Cost-effective but clinically inappropriate: new NICE intervention thresholds in osteoporosis (Technology Appraisal 464)

PURPOSE

To comment on the latest technology appraisal of the National Institute for Clinical Excellence (NICE) in osteoporosis.

METHODS

Review of NICE Technology Appraisal (TA464) on bisphosphonate use in osteoporosis.

RESULTS

The NICE appraisal on bisphosphonate use in osteoporosis indicates that treatment with oral bisphosphonates may be instituted at a FRAX 10-year probability of major osteoporotic fracture above 1%. Implementation would mean that all women aged 50 years or older are deemed eligible for treatment, a position that would increase the burden of rare long-term side effects across the population.

CONCLUSION

Cost-effectiveness thresholds for low-cost interventions should not be used to set intervention thresholds but rather to validate the implementation of clinically driven intervention thresholds.

Type 2 diabetes mellitus and bone

Type 2 diabetes (T2DM) is a rapidly growing public health problem. It is associated with an increased risk of fracture, particularly of the hip, despite normal or high bone mineral density. Longer duration of disease and poor glycaemic control are both associated with higher fracture risk. The factors underlying increased fracture risk have not been clearly established, but increased falls risk, obesity, sarcopenia and co-morbidities are likely to contribute. The basis for reduced bone strength despite higher bone mineral density remains to be fully elucidated. Bone turnover is reduced in individuals with T2DM, with evidence of impaired bone formation. Most studies indicate normal or superior trabecular bone structure although reduced lumbar spine trabecular bone score (TBS) has been reported. Deficits in cortical bone structure have been demonstrated in some, but not all, studies whilst reduced bone material strength index (BMSi), as assessed by microindentation, has been a consistent finding. Accumulation of advanced glycation end products in bone may also contribute to reduced bone strength. The use of FRAX in individuals with T2DM underestimates fracture probability. Clinical management should focus on falls prevention strategies, avoidance of known risk factors, maintenance of good glycaemic control and bone protective intervention in individuals at high risk of fracture. Dietary and surgical strategies to reduce weight have beneficial effects on diabetes but may have adverse effects on skeletal health. Future research priorities include better definition of the mechanisms underlying increased fracture risk in T2DM and optimal strategies for identifying and treating those at high risk.

UK clinical guideline for the prevention and treatment of osteoporosis

INTRODUCTION

In 2008, the UK National Osteoporosis Guideline Group (NOGG) produced a guideline on the prevention and treatment of osteoporosis, with an update in 2013. This paper presents a major update of the guideline, the scope of which is to review the assessment and management of osteoporosis and the prevention of fragility fractures in postmenopausal women and men age 50 years or over.

METHODS

Where available, systematic reviews, meta-analyses and randomised controlled trials were used to provide the evidence base. Conclusions and recommendations were systematically graded according to the strength of the available evidence.

RESULTS

Review of the evidence and recommendations are provided for the diagnosis of osteoporosis, fracture-risk assessment, lifestyle measures and pharmacological interventions, duration and monitoring of bisphosphonate therapy, glucocorticoid-induced osteoporosis, osteoporosis in men, postfracture care and intervention thresholds.

CONCLUSION

The guideline, which has received accreditation from the National Institute of Health and Care Excellence (NICE), provides a comprehensive overview of the assessment and management of osteoporosis for all healthcare professionals who are involved in its management.

Access to fracture risk assessment by FRAX and linked National Osteoporosis Guideline Group (NOGG) guidance in the UK-an analysis of anonymous website activity

In the UK, fracture risk guidance is provided by the National Osteoporosis Guideline Group (NOGG). NOGG usage showed widespread access through direct web-based linkage to FRAX. The facilitated interaction between fracture risk assessment and clinical guidelines could usefully be adopted in other countries.

INTRODUCTION

In the UK, guidance on assessment of osteoporosis and fracture risk is provided by the National Osteoporosis Guideline Group ( www.shef.ac.uk/NOGG ). We wished to determine access to this guidance by exploring website activity.

METHODS

We undertook an analysis of FRAX and NOGG website usage for the year between 1^st July 2013 and 30^th June 2014 using Google Analytics software.

RESULTS

During this period, there was a total of 1,774,812 sessions (a user interaction with the website) on the FRAX website with 348,964 of these from UK-based users; 253,530 sessions were recorded on the NOGG website. Of the latter, two-thirds were returning visitors, with the vast majority (208,766; 82 %) arising from sites within the UK. The remainder of sessions were from other countries demonstrating that some users of FRAX in other countries make use of the NOGG guidance. Of the UK-sourced sessions, the majority was from England, but the session rate (adjusted for population) was the highest for Scotland. Almost all (95.7 %) of the UK sessions arose from calculations being passed through from the FRAX tool ( www.shef.ac.uk/FRAX ) to the NOGG website, comprising FRAX calculations in patients without a bone mineral density (BMD) measurement (74.5 %) or FRAX calculations with a BMD result (21.2 %). National Health Service (NHS) sites were identified as the major source of visits to the NOGG website, comprising 79.9 % of the identifiable visiting locations, but this is an underestimate as many sites from within the NHS are not classified as such.

CONCLUSION

The study shows that the facilitated interaction between web-based fracture risk assessment and clinical guidelines is widely used in the UK. The approach could usefully be adopted in other countries for which a FRAX model is available.

