The FRAX tool in French women: How well does it describe the real incidence of fracture in the OFELY cohort?

The FRAX tool estimates an individual's fracture probability over 10 years from clinical risk factors with or without bone mineral density (BMD) measurement. The aim of our study was to compare the predicted fracture probabilities and the observed incidence of fracture in French women during a 10-year follow-up. The probabilities of fracture at four major sites (hip, clinical spine, shoulder, or wrist) and at the hip were calculated with the FRAX tool in 867 women aged 40 years and over from the Os des Femmes de Lyon (OFELY) cohort.The incidence of fracture was observed over 10 years. Thus 82 women sustained 95 incident major osteoporotic (OP) fractures including 17 fractures at the hip. In women aged at least 65 years (n = 229), the 10-year predicted probabilities of fracture with BMD were 13% for major OP fractures and 5% for hip fractures, contrasting with 3.6% and 0.5% in women younger than 65 years (p < .0001). The predicted probabilities of both major OP and hip fractures were significantly higher in women with osteoporosis (n = 77, 18% and 10%) and osteopenia (n = 390, 6% and 2%) compared with women with normal BMD (n = 208, 3% and <1%; p < .0001. The predicted probabilities of fracture were two and five times higher in women who sustained an incident major OP fracture and a hip fracture compared with women who did not (p < .0001). Nevertheless, among women aged at least 65 years with low BMD values (T-score < or = -1; n = 199), the 10-year predicted probability of major OP fracture with BMD was 48% lower than the observed incidence of fractures (p < .01). A 10-year probability of major OP fracture higher than 12% identified more women with incident fractures than did BMD in the osteoporotic range (p < .05). In French women from the OFELY cohort, the observed incidence of fragility fractures over 10 years increased with age following a pattern similar to the predicted probabilities given by the FRAX tool. However, in women aged at least 65 years with low BMD, the observed incidence of fractures was substantially higher than the predicted probability.

Impact of prevalent fractures on quality of life: baseline results from the global longitudinal study of osteoporosis in women

OBJECTIVE

To examine several dimensions of health-related quality of life (HRQL) in postmenopausal women who report previous fractures, and to provide perspective by comparing these findings with those in other chronic conditions (diabetes, arthritis, lung disease).

PATIENTS AND METHODS

Fractures are a major cause of morbidity among older women. Few studies have examined HRQL in women who have had prior fractures and the effect of prior fracture location on HRQL. In this observational study of 57,141 postmenopausal women aged 55 years and older (enrollment from December 2007 to March 2009) from 17 study sites in 10 countries, HRQL was measured using the European Quality of Life 5 Dimensions Index (EQ-5D) and the health status, physical function, and vitality questions of the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36).

RESULTS

Reductions in EQ-5D health-utility scores and SF-36-measured health status, physical function, and vitality were seen in association with 9 of 10 fracture locations. Spine, hip, and upper leg fractures resulted in the greatest reductions in quality of life (EQ-5D scores, 0.62, 0.64, and 0.61, respectively, vs 0.79 without prior fracture). Women with fractures at any of these 3 locations, as well as women with a history of multiple fractures (EQ-5D scores, 0.74 for 1 prior fracture, 0.68 for 2, and 0.58 for >/=3), had reductions in HRQL that were similar to or worse than those in women with other chronic diseases (0.67 for diabetes, 0.69 for arthritis, and 0.71 for lung disease).

CONCLUSION

Previous fractures at a variety of bone locations, particularly spine, hip, and upper leg, or involving more than 1 location are associated with significant reductions in quality of life.

Assessment of hand bone loss in rheumatoid arthritis by high-resolution peripheral quantitative CT

OBJECTIVES

A new high-resolution peripheral quantitative CT (HR-pQCT) system allows for in vivo assessment of bone microarchitecture and volumetric bone mineral density (vBMD) with an 82 microm isotropic resolution. With this device, the microarchitecture impairment was evaluated in patients with rheumatoid arthritis (RA) in comparison with healthy controls and measured the erosion volume at metacarpal heads (MCPs).

METHODS

In this cross-sectional study, the reproducibility was first assessed by 3 HR-pQCT exams with repositioning in 14 patients with late RA and 14 healthy subjects. Then, HR-pQCT parameters were measured in a group of 93 patients with RA and 31 healthy controls. Two RA subgroups were distinguished: early RA (disease duration < or =2 years) (n=36) and late RA (n=57) and compared them to healthy controls.

