What PROOF proves about calcitonin and clinical trials

Effects of Calcitonin Administration on the Amount of Bone Formation After Sutural Expansion Using Micro-CT

OBJECTIVE

Calcitonin injections were used in this investigation to see whether they influenced the quantity of bone formation after a rabbit model was subjected to micro-computed tomography expansion.

MATERIALS AND METHODS

Research was conducted on a total of 16 white male rabbits. Randomly, 4 groups of 4 rabbits each had their bone-borne expanders triggered by the Hyrax appliances as follows: In the first group (the control), the expansion was (0.5) mm per day for 12 days. In the second group, the same expansion protocol was used with 3 subcutaneous injections of calcitonin). In the third group, the expansion was (2.5) mm per day for 7 days followed by (0.5) mm per day for 7 days. In the fourth group, the same expansion protocol was used with 3 subcutaneous injections of calcitonin. As a result, all groups had their Hyrax devices expanded by 6 mm in total. Sutural separation and new bone growth were examined by micro-computed tomography after 6 weeks of retention. To end the experiment, the rabbits were given a high dosage of phenobarbitone (90 mg/kg).

RESULTS

In the calcitonin-receiving group, there was a significant increase in anterior and posterior sutural separation, when compared with non-calcitonin-receiving groups. In the (2.5) mm instant expansion protocol, there was a significant increase in anterior and posterior sutural separation, when compared with the (0.5) mm instant expansion protocol.

CONCLUSION

Calcitonin and the instant expansion protocol enhance new bone formation in rabbits.

Medullary thyroid carcinoma: a narrative historical review

INTRODUCTION

Sporadic or hereditary medullary thyroid carcinoma (MTC) is an uncommon thyroid malignancy arising from calcitonin secreting parafollicular C cells. Interestingly, MTC and calcitonin were distinct entities that were discovered independently yet concurrently, and their association was unknown.

AREAS COVERED

This review aims to present a historical review of the evolution of our understanding of MTC and its tumor marker calcitonin to highlight the prominent individuals that influenced and shaped our knowledge of this uncommon thyroid cancer type up to the dawn of the 21^st century. An overview of all published reports of novel research and work summarizing important findings for MTC and calcitonin was carried out.

EXPERT OPINION

Surgery remains the cornerstone of treatment for localized MTC. However, several new treatment options are either available or in development for advanced or metastatic MTC, including several novel small molecules targeting oncogenic RET and peptide receptor radionuclide therapy, immunotherapy, radioimmunotherapy, and radiofrequency ablation. In the near future, these novel treatments hold promise for therapy of this very distinct thyroid cancer type.

Calcitonin and Bone Physiology: In Vitro, In Vivo, and Clinical Investigations

Calcitonin was discovered as a peptide hormone that was known to reduce the calcium levels in the systemic circulation. This hypocalcemic effect is produced due to multiple reasons such as inhibition of bone resorption or suppression of calcium release from the bone. Thus, calcitonin was said as a primary regulator of the bone resorption process. This is the reason why calcitonin has been used widely in clinics for the treatment of bone disorders such as osteoporosis, hypercalcemia, and Paget's disease. However, presently calcitonin usage is declined due to the development of efficacious formulations of new drugs. Calcitonin gene-related peptides and several other peptides such as intermedin, amylin, and adrenomedullin (ADM) are categorized in calcitonin family. These peptides are known for the structural similarity with calcitonin. Aside from having a similar structure, these peptides have few overlapping biological activities and signal transduction action through related receptors. However, several other activities are also present that are peptide specific. In vitro and in vivo studies documented the posttreatment effects of calcitonin peptides, i.e., positive effect on bone osteoblasts and their formation and negative effect on osteoclasts and their resorption. The recent research studies carried out on genetically modified mice showed the inhibition of osteoclast activity by amylin, while astonishingly calcitonin plays its role by suppressing osteoblast and bone turnover. This article describes the review of the bone, the activity of the calcitonin family of peptides, and the link between them.

