Effect of risedronate on the risk of hip fracture in elderly women. Hip Intervention Program Study Group

Intravenous zoledronic acid in postmenopausal women with low bone mineral density

BACKGROUND

Bisphosphonates are effective agents for the management of osteoporosis. Their low bioavailability and low potency necessitate frequent administration on an empty stomach, which may reduce compliance. Gastrointestinal intolerance limits maximal dosing. Although intermittent intravenous treatments have been used, the optimal doses and dosing interval have not been systematically explored.

METHODS

We studied the effects of five regimens of zoledronic acid, the most potent bisphosphonate, on bone turnover and density in 351 postmenopausal women with low bone mineral density in a one-year, randomized, double-blind, placebo-controlled trial. Women received placebo or intravenous zoledronic acid in doses of 0.25 mg, 0.5 mg, or 1 mg at three-month intervals. In addition, one group received a total annual dose of 4 mg as a single dose, and another received two doses of 2 mg each, six months apart. Lumbar-spine bone mineral density was the primary end point.

RESULTS

There were similar increases in bone mineral density in all the zoledronic acid groups to values for the spine that were 4.3 to 5.1 percent higher than those in the placebo group (P<0.001) and values for the femoral neck that were 3.1 to 3.5 percent higher than those in the placebo group (P<0.001). Biochemical markers of bone resorption were significantly suppressed throughout the study in all zoledronic acid groups. Myalgia and pyrexia occurred more commonly in the zoledronic acid groups, but treatment-related dropout rates were similar to that in the placebo group.

CONCLUSIONS

Zoledronic acid infusions given at intervals of up to one year produce effects on bone turnover and bone density as great as those achieved with daily oral dosing with bisphosphonates with proven efficacy against fractures, suggesting that an annual infusion of zoledronic acid might be an effective treatment for postmenopausal osteoporosis.

Effect of vitamin D on bone mineral density of elderly patients with osteoporosis responding poorly to bisphosphonates

BACKGROUND

Bisphosphonates are indicated in the prevention and treatment of osteoporosis. However, bone mineral density (BMD) continues to decline in up to 15% of bisphosphonate users. While randomized trials have evaluated the efficacy of concurrent bisphosphonates and vitamin D, the incremental benefit of vitamin D remains uncertain.

METHODS

Using data from the Canadian Database of Osteoporosis and Osteopenia (CANDOO), we performed a 2-year observational cohort study. At baseline, all patients were prescribed a bisphosphonate and counseled on vitamin D supplementation. After one year, patients were divided into two groups based on their response to bisphosphonate treatment. Non-responders were prescribed vitamin D 1000 IU daily. Responders continued to receive counseling on vitamin D.

RESULTS

Of 449 patients identified, 159 were non-responders to bisphosphonates. 94% of patients were women. The mean age of the entire cohort was 74.6 years (standard deviation = 5.6 years). In the cohort of non-responders, BMD at the lumbar spine increased 2.19% (p < 0.001) the year after vitamin D was prescribed compared to a decrease of 0.55% (p = 0.36) the year before. In the cohort of responders, lumbar spine BMD improved 1.45% (p = 0.014) the first year and 1.11% (p = 0.60) the second year. The difference between the two groups was statistically significant the first year (p < 0.001) but not the second (p = 0.60). Similar results were observed at the femoral neck but were not statistically significant.

CONCLUSION

In elderly patients with osteoporosis not responding to bisphosphonates, vitamin D 1000 IU daily may improve BMD at the lumbar spine.

[Approach of menopause in women at risk for breast cancer]

The small but significant increase in risk of discovering breast cancer in women with hormone replacement therapy and the recent discussion of coronary benefit of this treatment have led many authors to insist on the necessity to evaluate the benefit/risks ratio before administration. This evaluation is particularly important for women that are already at high risk of breast cancer because of some genetic predisposition, family history or some benign breast diseases. In these cases, it is important to evaluate the absolute risk of breast cancer, to define the patient's needs more precisely, to specify menopausal symptoms; it is also important to evaluate the risk of osteoporosis, to review the various therapeutic possibilities, which are not only estrogen/progestin treatments (there are alternative treatments), and to give the patients honest information. Before obtaining the results of current trials, we are proposing here a pragmatic attitude and a decision algorithm to adopt a therapeutic attitude more easily which will be decided together by both patients and their physicians.

