTCOMES AND MEASURES

Incident fractures and related morbidity and mortality, diagnostic and predictive accuracy, harms of screening or treatment.

RESULTS

One hundred sixty-eight fair- or good-quality articles were included. One randomized clinical trial (RCT) (n = 12 483) comparing screening with no screening reported fewer hip fractures (2.6% vs 3.5%; hazard ratio [HR], 0.72 [95% CI, 0.59-0.89]) but no other statistically significant benefits or harms. The accuracy of bone measurement tests to identify osteoporosis varied (area under the curve [AUC], 0.32-0.89). The pooled accuracy of clinical risk assessments for identifying osteoporosis ranged from AUC of 0.65 to 0.76 in women and from 0.76 to 0.80 in men; the accuracy for predicting fractures was similar. For women, bisphosphonates, parathyroid hormone, raloxifene, and denosumab were associated with a lower risk of vertebral fractures (9 trials [n = 23 690]; relative risks [RRs] from 0.32-0.64). Bisphosphonates (8 RCTs [n = 16 438]; pooled RR, 0.84 [95% CI, 0.76-0.92]) and denosumab (1 RCT [n = 7868]; RR, 0.80 [95% CI, 0.67-0.95]) were associated with a lower risk of nonvertebral fractures. Denosumab reduced the risk of hip fracture (1 RCT [n = 7868]; RR, 0.60 [95% CI, 0.37-0.97]), but bisphosphonates did not have a statistically significant association (3 RCTs [n = 8988]; pooled RR, 0.70 [95% CI, 0.44-1.11]). Evidence was limited for men: zoledronic acid reduced the risk of radiographic vertebral fractures (1 RCT [n = 1199]; RR, 0.33 [95% CI, 0.16-0.70]); no studies demonstrated reductions in clinical or hip fractures. Bisphosphonates were not consistently associated with reported harms other than deep vein thrombosis (raloxifene vs placebo; 3 RCTs [n = 5839]; RR, 2.14 [95% CI, 0.99-4.66]).

CONCLUSIONS AND RELEVANCE

In women, screening to prevent osteoporotic fractures may reduce hip fractures, and treatment reduced the risk of vertebral and nonvertebral fractures; there was not consistent evidence of treatment harms. The accuracy of bone measurement tests or clinical risk assessments for identifying osteoporosis or predicting fractures varied from very poor to good.

Bisphosphonates hinder osteoblastic/osteoclastic differentiation in the maxillary sinus mucosa-derived stem cells

OBJECTIVES

Although bisphosphonates (BPs) are known to be associated with osteonecrosis of the maxilla, the precise effects of BPs on bone metabolism in human maxillary sinus mucosal cells (HMSMCs) are not yet known. The purposes of this study were to examine the effects of the BPs zoledronate (ZOL) and alendronate (ALN) on osteoblastic and osteoclastic differentiation in HMSMCs and to investigate the signaling pathways involved.

MATERIALS AND METHODS

The effects of ZOL and ALN were assessed for osteoblast differentiation by alkaline phosphatase (ALP) activity, alizarin red staining, and RT-PCR for genes encoding Runx2 and osterix. Receptor activator of nuclear factor-κB ligand (RANKL)-mediated osteoclast differentiation in bone marrow macrophages (BMMs) was also examined.

RESULTS

ZOL and ALN both suppressed osteoblastic differentiation, as evidenced by their effects on ALP activity, mineralization nodule formation, and the mRNA expression levels of osteoblastic transcript factors. The RANKL/osteoprotegerin ratio in HMSMCs was increased by ALN, whereas ZOL had the opposite effect. Conditioned medium obtained from ALN-treated HMSMCs stimulated osteoclast formation and upregulated NFATc1 expression, whereas conditioned medium from ZOL-treated cells did not. ALN was more cytotoxic and stimulated apoptosis more strongly than ZOL. BPs decreased the protein levels of the non-canonical Wnt signaling protein Wnt5a and calmodulin-dependent kinase II. Moreover, recombinant human Wnt5a reversed the effects of BPs on osteoblastic and osteoclastic differentiation.

CONCLUSION

This study is the first demonstration that BPs exert negative effects on osteoblastic and osteoclastic processes via the non-canonical Wnt pathway in HMSMSCs.

CLINICAL RELEVANCE

It suggests that patients taking BPs during the period of maxillary sinus lifting and amentation should be given special attention.

A systematic review and economic evaluation of bisphosphonates for the prevention of fragility fractures

BACKGROUND

Fragility fractures are fractures that result from mechanical forces that would not ordinarily result in fracture.

OBJECTIVES

To evaluate the clinical effectiveness and safety of bisphosphonates [alendronic acid (Fosamax^® and Fosamax^® Once Weekly, Merck Sharp & Dohme Ltd), risedronic acid (Actonel^® and Actonel Once a Week^®, Warner Chilcott UK Ltd), ibandronic acid (Bonviva^®, Roche Products Ltd) and zoledronic acid (Aclasta^®, Novartis Pharmaceuticals UK Ltd)] for the prevention of fragility fracture and to assess their cost-effectiveness at varying levels of fracture risk.