Advances in osteoporosis from 1970 to 2018

In 1970, there were no drugs under study for osteoporosis. Estrogen was used, but little was known about the correct dose for preventing bone loss. At that time, fractures were not even recognized as a disease, but regarded as part of normal aging. From 1970 to this year (2018), there have been extensive advances in the osteoporosis field ranging from fracture epidemiology to the remarkable invention of bone density measurements. There have been major advances in therapeutic options available for patients for prevention and treatment of osteoporosis. In parallel, the advances in the laboratory helped elucidate the process of bone remodeling, not only at the macroscopic level but also at the cellular level. This led to rapid advances in translational research from cellular biology to new therapies exemplified by the development of monoclonal antibodies for osteoporosis. Further understanding of the signaling pathways in bone cells will lead to new small molecules made for osteoporosis treatment, perhaps causing less adverse events. University-based research throughout the world has been a leader in most of these advances, and Pharma support for phase 1 to 4 studies helped bring these discoveries to patients. In the osteoporosis field alone, one sees the tremendous value of grant support for university research by National funding agencies such as the National Institute of Health in this country and similar agencies in other countries. There are clinical challenges that have to be solved with long-term compliance with osteoporosis medication if we want to reduce fracture incidence in the long term.

The Activity of Peptides of the Calcitonin Family in Bone

Calcitonin was discovered over 50 yr ago as a new hormone that rapidly lowers circulating calcium levels. This effect is caused by the inhibition of calcium efflux from bone, as calcitonin is a potent inhibitor of bone resorption. Calcitonin has been in clinical use for conditions of accelerated bone turnover, including Paget's disease and osteoporosis; although in recent years, with the development of drugs that are more potent inhibitors of bone resorption, its use has declined. A number of peptides that are structurally similar to calcitonin form the calcitonin family, which currently includes calcitonin gene-related peptides (αCGRP and βCGRP), amylin, adrenomedullin, and intermedin. Apart from being structurally similar, the peptides signal through related receptors and have some overlapping biological activities, although other activities are peptide specific. In bone, in vitro studies and administration of the peptides to animals generally found inhibitory effects on osteoclasts and bone resorption and positive effects on osteoblasts and bone formation. Surprisingly, studies in genetically modified mice have demonstrated that the physiological role of calcitonin appears to be the inhibition of osteoblast activity and bone turnover, whereas amylin inhibits osteoclast activity. The review article focuses on the activities of peptides of the calcitonin family in bone and the challenges in understanding the relationship between the pharmacological effects and the physiological roles of these peptides.

A randomized, double-blind, multicenter, placebo-controlled study to evaluate the efficacy and safety of oral salmon calcitonin in the treatment of osteoporosis in postmenopausal women taking calcium and vitamin D

This randomized, double-blind, placebo-controlled phase III study was conducted to assess the efficacy and safety of oral calcitonin (SMC021) for the treatment of postmenopausal osteoporosis. A total of 4665 postmenopausal women with osteoporosis were randomized 1:1 to receive calcium and vitamin D plus either SMC021 tablets (0.8mg/d) or placebo for 36months. The primary endpoint was the proportion of patients with a new vertebral fracture. The two groups were well balanced at baseline with regards to demographic and clinical data. No effect of SMC021 on preventing new vertebral fractures was observed, nor was any effect seen on new hip or non-vertebral fractures. Women receiving SMC021 had a mean 1.02% (±0.12%) increase in lumbar spine bone mineral density (BMD) compared with a mean 0.18% (±0.12%) increase in the placebo group by the end of the study (p<0.0001). Similarly, small increases in BMD were observed at the femoral neck and hip in both groups. Levels of the biomarkers of bone turnover, urinary CTX-I and CTX-II, were 15% lower in the SMC021 group than in the placebo arm at 12 and 24months, but not at 36months. No change in quality of life between groups, assessed by the Qualeffo-14 questionnaire, was observed in either group between baseline and month 36. Pharmacokinetics analysis confirmed exposure to SMC021, but the drug levels were markedly lower than expected. Approximately 92% of subjects in each treatment group experienced an adverse event (AE), the majority of which were mild or moderate in intensity. AEs associated with SMC021 were primarily of gastrointestinal origin and included nausea, vomiting and abdominal pain, as well as hot flushes which were the reason for the slightly higher drop-out rate in the active treatment arm compared to placebo. The number of severe AEs was low in both groups. Thirty-five deaths were reported but none were considered treatment-related. Due to the lack of efficacy in preventing fractures, the development of the orally formulated calcitonin was terminated despite the promising results in earlier studies.