Antiresorptive treatment of postmenopausal osteoporosis: comparison of study designs and outcomes in large clinical trials with fracture as an endpoint

Antiresorptive treatments for postmenopausal osteoporosis have been studied extensively, but due to the volume of published data and lack of head-to-head trials, it is difficult to evaluate and compare their fracture reduction efficacy. The objective of this review is to summarize the results from clinical trials that have fracture as an endpoint and to discuss the factors in study design and populations that can affect the interpretation of the results. Although there are numerous observational studies suggesting that estrogen and hormone replacement therapies may reduce the risk of vertebral and nonvertebral fractures, there is no large, prospective, randomized, placebo-controlled, double-blind clinical trial demonstrating fracture efficacy. The effects of raloxifene, alendronate, risedronate, and salmon calcitonin on increasing bone mineral density (BMD) and decreasing fracture risk have been shown in randomized, placebo-controlled, double-blind clinical trials of postmenopausal women with osteoporosis. Although the increases in lumbar spine BMD vary greatly in these trials, the decrease in relative risk of vertebral fractures is similar among therapies. However, nonvertebral fracture efficacy has not been consistently demonstrated. Combined administration of two antiresorptive therapies results in greater BMD increases, but the effects on fracture risk are unknown. Direct comparisons of clinical trial results should be considered carefully, given the differences in study design and populations. Differences in study design that may influence the efficacy of fracture risk reduction include calcium and vitamin D supplementation, primary fracture endpoints, definition of vertebral deformity or fracture, discontinuation rates, and statistical power. Factors in the study population that may influence fracture efficacy include the age of the population and the proportion of subjects with prevalent fractures. The use of surrogate endpoints such as BMD to predict fracture risk should be approached with caution, as the relationship between BMD changes and fracture risk reduction with antiresorptive therapies is uncertain. Consideration of these results from clinical trials can contribute to clinical judgment in selecting the best treatment option for postmenopausal osteoporosis.

COPD and osteoporosis

Osteoporosis, with resulting fractures, is a significant problem in patients with advanced COPD. The etiology for the bone loss is diverse but includes smoking, vitamin D deficiency, low body mass index, hypogonadism, sedentary lifestyle, and use of glucocorticoids. Effective strategies to prevent bone loss and/or to treat osteoporosis include calcium and vitamin D, hormone replacement when indicated, calcitonin, and bisphosphonate administration. However, many patients remain undiagnosed until their first fracture because of the lack of recognition of the disease. With an increased awareness by pulmonologists and the increased use of preventive strategies, the impact of osteoporosis on those patients with COPD should decrease.

Ten-year risk of osteoporotic fracture and the effect of risk factors on screening strategies

Bone mineral density (BMD) measurements are widely used to estimate the risk of osteoporotic fractures. In addition, many other risk factors have been identified, some of which are known to add to the risk independently of BMD measurements. The combination of BMD with such risk factors increases the gradient of risk/standard deviation (SD) than that achieved by BMD alone. In this paper, we report the fracture probabilities according to age, gender, and relative risk, and have investigated the effects of changes in the gradient of risk for osteoporotic fractures on the sensitivity and specificity of assessments, modeled on the population of Sweden. Ten-year risks of hip, clinical vertebral, forearm, or proximal humeral fracture were computed with increments in gradient of risk that varied from 1.5 to 6.0 per SD change in skeletal risk. The identification of high-risk groups had little effect on the specificity of assessments, but increased the sensitivity over a wide range of assumptions. The inclusion of all four fracture types had little effect on sensitivity, but increased the positive predictive value of the test. Positive predictive value also increased with age, so that values greater than 50% were obtained testing women at the age of 65 years with modest gradient of risk of 2.0-2.5/SD when small segments of the population were targeted (0.5-5%). Screening of women to direct intervention at the age of 65 years and targeting 25% of the population could save up to 23% of all fractures in women over the next 10 years by the use of multiple tests with a moderate gradient of risk (RR = 2.0/SD). Such gradients might be achieved with the use of multiple risk factors to identify patients at risk.