DATA SOURCES

For the clinical effectiveness review, six electronic databases and two trial registries were searched: MEDLINE, EMBASE, The Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, Web of Science and BIOSIS Previews, Clinicaltrials.gov and World Health Organization International Clinical Trials Registry Platform. Searches were limited by date from 2008 until September 2014.

REVIEW METHODS

A systematic review and network meta-analysis (NMA) of effectiveness studies were conducted. A review of published economic analyses was undertaken and a de novo health economic model was constructed. Discrete event simulation was used to estimate lifetime costs and quality-adjusted life-years (QALYs) for each bisphosphonate treatment strategy and a strategy of no treatment for a simulated cohort of patients with heterogeneous characteristics. The model was populated with effectiveness evidence from the systematic review and NMA. All other parameters were estimated from published sources. A NHS and Personal Social Services perspective was taken, and costs and benefits were discounted at 3.5% per annum. Fracture risk was estimated from patient characteristics using the QFracture^® (QFracture-2012 open source revision 38, Clinrisk Ltd, Leeds, UK) and FRAX^® (web version 3.9, University of Sheffield, Sheffield, UK) tools. The relationship between fracture risk and incremental net benefit (INB) was estimated using non-parametric regression. Probabilistic sensitivity analysis (PSA) and scenario analyses were used to assess uncertainty.

RESULTS

Forty-six randomised controlled trials (RCTs) were included in the clinical effectiveness systematic review, with 27 RCTs providing data for the fracture NMA and 35 RCTs providing data for the femoral neck bone mineral density (BMD) NMA. All treatments had beneficial effects on fractures versus placebo, with hazard ratios varying from 0.41 to 0.92 depending on treatment and fracture type. The effects on vertebral fractures and percentage change in BMD were statistically significant for all treatments. There was no evidence of a difference in effect on fractures between bisphosphonates. A statistically significant difference in the incidence of influenza-like symptoms was identified from the RCTs for zoledronic acid compared with placebo. Reviews of observational studies suggest that upper gastrointestinal symptoms are frequently reported in the first month of oral bisphosphonate treatment, but pooled analyses of placebo-controlled trials found no statistically significant difference. A strategy of no treatment was estimated to have the maximum INB for patients with a 10-year QFracture risk under 1.5%, whereas oral bisphosphonates provided maximum INB at higher levels of risk. However, the PSA suggested that there is considerable uncertainty regarding whether or not no treatment is the optimal strategy until the QFracture score is around 5.5%. In the model using FRAX, the mean INBs were positive for all oral bisphosphonate treatments across all risk categories. Intravenous bisphosphonates were estimated to have lower INBs than oral bisphosphonates across all levels of fracture risk when estimated using either QFracture or FRAX.

LIMITATIONS

We assumed that all treatment strategies are viable alternatives across the whole population.

CONCLUSIONS

Bisphosphonates are effective in preventing fragility fractures. However, the benefit-to-risk ratio in the lowest-risk patients may be debatable given the low absolute QALY gains and the potential for adverse events. We plan to extend the analysis to include non-bisphosphonate therapies.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013006883.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Bone Turnover Markers in the Diagnosis and Monitoring of Metabolic Bone Disease

BACKGROUND

Disorders of bone metabolism, most notably osteoporosis, are highly prevalent and predispose to fractures, causing high patient morbidity and mortality. Diagnosis and monitoring of bone metabolic defects can present a major challenge as these disorders are largely asymptomatic and radiographic measures of bone mass respond slowly to changes in bone physiology.

CONTENT

Bone turnover markers (BTMs) are a series of protein or protein derivative biomarkers released during bone remodeling by osteoblasts or osteoclasts. BTMs can offer prognostic information on fracture risk that supplements radiographic measures of bone mass, but testing using BTMs has to take into account the large number of preanalytic factors and comorbid clinical conditions influencing BTM levels. BTMs respond rapidly to changes in bone physiology, therefore, they have utility in determining patient response to and compliance with therapies for osteoporosis.

SUMMARY

BTMs are a useful adjunct for the diagnosis and therapeutic monitoring of bone metabolic disorders, but their use has to be tempered by the known limitations in their clinical utility and preanalytic variables complicating interpretation.