Salmon calcitonin use and associated cancer risk

OBJECTIVE

To evaluate the strength of evidence supporting a possible association between salmon calcitonin (SCT) use and cancer incidence.

DATA SOURCES

Searches of MEDLINE/PubMed, MEDLINE/OVID, and EMBASE (January 1973 to September 2013) were performed using the key search terms salmon calcitonin, humans, nasal calcitonin, and (for EMBASE only) randomized controlled trial. We also performed a manual review of data reviewed by the US Food and Drug Administration (FDA) committee in 2013.

STUDY SELECTION AND DATA EXTRACTION

All articles identified from the data sources were evaluated and all information deemed relevant was included for this review.

DATA SYNTHESIS

Intranasal and injectable SCT are FDA-approved for the treatment of postmenopausal osteoporosis. After a safety signal suggested a possible link between SCT use and prostate cancer, the European Medicines Agency and FDA regulatory agencies conducted analyses of SCT randomized controlled trial data to assess cancer-related adverse events and to readdress the approval status of SCT. Eighteen studies were found that compared nasal or oral SCT and placebo. In 15 of the 18 studies, the percentage of malignancy was greater in the SCT arm. The studies varied in quality, outcomes, and length. Most of the studies had poor-quality methods to assess new cancer cases.

CONCLUSIONS

Current evidence may suggest an association between SCT use and cancer incidence based on studies with poor-quality cancer assessment methods. However, considering the lack of demonstrated efficacy of SCT to reduce fractures, clinicians should consider discontinuing its use for osteoporosis treatment regardless of the FDA's final approval decision.

Calcitonin: a drug of the past or for the future? Physiologic inhibition of bone resorption while sustaining osteoclast numbers improves bone quality

Postmenopausal osteoporosis results from a continuous imbalance between bone resorption and bone formation, favoring bone resorption. An increasing number of treatments for osteoporosis are in development and on the market. A range of differences and similarities are found between these treatment options, and these need to be carefully evaluated before the initiation of treatment. This article summarizes data from in vitro and animal studies, as well as clinical trials, on the effect of calcitonin on bone turnover. Calcitonin was found to exert its antiresorptive effects via directly reducing osteoclastic resorption, and thus leads to an increase in bone mineral density and bone strength. Furthermore, calcitonin appears to mainly target the most active osteoclasts, and in contrast to most other antiresorptive agents it does not reduce the number of osteoclasts. Finally, in humans, while attenuating resorption, calcitonin treatment does not interfere markedly with bone formation, in contrast to other currently available antiresorptive agents. Thus, we speculate that calcitonin treatment will lead to a continuously positive bone balance in contrast with other antiresorptive agents currently on the market and thereby, in a physiologic manner, result in improved bone quality. Calcitonin is currently only available in injectable and nasal formulations. An oral formulation may, however, improve patient acceptance and compliance. Currently, several different routes are being pursued to identify an optimal oral formulation, of which the technology based on 5-CNAC is the most advanced. There are promising clinical data available for this formulation from both osteoarthritis and osteoporosis clinical trials, although the antifracture efficacy is not yet known.

Understanding risk factors, screening, and treatment of postmenopausal osteoporosis

Between 30% and 50% of American women will endure a clinical fracture during their lifetime due to the loss of bone mineral density that occurs with menopausal estrogen loss. This article is part one in a two-part series on osteoporosis. Part two will appear in the August 2008 issue of ORTHOPEDICS.