RESULTS

The precision of the HR-pQCT volumetric measurements as assessed with coefficient of variation ranged from 0.7% to 1.8% in patients with late RA and from 0.6% to 1.4% in healthy subjects at MCPs. Total and trabecular vBMD and trabecular thickness were significantly decreased in patients with RA compared to healthy subjects and were significantly correlated to disease activity. The erosion volume was highly correlated to a semiquantitative assessment using the Outcome Measures in Rheumatoid Arthritis Clinical Trials (OMERACT) scoring system applied to the HR-pQCT slices.

CONCLUSIONS

This study demonstrated the good reproducibility of the HR-pQCT volumetric measurements at MCPs and confirmed the involvement of trabecular compartment in periarticular osteopoenia. Thus, HR-pQCT appears interesting to simultaneously assess differences in bone volumetric density, microarchitecture and erosions.

Glucocorticoid use and risk of atrial fibrillation or flutter: a population-based, case-control study

BACKGROUND

Glucocorticoid use is associated with increased risk of myocardial infarction, stroke, and heart failure, but data are limited on the risk of atrial fibrillation or flutter. We examined whether glucocorticoid use is associated with the risk of atrial fibrillation or flutter.

METHODS

For this population-based, case-control study, we identified all patients with a first hospital diagnosis of atrial fibrillation or flutter from January 1, 1999, through December 31, 2005, in Northern Denmark (population, 1.7 million). For each case we selected 10 population controls matched by age and sex. We obtained data on glucocorticoid prescriptions within 60 days (current users) or longer before the index date (former users), comorbidity, and medications from medical databases. We used conditional logistic regression to compute odds ratios (ORs), controlling for potential confounders.

RESULTS

Among 20,221 patients with atrial fibrillation or flutter, 1288 (6.4%) were current glucocorticoid users and 2375 (11.7%) were former users. Among 202,130 population controls, 5245 (2.6%) were current glucocorticoid users and 19 940 (9.9%) were former users. Current glucocorticoid use was associated with an increased risk of atrial fibrillation or flutter compared with never use (adjusted OR, 1.92; 95% confidence interval [CI], 1.79-2.06). Among new glucocorticoid users, the adjusted OR was 3.62 (95% CI, 3.11-4.22) and among long-term users it was 1.66 (95% CI, 1.53-1.80). The increased risk remained robust in patients with and without pulmonary and cardiovascular diseases. Former glucocorticoid use was not associated with increased risk (adjusted OR, 1.00; 95% CI, 0.96-1.06).

CONCLUSION

Current glucocorticoid use was associated with an almost 2-fold increased risk of atrial fibrillation or flutter.

Bone microdamage: a clinical perspective

INTRODUCTION

Microdamage accumulation due to fatigue loading may lead to fracture. In addition, several studies using animal models have suggested in recent years that bisphosphonates might increase microdamage accumulation.

METHODS

We have reviewed the literature after a PubMed search, to examine the techniques to look for microcracks, the relationship between microdamage and bone strength, and the influence of anti-osteoporosis agents.

RESULTS

Currently, the search for microcracks relies on bulk staining of bone samples, which are then examined on optic microscopy and fluorescence or confocal microscopy. The accumulation of microdamage is associated with fatigue loading and is likely to trigger targeted bone remodeling, especially in cortical bone. Several studies examining beagle dogs receiving bisphosphonates have shown a dose-dependent accumulation of microdamage in bone, with conflicting results regarding the consequences on bone mechanical properties. In living humans, obtaining data is limited to the iliac crest bone. The potential association between long-term bisphosphonate use and microcrack accumulation at the iliac crest bone has not been established unequivocally.

CONCLUSIONS

Bone microdamage is critical in the understanding of bone quality. Assessment of microdamage is technically difficult, especially in humans. The clinical impact of microdamage potentially induced by bone drugs has not been established in humans.

Treatment of osteoporosis with annual iv zoledronic acid: effects on hip fracture

BACKGROUND

Several treatments for postmenopausal osteoporosis have been available in the past decade, but adherence to these treatments has been judged inadequate. The prevention of hip fracture by these medications is still modest.

METHODS

A literature search was performed for treatment with zoledronic acid for the prevention of hip fracture.