Targeted disruption of BMP signaling through type IA receptor (BMPR1A) in osteocyte suppresses SOST and RANKL, leading to dramatic increase in bone mass, bone mineral density and mechanical strength

Recent studies suggest a critical role of osteocytes in controlling skeletal development and bone remodeling although the molecular mechanism is largely unknown. This study investigated BMP signaling in osteocytes by disrupting Bmpr1a under the Dmp1-promoter. The conditional knockout (cKO) mice displayed a striking osteosclerotic phenotype with increased trabecular bone volume, thickness, number, and mineral density as assessed by X-ray and micro-CT. The bone histomorphometry, H&E, and TRAP staining revealed a dramatic increase in trabecular and cortical bone masses but a sharp reduction in osteoclast number. Moreover, there was an increase in BrdU positive osteocytes (2-5-fold) and osteoid volume (~4-fold) but a decrease in the bone formation rate (~85%) in the cKO bones, indicating a defective mineralization. The SEM analysis revealed poorly formed osteocytes: a sharp increase in cell numbers, a great reduction in cell dendrites, and a remarkable change in the cell distribution pattern. Molecular studies demonstrated a significant decrease in the Sost mRNA levels in bone (>95%), and the SOST protein levels in serum (~85%) and bone matrices. There was a significant increase in the β-catenin (>3-fold) mRNA levels as well as its target genes Tcf1 (>6-fold) and Tcf3 (~2-fold) in the cKO bones. We also showed a significant decrease in the RANKL levels of serum proteins (~65%) and bone mRNA (~57%), and a significant increase in the Opg mRNA levels (>20-fold) together with a significant reduction in the Rankl/Opg ratio (>95%), which are responsible for a sharp reduction in the cKO osteoclasts. The values of mechanical strength were higher in cKO femora (i.e. max force, displacement, and work failure). These results suggest that loss of BMP signaling specifically in osteocytes dramatically increases bone mass presumably through simultaneous inhibition of RANKL and SOST, leading to osteoclast inhibition and Wnt activation together. Finally, a working hypothesis is proposed to explain how BMPR1A controls bone remodeling by inhibiting cell proliferation and stimulating differentiation. It is reported that RANKL and SOST are abundantly expressed by osteocytes. Thus, BMP signaling through BMPR1A plays important roles in osteocytes.

Clinical effectiveness of bisphosphonates for the prevention of fragility fractures: A systematic review and network meta-analysis

OBJECTIVES

To assess the relative efficacy of bisphosphonates (alendronate, risedronate, ibandronate and zoledronic acid) for the treatment of osteoporosis using network meta-analysis (NMA).

METHODS

A systematic review of the literature was conducted using PRISMA guidelines. A network meta-analysis was used to determine the relative efficacy of treatments on four fracture outcomes (vertebral, non-vertebral, hip and wrist) and percentage change in femoral neck bone mineral density (BMD). Treatment effects were modelled using an exchangeable treatment effects model. Heterogeneity in treatment effects was explored by considering potential treatment effect modifiers using meta-regression. Where appropriate, inconsistency between direct and indirect evidence was assessed using node-splitting.

RESULTS

46 randomised controlled trials (RCTs) were identified. Twenty seven RCTs provided fracture data and 35 RCTs provided BMD data for analysis. Zoledronic acid was associated with the greatest treatment effect on vertebral fractures (HR 0.41, 95% CrI: 0.28, 0.56) and percentage change in BMD (3.21, 95%: CrI 2.52, 3.86) compared to placebo. The greatest treatment effect on non-vertebral and wrist fractures was given by risedronate (HR 0.72, 95%: CrI 0.53, 0.89 and HR 0.77, 95%: CrI 0.44, 1.24, respectively). For hip fractures the greatest treatment effect was given by alendronate (HR 0.78, 95% CrI: 0.44, 1.30).

CONCLUSIONS

All treatments examined were associated with beneficial effects on fractures and femoral neck BMD relative to placebo. For vertebral fractures and percentage change in femoral neck BMD the treatment effects were statistically significant for all treatments. Pairwise comparisons between treatments indicated that no active treatment was statistically significantly more effective than any other active treatment for fracture outcomes. There was some heterogeneity in treatment effects between studies suggesting differential treatment effects according to study characteristics; however, there was no evidence of differential treatment effects with respect to gender and age.

Inhibition of Osteoclast Differentiation and Bone Resorption by Bisphosphonate-conjugated Gold Nanoparticles

In recent years, gold nanoparticles (GNPs) have been reported to affect the regeneration of bone tissue. The goal of this study was to improve bone tissue regeneration by using targeted GNPs. We fabricated a functionalized GNPs conjugated with alendronate (ALD), of the bisphosphonate group. Subsequently, the ALD, GNPs, and ALD conjugated GNPs (GNPs-ALD) were analyzed by ultraviolet-visible absorbance (UV-vis) spectrophotometer, Attenuated total reflectance Fourier transform infrared spectrometer (ATR-FTIR), and thermo gravimetric analysis (TGA). The prepared GNPs-ALD were used to investigate their inhibitory effects on the receptor activator of nuclear factor- κb ligand (RANKL)-induced osteoclastogenesis in bone marrow-derived macrophages (BMMs). Additionally, the GNPs-ALD were applied to ovariectomy (OVX)-induced osteoporotic mice and the experiments were evaluated. ALD was found to be successfully conjugated to the GNPs surface, and it displayed significant adhesion onto the bone surface. The in-vitro study indicated that the GNPs, ALD and GNPs-ALD suppressed osteoclast formation in a dose-dependent manner. Furthermore, in the OVX mouse model, the mice treated GNPs-ALD had higher bone density as compared to other OVX mice groups. The results from these tests indicated that GNPs-ALD can be useful agents for preventing and treating osteoporosis.