The role of tenofovir alafenamide in future HIV management

HIV infection has become a chronic condition rather than an acute life-threatening disease in developed countries, thanks to consistent innovation and evolution of effective interventions. This has altered HIV management and created new challenges. People living with HIV (PLWHIV) are living longer and so encounter comorbidities linked not only with their disease, but also with ageing, lifestyle and chronic exposure to antiretroviral therapy (ART). Although longevity, viral suppression and the prevention of viral transmission remain key goals, more needs to be achieved to encompass the vision of attaining an optimum level of overall health. Treatment choices and management practices should ensure patients' long-term health with minimal comorbidity. Treatments that balance optimal efficacy with the potential for improved long-term safety are needed for all patients. In this review, we consider the evolution and development of tenofovir alafenamide (TAF), a novel prodrug of tenofovir which offers high antiviral efficacy at doses over ten times lower than that of tenofovir disoproxil fumarate (TDF). Emerging clinical data suggest that elvitegravir, cobicistat, emtricitabine and TAF (E/C/F/TAF) as a single-tablet regimen offers highly effective viral suppression in treatment-naïve and treatment-experienced patients with an improved renal and bone safety profile compared with TDF, this having been demonstrated in diverse groups including patients with existing renal impairment and adolescents. The profile of TAF identifies it as an agent with a promising role within future ART regimens that aim to deliver the vision of undetectable viral load, while requiring less monitoring and having a safety profile designed to minimize comorbid risks while supporting good long-term health.

HIV infection and bone disease

The success of antiretroviral therapy in treating HIV infection has greatly prolonged life expectancy in affected individuals, transforming the disease into a chronic condition. A number of HIV-associated non-AIDS comorbidities have emerged in the ageing HIV-infected population, including osteoporosis and increased risk of fracture. The pathogenesis of fracture is multifactorial with contributions from both traditional and HIV-specific risk factors. Significant bone loss occurs on initiation of antiretroviral therapy but stabilizes on long-term therapy. Fracture risk assessment should be performed in HIV-infected individuals and bone mineral density measured when indicated. Lifestyle measures to optimize bone health should be advised and, in individuals at high risk of fracture, treatment with bisphosphonates considered.

Osteonecrosis of the jaw (ONJ): diagnosis and management in 2015

Osteonecrosis of the jaw (ONJ) has been associated with the use of aminobisphosphonates and denosumab. The vast majority (>90%) of cases occur in the oncology patient population receiving high doses of intravenous bisphosphonates or subcutaneous denosumab. The incidence of ONJ in the osteoporosis patient population is very low and is estimated at 1-90 per 100,000 patient-years of exposure. In the oncology patient population the incidence appears to be related to dose and duration of exposure, and prevalence has been estimated to be as high as 18.6%. A number of risk factors in addition to antiresorptive therapy have been identified. These include the presence of periodontal disease, oral surgical procedures with extractions or implants, radiation therapy, chemotherapy, diabetes, glucocorticoid use, and smoking. Antiangiogenic agents appear to contribute to the risk of ONJ, however, data at this time are limited and further evidence is required prior to confirming a causal relationship. ONJ may be prevented with optimization of oral hygiene, the use of oral antimicrobial mouth rinses, as well as systemic antibiotic therapy. Individuals not responding to conservative management or in the advanced stages of ONJ may be considered for surgery, as data over the past several years have demonstrated surgical success in this patient population. Case reports have indicated that teriparatide may enhance healing. A number of experimental therapies are being evaluated and include the use of bone marrow stem cell intralesional transplantation, local application of platelet-derived growth factor, hyperbaric oxygen, tissue grafting, and low-level laser therapy. This paper summarizes the current research as well as the international consensus on the diagnosis and management of ONJ.

FRAX-based assessment and intervention thresholds--an exploration of thresholds in women aged 50 years and older in the UK

Under current guidelines, based on prior fracture probability thresholds, inequalities in access to therapy arise especially at older ages (≥70 years) depending on the presence or absence of a prior fracture. An alternative threshold (a fixed threshold from the age of 70 years) reduces this disparity, increases treatment access and decreases the need for bone densitometry.

INTRODUCTION

Several international guidelines set age-specific intervention thresholds at the 10-year probability of fracture equivalent to a woman of average BMI with a prior fracture. At older ages (≥70 years), women with prior fracture selected for treatment are at lower average absolute risk than those selected for treatment in the absence of prior fracture, prompting consideration of alternative thresholds in this age group.

METHODS

Using a simulated population of 50,633 women aged 50-90 years in the UK, with a distribution of risk factors similar to that in the European FRAX derivation cohorts and a UK-matched age distribution, the current NOGG intervention and assessment thresholds were compared to one where the thresholds remained constant from 70 years upwards.

RESULTS

Under current thresholds, 45.1% of women aged ≥70 years would be eligible for therapy, comprising 37.5% with prior fracture, 2.2% with high risk but no prior fracture and 5.4% selected for treatment after bone mineral density (BMD) measurement. Mean hip fracture probability was 11.3, 23.3 and 17.6%, respectively, in these groups. Under the alternative thresholds, the overall proportion of women treated increased from 45.1 to 52.9%, with 8.4% at high risk but no prior fracture and 7.0% selected for treatment after BMD measurement. In the latter group, the mean probability of hip fracture was identical to that observed in women with prior fracture (11.3%). The alternative threshold also reduced the need for BMD measurement, particularly at older ages (>80 years).

CONCLUSIONS

The alternative thresholds equilibrate fracture risk, particularly hip fracture risk, in those with or without prior fracture selected for treatment and reduce BMD usage at older ages.