RESULTS

In the The Health Outcomes and Reduced Incidence with Zoledronic Acid Once Yearly (HORIZON) Pivotal Fracture Trial, involving 7765 postmenopausal women with low bone mineral density or with prevalent vertebral fracture, women taking zoledronic acid had a 41% relative risk reduction for hip fracture, at 3 years, compared to placebo. In the HORIZON Recurrent Fracture Trial, 2127 patients (76% were women) were randomized to receive either zoledronic acid or placebo after sustaining a first hip fracture. A reduction of 30% in the second hip fracture risk was observed, but it did not reach statistical significance. Zoledronic acid was generally safe in these trials, although a slightly increased rate of severe atrial fibrillations was observed in the HORIZON Prevention Fracture Trial, but not in the HORIZON Recurrent Fracture Trial.

CONCLUSION

Yearly zoledronic acid reduces the risk of hip fracture, both in postmenopausal osteoporotic women with and without prevalent vertebral fracture and in men and women with a recent first hip fracture.

Fibrous dysplasia of bone and McCune-Albright syndrome

Fibrous dysplasia of bone is a genetic, non-inheritable disease, characterized by bone pain, bone deformities and fracture, involving one or several bones. It is caused by mis-sense mutations occurring post-zygotically in the gene coding for the alpha-subunit of the stimulatory G-protein, Gs, in the guanine nucleotide binding, alpha stimulating (GNAS) complex locus in chromosome 20q13. This mutation results in osteoblastic differentiation defects, and bone resorption is often increased. The bone lesions may be associated with endocrine dysfunctions and café-au-lait spots; this is known as McCune-Albright syndrome. Patients with polyostotic fibrous dysplasia often have renal phosphate wasting. The disease, however, has a wide clinical spectrum, so many patients are asymptomatic. Diagnosis relies on radiographs and pathology. Bisphosphonates have been used in the treatment of fibrous dysplasia to relieve bone pain and improve lytic lesions, but they are still under clinical evaluation. Calcium, vitamin D and phosphorus supplements may be useful in some patients. Surgery is also helpful to prevent and treat fracture and deformities.

Use of bisphosphonates among women and risk of atrial fibrillation and flutter: population based case-control study

OBJECTIVE

To assess the association between atrial fibrillation and flutter and use of bisphosphonates for osteoporosis among women.

DESIGN

Population based case-control study, using medical databases from Denmark.

SETTING

Northern Denmark.

PARTICIPANTS

13 586 patients with atrial fibrillation and flutter and 68 054 population controls, all with complete hospital and prescription history.

MAIN OUTCOME MEASURE

Adjusted relative risk of atrial fibrillation and flutter.

RESULTS

435 cases (3.2%) and 1958 population controls (2.9%) were current users of bisphosphonates for osteoporosis. Etidronate and alendronate were used with almost the same frequency among cases and controls. The adjusted relative risk of current use of bisphosphonates compared with non-use was 0.95 (95% confidence interval 0.84 to 1.07). New users had a relative risk of 0.75 (95% confidence interval 0.49 to 1.16), broadly similar to the estimate for continuing users (relative risk 0.96, 95% confidence interval 0.85 to 1.09). The relative risk estimates were independent of number of prescriptions and the position of the atrial fibrillation and flutter diagnosis in the discharge record, and were similar for inpatients and outpatients.

CONCLUSION

No evidence was found that use of bisphosphonates increases the risk of atrial fibrillation and flutter.

Microcrack frequency and bone remodeling in postmenopausal osteoporotic women on long-term bisphosphonates: a bone biopsy study

We sought whether microdamage could rise in postmenopausal osteoporotic women on long-term bisphosphonates, as suggested by recent animal studies. We found few microcracks in iliac bone biopsies, despite a marked reduction in bone turnover.

INTRODUCTION

Animal studies suggest that bisphosphonates (BPs) could increase microdamage frequency in a dose-dependent manner, caused by excessively suppressed bone turnover. However, there is limited data in humans receiving BP therapeutic doses for >3 yr.