Prior fractures are common in patients with subsequent hip fractures

Treating osteoporosis in patients with prior fractures potentially results in a 50% reduction of risk of future fractures. We retrospectively reviewed 632 patients with incident hip fractures to evaluate (1) the prevalence of prior fractures in incident hip fractures, (2) whether prior fractures led to an increase in the treatment of osteoporosis, and (3) the cost utility of osteoporosis treatment after a prior fracture. The patients were treated at three hospitals from January 2000 to June 2001 and 514 (80%) were women. A minimal trauma fracture was defined as a fracture resulting from a fall while standing or walking or falling from a height less than 4 feet. Two hundred eighty-two patients (45%) with incident hip fractures described a prior minimal trauma fracture. Osteoporosis was diagnosed in 43 (13%) women and three (5%) men. In 107 cases (17%), the incident hip fracture was the second hip fracture. A prior minimal trauma fracture did not increase treatment for osteoporosis. Presuming a 50% reduction in fracture risk with medications, treating the 282 patients with prior minimal trauma fracture would have resulted in a savings of $3.5 million.

Development and characterization of biphenylsulfonamides as novel inhibitors of bone resorption

Increased osteoclastic bone resorption plays a central role in the pathogenesis of many bone diseases, and osteoclast inhibitors are the most widely used treatments for these diseases. We have identified and characterized a series of novel biphenylsulfonamide derivatives that have potent inhibitory effects on osteoclastic bone resorption in vitro and that prevent ovariectomy-induced bone loss in vivo. A number of aromatic substituted derivatives were prepared and a QSAR model was generated, which allowed accurate prediction of compound potency. Using this model, we have prepared compounds able to inhibit osteoclast formation and bone resorption in vitro at concentrations in the nanomolar range. One such compound, 55 (ABD295) (Greig, I. R.; Mohamed, A. I.; Ralston, S. H.; van't Hof, R. J. Alkyl Aryl Sulfonamides as Therapeutic Agents for the Treatment of Bone Conditions. GB Patent WO2005118528, 2005), fully reversed ovariectomy-induced bone loss in mice at a dose of 5 (mg/kg)/day. In conclusion, biphenylsulfonamides like 55 form a new class of potent antiresorptive agents with possible therapeutic use in diseases characterized by increased bone resorption.

Osteoporosis

Osteoporosis is a serious public health issue. The past 10 years have seen great advances in our understanding of its epidemiology, pathophysiology, and treatment, and further advances are rapidly being made. Clinical assessment will probably evolve from decisions mainly being made on the basis of bone densitometry, to use of algorithms of absolute fracture risk. Biochemical markers of bone turnover are also likely to become more widely used. Bisphosphonates will probably remain the mainstay of therapy, but improved understanding of the optimum amount of remodelling suppression and duration of therapy will be important. At the same time, other diagnostic and therapeutic approaches, including biological agents, are likely to become more widespread.

Update of current therapeutic options for the treatment of postmenopausal osteoporosis

BACKGROUND

Osteoporosis is a common chronic condition in elderly women and is associated with decreased bone strength and an increased risk for fractures. As the incidence of osteoporotic fractures continues to rise, it is important to identify the most effective therapies for reducing patients' risk of fracture.

OBJECTIVE

This article reviews the medication classes commonly used for treating osteoporosis and the efficacy, tolerability, and drug-interaction potential of specific medications. The evidence for the use of combination therapies is summarized, as are the agents under investigation.

METHODS

Relevant articles were identified through a search of MEDLINE (August 1985-August 2005) using the terms osteoporosis, postmenopausal, fracture, and efficacy combined with drug therapy, calcium, vitamin D, estrogen, progesterone, selective estrogen modulators, calcitonin, strontium ranelate, bisphosphonates, alendronate, risedronate, ibandronate, pamidronate, parathyroid hormone, combination therapy, and zoledronic acid. The identified articles were reviewed for suitability, with priority given to meta-analyses.

RESULTS

Among the therapeutic options for the treatment of osteoporosis, the bisphosphonates appear to provide the greatest antiresorptive efficacy, with some bisphosphonates providing 7% to 8% increases in bone mineral density and 60% to 70% decreases in markers of bone resorption. Bisphosphonates also may reduce the incidence of new vertebral fractures by 50% to 52%.