Epidemiological burden of postmenopausal osteoporosis in Italy from 2010 to 2020: estimations from a disease model

The article describes the adaptation of a model to estimate the burden of postmenopausal osteoporosis in women aged 50 years and over in Italy between 2010 and 2020. For this purpose, a validated postmenopausal osteoporosis disease model developed for Sweden was adapted to Italy. For each year of the study, the 'incident cohort' (women experiencing a first osteoporotic fracture) was identified and run through a Markov model using 1-year cycles until 2020. Health states were based on the number of fractures and deaths. Fracture by site (hip, clinical vertebral, non-hip non-vertebral) was tracked for each health state. Transition probabilities reflected fracture site-specific risk of death and subsequent fractures. Model inputs specific to Italy included population size and life tables from 1970 to 2020, incidence of hip fracture and BMD by age in the general population (mean and standard deviation). The model estimated that the number of postmenopausal osteoporotic women would increase from 3.3 million to 3.7 million between 2010 and 2020 (+14.3%). Assuming unchanged incidence rates by age group over time, the model predicted the overall number of osteoporotic fractures to increase from 285.0 to 335.8 thousand fractures between 2010 and 2020 (+17.8%). The estimated expected increases in hip, vertebral and non-hip non-vertebral fractures were 22.3, 17.2 and 16.3%, respectively. Due to demographic changes, the burden of fractures is expected to increase markedly by 2020.

Diagnosis and management of osteoporosis in postmenopausal women and older men in the UK: National Osteoporosis Guideline Group (NOGG) update 2013

Since the launch in 2008 by the National Osteoporosis Guideline Group (NOGG), of guidance for the diagnosis and management of osteoporosis in postmenopausal women and older men in the UK there have been significant advances in risk assessment and treatment. These have been incorporated into an updated version of the guideline, with an additional focus on the management of glucocorticoid-induced osteoporosis, the role of calcium and vitamin D therapy and the benefits and risks of long-term bisphosphonate therapy. The updated guideline is summarised below. The recommendations in the guideline are intended to aid management decisions but do not replace the need for clinical judgement in the care of individuals in clinical practice.

Osteoporosis in the European Union: a compendium of country-specific reports

This report describes epidemiology, burden, and treatment of osteoporosis in each of the 27 countries of the European Union (EU27).

INTRODUCTION

In 2010, 22 million women and 5.5 million men were estimated to have osteoporosis in the EU; and 3.5 million new fragility fractures were sustained, comprising 620,000 hip fractures, 520,000 vertebral fractures, 560,000 forearm fractures and 1,800,000 other fractures. The economic burden of incident and prior fragility fractures was estimated at € 37 billion. Previous and incident fractures also accounted for 1,180,000 quality-adjusted life years lost during 2010. The costs are expected to increase by 25 % in 2025. The majority of individuals who have sustained an osteoporosis-related fracture or who are at high risk of fracture are untreated and the number of patients on treatment is declining. The aim of this report was to characterize the burden of osteoporosis in each of the EU27 countries in 2010 and beyond.

METHODS

The data on fracture incidence and costs of fractures in the EU27 were taken from a concurrent publication in this journal (Osteoporosis in the European Union: Medical Management, Epidemiology and Economic Burden) and country specific information extracted.

RESULTS

The clinical and economic burden of osteoporotic fractures in 2010 is given for each of the 27 countries of the EU. The costs are expected to increase on average by 25 % in 2025. The majority of individuals who have sustained an osteoporosis-related fracture or who are at high risk of fracture are untreated and the number of patients on treatment is declining.

CONCLUSIONS

In spite of the high cost of osteoporosis, a substantial treatment gap and projected increase of the economic burden driven by aging populations, the use of pharmacological prevention of osteoporosis has decreased in recent years, suggesting that a change in healthcare policy concerning the disease is warranted.

Osteoporosis in the European Union: medical management, epidemiology and economic burden. A report prepared in collaboration with the International Osteoporosis Foundation (IOF) and the European Federation of Pharmaceutical Industry Associations (EFPIA)

This report describes the epidemiology, burden, and treatment of osteoporosis in the 27 countries of the European Union (EU27).

INTRODUCTION

Osteoporosis is characterized by reduced bone mass and disruption of bone architecture, resulting in increased risk of fragility fractures which represent the main clinical consequence of the disease. Fragility fractures are associated with substantial pain and suffering, disability and even death for affected patients and substantial costs to society. The aim of this report was to characterize the burden of osteoporosis in the EU27 in 2010 and beyond.

METHODS

The literature on fracture incidence and costs of fractures in the EU27 was reviewed and incorporated into a model estimating the clinical and economic burden of osteoporotic fractures in 2010.

RESULTS

Twenty-two million women and 5.5 million men were estimated to have osteoporosis; and 3.5 million new fragility fractures were sustained, comprising 610,000 hip fractures, 520,000 vertebral fractures, 560,000 forearm fractures and 1,800,000 other fractures (i.e. fractures of the pelvis, rib, humerus, tibia, fibula, clavicle, scapula, sternum and other femoral fractures). The economic burden of incident and prior fragility fractures was estimated at <euro> 37 billion. Incident fractures represented 66 % of this cost, long-term fracture care 29 % and pharmacological prevention 5 %. Previous and incident fractures also accounted for 1,180,000 quality-adjusted life years lost during 2010. The costs are expected to increase by 25 % in 2025. The majority of individuals who have sustained an osteoporosis-related fracture or who are at high risk of fracture are untreated and the number of patients on treatment is declining.

CONCLUSIONS

In spite of the high social and economic cost of osteoporosis, a substantial treatment gap and projected increase of the economic burden driven by the aging populations, the use of pharmacological interventions to prevent fractures has decreased in recent years, suggesting that a change in healthcare policy is warranted.