Different effects of antiresorptive therapies on vertebral and nonvertebral fractures in postmenopausal osteoporosis

In postmenopausal osteoporosis, controlled clinical trials with antiresorptive therapies have shown consistent effects on vertebral fracture incidence while their effects on nonvertebral fractures, especially at the hip, have been reported with some agents, but not others. These discrepancies stress the differences in the pathogenesis of vertebral and nonvertebral fractures as discussed below, and the need to further investigate the mechanisms of action of various antiresorptive agents.

What is the role of serial bone mineral density measurements in patient management?

The ability of dual X-ray absorptiometry (DXA) to monitor bone mineral density (BMD) has been well documented in epidemiologic and pharmaceutical trials. However, its application to monitoring of patients in clinical practice has been subject to recent controversies. Despite these controversies, most clinical centers rely on DXA for monitoring of patients, and therefore guidance is needed. In this article, we report the positions developed by an expert panel of the International Society for Clinical Densitometry on the use of densitometry for the serial measurement of bone mass for monitoring change in BMD. The panel found DXA to be a precise method of measuring change in BMD if used with an appropriate level of least significant change (LSC), at anatomic sites with good precision and response to therapy, and at 1- to 2-yr time intervals. Monitoring is acceptable for determining when therapy is indicated, and if an agent is not therapeutically effective (i.e., when bone loss occurs despite treatment). Each densitometry center should perform an in vivo precision study on individuals similar to the patient population at the center and determine LSC at a 95% confidence level. If such a precision study cannot be performed, benchmark precision might be used, although there was no agreement on what values should be used. The PA spine is the preferred anatomic site for monitoring. The total hip can be used when the spine study is technically invalid. We conclude with recommendations for further research.

Efficacy and tolerability of cyclical intravenous pamidronate in patients with low bone mass

Oral bisphosphonates are an established mode of therapy for the prevention and treatment of osteoporosis. However, many patients are unable to take them either because of poor tolerability or some established contraindications. This retrospective study describes our clinical experience with the efficacy and tolerability of cyclical intravenous pamidronate in patients with osteopenia or osteoporosis at the American University of Beirut Medical Center. Twenty patients received intravenous pamidronate, as a 30-mg infusion administered intravenously over 2 h every 3 mo. All patients were maintained on calcium and vitamin D supplementation: 1000 mg of calcium and 400-800 IU of vitamin D, respectively. Bone mineral densities of the spine and/or hip were measured at baseline and within an average of 14 mo of study entry while on cyclical pamidronate. Two-thirds of patients had a significant increase in bone mineral density either at the lumbar spine or hip. Five patients (25%) developed the expected acute-phase reaction symptoms. Pamidronate constitutes an attractive alternative therapy in patients who cannot tolerate oral bisphosphonates.

Bone mineral density testing in healthy postmenopausal women. The role of clinical risk factor assessment in determining fracture risk

The ease of measurement and the quantitative nature of bone mineral densitometry (BMD) is clinically appealing. Despite BMD's proven capability to stratify fracture risk, data indicate that clinical risk factors provide complementary information on fracture susceptibility that is independent of BMD. Methods to quantify fracture risk using both clinical and BMD variables would have great appeal for clinical decision-making. We describe a procedure for quantifying hip fracture risk (5-yr and remaining lifetime) based on (1) the individual's age alone (base model, assuming average clinical risk factors and bone density), (2) incorporation of multiple patient-specific clinical risk factor data in the base model, and (3) incorporation of both patient-specific clinical risk factor data and BMD results.

Anabolic agents for treating postmenopausal osteoporosis

The main efficacy criterion for drugs against osteoporosis is protection against fractures. Many resorption-inhibiting agents meet this criterion, including estrogens, alendronate, risedronate, raloxifene, calcitonin, and calcium-vitamin D supplements). Conversely, among anabolic agents, only parathyroid hormone (PTH) is known to reduce the fracture risk, the mechanism being increased bone matrix production by osteoblasts with no alterations in the mechanical properties of bone. Although fluoride salts induce a marked increase in bone mineral density (BMD), there is no evidence that this protects against vertebral or peripheral fractures. Growth hormone, IGF-I, statins, and strontium ranelate are under investigation. A recent controlled clinical trial in 1,637 women with osteoporosis showed that daily subcutaneous injections of PTH (1-34) (20 or 40 microg) for 21 months reduced the fracture risk. With 20 microg/day, the reductions were 65% for vertebral fractures and 57% for extravertebral fractures, 11% of patients had moderate postinjection hypercalcemia, and BMD increased by 9% at both the lumbar spine and the femoral neck. These findings open up the exciting possibility that PTH used alone or in combination with resorption-inhibiting agents may be helpful. To date, PTH is the only anabolic agent that has proved capable of reducing the risk of vertebral and extravertebral fractures in women with established postmenopausal osteoporosis.