MATERIALS AND METHODS

We measured microcrack frequency and histomorphometry parameters on transiliac bone biopsies in 50 postmenopausal osteoporotic women (mean age = 68 yr) who had received BP therapy (3 on intravenous pamidronate, 37 on oral alendronate, and 10 on oral risedronate) for at least 3 yr (mean treatment duration = 6.5 yr). We compared these results with transiliac bone biopsies obtained from 12 cadavers. We used bulk staining with green calcein as a fluorochrome. The microcracks were quantified in three 100-microm-thick sections using optic microscopy and were confirmed by laser confocal microscopy. Microcrack frequency (number of microcracks/mm2 of bone tissue) was compared between treated women and controls using nonparametric tests. We also explored predictors of microcrack frequency, including age, duration of BP therapy, and activation frequency.

RESULTS

Among treated women, cancellous bone microcrack frequency was low (mean, 0.13 microcracks/mm2) and did not differ significantly from that observed in controls (0.05 microcracks/mm2; p = 0.59). Of note, 54% of the treated women and 58% of the controls had no observable microcracks. There was no association between microcrack frequency and the duration of BP therapy (for microcracks/mm2 and duration, Spearman r = 0.04, p = 0.80) and between patients' ages and the number of microcracks (Spearman r = -0.09, p = 0.61). Although bone remodeling parameters were suppressed in treated women, we found no relationship between microcrack density and activation frequency (Spearman r = -0.003, p = 0.99). Also, microcrack frequency was not increased in women with prevalent vertebral fracture compared with those without fractures.

CONCLUSIONS

Among postmenopausal osteoporotic women on long-term BPs, microcrack frequency in the iliac bone is low, despite a marked reduction of bone turnover.

Medical therapy in adults with fibrous dysplasia of bone

In open studies, bisphosphonate therapy (pamidronate, alendronate) reduced bone pain associated with fibrous dysplasia of bone and was associated to some radiological improvement. Calcium, vitamin D, and phosphorus supplements may be useful in patients with deficiency. We are awaiting results from controlled trials testing bisphosphonates.

INTRODUCTION

Fibrous dysplasia of bone (FD), a rare disease caused by osteoblastic lineage differentiation defects, is associated with bone pain, fracture, and bone deformity, but few therapeutic options are available.

MATERIALS AND METHODS

We reviewed published data on the treatment of FD with bisphosphonates (pamidronate, alendronate), calcium, vitamin D, and phosphorus. We also present new results on FD therapy with a more potent bisphosphonate, zoledronic acid, given intravenously at the dose of 4 mg every 6 months.

RESULTS

Pamidronate therapy, given intravenously every 6 months at a dose of 180 mg in adults, relieved bone pain, decreased bone resorption, and improved the radiological aspect (filling of lytic lesions and/or thickening of cortices) in approximately 50% of patients. BMD in affected sites was also significantly increased after pamidronate treatment. Those results have been obtained only in open studies, without controls, by several research groups. In a series of nine patients on long-term pamidronate treatment, but resisting to this medication and switched to intravenous zoledronic acid, no substantial improvement was observed. There is some biological rationale supporting the use of calcium and vitamin D in patients with deficiency to improve FD lesions by limiting secondary hyperparathyroidism. Phosphorus supplementation may prevent mineralization defects in those patients who have both FD and renal phosphate wasting. However, we are lacking clinical evidence for the efficacy of such supplements.

CONCLUSIONS

Bisphosphonate treatment reduces increased osteoclastic activity in FD and probably improves bone pain, but their use should be better studied in randomized controlled trials.

Drug insight: Bisphosphonates for postmenopausal osteoporosis

Bisphosphonates are potent antiresorptive agents, which have largely been used for the treatment of postmenopausal osteoporosis during the past 10 years. When embedded in bone matrix, bisphosphonates are taken up by osteoclasts engaged in bone resorption, leading--mainly by inhibition of farnesyl diphosphate synthase, a key enzyme of the mevalonate pathway--to osteoclast apoptosis. Bone resorption decreases, with consequent improvement in the mechanical properties of bone and a reduced risk of fracture. Alendronate and risedronate are oral nitrogen-containing bisphosphonates. Several randomized, placebo-controlled trials have shown the ability of these bisphosphonates to halve the risk of vertebral fracture when taken daily for 3 years. Nonvertebral fracture risk, including that at the hip, was also significantly decreased. Weekly regimens have simplified the administration of bisphosphonates and, probably, improved adherence to treatment. A significant reduction in the risk of vertebral fracture has also been demonstrated with an intermittent regimen of ibandronate, which is a new, potent, nitrogen-containing bisphosphonate. Ibandronate was recently marketed for use in an oral, once-monthly dose of 150 mg, with the goal of improving compliance. Bisphosphonates are usually well tolerated in the long term. Intravenous administration of bisphosphonates in women with osteoporosis, which is currently under investigation, might be an interesting future option for women who cannot tolerate oral regimens, and for enhancing compliance.