Protective Effects of Simvastatin Against Alendronate-Induced Gastric Mucosal Injury in Rats

BACKGROUND

It has been reported that simvastatin, a statin commonly prescribed for its anti-inflammatory and antioxidant effects, has gastroprotective effects in indomethacin and ethanol-induced gastric ulcers. However, the effects of simvastatin on alendronate-induced gastric mucosal injury remain unexplored.

AIM

This study investigated the use of simvastatin for the treatment of alendronate-induced gastric ulcers in rats.

METHODS

Female rats were pretreated with vehicle or simvastatin (20 and 60 mg/kg p.o.). After 1 h, the rats received alendronate (50 mg/kg p.o.). Simvastatin was administered once daily for 7 days, and from the fourth day of simvastatin treatment, alendronate was administered once daily for 4 days. On the final day of treatment, 4 h after alendronate administration, animals were euthanized, their stomachs were removed, and gastric damage was measured. Samples of the stomach were fixed in 10 % formalin immediately after their removal for subsequent histopathological assessment. Unfixed samples were weighed, frozen at -80 °C until assayed for glutathione (GSH), malondialdehyde (MDA), and cytokine levels and myeloperoxidase (MPO) activity. A third group was used to measure mucus and gastric secretion.

RESULTS

Pretreatment with simvastatin prevented alendronate-induced macroscopic gastric damage and reduced the levels of MDA and GSH, TNF-α and IL-1β, MPO activity, and mucus levels, in the stomach.

CONCLUSIONS

This study demonstrates the protective effects of simvastatin against alendronate-induced gastric ulceration. Maintenance of mucosal integrity, inhibition of neutrophil activity, and reduced oxidative stress associated with decreased gastric acidity may explain the gastroprotective effects of simvastatin.

Relationship of Bisphosphonate Therapy and Atrial Fibrillation/Flutter: Outcomes of Sleep Disorders in Older Men (MrOS Sleep) Study

BACKGROUND

Prior studies suggested an association between bisphosphonates and atrial fibrillation/flutter (AF) in women. This relationship in men, including those with sleep-disordered breathing (SDB), remains unclear. This study evaluated the relationship between bisphosphonate use and prevalent (nocturnal) and incident (clinically relevant) AF in a population of community-dwelling older men.

METHODS

A total of 2,911 male participants (mean age, 76 years) of the prospective observational Osteoporotic Fractures in Men Study sleep cohort with overnight in-home polysomnography (PSG) constituted the analytic cohort. Nocturnal AF from ECGs during PSG and incident AF events were centrally adjudicated. The association of bisphosphonate use and AF was examined using multivariable-adjusted logistic regression for prevalent AF and Cox proportional hazards regression for incident AF.

RESULTS

A total of 123 (4.2%) men were current bisphosphonate users. Prevalent nocturnal AF was present in 138 participants (4.6%). After multivariable adjustment, there was a significant association between current bisphosphonate use and prevalent AF (OR, 2.33; 95% CI, 1.13-4.79). In the subset of men with moderate to severe SDB, this association was even more pronounced (OR, 3.22; 95% CI, 1.29-8.03). However, the multivariable-adjusted relationship between bisphosphonate use and incident AF did not reach statistical significance (adjusted hazard ratio, 1.53; 95% CI, 0.96-2.45).

CONCLUSIONS

These results support an association between bisphosphonate use and prevalent nocturnal AF in community-dwelling older men. The data further suggest that those with moderate to severe SDB may be a particularly vulnerable group susceptible to bisphosphonate-related AF. Similar associations were not seen for bisphosphonate use and clinically relevant incident AF.

An overview of normocalcemic primary hyperparathyroidism

PURPOSE OF REVIEW

Normocalcemic primary hyperparathyroidism (PHPT) received special attention in the publication of the conference proceedings from the Fourth International Workshop on the Management of Asymptomatic PHPT, although much remains unknown about the disorder.

RECENT FINDINGS

Observational studies have found that despite maintaining normocalcemia, patients with normocalcemic PHPT have a high incidence of kidney stones and osteoporosis. Small studies focusing on the cardiovascular implications of normocalcemic PHPT have shown a possible association with hypertension and an atherogenic lipid profile, but not insulin resistance. Recent data from small cohorts show that subjects with normocalcemic PHPT respond to medical therapy and have a positive densitometric response following parathyroid surgery.

SUMMARY

The available evidence suggests that patients with normocalcemic PHPT develop complications of PHPT, despite having normal calcium levels. Most data come from referral populations and information regarding a mild, asymptomatic form of the disease is lacking. Future research requires a standardized approach to the diagnostic criteria of normocalcemic PHPT.