Hormone replacement therapy and prevention of vertebral fractures: a meta-analysis of randomised trials

BACKGROUND

Hormone replacement therapy (HRT) is often seen as the treatment of choice for preventing fractures in women. We undertook a recent meta-analysis of randomised trials which suggested that HRT reduced non-vertebral fractures by 30%. In this analysis we extend that analysis to vertebral fractures.

METHODS

We searched the main electronic databases until the end of August 2001. We sought all randomised controlled trials (RCTs) of HRT where women had been randomised to at least 12 months of HRT or to no HRT.

RESULTS

We found 13 RCTs. Overall there was a 33% reduction in vertebral fractures (95% confidence interval (CI) 45% to 98%).

CONCLUSIONS

This review and meta-analysis showed a significant reduction in vertebral fractures associated with HRT use.

Diagnosis and treatment of osteoporosis

Osteoporosis is a serious, debilitating and potentially fatal chronic disease which places a major burden on both the patient and the NHS. In order to tackle this growing problem successfully, it is essential that it is diagnosed in its early stages so that fractures can be prevented. Nurses in particular can make a big difference, as they are ideally placed to proactively identify those who may be at risk from osteoporosis. This article explains the essential role the nurse can play, highlights the risk factors and symptoms nurses should be looking out for, and provides a brief summary of all the management options available, so that nurses can make informed recommendation on the most appropriate treatment.

Bisphosphonates in renal osteodystrophy

The present review considers the role that bisphosphonates might have in patients with renal failure. Although bisphosphonates are widely used to reduce fracture risk in patients with osteoporosis, few studies have documented their effect in patients with renal osteodystrophy. The pathogenesis of bone loss after renal transplantation and the role of the recently identified osteoprotegerin/receptor activating nuclear factor-kappaB system is described. Inhibition of bone resorption may prove beneficial when high bone turnover is present, but there are potential drawbacks to widespread use of bisphosphonates. These issues are discussed, with emphasis placed on reports published within the past 18 months.

Osteoporosis in children and adolescent girls: case report of idiopathic juvenile osteoporosis and review of the literature

The diagnosis and treatment of osteoporosis is an important aspect of gynecologic training and practice. Idiopathic juvenile osteoporosis (IJO) is a rare disease of children and adolescents that resolves after the onset of puberty. A case report is presented and current methods of diagnosis and treatment of IJO are discussed as well as the differential diagnosis. A MEDLINE search was performed of the following terms: idiopathic juvenile osteoporosis, pediatric osteoporosis, adolescent osteoporosis, bisphosphonates pediatric adolescent, and pregnancy osteoporosis, and references from bibliographies of selected papers were used as well. All papers in English, French, and German are considered in this review. There were 114 papers selected as relevant to the topic. Data relevant to the diagnosis, pathogenesis, methods of imaging, laboratory evaluation, differential diagnosis, and treatment of IJO are presented. IJO is a diagnosis of exclusion in the pediatric and adolescent patient with osteoporosis. Although bone density gradually improves after the onset of puberty, treatment of currently affected children and adolescents involves activity restriction, calcium, vitamin D, and bisphosphonate therapy. Future reproductive concerns are discussed and areas requiring additional study are reviewed.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians

LEARNING OBJECTIVES

After completion of this article, the reader will be able to describe the condition idiopathic juvenile osteoporosis, compare the clinical features of this condition to other similar conditions, outline the diagnostic workup of a child with this condition, and list the potential therapeutic options for a patient with idiopathic juvenile osteoporosis.