Effectiveness of instant vertebral assessment to detect prevalent vertebral fracture

INTRODUCTION

Vertebral fracture is currently underdiagnosed, despite its common severity and its value to predict further osteoporotic fracture. Morphometry using dual X-ray absorptiometry (DXA) [vertebral fracture assessment (VFA)] is a new technique that may facilitate detection of many vertebral fractures, as images are obtained at the same time as bone mineral density (BMD) measurement, and would also allow avoiding spine radiographs.

METHODS

We conducted a cross-sectional study to assess the diagnostic value of Instant Vertebral Assessment (IVA), which is a morphometry scan using the Hologic Delphi densitometer, to detect prevalent vertebral fracture in postmenopausal women. Interobserver precision was assessed, then IVA scans were compared with lateral spine radiographs, considered the gold standard, to test diagnostic agreement between the two techniques. Sensitivity, specificity and predictive values were calculated, as well as the likelihood ratio of the positive test, using sensitivity and specificity at each vertebral level.

RESULTS

Among 85 patients of whom 50% had at least one vertebral fracture identified with radiographs, we found that interobserver precision was moderate, with frequent difficulties in discerning upper thoracic vertebrae. On a per-vertebra basis, sensitivity was around 70% from L4 to T11 and lower above T11 whereas specificity was above 90% for all vertebrae, and the negative predictive value remained above 80% from L4 to T7 and decreased above T7. On a per-patient basis, sensitivity was 0.69, specificity 0.74, positive predictive value equalled 0.72 and negative predictive value 0.71. When only grades 2 and 3 fractures were considered, results were comparable, with slightly improved specificity. Then, with the likelihood ratios calculated in our sample, we obtained posttest probabilities using the prevalence of vertebral fracture at lumbar and thoracic levels in a large sample of postmenopausal women with osteopenia and osteoporosis with and without vertebral fracture [baseline data in women of the Multiple Outcomes on Raloxifene Evaluation (MORE) trial]. At levels where fractures were most common, likelihood ratios of the positive test were good or excellent, associated with sizeable posttest probabilities.

CONCLUSION

IVA allowed diagnosis of vertebral fracture at levels where vertebral fracture were most common, i.e., the lumbar and mid and lower thoracic levels, but its value was weaker at the upper thoracic levels.

Risk of fracture among women who lose bone density during treatment with alendronate. The Fracture Intervention Trial

It is commonly believed that the response to treatment in patients on alendronate is proportional to the increase in bone mineral density (BMD), and that those who lose BMD during treatment might not respond to treatment. In the Fracture Intervention Trial 6,459 women were randomly assigned to treatment with alendronate or placebo; BMD was measured annually, and new spine fractures were assessed by lateral spine films, taken at baseline and end of follow-up. Among subjects who took at least 70% of the study drug (5,220 women), we compared reductions in risk of spine fractures at end of follow-up (3 or 4 years) within various levels of change in total hip and spine BMD after 1 and 2 years of treatment, after adjustment for differences in characteristics between the treatment and control groups. Women "losing" BMD at the lumbar spine (0% to 4%) while on alendronate had a reduction of 60% in vertebral fracture risk [OR = 0.40 (0.16, 0.99)] compared to their counterparts in the placebo group. The few women that lost more than 4% did not have a significant benefit [OR = 0.15 (0.02, 1.29)]. Those who "gained" BMD (0% to 4%) during treatment had a reduction in risk of 51% [OR = 0.49 (0.30, 0.78)]. Similarly, women who "lost" total hip BMD (0% to 4%) during the first year on alendronate had a 53% decreased risk of vertebral fracture compared to their controls taking placebo [OR = 0.47 (0.27, 0.81)], whereas those "gaining" BMD (0% to 4%) had a comparable risk reduction [OR = 0.49 (0.34, 0.71)]. This was not observed for the few women who lost more than 4% [OR = 0.61 (0.11, 3.45)]. Patients who lost BMD at both the hip and spine were not protected by alendronate. Among patients who adhere to treatment with alendronate, even those who lose BMD benefit from a substantial reduction in risk of vertebral fracture. So, the reduction in bone turnover induced by alendronate might be more important than BMD changes. The few women who lose the most BMD (more than 4% per year) might not benefit from the treatment.