Burden of postmenopausal osteoporosis in Germany: estimations from a disease model

This article describes the adaptation of a model assessing the incidence of osteoporotic fractures and prevalence of postmenopausal osteoporosis (PMO) in Germany.

PURPOSE

The purpose of this paper is to estimate the epidemiological burden of PMO in Germany from 2010 to 2020.

METHODS

For each year of the study, the 'incident cohort' (women experiencing a first osteoporotic fracture) was identified and run through a Markov model using 1-year cycles until 2020. Health states were based on the number of fractures (1, 2 or ≥3) and deaths. Although the fracture site was not explicitly accounted for in the model structure, the site (hip, vertebral, non-hip non-vertebral) was tracked for each health state. Transition probabilities reflected the site-specific risk of death and of subsequent fractures. Model inputs included population size and life tables from 1970 to 2020, incidence of fracture and BMD by age in the general population (mean and standard deviation).

RESULTS

In 2010, the number of osteoporotic fractures was estimated at 349,560 in women aged 50 years or more, including 80,177 hip and 48,550 vertebral fractures. By 2020, the population is expected to grow by 13.1 %. As a result, the number of fractures is predicted to increase by 15.2 %. The improvement in life expectancy is predicted to lead to a relatively smaller increase in the number of deaths attributable to fractures (+12.8 %), but also to an increase in the prevalence of women with multiple prior fractures (+25.5 %).

CONCLUSION

The PMO disease model, first developed for Sweden, was adapted to Germany. Due to the ageing of the population, the number of osteoporotic fractures is expected to increase markedly by +15.2 % by 2020.

Epidemiological burden of postmenopausal osteoporosis in France from 2010 to 2020: estimations from a disease model

This article estimates the present and future burden of postmenopausal osteoporosis in France in women aged 50 years and over.

METHODS

We adapted an existing model developed for Sweden to France. For each year of the study from 1970 to 2020, the 'incident cohort' (women experiencing a first osteoporotic fracture) was identified and run through a Markov model using annual cycles. Health states were based on the number of fractures (hip, vertebral, non-hip non-vertebral) and deaths. Transition probabilities reflected fracture site-specific risks of subsequent fractures and of death. Country-specific model inputs included population size and life tables from 1970 to 2020 and incidence of hip fracture.

RESULTS

The model estimated that the number of postmenopausal osteoporotic women was expected to increase from 3.0 million to 3.4 million between 2010 and 2020 (+15.3 %). Assuming that the incidence of fracture by age group does not change over time, the model predicted that the overall number of osteoporotic fractures would increase from 204,234 fractures in 2010 to 241,261 in 2020 (+18.1 %), hip (20.3 %), vertebral (19.0 %) and non-hip non-vertebral fractures (17.0 %).

CONCLUSION

The aging of the population is expected to drive a marked increase in the prevalence of osteoporosis and in the number of osteoporotic fractures. These data may assist future planning for appropriate heath care provision.

Antidepressant medications and osteoporosis

Use of antidepressant medications that act on the serotonin system has been linked to detrimental impacts on bone mineral density (BMD), and to osteoporosis. This article reviews current evidence for such effects, and identifies themes for future research. Serotonin receptors are found in all major types of bone cell (osteoblasts, osteocytes, and osteoclasts), indicating an important role of the neuroendocrine system in bone. Observational studies indicate a complex relationship between depression, antidepressants, and fracture. First, the presence of depression itself increases fracture risk, in relation with decreased BMD and an increase in falls. A range of aspects of depression may operate, including behavioral factors (e.g., smoking and nutrition), biological changes, and confounders (e.g., comorbidities and concomitant medications). A substantial proportion of depressed patients receive antidepressants, mostly selective serotonin reuptake inhibitors (SSRIs). Some of these have been linked to decreased BMD (SSRIs) and increased fracture risk (SSRIs and tricyclic agents). Current use of SSRIs and tricyclics increases fracture risk by as much as twofold versus nonusers, even after adjustment for potential confounders. While there is a dose-response relationship for SSRIs, the effect does not appear to be homogeneous across the whole class of drugs and may be linked to affinity for the serotonin transporter system. The increase in risk is the greatest in the early stages of treatment, with a dramatic increase after initiation, reaching a peak within 1 month for tricyclics and 8 months for SSRIs. Treatment-associated increased risk diminishes towards baseline in the year following discontinuation. The body of evidence suggests that SSRIs should be considered in the list of medications that are risk factors for osteoporotic fractures.

A comparison of case-finding strategies in the UK for the management of hip fractures

Treatment criteria published by the National Osteoporosis Guideline Group (NOGG) in the UK make more efficient use of bone mineral density (BMD) resources than the previous Royal College of Physicians (RCP) guideline.

INTRODUCTION

We compared the effectiveness of the RCP case-finding strategy previously used in the UK and the updated guideline published by NOGG, which incorporates the FRAX® fracture probability tool.

METHODS

Comparisons were made by simulating population samples of 1000 women at ages between 50 and 85 years, using age-specific prevalence of risk factors and UK-derived fracture and mortality rates. Comparators comprised the number identified at high risk, the incidence of hip fracture and the femoral neck BMD in those identified, the number needed to scan to identify a hip fracture, the acquisition cost and the cost per hip fracture averted

RESULTS

Compared with the RCP strategy, NOGG identified slightly reduced numbers of women at high risk (average 34.6% vs. 35.7% across all ages), but with lower numbers of scans required at each age. For example, NOGG required only 3.5 scans at the age of 50 years to identify one case of hip fracture, whereas RCP required 13.9. At 75 years, the corresponding numbers were 0.9 and 1.5. Thus, the acquisition costs for identifying a hip fracture case and the total costs (acquisition and treatment) per hip fracture averted were lower.

