Treatment with once-weekly alendronate 70 mg compared with once-weekly risedronate 35 mg in women with postmenopausal osteoporosis: a randomized double-blind study

Risk of atypical femoral fracture during and after bisphosphonate use

BACKGROUND AND PURPOSE

Use of bisphosphonates in women is associated with higher risk of atypical femoral fractures. The risk in terms of timing of use and type of bisphosphonate, and in men, remains unclear.

PATIENTS AND METHODS

We reviewed radiographs of 5,342 Swedish women and men aged 55 years or more who had had a fracture of the femoral shaft in the 3-year period 2008-2010 (97% of those eligible), and found 172 patients with atypical fractures (93% of them women). We obtained data on medication and comorbidity. The risk of atypical fracture associated with bisphosphonate use was estimated in a nationwide cohort analysis. In addition, we performed a case-control analysis with comparison to 952 patients with ordinary shaft fractures. A short report of the findings has recently been presented (Schilcher et al. 2014a). Here we provide full details.

RESULTS

The age-adjusted relative risk (RR) of atypical fracture associated with bisphosphonate use was 55 (95% CI: 39-79) in women and 54 (CI: 15-192) in men. In bisphosphonate users, women had a 3-fold higher risk than men (RR = 3.1, CI: 1.1-8.4). Alendronate users had higher risk than risedronate users (RR = 1.9, CI: 1.1-3.3). The RR after 4 years or more of use reached 126 (CI: 55-288), with a corresponding absolute risk of 11 (CI: 7-14) fractures per 10,000 person-years of use. The risk decreased by 70% per year since last use.

INTERPRETATION

Women have a higher risk of atypical femoral fracture than men. The type of bisphosphonate used may affect risk estimates and the risk decreases rapidly after cessation.

Comparison of the effects of three oral bisphosphonate therapies on the peripheral skeleton in postmenopausal osteoporosis: the TRIO study

We compared the effects of oral alendronate, ibandronate and risedronate on the central and peripheral skeleton over 2 years. We report differences in effect on the central skeleton but not on the peripheral skeleton. Greater effects were observed for ibandronate (and alendronate) than risedronate at the spine but not the hip.

INTRODUCTION

Generally, comparative clinical trials of bisphosphonates have examined changes in bone within central skeletal regions. We have examined the effects of bisphosphonate treatment on the peripheral skeleton.

METHODS

We conducted a 2-year, open-label, parallel randomised control trial of three orally administered bisphosphonates, at their licensed dose, to examine and compare their effects on the peripheral skeleton using multiple modes of measurement. We studied 172 postmenopausal women (53-84 years) who had either a bone mineral density (BMD) T-score of  ≤ -2.5 at the spine and/or total hip or  < -1.0 at either site plus a previous low trauma fracture. Participants were randomised to receive either (i) ibandronate 150 mg/month, (ii) alendronate 70 mg/week or (iii) risedronate 35 mg/week, plus calcium (1,200 mg/day) and vitamin D (800 IU/day), for 2 years. Premenopausal women (33-40 years, n = 226) were studied to monitor device stability.

RESULTS

We measured central BMD of the lumbar spine, total hip, total body and forearm using dual-energy X-ray absorptiometry. We measured calcaneus BMD (using dual-energy X-ray absorptiometry plus laser), radius and tibia BMD (using peripheral quantitative computed tomography), finger BMD (using radiographic absorptiometry), and phalangeal and calcaneal ultrasound variables (using quantitative ultrasound). Mixed effects regression models were used to evaluate effects of time and treatment allocation on BMD change. By 2 years, there were significant increases (p < 0.05) in central BMD sites (lumbar spine, total hip). In the peripheral skeleton, only significant changes in calcaneus BMD, 33 % total radius BMD and quantitative ultrasound (QUS)-2 broadband ultrasound attenuation (BUA) were evident for women receiving oral bisphosphonates.

CONCLUSIONS

The increases in lumbar spine and total body BMD were greater with ibandronate and alendronate than with risedronate. Treatment effects on peripheral measurements did not differ between the three bisphosphonates.

Goal-directed treatment of osteoporosis in Europe

Despite the proven predictive ability of bone mineral density, Fracture Risk Assessment Tool (FRAX®), bone turnover markers, and fracture for osteoporotic fracture, their use as targets for treatment of osteoporosis is limited.

INTRODUCTION

Treat-to-target is a strategy applied in several fields of medicine and has recently become an area of interest in the management of osteoporosis. Its role in this setting remains controversial. This article was prepared following a European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) working group meeting convened under the auspices of the International Osteoporosis Foundation (IOF) to discuss the feasibility of applying such a strategy in osteoporosis in Europe.

METHODS

Potential targets range from the absence of an incident fracture to fixed levels of bone mineral density (BMD), a desired FRAX® score, a specified level of bone turnover markers or indeed changes in any one or a combination of these parameters.

RESULTS

Despite the proven predictive ability of all of these variables for fracture (particularly BMD and FRAX), their use as targets remains limited due to low sensitivity, the influence of confounders and current lack of evidence that targets can be consistently reached.

CONCLUSION

ESCEO considers that it is not currently feasible to apply a treat-to-target strategy in osteoporosis, though it did identify a need to continue to improve the targeting of treatment to those at higher risk (target-to-treat strategy) and a number of issues for the research agenda. These include international consensus on intervention thresholds and definition of treatment failure, further exploration of the relationship between fracture and BMD, and FRAX and treatment efficacy and investigation of the potential of short-term targets to improve adherence.