Clodronate: new directions of use

Clodronate is the father of bisphosphonates. For over three decades it has been subject of study in biological and clinical areas, proving to be an extremely interesting molecule from different points of view. It has been the first drug for osteoporosis that can be administered pulsatorily (once every 15 days or once a week). This, along with good tolerability, has been the first cause of its success, when there were no solid data in literature about its antifracture efficacy. There are three published studies that prove its antifracture effect: two by McCloskey published in 2004 and 2007 on BMR, and our study about fracture prevention in corticosteroids OP. In these studies a dose of 800 mg/day orally administered or 100 mg/week I.M. was used, and they are basically the same if you consider that clodronate absorption, orally administered, is on average 1.9%. However, a series of works where higher doses were used (1600 mg orally administered) with greater effectiveness on bone mass, especially in higher risk populations, lead us to consider the use of 200 mg i.m. formulation. First of all, we proved densitometric equivalence of 200 mg i.m./14 days and 100 mg i.m./week in a first study; then, in a second study, we proved a greater densitometric efficacy of 200 mg/week compared to 100 mg/week, clearer at femoral level, where the drug had not proven to prevent femoral fracture because of inadequate bone mass increase at that level. Moreover, as for ibandronate case, monthly dose was doubled compared to pivotal trial, in order to maximize the effects on femoral bone mass and therefore prevent femoral fractures. Consequently, on the basis of the risk envelope, whether it is identified according to BMD and the presence of one risk factor at least or more correctly identified through risk chart (FRAX or DeFRA), you can put forward a differential use of 100 mg i.m. and 200 mg i.m., weekly, "off-label" or every 14 days, adjusting doses in relation to fracture risk and painful symptoms gravity, as well as improving its ease of use and therefore assist compliance. Common experience and clinical and biological works have proved that clodronate has an analgesic effect that can be increased by doubling the doses. The analgesic effect is present not only with patients with fractures, but also with patients suffering from osteoarthritis or arthritis. Therefore, the drug would fit well in the therapeutic program of rheumatic patient, also because of its symptomatic effects. Clodronate at small doses (2 mg) could also have protective effects on cartilage (introduction of intra-articular formulation is expected) and at 10-100 fold higher doses it has certainly anti-inflammatory effects and more specifically antimacrophage and anticytokine effects (IL-1, IL-6, TNFalpha, PGE). These effects are amplified by putting clodronate in monolayer liposomes. This drug, therefore, has to be considered as adjuvant in arthritis therapy, whose origin can be linked to a strong osteoclastic activation caused by an increase of cytokines and the RANKL/OPG relationship. It is clear that clodronate can work on cytokine at first and on osteoclastic effector in the end. The drug has been used "off-label" for decades intravenously in complex regional pain syndrome (CRPS type 1) in relation to schemes that change according to different Authors and according to cumulative doses ranging from 3 to 5 g. The introduction on the market of the 200 mg i.m. formulation could allow to get more practical but equally effective schemes. For example, we used this scheme: 200 mg/day for 10 days and then 200 mg every other day for 20 days (cumulative dose of 4 g in a month). Said scheme can be repeated in the following months in particular cases. Results, as for efficacy and lack of relapses, show that clodronate is the leader drug for this syndrome. In recent years, relationship between costs and benefits has started to matter, especially after the creation of some algorithms, such as FRAX, that let us choose patients with a higher fracture risk in 10 years, and after pharmaceutic-economic models that let us calculate FRAX intervention threshold, on the basis of drug price and monitoring, antifracture efficacy, quality of life and how much a community can or wants to spend. In this respect, a sub-analysis of McCloskey's study on people over the age of 75, conducted on 3974 subjects, shows that clodronate is more efficient with patients with a higher fracture risk, calculated according to FRAX. Furthermore, another study by McCloskey revealed that, for a 100-pound/year drug (very similar to clodronate), 'cost effective' intervention threshold is about 7-10%. In conclusion, clodronate prevents fractures, decrease osteo-articular pain, is easy to handle, tolerable and had a great cost/benefit relationship.

Drug induced osteonecrosis of the jaw

Despite the widespread use of bisphosphonates and their unequivocal efficacy for the treatment of various disease states, osteonecrosis of the jaw remains one of the most feared complications associated with their use. Current evidence, however, suggests that there is also a relationship between occurrence of osteonecrosis of the jaw and use of other classes of pharmacotherapies namely RANKL inhibitors as well as angiogenesis inhibitors. Although these drugs have different mechanisms of action than bisphosphonates, they all seem to interfere with the bone remodeling process i.e. alter the balance between bone resorption and bone formation which may be the most plausible explanation for pathogenesis of osteonecrosis of the jaw. The main objective of this review is to introduce the readership to a number of relatively new medications that may cause osteonecrosis of the jaw. Accordingly, we will summarize latest findings from clinical studies, meta analyses and case reports published in medical literature on this topic. For some of these medications, the evidence may not appear as robust as that for bisphosphonates; yet, the possibility of this adverse event occurring with these non bisphosphonate drugs should never be precluded unless proven otherwise. Thus, it is imperative that health care providers implement preventive measures so as to circumvent the incidence of osteonecrosis of the jaw. In this day of age where medical care is becoming personalized, we will highlight some of significant findings from studies seeking to identify genetic markers that may potentially play a role in development of osteonecrosis of the jaw.