Assessment of vertebral fracture using densitometric morphometry

Diagnosis of vertebral fracture is critical for management of osteoporosis, as existence of such deformities substantially increases the risk of subsequent fracture. Thus, accurate and precise techniques allowing detection of such deformities are essential to clinicians. So far, this detection has been performed by spinal lateral X-rays. More advanced techniques have recently been developed, based on dual energy X-ray absorptiometry (DXA). This review describes these different techniques and discusses the effectiveness of the DXA technique to assess vertebral deformities compared to X-ray. The use of DXA detection of vertebral fracture for clinical practice and clinical trials is discussed. Specifically, vertebral morphometry using DXA provides an excellent specificity, with moderate sensitivity. The major limitation of the DXA vertebral assessment is the poor quality of images of thoracic vertebrae. The clinical utility of vertebral morphometry using densitometry may help screening patients with vertebral fracture, but technological improvements are necessary to improve image quality.

Clinical Pharmacology of Potent New Bisphosphonates for Postmenopausal Osteoporosis

Bisphosphonates are potent inhibitors of bone resorption, used in most bone diseases associated with high bone resorption levels. Several bisphosphonates, developed to prevent and treat postmenopausal osteoporosis, increase bone mineral density and decrease biochemical markers of bone turnover, and more importantly, reduce fracture risk. Alendronate and risedronate have proven their efficacy to reduce vertebral and hip fracture risk among postmenopausal osteoporotic women, using daily regimens. Weekly intermittent schedules, however, are now most commonly prescribed, because they have shown pharmacologic equivalence to the daily regimen. Ibandronate has been the first bisphosphonate to demonstrate vertebral fracture risk reduction using an intermittent regimen. Studies using ibandronate as intravenous injections every 3 months are under way. Zoledronic acid may also be an attractive option for the treatment of postmenopausal osteoporosis if a large ongoing trial proves that a single annual injection of this compound allows osteoporotic fracture risk reduction.

Treatment of fibrous dysplasia of bone with intravenous pamidronate: long-term effectiveness and evaluation of predictors of response to treatment

Fibrous dysplasia (FD) of bone is a rare but potentially severe bone disease that often entails fractures, deformities, and bone pain. An activating mutation of the alpha subunit of Gs proteins leads to differentiation abnormalities of the osteoblastic lineage, which are responsible for development of fibrous tissue in the medulla and increased osteoclastic activity. This increased bone resorption has been the rationale to use bisphosphonates in our center since 1988. So, we have analyzed the largest series, so far, of patients treated with the bisphosphonate pamidronate and sought predictors of response to treatment. We have treated 58 patients (41 adults and 17 under 18 years of age) with FD in an open study, using intravenous (IV) pamidronate 180 mg every 6 months and calcium and vitamin D supplements, in combination with oral phosphate and calcitriol in patients with FD who also had renal phosphate wasting. Patients were followed up with biannual visits, for an average 50 months, with pain assessment, annual radiographs of affected bones, measurement of biochemical markers of bone turnover, and annual bone mineral density measurements in the case of affected hips. We found that pain intensity significantly decreased with treatment in the 44 patients who had bone pain at baseline, biochemical markers of bone turnover were significantly reduced, and about 50% of patients had improvement of bone lesions on radiographs, evidenced by filling of osteolytic lesions and/or cortex thickening. Bone mineral density was substantially increased in the 12 patients who had hip FD. There was no significant clinical or biological predictor of positive radiographic response to pamidronate treatment. Long-term treatment with pamidronate was safe, in particular among the 12 patients who were followed up for more than 8 years. Despite the lack of a control group, our results suggest that intravenous pamidronate improves radiological aspect in half of the patients with FD, decreases bone turnover, and may decrease pain intensity.