CONCLUSION

Compared to the RCP strategy, the FRAX-based NOGG strategy uses BMD resources more efficiently with lower acquisition costs and lower costs per hip fracture averted.

Quantitative ultrasound of the heel and fracture risk assessment: an updated meta-analysis

Meta-analysis of prospective studies shows that quantitative ultrasound of the heel using validated devices predicts risk of different types of fracture with similar performance across different devices and in elderly men and women. These predictions are independent of the risk estimates from hip DXA measures.

INTRODUCTION

Clinical utilisation of heel quantitative ultrasound (QUS) depends on its power to predict clinical fractures. This is particularly important in settings that have no access to DXA-derived bone density measurements. We aimed to assess the predictive power of heel QUS for fractures using a meta-analysis approach.

METHODS

We conducted an inverse variance random effects meta-analysis of prospective studies with heel QUS measures at baseline and fracture outcomes in their follow-up. Relative risks (RR) per standard deviation (SD) of different QUS parameters (broadband ultrasound attenuation [BUA], speed of sound [SOS], stiffness index [SI], and quantitative ultrasound index [QUI]) for various fracture outcomes (hip, vertebral, any clinical, any osteoporotic and major osteoporotic fractures) were reported based on study questions.

RESULTS

Twenty-one studies including 55,164 women and 13,742 men were included in the meta-analysis with a total follow-up of 279,124 person-years. All four QUS parameters were associated with risk of different fracture. For instance, RR of hip fracture for 1 SD decrease of BUA was 1.69 (95% CI 1.43-2.00), SOS was 1.96 (95% CI 1.64-2.34), SI was 2.26 (95%CI 1.71-2.99) and QUI was 1.99 (95% CI 1.49-2.67). There was marked heterogeneity among studies on hip and any clinical fractures but no evidence of publication bias amongst them. Validated devices from different manufacturers predicted fracture risks with similar performance (meta-regression p values > 0.05 for difference of devices). QUS measures predicted fracture with a similar performance in men and women. Meta-analysis of studies with QUS measures adjusted for hip BMD showed a significant and independent association with fracture risk (RR/SD for BUA = 1.34 [95%CI 1.22-1.49]).

CONCLUSIONS

This study confirms that heel QUS, using validated devices, predicts risk of different fracture outcomes in elderly men and women. Further research is needed for more widespread utilisation of the heel QUS in clinical settings across the world.

Pathophysiology of atypical femoral fractures and osteonecrosis of the jaw

In recent years, atypical femoral fractures and osteonecrosis of the jaw have emerged as potential complications of long-term bisphosphonate therapy; osteonecrosis of the jaw has also been reported in patients receiving high doses of denosumab. The pathophysiology of both conditions is poorly defined, and the underlying mechanisms are likely to differ. The initiation of atypical fractures in the lateral femoral shaft suggests that reduced tensile strength, possibly secondary to alterations in the material properties of bone resulting from low bone turnover, may be an important pathogenetic factor. Osteonecrosis of the jaw is characterised by infection, inflammation, bone resorption and bone necrosis, but the sequence in which these occur has not been established. However, the observation that bone resorption occurs in close proximity to microbial structures suggests that infection may be the most important trigger, often as a result of dental disease. Other possible pathogenetic factors include suppression of bone turnover, altered immune status and adverse effects of bisphosphonates on the oral mucosa.

Development and validation of a disease model for postmenopausal osteoporosis

This article describes the development of a model for postmenopausal osteoporosis (PMO) based on Swedish data that is easily adaptable to other countries.

INTRODUCTION

The aims of the study were to develop and validate a model to describe the current/future burden of PMO in different national settings.

METHODS

For validation purposes, the model was developed using Swedish data and provides estimates from 1990. For each year of the study, the "incident cohort" (women experiencing a first osteoporotic fracture) was identified and run through a Markov model using 1-year cycles until 2020. Health states were based on the number of fractures and death. Fracture by site (hip, vertebral, and non-hip non-vertebral) was tracked for each health state. Transition probabilities reflected site-specific risk of death and subsequent fractures. Bone mineral density (BMD) was included as a model output; model inputs included population size and life tables from 1970 to 2020, incidence of fracture, relative risk of subsequent fractures based on prior fracture, relative risk of death following a fracture by site, and BMD by age (mean and standard deviation).

RESULTS

Model predictions averaged across age groups estimated the incidence of hip, vertebral, and other osteoporotic fractures within a 5% margin of error versus published data. In Sweden, the number of osteoporotic fractures is expected to rise by 11.5% between 2009 and 2020, with a shift towards more vertebral fractures and multiple fractures.

CONCLUSION

The current PMO disease model is easily adaptable to other countries, providing a consistent measure of present and future burden of PMO in different settings.

Low rates of treatment in postmenopausal women with a history of low trauma fractures: results of audit in a Fracture Liaison Service

BACKGROUND

A past history of low trauma fracture is a strong risk factor for future fractures in postmenopausal women and national guidance recommends treatment in the majority of such women

AIM

To establish the prevalence of bone protective therapy use in postmenopausal women with a history of low trauma fracture Design and

METHODS

Clinical audit of 1641 postmenopausal women presenting with a low trauma fracture to the Fracture Liaison Service at Addenbrooke's Hospital, Cambridge between January 2006 and December 2007.