The use of scintigraphy to demonstrate the rapid esophageal transit of the oval film-coated placebo risedronate tablet compared to a round uncoated placebo tablet when administered with minimal volumes of water

As our population ages, and the consumption of pharmaceutical products rises, the incidence of solid oral dosage forms lodging in the esophagus is likely to increase and may be formulation dependent. The aim of this study was to compare the esophageal transit of the commercial film-coated risedronate tablet and a round uncoated tablet resembling the alendronate 10 mg tablet which is reported to cause esophagitis if ingested with little to no water. Water volumes of 30 ml and 50 ml were selected as these volumes can detect formulations prone to esophageal adhesion and a habits and practice study showed that these volumes are within the range preferred by women (7-385 ml). A total of 28 healthy postmenopausal women completed the four-way crossover scintigraphy study. For both volumes of water, the film-coated placebo risedronate tablet had a statistically significant faster esophageal transit time than the uncoated placebo tablet (P=0.002 for 30 ml water and P<0.001 for 50 ml water). Among those taking the round, flat, uncoated tablet, five subjects had esophageal stasis (transit >20 s) and in three subjects the tablet remained in the esophagus at the end of the 10-min imaging period. No stasis was observed for the oval film-coated placebo risedronate tablet. This study demonstrates that tablet size, shape and coating are pharmaceutical parameters which can be controlled to minimize esophageal contact of a dosage form with esophageal tissue.

Glucocorticoid-induced osteoporosis

Glucocorticoids remain a key component in the management of many inflammatory disorders but the adverse consequences, especially on bone, can be devastating. The incidence of glucocorticoid-induced osteoporosis (GIO) may be as high as 50% after 6 months' treatment with steroids. This manifests itself as a 30 to 400% increase in the incidence of low trauma fractures. The incidence rates can be even greater in specific clinical settings such as following organ transplantation. The pathogenesis of glucocorticoid-induced osteoporosis remains complex and perplexing.The concomitant prescription of bone-active drugs for the prevention and treatment of GIO in the United Kingdom population remains low, despite the availability of effective therapies. In addition, there remain many unanswered questions about the pathogenesis of GIO and clinical management. These include identification of the optimum bone mineral density threshold at which to intervene with bone-active drugs, the dose or duration of exposure to steroid therapy that warrants intervention, and the demonstration of the efficacy of fracture prevention for different bone-active drugs or for a combination of these drugs.

Monitoring treatment for osteoporosis by using bone densitometry

In recent years, the range of treatments available for patients with osteoporosis has greatly increased. A decade ago, the only proven therapy was estrogen, but today the choices include bisphosphonates, selective estrogen-receptor modulators, calcitonin, and parathyroid hormone. Clinical trials involving bone mineral density (BMD) scans of the spine and femur have had an important role in the evaluation of these new therapies. In particular, the efficacy of treatments has now been verified in large studies powered to show reductions in fracture risk. In contrast with the use of BMD scans in research studies, their value for monitoring response to treatment in individual patients is less certain. In many cases, the increases in BMD are too small to reliably distinguish between true changes and measurement error. However, experience with estrogen and bisphosphonates suggests that these treatments have a beneficial effect on bone in most patients. Follow-up scans for patients taking these agents are therefore of limited value, apart from offering reassurance to the patient and the doctor. However, when new therapies are first introduced, follow-up scans have a useful role in building up the physician's experience and confidence.

Parathyroid hormone added to established hormone therapy: effects on vertebral fracture and maintenance of bone mass after parathyroid hormone withdrawal

Our best pharmacologic agents for osteoporosis treatment prevent no more than 40-60% of osteoporotic fractures in patients at highest risk. Thus, there is a need for agents that can further augment bone mass and reduce fracture risk more substantially. To this end, we investigated the utility of parathyroid hormone (PTH) in combination with established hormone-replacement therapy (HRT) in women with osteoporosis. Fifty-two women who had been on HRT for at least 2 years were enrolled in this trial in which 25 were assigned randomly to remain on HRT alone and 27 were assigned to remain on HRT and also receive daily subcutaneous PTH(1-34) 400 U (25 microg) per day for 3 years. Bone mineral density (BMD) measurements at the spine, hip, and total body as well as biochemical determinations of bone turnover and calcium homeostasis were obtained every 6 months. Lateral thoracic and lumbar spine X-rays were obtained at baseline and annually. Subjects also had measurements of bone density and biochemical indices of bone turnover 1 year after discontinuation of PTH, while HRT was continued. In the group receiving HRT alone, bone density and biochemical variables of bone turnover remained stable throughout the 3-year treatment trial and 1-year follow-up. In the PTH + HRT group, biochemical variables of bone formation and resorption peaked at 6 months and subsequently remained elevated until 30 months at which time levels were indistinguishable from baseline. Subjects in the PTH + HRT group increased bone mass by 13.4+/-1.4% in the spine, 4.4+/-1.0% in the total hip, and 3.7+/-1.4% in the total body. Bone density measurements remained stable 1 year after discontinuation of PTH without any significant loss while women continued HRT. Biochemical variables did not change significantly after cessation of PTH through the 1-year follow-up period. PTH + HRT reduced the percent of women who had vertebral fractures from 37.5% to 8.3% (using a 15% height reduction criterion) and from 25% to 0% (using a 20% height reduction criterion) compared with women receiving HRT alone (p < 0.02 for both). We conclude that ongoing HRT maintains almost all of the PTH-induced bone mass increment for 1 year after discontinuation of PTH. Furthermore, PTH in combination with hormone therapy is an effective means of increasing bone mass throughout the skeleton and specifically reducing vertebral fracture occurrence by 75-100%, compared with HRT alone.