The potential impact of new effervescent alendronate formulation on compliance and persistence in osteoporosis treatment

Osteoporotic fractures are a public health problem and their incidence and subsequent economic and social costs are expected to rise in the next future. Different drugs have been developed to reduce osteoporosis and the risk of osteoporotic fractures, and among them, antiresorptive agents, and in particular oral alendronate, are the most widely utilized. However, one of the most common problems with antiresorptive drugs is poor adherence to treatment, which is associated with a high fracture incidence and with an increase in hospitalization costs. One of the main reasons of poor adherence to these treatments is the occurrence of adverse events, mainly at gastrointestinal (GI) level, including dyspepsia, dysphagia, and esophageal ulcers. In light of these considerations the aim of this paper is to perform a literature review to show the pathophysiologic bases of GI alendronate-induced adverse events and how new bisphosphonate formulations like effervescent alendronate can improve compliance and persistence to treatment and decrease the fracture rate incidence in osteoporotic patients.

User-only design to assess drug effectiveness in clinical practice: application to bisphosphonates and secondary prevention of fractures

PURPOSE

Different strategies applicable to control for confounding by indication in observational studies were compared in a large population-based study regarding the effect of bisphosphonates (BPs) for secondary prevention of fractures.

METHODS

The cohort was drawn from healthcare utilization databases of 13 Italian territorial units. Patients aged 55 years or more who were hospitalized for fracture during 2003-2005 entered into the cohort. A nested case-control design was used to compare BPs use in cohort members who did (cases) and who did not experience (controls) a new fracture until 2007 (outcome). Three designs were employed: conventional-matching (D1 ), propensity score-matching (D2 ), and user-only (D3 ) designs. They differed for (i) cohort composition, restricted to patients who received BPs straight after cohort entry (D3 ); (ii) using propensity score for case-control matching (D2 ); and (iii) compared groups of BPs users versus no users (D1 and D2 ) and long-term versus short-term users (D3 ).

RESULTS

Bisphosphonate users had odds ratios (95% confidence interval) of 1.20 (1.01 to 1.44) and 0.95 (0.74 to 1.24) by applying D1 and D2 designs, respectively. Statistical evidence that long-term BPs use protects the outcome onset with respect to short-term use was observed for user-only design (D3 ) being the corresponding odds ratio (95% confidence interval) 0.64 (0.44 to 0.93).

CONCLUSIONS

User-only design yielded closer results to those seen in RCTs. This approach is one possible strategy to account for confounding by indication.

Systematic review and meta-analysis of the efficacy and safety of alendronate and zoledronate for the treatment of postmenopausal osteoporosis

The aim of this meta-analysis was to evaluate the efficacy and safety of two bisphosphonates (alendronate and zoledronate) in the treatment of postmenopausal osteoporosis. The incidence of fractures was considered as primary endpoint. Only randomized trials with a follow-up period of 1 year or more were included in this systematic review and meta-analysis. We excluded studies that included patients with secondary osteoporosis especially in relation to therapy with corticosteroids or other drugs or diseases known to affect bone mineral density. Studies published as subgroup analysis, extension studies, economic evaluations, and comparisons with active control were excluded. The methodological quality of controlled clinical trials that met these inclusion criteria was evaluated. No studies were excluded from analysis due to lack of quality. The risk ratio of hip, vertebral and wrist fractures for alendronate were 0.61 [95% confidence interval (CI) 0.40-0.93], 0.54 (95% CI 0.44-0.66) and 0.65 (95% CI 0.33-1.25), respectively. Zoledronate risk ratio was 0.62 (95% CI 0.46-0.82) and 0.38 (95% CI 0.22-0.67) for hip and vertebral fractures, respectively.

Adherence to raloxifene therapy: assessment methods and relationship with efficacy

Response to therapy depends on patient compliance but accurate assessment is difficult and adequate levels of adherence are uncertain. Adherence to raloxifene treatment may be assessed more accurately by electronic monitoring than by counting returned tablets. The level of adherence is positively associated with the degree of bone response.

INTRODUCTION

Adherence to study medication is usually estimated by counting returned tablets. This method relies on subjects' honesty and may be inaccurate. We aimed to assess adherence more accurately, and examine its effect on measures of bone response, by using electronic monitoring.

METHODS

Osteopenic women, ages 50 to 80, were prescribed daily raloxifene for 2 years. Electronic bottle caps (Medication Event Monitoring System (MEMS), Aardex) recorded the date and time on opening. Returned tablets were also counted. We measured bone mineral density (BMD) in duplicate at the spine and hip at baseline and 2 years. We also measured urinary N-terminal cross-linked telopeptide of type I collagen (NTX) at baseline, 1 and 2 years. We calculated the percentage changes in BMD and NTX from mean baseline to mean follow up measurements. Percentage adherence was assessed by both methods for 71 subjects that completed the study.