Incidence and risk factors for a second hip fracture in elderly women. The Study of Osteoporotic Fractures

Women with hip fracture have an increased risk of second hip fracture but other risk factors for a second hip fracture have not been established. We sought to determine the incidence and risk factors for second hip fracture, in a prospective cohort study of community-dwelling postmenopausal women over 65 years: the Study of Osteoporotic Fractures. From a cohort of 9,704 women, 632 women with a documented first hip fracture during the study were followed up until a second hip fracture or the end of follow-up. Clinical risk factors and bone mineral density were assessed at the beginning of the study. Fifty-three second hip fractures were validated by radiographs. Women with hip fracture had a 2.3% per year risk of second hip fracture. Women who walked for exercise at baseline were less likely to sustain a second hip fracture with a relative risk (RR) of 0.5 [0.3-0.9], as were those who had normal depth perception (RR=0.5 [0.3-0.9]). Women who lost weight since age 25 years had an increased risk of second incident hip fracture (RR = 2.7 [1.6-4.6]), as did those who had a low calcaneal bone mineral density (RR=1.5 [1.1-2.0] per standard deviation decrease in bone mineral density). Current use of estrogen replacement therapy at baseline was protective (RR=0.5 [0.3-0.9]) up to 2 years of follow-up. We conclude that community-dwelling women with a first hip fracture have a high risk of second hip fracture, and risk factors for this second fracture are similar to those of first hip fracture.

Review of ibandronate in the treatment of osteoporosis

Several antiresorptive treatments that reduce the risk of osteoporotic fracture are now available, including bisphosphonates. Ibandronate is a new potent bisphosphonate, currently under development, with unique features. In several animal models of human osteoporosis, it has been shown to inhibit bone resorption and improve bone mechanical properties. Ibandronate is more potent than most current bisphosphonates. Several dosages and schedules have been tested in humans. With the oral daily dose of 2.5 mg, a reduction of 62% in the incidence of vertebral fracture has been demonstrated in a randomised, placebo-controlled trial. In the same trial, a reduction of 50% has been observed - for the first time using a bisphosphonate - with an intermittent regimen (20 mg every other day for the first 24 days, followed by 9 weeks without the treatment). In contrast, another randomised, placebo-controlled trial failed to find a significant reduction in vertebral fracture risk using an dose of 1 mg i.v. every 3 months. Thus, ibandronate can be considered as a promising new option for the treatment of postmenopausal osteoporotic women.

Does follow-up of osteoporotic women treated with antiresorptive therapies improve effectiveness?

The use of biochemical markers of bone turnover has been advocated to improve follow-up of women receiving antiresorptive therapies for osteoporosis, but this strategy is not yet supported by trials showing it improves effectiveness of treatments. To explore the potential value of markers of bone turnover to monitor antiresorptive treatments of osteoporosis, we conducted a decision analysis using a decision tree and Markov modeling. We have compared two strategies: treatment of a woman without specific monitoring; and treatment of this woman with measurement of a serum marker of bone resorption after 3 months of treatment, with change of treatment if response to treatment assessed by this marker was not satisfactory. The base case is the treatment of a 60-year-old osteoporotic woman with a total hip T-score of -3, using a second generation bisphosphonate during 5 years. We found that follow-up produced slightly greater quality adjusted life years (QALYs) than no follow-up (8.1560 vs 8.1532, i.e. a one day difference). In a two-way sensitivity analysis, the follow-up option produced higher QALYs so long as adherence rate with follow-up was equal or superior to the proportion of women who adhered without follow-up. For example, if the proportion of women adherent to treatment was increased from 50% to 60% by follow-up, then the expected value of the follow-up branch was increased from 8.1560 QALYs to 8.1800 QALYs (i.e. a difference of 9 days). In addition, the higher the non-response rate, the greater the benefit from monitoring with a biochemical marker. In conclusion, our decision analysis model suggests that follow-up of osteoporotic women treated with a second generation bisphosphonate during a 5-year period using an early measurement of a serum marker of bone resorption may increase effectiveness of the treatment on quality of life, but the effect is very small. So, the use of follow-up measures of bone turnover may be based on patient and physician preferences.