RESULTS

A total of 526 (31%) women presenting with a fracture had a past history of fracture, defined as a low trauma fracture after the age of 45 years. The wrist was the most common site of previous fracture, followed by hip, hand or foot, lower leg and humerus. Of these women, only 27.6% were receiving bone protective therapy with a bisphosphonate (89%) or other medication. Calcium and vitamin D supplements were received by 35.6%. The highest rates of treatment were seen for spine and hip fracture (61.9 and 49.3%, respectively). Only 45.1% of women aged 75 years and over with a previous history of fracture were receiving bone protective therapy.

CONCLUSION

The results of our audit demonstrate low rates of treatment in postmenopausal women with a history of low trauma fracture. Better education of healthcare professionals, more consistent recording of fractures in primary care and the use of clearly defined care pathways that involve patients and their carers provide rational approaches to reducing this care gap.

Effects of long-term strontium ranelate treatment on vertebral fracture risk in postmenopausal women with osteoporosis

SUMMARY

Vertebral fractures are a major adverse consequence of osteoporosis. In a large placebo-controlled trial in postmenopausal women with osteoporosis, strontium ranelate reduced vertebral fracture risk by 33% over 4 years, confirming the role of strontium ranelate as an effective long-term treatment in osteoporosis.

INTRODUCTION

Osteoporotic vertebral fractures are associated with increased mortality, morbidity, and loss of quality-of-life (QoL). Strontium ranelate (2 g/day) was shown to prevent bone loss, increase bone strength, and reduce vertebral and peripheral fractures. The preplanned aim of this study was to evaluate long-term efficacy and safety of strontium ranelate.

METHODS

A total of 1,649 postmenopausal osteoporotic women were randomized to strontium ranelate or placebo for 4 years, followed by a 1-year treatment-switch period for half of the patients. Primary efficacy criterion was incidence of patients with new vertebral fractures over 4 years. Lumbar bone mineral density (BMD) and QoL were also evaluated.

RESULTS

Over 4 years, risk of vertebral fracture was reduced by 33% with strontium ranelate (risk reduction = 0.67, p < 0.001). Among patients with two or more prevalent vertebral fractures, risk reduction was 36% (p < 0.001). QoL, assessed by the QUALIOST(R), was significantly better (p = 0.025), and patients without back pain were greater (p = 0.005) with strontium ranelate than placebo over 4 years. Lumbar BMD increased over 5 years in patients who continued with strontium ranelate, while it decreased in patients who switched to placebo. Emergent adverse events were similar between groups.

CONCLUSION

In this 4- and 5-year study, strontium ranelate is an effective and safe treatment for long-term treatment of osteoporosis in postmenopausal women.

The Global Longitudinal Study of Osteoporosis in Women (GLOW): rationale and study design

SUMMARY

The Global Longitudinal study of Osteoporosis in Women (GLOW) is a prospective cohort study involving 723 physicians and 60,393 women subjects >or=55 years. The data will provide insights into the management of fracture risk in older women over 5 years, patient experience with prevention and treatment, and distribution of risk among older women on an international basis.

INTRODUCTION

Data from cohort studies describing the distribution of osteoporosis-related fractures and risk factors are not directly comparable and do not compare regional differences in patterns of patient management and fracture outcomes.

METHODS

The GLOW is a prospective, multinational, observational cohort study. Practices typical of each region were identified through primary care networks organized for administrative, research, or educational purposes. Noninstitutionalized patients visiting each practice within the previous 2 years were eligible. Self-administered questionnaires were mailed, with 2:1 oversampling of women >or=65 years. Follow-up questionnaires will be sent at 12-month intervals for 5 years.

RESULTS

A total of 723 physicians at 17 sites in ten countries agreed to participate. Baseline surveys were mailed (October 2006 to February 2008) to 140,416 subjects. After the exclusion of 3,265 women who were ineligible or had died, 60,393 agreed to participate.

CONCLUSIONS

GLOW will provide contemporary information on patterns of management of fracture risk in older women over a 5-year period. The collection of data in a similar manner in ten countries will permit comparisons of patient experience with prevention and treatment and provide insights into the distribution of risk among older women on an international basis.

Non-compliance: the Achilles' heel of anti-fracture efficacy

About 50% of patients fail to comply or persist with anti-osteoporosis treatment regimens within 1 year. Poor compliance is associated with higher fracture rates. Causes of poor compliance are unknown. As it is not possible to predict poor compliance, close monitoring of compliance is needed. Despite evidence supporting the anti-fracture efficacy of several pharmacological agents, approximately 50% of patients do not follow their prescribed treatment regimen and/or discontinue treatment within 1 year. Poor compliance is associated with higher fracture rates and increased morbidity, mortality and cost. However, as poor compliance, even to placebo, is associated with adverse outcomes, the higher morbidity appears to be only partly the result of lack of treatment: as yet, undefined characteristics place poor compliers at higher risk of morbidity and mortality. Only a small proportion (e.g., 6%) of the variability in compliance is explained by putative causal factors such as older age, co-morbidity or greater number of medications. Regimens with longer dosing intervals, such as weekly dosing, improve compliance, persistence and outcomes, but only modestly. As it is not possible to predict poor compliance, close monitoring of compliance should be an obligatory duty in clinical care. How this is best achieved has yet to be established, but poor persistence occurs as early as 3 months of starting treatment, indicating the need for early monitoring.