RESULTS

The two methods correlated significantly (p <0.001, Spearman's rho = 0.73) but the tablet count showed a higher median adherence than the MEMS caps (95.7 vs. 85.0%, p <0.001), with greater divergence at lower adherence levels. MEMS adherence in 65 subjects with complete data correlated with NTX response (p <0.01, rho = -0.33) but with BMD response only at the femoral neck. However, adherence in the lowest quartile was associated with poorer BMD response at all sites (p <0.05).

CONCLUSION

Tablet counts may give similar results overall but conceal substantial individual non-adherence. Monitoring caps may assess adherence more accurately than tablet counts and would be the preferred method in clinical trials. The degree of adherence is associated with both bone turnover and BMD responses to anti-resorptive therapy.

Effect of odanacatib on bone turnover markers, bone density and geometry of the spine and hip of ovariectomized monkeys: a head-to-head comparison with alendronate

Odanacatib (ODN) is a selective and reversible Cathepsin K (CatK) inhibitor currently being developed as a once weekly treatment for osteoporosis. Here, effects of ODN compared to alendronate (ALN) on bone turnover, DXA-based areal bone mineral density (aBMD), QCT-based volumetric BMD (vBMD) and geometric parameters were studied in ovariectomized (OVX) rhesus monkeys. Treatment was initiated 10 days after ovariectomy and continued for 20 months. The study consisted of four groups: L-ODN (2 mg/kg, daily p.o.), H-ODN (8/4 mg/kg daily p.o.), ALN (15 μg/kg, twice weekly, s.c.), and VEH (vehicle, daily, p.o.). L-ODN and ALN doses were selected to approximate the clinical exposures of the ODN 50-mg and ALN 70-mg once-weekly, respectively. L-ODN and ALN effectively reduced bone resorption markers uNTx and sCTx compared to VEH. There was no additional efficacy with these markers achieved with H-ODN. Conversely, ODN displayed inversely dose-dependent reduction of bone formation markers, sP1NP and sBSAP, and L-ODN reduced formation to a lesser degree than ALN. At month 18 post-OVX, L-ODN showed robust increases in lumbar spine aBMD (11.4%, p<0.001), spine trabecular vBMD (13.7%, p<0.001), femoral neck (FN) integral (int) vBMD (9.0%, p<0.001) and sub-trochanteric proximal femur (SubTrPF) int vBMD, (6.4%, p<0.001) compared to baseline. L-ODN significantly increased FN cortical thickness (Ct.Th) and cortical bone mineral content (Ct.BMC) by 22.5% (p<0.001) and 21.8% (p<0.001), respectively, and SubTrPF Ct.Th and Ct.BMC by 10.9% (p<0.001) and 11.3% (p<0.001) respectively. Compared to ALN, L-ODN significantly increased FN Ct. BMC by 8.7% (p<0.05), and SubTrPF Ct.Th by 7.6% (p<0.05) and Ct.BMC by 6.2% (p<0.05). H-ODN showed no additional efficacy compared to L-ODN in OVX-monkeys in prevention mode. Taken together, the results from this study have demonstrated that administration of ODN at levels which approximate clinical exposure in OVX-monkeys had comparable efficacy to ALN in DXA-based aBMD and QCT-based vBMD. However, FN cortical mineral content clearly demonstrated superior efficacy of ODN versus ALN in this model of estrogen-deficient non-human primates.

Does estrogen play a role in response to adjuvant bone-targeted therapies?

Bone remains the most common site of breast cancer recurrence. The results of population studies, pre-clinical research and clinical studies in patients with metastatic disease provided a rationale for testing bone-targeted agents in the adjuvant setting. Despite the initial optimism, results from eight prospectively designed, randomized control studies powered to assess the value of adjuvant bone-targeted therapy in early breast cancer are conflicting. Data have shown that, where benefit exists, it tends to be in women with a “low estrogen environment”, either through menopause or suppression of ovarian function. In this manuscript, we review clinical data supporting the hypothesis that estrogen levels may play a part in explaining the response of patients to bone-targeted agents in the adjuvant setting. The results presented to date suggest that there may be data supporting a unifying role for estrogen in adjuvant trials. However, in the absence of any prospective randomized trials in which estrogen data has been systematically collected we cannot specifically answer this question. We await the results of the Oxford overview analysis of individual patient data with interest.

Adherence with bisphosphonate therapy and change in bone mineral density among women with osteoporosis or osteopenia in clinical practice

In clinical practice, adherence with bisphosphonate therapy varies greatly among women with osteoporosis or osteopenia. Our study suggests that better adherence with bisphosphonates confers tangible benefits in terms of graded increases in bone mineral density. Interventions to improve drug adherence should be an important component of disease management.

INTRODUCTION

In clinical trials, bisphosphonates have been found to increase bone mineral density (BMD) in women with osteoporosis or osteopenia. In clinical practice, where drug adherence is more variable, change in BMD with bisphosphonate therapy-overall and by level of adherence-is largely unknown.