CONCLUSIONS

Bisphosphonates are currently the first choice for the treatment of osteoporosis. Use of intermittent regimens of the newer bisphosphonates appears to be a promising alternative to administration of daily or weekly treatment.

A comparison of teriparatide and calcitonin therapy in postmenopausal Asian women with osteoporosis: a 6-month study

OBJECTIVE

The number of hip fractures is expected to double in the next 20 years, with current estimates that Asia will account for 37% of these cases. As bone mineral density (BMD) may be used as a measure of fracture risk, we sought to compare the effects of teriparatide with salmon calcitonin treatment on changes in BMD, biochemical bone markers, and safety in postmenopausal Asian women with osteoporosis.

METHODOLOGY

A total of 104 patients (n = 47 teriparatide [20 g/day subcutaneously] and n = 57 calcitonin [100 IU/day subcutaneously]) were enrolled in Hong Kong, Singapore, Philippines, Malaysia, and Thailand. Calcium (> or = 500 mg/day) and vitamin D (200-400 IU/day) supplements were taken throughout the 6-month controlled, randomized study.

RESULTS

Teriparatide was associated with a 5.03 +/- 4.77% increase in lumbar spine BMD (p < 0.0001, mean +/- SD change from baseline), whereas changes in lumbar spine BMD for patients on calcitonin were not statistically significant (mean change of 0.36 +/- 4.12%, p = 0.16). Comparison of the two groups indicated that teriparatide treatment improved lumbar spine BMD statistically significantly more than calcitonin (p < 0.0001). No statistically significant changes were observed for total hip or femoral neck BMD. Serum bone-specific alkaline phosphatase (BSAP) increased by 55.9% (median change from baseline, p < 0.0001) in the teriparatide group, and remained stable with calcitonin (5.0% change, p = 0.24); osteocalcin increased by 156.15% (median change from baseline, p < 0.0001) with teriparatide, and decreased with calcitonin (-15.25%, p = 0.03). Similar rates of adverse events were observed, with nausea and dizziness the most commonly reported for both groups (teriparatide versus calcitonin, 13.0% versus 23.2% p = 0.21, 10.9% versus 21.4% p = 0.19, respectively). There were no clinically relevant changes observed in laboratory parameters.

CONCLUSIONS

Both treatments were similarly tolerated, however teriparatide was associated with greater increases in lumbar spine BMD and bone formation markers, demonstrating the unique mechanism of action and safety of this treatment for osteoporosis in these Asian women.

Unraveling multiple complaints in an 82-year-old woman

With this issue, The Consultant Pharmacist begins a new series, Case Studies in Geriatric Pharmacotherapy. This column will present case studies in which the pharmacist identifies actual or potential patient medication-related problems, presents an evidence-based discussion of options, and develops a patient management plan. As part of this evaluation, the pharmacist consults with both the patient's physicians and family members. Because older individuals generally consume a large number of medications, such a complex, multidisciplinary approach is critical to patient care and one that only pharmacists can provide. The growing consumption of both prescription and over-the-counter drugs by older adults increases the risk of medication-related problems. Pharmacists have an obligation to continually develop skills for identifying, treating, and preventing these medication-related problems.

Effectiveness of salmon calcitonin nasal spray in the treatment of lumbar canal stenosis: a double-blind, randomized, placebo-controlled, parallel group trial

STUDY DESIGN

Double-blind, randomized, placebo-controlled study to assess the effectiveness of calcitonin nasal spray on symptoms and function in patients with lumbar canal stenosis.

OBJECTIVE

To compare effectiveness of calcitonin administered by nasal spray with placebo in patients with clinically symptomatic lumbar canal stenosis.

SUMMARY OF BACKGROUND DATA

Lumbar canal stenosis is the most common reason for spine surgery in individuals over 65 years of age. Nonoperative approaches have been not well studied and limited primarily to physical therapy exercises. Several small trials in the past have suggested that subcutaneous and intramuscular calcitonin is an effective nonsurgical option in treating the symptoms of spinal stenosis patients. Only three trials were randomized and placebo-controlled.