Cross-calibration of dual-energy X-ray densitometers for a large, multi-center genetic study of osteoporosis

Osteoporosis is a common disease with a strong genetic component characterized by reduced bone mass and an increased risk of fragility fractures. Bone mineral density (BMD) is the most important determinant of osteoporotic fracture risk, but the genes responsible for BMD regulation and fracture are incompletely defined. To enable multi-center studies to examine the genetic influences on BMD there is a requirement to standardize measurements across different manufacturers of bone densitometers, different versions of machines and different normative ranges. This paper describes a method developed to allow near-identical subjects with low age-adjusted BMD (based on Z-scores) to be recruited in 17 centers using 27 different densitometers. Cross-calibration was based on measurements using a European spine phantom circulated to all centers and measured ten times on each individual machine. From theses values an individual exponential curve, based on nominal versus observed BMD, was derived for each machine. As expected, there were large and significant variations in nominal BMD values, not only between scanners from different manufacturers but also between different versions of scanners from the same manufacturer. Hologic scanners tended to underestimate the nominal BMD, while Lunar scanners overestimated the value. Norland scanners gave mixed values over estimating BMD at the lower nominal value (0.5 g/cm2) while underestimating the value at the higher value (1.5 g/cm2). The validity of the exponential equations was tested using hip and spine measurements on 991 non-proband women from a familial osteoporosis study (FAMOS). After cross-calibration there was a considerable reduction in variation between machines. This observation, coupled with the absence of a similar reduction in variation attributable to a linear regression on age, demonstrated the validity of the cross-calibration approach. Use of the cross-calibration curves along with a standard normative range (in the case of this study, the Hologic normative range) allowed age-specific Z-scores to be used as an inclusion criterion in this genetic study, a method that will be useful for other trials where age-specific BMD inclusion criteria are required.

Strontium ranelate reduces the risk of nonvertebral fractures in postmenopausal women with osteoporosis: Treatment of Peripheral Osteoporosis (TROPOS) study

BACKGROUND

Strontium ranelate, a new oral drug shown to reduce vertebral fracture risk in postmenopausal women with osteoporosis, was studied in the Treatment of Peripheral Osteoporosis (TROPOS) study to assess its efficacy and safety in preventing nonvertebral fractures also.

METHODS

Strontium ranelate (2 g/d) or placebo were randomly allocated to 5091 postmenopausal women with osteoporosis in a double-blind placebo-controlled 5-yr study with a main statistical analysis over 3 yr of treatment.

FINDINGS

In the entire sample, relative risk (RR) was reduced by 16% for all nonvertebral fractures (P = 0.04), and by 19% for major fragility fractures (hip, wrist, pelvis and sacrum, ribs and sternum, clavicle, humerus) (P = 0.031) in strontium ranelate-treated patients in comparison with the placebo group. Among women at high risk of hip fracture (age > or = 74 yr and femoral neck bone mineral density T score < or = -3, corresponding to -2.4 according to NHANES reference) (n = 1977), the RR reduction for hip fracture was 36% (P = 0.046). RR of vertebral fractures was reduced by 39% (P < 0.001) in the 3640 patients with spinal x-rays and by 45% in the subgroup without prevalent vertebral fracture. Strontium ranelate increased bone mineral density throughout the study, reaching at 3 yr (P < 0.001): +8.2% (femoral neck) and +9.8% (total hip). Incidence of adverse events (AEs) was similar in both groups.

CONCLUSION

This study shows that strontium ranelate significantly reduces the risk of all nonvertebral and in a high-risk subgroup, hip fractures over a 3-yr period, and is well tolerated. It confirms that strontium ranelate reduces vertebral fractures. Strontium ranelate offers a safe and effective means of reducing the risk of fracture associated with osteoporosis.

Secondary prevention of osteoporosis: when should a non-vertebral fracture be a trigger for action?

The burden of non-vertebral fractures is enormous. Hip fractures account for nearly 10% of all fractures (and a much greater proportion in the elderly), while wrist fractures may account for up to 23% of all limb fractures. The best available predictors of non-vertebral fracture risk are low BMD and a tendency to fall. Hip, forearm, proximal humerus and rib fractures have all been associated with low BMD, though ankle fracture is not strongly related to osteoporosis. Although clinical risk factors identify only about one-third of postmenopausal women at increased risk of osteoporotic fracture, the occurrence of one fracture commonly predicts a second fracture. Guidelines are presented for identifying and treating patients at risk of non-vertebral osteoporotic fractures, especially those with a previous fracture, based on the algorithm recently published by the Royal College of Physicians and the Bone and Tooth Society. Prevention of falls and use of external hip protectors may reduce the occurrence of hip fracture. Treatment options for patients presenting with hip fracture include HRT, bisphosphonates, and calcium plus vitamin D, and for Colles' fracture include general measures, HRT, bisphosphonates, or calcitonin plus calcium.

Secondary causes of osteoporosis in men

Important underlying causes of osteoporotic fracture in men include glucocorticoid therapy, low body weight, and reduced physical activity. Tobacco and alcohol use have been consistently identified as risk factors for vertebral fracture but there is less evidence that they contribute to hip fracture. Clinically overt hypogonadism is a strong risk factor for osteoporosis in men; however, the role of more subtle subclinical changes, as defined by biochemical criteria, remains to be established. The high comorbidity associated with osteoporosis, particularly in elderly men, contributes to fracture risk both through effects on bone mass and risk of falling. The management of osteoporosis in men includes diagnosis of and, where possible, correction of underlying contributory causes. Evidence from recent randomized controlled trials indicates that bisphosphonates are effective in the prevention of glucocorticoid-induced osteoporosis in men but the optimal criteria for selection of individuals for treatment requires further study.