Osteoporotic vertebral fractures

Osteoporosis is a significant public health problem. Vertebral fractures are the most common fracture in patients with osteoporosis, occurring in approximately 750,000 cases each year. The fractures may cause acute or chronic pain, reduce the quality of life, and shorten life expectancy. Several medications are available that reduce the risk of fracture. Vertebroplasty and kyphoplasty (balloon-inflated expansion of collapsed vertebrae followed by injection of bone cement) may reduce or relieve pain in selected patients. Although surgery is rarely necessary for the management of osteoporotic vertebral fractures, it may be indicated for other reasons. No studies have been conducted to determine if the outcome of spinal fusion is different in patients with osteoporosis and, if it is, whether management of the patient's osteoporosis will improve the outcome.

Risedronate

Risedronate is a novel orally administered pyridinyl bisphosphonate indicated for the prevention or treatment of postmenopausal and glucocorticoid-induced osteoporosis and Paget's disease. The drug reduces bone turnover and decreases resorption chiefly through osteoclastic effects, with no undesirable effects on cortical porosity or thickness or on cancellous bone volume. Four randomised, double-blind trials have been carried out in 4873 patients with postmenopausal osteoporosis. In 2 of these studies, the primary end-point of vertebral fracture incidence was reduced by risedronate 5mg once daily by up to 65 and 49% relative to placebo after 1 and 3 years, respectively. Across all 4 trials, risedronate improved lumbar spine, femoral neck and femoral trochanter bone mineral density (BMD) statistically significantly relative to placebo. The drug also prevented bone loss in a study in 383 women with recent menopause, and reduced the risk of hip fracture in elderly women with confirmed osteoporosis in a trial involving a total of 9331 patients. Risedronate 5 mg/day plus estrogen has been shown to be superior to estrogen alone in a 12-month double-blind study in 524 women with at least 1-year's history of menopause. Two randomised, double-blind and placebo-controlled 12-month studies in a total of 518 patients have shown risedronate 5 mg/day to prevent or reverse bone loss in patients receiving glucocorticoid therapy. Risedronate 30 mg/day was associated with statistically significant reductions in mean serum levels of alkaline phosphatase (ALP) in noncomparative studies in patients with Paget's disease. ALP normalisation rates ranged from 53.8 to 65% across two 84-day treatment cycles in 2 of these trials in 180 patients. In a randomised, double-blind study in 123 patients, risedronate 30 mg/day for 2 months evoked significantly greater serum ALP responses than etidronate 400 mg/day for 6 months. The overall tolerability profile of risedronate was similar to that of placebo in clinical studies, with no evidence of acute-phase reactions or mineralisation defects, or excess incidence of upper GI lesions, in patients receiving the drug.

CONCLUSIONS

Risedronate is an effective and well tolerated novel bisphosphonate that is suitable for first-line therapy in Paget's disease. The rapid and sustained reductions in vertebral fracture incidence and BMD changes seen in patients with postmenopausal and glucocorticoid-induced osteoporosis indicate the drug to be a valuable treatment option with first-line potential, particularly in patients for whom hormonal therapy is inappropriate. The effects of the drug on hip fracture incidence in elderly women with confirmed osteoporosis point to a particular role in older patients, or those with more advanced disease.