METHODS

Fifty-five patients with clinical lumbar canal stenosis (pseudoclaudication), confirmatory MR imaging, and pain intensity index (VAS) of > or =6 were randomized to either placebo or intranasal calcitonin daily for 6 weeks, followed by an open label 6-week extension, during which all patients received active drug. Outcome parameters performed at baseline, 6 weeks, and 12 weeks, included pain intensity index, walking time and distance to pain, SF-36, and Oswestry disability index.

RESULTS

Thirty-six patients received calcitonin, and 19 placebo. Eight (14.54%) calcitonin and 4 (7.27%) placebo patients withdrew from the study. The mean baseline pain score for calcitonin group was 7.8 and 7.5 for placebo. Comparisons at week 6 showed no statistically significant difference in the change in pain intensity (VAS) between calcitonin group (-2.9) and placebo (-2.4) (P = 0.4382) from baseline. There was no significant difference in walking time to pain (calcitonin -10.0 seconds; placebo +32.2 seconds; P = 0.5136). Walking distance to pain showed a mean improvement of +91.4 ft in the calcitonin group and +254.7 ft in the placebo group (P = 0.4948). No significant difference was observed in the SF-36 score between the treatment groups. Using a threshold of at least 50% reduction in pain from baseline to 6 weeks, 12 of 29 (41.37%) of calcitonin patients were considered responders versus 7 of 18 (38.88%) of placebo patients (P = 0.4238)

CONCLUSIONS

In this first ever largest randomized placebo-controlled parallel group trial of nasal calcitonin in spinal stenosis, nasal calcitonin was not superior to placebo in treating the symptoms of spinal stenosis at 6 weeks. Based on this study, nasal calcitonin does not appear to have a role in nonoperative treatment of lumbar canal stenosis.

Identification of biphenylcarboxylic acid derivatives as a novel class of bone resorption inhibitors

A novel class of biphenylcarboxylic acid derivatives are described that inhibit osteoclastic bone resorption in vitro by promoting osteoclast apoptosis and that prevent ovariectomy-induced bone loss in vivo. The compounds act by a novel mechanism that seems to be distinct from existing antiresorptive drugs.

INTRODUCTION

Many common bone diseases such as osteoporosis, Paget's disease, and cancer-associated bone disease are characterized by excessive bone loss caused by increased osteoclastic activity. Successful treatment of these diseases is based on osteoclast inhibition. The osteoclast inhibitory drugs that are currently available fall into relatively few mechanistic classes, indicating the need to identify novel antiresorptives. Here we describe a series of biphenylcarboxylic acid derivatives that have potent inhibitory effects on osteoclastic bone resorption in vitro and on ovariectomy-induced bone loss in vivo.

MATERIALS AND METHODS

Compounds were tested for inhibitory effects on bone resorption in vitro using mouse osteoblast-bone marrow co-cultures, isolated rabbit osteoclasts, and mouse osteoclasts generated from bone marrow. Some experiments were also performed on human osteoclasts generated from peripheral blood mononuclear cells. We also investigated the effects of specific compounds on ovariectomy-induced bone loss in vivo in mice.

RESULTS

One of the most potent compounds identified was the butanediol ester of biphenyl carboxylic acid (ABD056), which inhibited osteoclast formation in mouse osteoblast-bone marrow co-cultures by 50% (IC50) at a concentration of 26 microM and in macrophage-colony stimulating factor (M-CSF)- and RANKL-stimulated mouse bone marrow cultures with an IC50 of 8 microM. Mechanistic studies showed that ABD056 caused osteoclast apoptosis and inhibited TNFalpha-induced NF-kappaB activation. No inhibitory effects on osteoblast growth or differentiation were observed at concentrations of up to 100 microM. When administered to mice at doses of 5 and 10 mg/kg/day, ABD056 prevented ovariectomy-induced bone loss.

CONCLUSIONS

Butanediol biphenylcarboxylic acid derivatives represent a new class of antiresorptive drug that might be of therapeutic value in the prevention and treatment of diseases characterized by osteoclast activation such as osteoporosis, cancer-associated bone disease, and Paget's disease of bone.