Colocalization of glucocorticoid and mineralocorticoid receptors in human bone

Osteoporosis is a poorly understood but common complication of glucocorticoid therapy. The actions of glucocorticoids are mediated via glucocorticoid receptors (GRs), but in vitro, glucocorticoids also can bind to mineralocorticoid receptors (MRs). It is not known if MR protein is present in human bone and little is known of GR isoform expression (GRalpha and GRbeta). GR and MR protein expression and possible sites of action were investigated in neonatal rib and adult iliac crest biopsy specimens using antibodies specific for MR, GRalpha, and GRalphabeta. Colocalization [MR GRalpha] [MR GRalphabeta] was performed using fluorescent-conjugated secondary antibodies. GRalpha, GRbeta, and MR show distinct but overlapping patterns of expression, suggesting important functions for each receptor type. Osteoclasts showed no staining for GRalpha but strong staining for GRalphabeta, indicating expression of GRbeta and a specific role in addition to antagonizing the transcriptional activity of GRalpha. MR also was observed in osteoclasts and colocalized with GRalphabeta. Coexpression of MR, GRalpha, and GRalphabeta was seen in osteoblasts. Reverse-transcription-polymerase chain reaction (RT-PCR) of cultured osteoblast RNA confirmed expression of both GRalpha and GRbeta. Osteocytes stained with MR, GRalpha, and GRalphabeta antibodies but to a lesser degree than osteoblasts. In the neonatal rib cartilage, staining for GRalpha, GRalphabeta, and MR was present in approximately one-half of the resting and hypertrophic chondrocytes and in most of proliferating chondrocytes and chondrocytes within the mineralizing matrix. Identification of MR raises the possibility that the physiological and pharmacologic effects of glucocorticoids on bone may be mediated via MR as well as GR and that GRalpha, GRbeta, and MR synergize to influence corticosteroid metabolism in human bone.

Estrogen receptors alpha and beta are differentially expressed in developing human bone

Estrogen plays an essential role in the development and maintenance of the skeleton; its effects are mediated via interactions with two estrogen receptor (ER) subtypes, alpha and beta. The aim of this study was to establish the cellular distribution of ERalpha and ERbeta in neonatal human rib bone. ERalpha and ERbeta immunoreactivity was seen in proliferative and prehypertrophic chondrocytes in the growth plate, with lower levels of expression in the late hypertrophic zone. Different patterns of expression of the two ERs were seen in bone. In cortical bone, intense staining for ERalpha was observed in osteoblasts and osteocytes adjacent to the periosteal-forming surface and in osteoclasts on the opposing resorbing surface. In cancellous bone, ERbeta was strongly expressed in both osteoblasts and osteocytes, whereas only low expression of ERalpha was seen in these areas. Nuclear and cytoplasmic staining for ERbeta was apparent in osteoclasts. These observations demonstrate distinct patterns of expression for the two ER subtypes in developing human bone and indicate functions in both the growth plate and mineralized bone. In the latter, ERalpha is predominantly expressed in cortical bone, whereas ERbeta shows higher levels of expression in cancellous bone.

Bone structure in patients with low bone mineral density with or without vertebral fractures

Vertebral fractures (VFX) are caused by low bone mass and microstructural deterioration of bone tissue. The latter is not well defined. We investigated bone structure in transiliac biopsy specimens from 88 volunteers. Biopsy specimens were obtained at baseline in the Multiple Outcomes of Raloxifene Evaluation trail, a prospective study in osteoporotic (BMD < or = -2.5 T score) postmenopausal women without or with VFX on standardized lateral spinal radiographs. Bone biopsy specimens were embedded in methylmethacrylate (MMA). Histomorphometry was done in 8 microns (U.S.A.) or 5 microns (Europe) Goldner stained sections. Vertebral fracture status (yes/no) was the outcome variable in logistic regression models adjusted for age and biopsy specimen origin (U.S.A. vs. Europe). Patients with and without VFX (26/62) were similar regarding age (69.2 +/- 5.2 years vs. 67.3 +/- 6.7 years), bone volume (BV/TV; 17.7 +/- 4.7% vs. 19.0 +/- 5.8%), and bone surface (BS/TV; 2.7 +/- 0.6 mm2/mm3 vs. 2.8 +/- 0.6 mm2/mm3). A lower cortical thickness (C.Th; 652 +/- 267 microns vs. 822 +/- 325 microns), total strut length (TSL; 826 +/- 226 microns/mm2 vs. 922 +/- 256 microns/mm2), node-to-loop (Nd-Lp) strut length (10.1 +/- 10.3% vs. 15.0 +/- 13.6%), together with a higher node-to-terminus (Nd-Tm) strut length (45.6 +/- 9.7% vs. 39.1 +/- 9.3%) were each associated with prevalent VFX (0.01 < p < 0.10). Differences in BV/TV did not explain these associations. In conclusion, cortical thinning and disruption of trabecular lattice are possible pathogenic mechanisms in patients with VFX.

Prevention of osteoporotic fractures in post-menopausal women

A number of pharmacological interventions are now available for the prevention of osteoporotic fractures in post-menopausal women. These include hormone replacement therapy, bisphosphonates, raloxifene, calcitonin, calcitriol and combined calcium and vitamin D. Factors influencing the positioning of these agents in clinical practice include their efficacy in preventing fractures at both the spine and the hip, tolerability, side-effects, cost and, in the case of raloxifene and hormone replacement therapy, the extra-skeletal risks and benefits of long-term treatment. The rates of onset and offset of the treatment effect are also important considerations; the observations that relatively short-term intervention produces a significant reduction in fracture risk in women with established osteoporosis, that treatment benefits are greatest in those with low bone mineral density and that the beneficial skeletal effects are not maintained after the withdrawal of treatment have resulted in a shift from long-term preventive strategies towards the targeting of high-risk individuals for intervention.