METHODS

A retrospective cohort study was conducted at Henry Ford Health System (Detroit, MI, USA). Study subjects were women who had low BMD at the left total hip (T-score<-1.0), began oral bisphosphonate therapy, and had ≥1 BMD measurements at the left total hip≥6 months following treatment initiation. Change in BMD was calculated between the most recent pretreatment scan and the first follow-up scan. Adherence (i.e., medication possession ratio (MPR)) was measured from therapy initiation to the first follow-up scan.

RESULTS

Among 644 subjects, mean age was 66 years, pretreatment BMD was 0.73 g/cm2, and pretreatment T-score was -1.8. Over a mean follow-up of 27.1 months, mean MPR was 0.57 (95% CI, 0.54 and 0.59), and mean percentage change in BMD was 1.5% (1.1 and 1.9%). Within the MPR strata (five consecutive equi-intervals, from low (0-0.19) to high (0.80-1.0)), mean change in BMD was -0.8% (-1.6 and 0.1%), 0.7% (-0.3 and 1.7%), 2.1% (1.1 and 3.0%), 2.1% (1.4 and 2.9%), and 2.9% (2.3 and 3.5%), respectively. In adjusted analyses, percentage change in BMD was higher (by 1.4-3.4%, p<0.05 for all) in the highest four MPR intervals, respectively, versus MPR 0-0.19.

CONCLUSIONS

Among women with osteoporosis or osteopenia in clinical practice, better adherence with bisphosphonates appears to confer tangible benefits in terms of increases in BMD.

Bisphosphonate therapy for osteoporosis: benefits, risks, and drug holiday

The amino-bisphosphonates are first-line therapy for the treatment of most patients with osteoporosis, with proven efficacy to reduce fracture risk at the spine, hip, and other nonvertebral skeletal sites. Further, bisphosphonates have been associated with a significant decrease in morbidity and increase in survival. Following the use of bisphosphonates in millions of patients in clinical practice, some unexpected possible adverse effects have been reported, including osteonecrosis of the jaw, atypical femur fractures, atrial fibrillation, and esophageal cancer. Because bisphosphonates are incorporated into the skeleton and continue to exert an antiresorptive effect for a period of time after dosing is discontinued, the concept of a drug holiday has emerged, whereby the risk of adverse effects might be decreased while the patient still benefits from antifracture efficacy. Patients receiving bisphosphonates who are not at high risk for fracture are potential candidates for a drug holiday, while for those with bone mineral density in the osteoporosis range or previous history of fragility fracture, the benefits of continuing therapy probably far outweigh the risk of harm.

A meta-analysis characterizing the dose-response relationships for three oral nitrogen-containing bisphosphonates in postmenopausal women

A meta-analysis of spine BMD dose-response relationships for alendronate, risedronate, and ibandronate was performed. Data from all three oral bisphosphonates conform to a log-linear relationship between dose and change in spine BMD relative to placebo at 1 year, with an incremental gain of about 1 % for each doubling of dose.

INTRODUCTION

Animal data suggesting differences in potency and differences in approved oral dosage strengths for alendronate, risedronate, and ibandronate in the treatment of osteoporosis raise questions about their dose-response relationships and relative potencies in humans.

METHODS

A meta-analysis of dose-response relationships for spine BMD increases for these three bisphosphonates was performed using data from 21 placebo-controlled trials that collectively included over 13,000 patients on active treatment and over 8,000 on placebo.

RESULTS

For alendronate over the range of 1 to 20 mg/day, there was a strong log-linear relationship between dose and the increase in spine BMD relative to placebo at 1 year (R (2) = 0.994 using sample-weighted means). For each doubling in alendronate dose, there was an incremental gain of about 1 % in spine BMD. On the same scale, risedronate and ibandronate are approximately equipotent to alendronate on a weight-for-weight basis. The increases in BMD efficacy with each doubling of dose are parallel for all three nitrogen-containing bisphosphonates (NCBPs).

CONCLUSIONS

All three NCBPs are approximately equipotent and exhibit a log-linear relationship between dose and the increase in spine BMD. Differences in efficacy between the available oral bisphosphonate regimens appear to be a function of dose rather than inherent differences in therapeutic potential.

Bisphosphonate-induced Severe Hypocalcemia - A Case Report -

Bisphosphonate generally seems to be safe, but hypocalcemia may occasionally develop in the course of bisphosphonate treatment. Hypocalcemia induced by bisphosphonate is usually mild and asymptomatic, but unrecognized or poorly treated hypocalcemia can lead to life-threatening state. A 78-year-old woman who had a history of hip arthroplasty and intravenous zoledronate treatment for femur neck fracture was presented to emergency department with altered mental status. It turned out that her symptom was due to severe hypocalcemia which was caused by intravenous zoledronate treatment. She also had renal dysfunction. She was treated by intravenous calcium gluconate and calcitriol administration. This case supports the need for evaluation of renal dysfunction, vitamin D deficiency and parathyroid gland dysfunction before bisphosphonate treatment and accurate monitoring of plasma calcium and creatinine levels. In addition, vitamin D and calcium supply during treatment with bisphosphonate is mandatory.