Oral bisphosphonates and upper gastrointestinal tract problems: what is the evidence?

OBJECTIVE

To review and evaluate the evidence regarding possible associations of bisphosphonate use with upper gastrointestinal (GI) tract adverse events (AEs).

METHODS

We reviewed and summarized published information and abstracts regarding upper GI tract safety and tolerability of bisphosphonates, including laboratory and animal studies, epidemiological (observational) studies, endoscopy studies, and randomized controlled trials (RCTs). The evidence was summarized by using the principles of evidence-based medicine, giving the greatest credence to high-quality RCTs.

RESULTS

Clinical reports of esophagitis associated with bisphosphonate use appear to have declined in frequency once the importance of proper administration was explained to physicians after early reports of complications. Conflicting results have been reported in endoscopy studies; some reported no significant increase in upper GI tract lesions, whereas others reported a higher incidence of gastric (but not esophageal) lesions among patients taking oral bisphosphonates. Endoscopy studies that reported differences were of short duration (2 weeks) and were not of double-blind design. Results from large RCTs involving thousands of participants detected no increase in upper GI tract AEs among individuals treated with bisphosphonates. Other studies of patients who discontinued taking bisphosphonates and were randomized to blinded re-treatment with either a bisphosphonate or placebo show that most patients (>85%) were able to continue treatment, with no difference in AEs between the bisphosphonate and placebo groups.

CONCLUSIONS

The highest level of evidence, RCTs, suggests little or no increase in risk of upper GI tract problems if bisphosphonates are administered properly. Upper GI tract symptoms are common among patients with osteoporosis. The evidence suggests that many upper GI tract AEs reported during therapy with bisphosphonates may reflect a high background incidence of upper GI tract complaints and an increased sensitivity to detection rather than a causal relationship to therapy.

Osteoporosis in elderly: prevention and treatment

Osteoporosis is a major clinical problem in older women and men. Almost any bone can fracture as a result of the increased bone fragility of osteoporosis. These fractures are associated with higher health care costs, physical disability, impaired quality of life, and increased mortality. Because the incidence of osteoporotic fracture increases with advancing age, measures to diagnose and prevent osteoporosis and its complications assume a major public health concern. BMD is a valuable tool to identify patients at risk for fracture, to make therapeutic decisions, and to monitor therapy. Several other modifiable and nonmodifiable risk factors for osteoporosis have also been identified. Treatment of potentially modifiable risk factors along with exercise and calcium and vitamin D supplementation forms an important adjunct to pharmacologic management of osteoporosis. Improved household safety can reduce the risk of falls. Hip protectors have been found to be effective in nursing home population. The pharmacologic options include bisphosphonates, HRT, SERMs and calcitonin. PTH had received FDA advisory committee approval. Alendronate has been approved for treatment of osteoporosis in men, and other treatments for men are under evaluation.

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.

How to prevent fractures in the individual with osteoporosis

The high rate of osteoporotic fracture in Western populations has resulted in a significant burden in terms of morbidity, mortality and health care costs. The use of DXA has made the diagnosis of osteoporosis easier and identified a subgroup of individuals who are at a higher risk of fracture. It is a useful tool in determining therapy in those at greatest risk of fracture. However, widespread use of such treatments is low and greater uptake remains an elusive goal. There are now many different treatments that reduce fracture rate, and can accompany lifestyle measures such as smoking cessation, diet and exercise. Dietary supplementation with calcium has been shown to reduce the risk of vertebral fracture, and the combination of calcium with vitamin D has been shown to reduce fracture at non-vertebral sites, including the hip. Although ERT, SERMs and tibolone all retard bone loss, prospective fracture prevention has only been shown for SERMs and then only at the spine. Bisphosphonates represent a class of potent anti-resorptive agents, which have been shown to reduce fracture rate at vertebral and non-vertebral sites. Other agents such as calcitonin, PTH and fluoride are of less certain benefit in preventing fracture.