Changes in biochemical markers of bone turnover in women treated with raloxifene: influence of regression to the mean

Measures with extreme magnitude are most likely to be the result of measurement variability. Repeated measurements genuinely lessen such variability, leading to a phenomenon known as regression to the mean (RTM), which may affect biochemical markers of bone turnover. We therefore studied four markers of bone turnover in the Multiple Outcomes of Raloxifene Evaluation (MORE) trial--serum procollagen type I C-propeptide (PICP), osteocalcin (OC), bone-specific alkaline phosphatase (BAP) and urinary type I collagen breakdown product (CTX)--among the 1704 women treated with raloxifene who had marker measurements and were at least 70% adherent, and among 915 control group patients. We examined the existence of RTM, and applied a method of adjustment for RTM of both baseline and follow-up results. We found that women who had the most extreme values tended to go in the opposite direction with the subsequent measurement, i.e., exhibited a pattern of RTM. For example, among women whose urinary CTX decreased at least 60% in the first 6 months, 61% had an increase in the next 6 months; and among those who had an increase in the first 6 months, 81% had a decrease in the next 6 months. We found a similar pattern for each of the four markers. When adjusting for RTM we obtained estimated true values of both baseline values and change in markers. These estimated true values were substantially different from the observed value when the latter was further from the mean. For example, for a 10% increase in urinary CTX in the first 6 months, after accounting for RTM we estimate that there was in fact a 3% decrease (80% confidence interval: -38% to 53%). We conclude that the few initial extreme marker responses observed in women treated with raloxifene represent RTM, and that one practical consequence is that patients with an increase in markers during the first 6 months should be continued on raloxifene therapy, because the values usually decrease later on.

Association between endogenous hormones and sex hormone-binding globulin and bone turnover in older women: study of osteoporotic fractures

Estrogen therapy decreases bone remodeling, but the association between endogenous estradiol (E2), estrone (E1), testosterone (T), and bone turnover in older women is not clear. To test the association of serum E2, E1, free T, and sex hormone-binding globulin (SHBG) with bone turnover, we analyzed cross-sectional relationships among E2, E1, T, SHBG, and biochemical markers of bone turnover serum osteocalcin [OC], serum bone-specific alkaline phosphatase [bAP], and serum breakdown products of C telopeptide of type I collagen [CTx] in 704 women enrolled in the Study of Osteoporotic Fractures. Women with lower estradiol levels tended to have higher levels of bone turnover, but the association was weak (R(2) = 0.01 for the association E2-OC, p = 0.03; and R(2) = 0.024 for E2-CTx, p = 0.001). Relationships between SHBG and turnover were also weak (R(2) for the association SHBG-OC was 0.07, p < 0.001, and 0.03 for SHBG-sCTx, p = 0.03), or not significant (R(2) < 0.01 for the association SHBG-bAP). Associations of E1 and T with these markers were of the same magnitude. These results were not modified after adjustment for age, weight, and smoking status. We conclude that older women with low endogenous hormones have somewhat higher bone turnover, but these associations are weak. Bone turnover is determined mainly by factors other than endogenous concentrations of sex hormones.

Influence of smoking on the antiosteoporotic efficacy of raloxifene

The efficacy of estrogen therapy may be modified in women who smoke because of increased catabolism of estrogen and the interaction of tobacco products with the estradiol receptor. We examined whether the efficacy of raloxifene differed in smoking vs. nonsmoking women. We compared change in bone mineral density and biochemical markers of bone turnover, and incidence of new vertebral fracture in postmenopausal women of the Multiple Outcomes on Raloxifene Efficacy trial, who were randomized to either raloxifene (60 or 120 mg/d) or placebo. In the 17% of women who were current smokers, we found, compared with nonsmokers, lowered baseline trochanter bone mineral density (0.540 vs. 0.557 g/cm(2); P < 0.001) and serum osteocalcin (24.8 vs. 26.6 ng/liter; P < 0.001). Baseline urinary type I collagen breakdown products was increased among smokers (291.8 vs. 276.9 micromol/liter; P = 0.04). Body mass index was also lower in smokers (24.3 vs. 25.4; P < 0.001). After 6 months of treatment, there was no significant difference in reduction of bone turnover between smokers and nonsmokers. After 4 yr of treatment, the smoking-treatment interaction was not significant between smokers and nonsmokers for the percent increase in femoral neck bone mineral density (P = 0.25), trochanter bone mineral density (P = 0.24), and spine bone mineral density (P = 0.37). The smoking-treatment interaction for reduction in vertebral fracture risk was not significant either [odds ratio for fracture, 0.67 (0.45-0.98) for smokers and 0.56 (0.47-0.68) for nonsmokers; P = 0.44]. These results were not modified after stratification by tertiles of body mass index or when comparing heavy smokers vs. light smokers. We conclude that smoking does not influence the antiosteoporotic effect of raloxifene. This may represent an advantage over estrogen replacement therapy.