Establishing reference intervals for bone turnover markers in healthy postmenopausal women in a nonfasting state

In order to interpret bone turnover markers (BTMs), we need to establish healthy reference intervals. It is difficult to establish reference intervals for older women because they commonly suffer from diseases or take medications that affect bone turnover. The aims of this study were: (1) to identify diseases and drugs that have a substantial effect on BTMs; (2) to establish reference intervals for premenopausal and postmenopausal women; and (3) to examine the effects of other factors on BTMs in healthy postmenopausal women. We studied women aged 30-39 years (n=258) and women aged 55-79 years (n=2419) from a five-European centre population-based study. We obtained a nonfasting serum and second morning void urine samples at a single baseline visit. BTMs were measured using automated immunoassay analysers. BTMs were higher in patients with vitamin D deficiency and chronic kidney disease. Three or more BTMs were higher in women who were osteoporotic and at least two BTMs were lower in women who were oestrogen replete, taking osteoporosis treatments or having diseases known to affect bone turnover. These were used as exclusion criteria for selecting the populations for the reference intervals. The reference intervals for BTMs were higher in postmenopausal than premenopausal women. Levels of BTMs were not dependent on geographical location and increased with age.

Effects of eight-month treatment with ONO-5334, a cathepsin K inhibitor, on bone metabolism, strength and microstructure in ovariectomized cynomolgus monkeys

This study examined the effect of ONO-5334, a cathepsin K inhibitor, on bone turnover, mineral density (BMD), mechanical strength and microstructure in ovariectomized (OVX) cynomolgus monkeys. Vehicle, ONO-5334 (3, 10 or 30 mg/kg) or alendronate (0.5 mg/kg) was orally administered for eight months to sham- and OVX-operated monkeys. ONO-5334 dose-dependently suppressed OVX-induced increase in bone turnover markers (urinary C-terminal cross-linking telopeptide of type I collagen (CTX) and serum osteocalcin). At the dose of 30 mg/kg, ONO-5334 maintained urinary CTX at nearly zero level and kept serum osteocalcin around the level of the sham animals. Marker levels in the alendronate-treated animals were similar to those in the sham animals throughout the study. ONO-5334 dose-dependently reversed the effect of OVX on vertebral BMD as measured by dual-energy X-ray absorptiometry (DXA) with improvement of bone mechanical strength. Both ONO-5334 and alendronate suppressed OVX-induced changes in vertebral microstructure and turnover state. In the femoral neck, peripheral quantitative computed tomography (pQCT) analysis showed that ONO-5334 increased total and cortical BMD. In particular, ONO-5334 significantly increased cortical BMD with improvement of bone mechanical strength. In microstructural analysis, alendronate suppressed OVX-induced increase in femoral mid-shaft osteonal bone formation rate (BFR) to a level below that recorded in the sham group, whereas ONO-5334 at 30 mg/kg did not suppress periosteal, osteonal and endocortical BFR. This finding supports the significant effect of ONO-5334 on cortical BMD and mechanical strength in the femoral neck. The results of this study suggest that ONO-5334 has good therapeutic potential for the treatment of osteoporosis.

Safety of drugs used in the treatment of osteoporosis

A number of drug classes are licensed for the treatment of osteoporosis including bisphosphonates, recombinant human parathyroid hormone (PTH), strontium, hormone replacement therapy (HRT), selective oestrogen receptor modulators (SERMS) and denosumab. This review discusses the safety of osteoporosis treatments and their efficacies. Recent concerns about the safety of calcium and high-dose vitamin D are discussed. Bisphosphonates have substantial postmarketing experience and a clearer picture of safety issues is emerging. Along with the well recognized effects on the gastrointestinal tract and kidney function, recently described adverse effects such as osteonecrosis of the jaw, oesophageal cancer, atrial fibrillation, subtrochanteric femur fractures and ocular complications of bisphosphonate therapy are discussed. Therapy with PTH is limited to two years' duration because of the development of osteogenic sarcomas in animal studies, which appeared related to dose, duration and timing of therapy. Strontium should be used with caution in patients with renal impairment and its use has been associated with venous thromboembolism. The role of HRT and SERMs in the treatment of postmenopausal osteoporosis is restricted as a result of an increased risk of stroke, venous thromboembolism and breast cancer. Postmarketing experience with denusomab is limited but a number of potential safety concerns including osteonecrosis of the jaw are emerging. All of these drugs have been proven to reduce fractures. The decision to use a drug to reduce fracture risk should be based on risk-benefit analysis of the drug and its suitability for individual patients.

Individual site-specific bone mineral density gain in normocalcemic primary hyperparathyroidism

In this study, we show that successful parathyroidectomy is followed at 1 year by a significant individual bone mineral density (BMD) gain in nearly half of normocalcemic PHPT patients with reduced bone mass. Alkaline phosphatase levels above median were identified as an independent predictor of individual BMD gain in normocalcemic PHPT patients.

INTRODUCTION

The aims of this study were to assess bone mineral density (BMD) gains after parathyroidectomy (PTX) in normocalcemic primary hyperparathyroidism (PHPT) at the individual level and to identify predictors of BMD gain after PTX in this context.

METHODS

Longitudinal cohort study of 55 PHPT patients referred for low bone mass and mild abnormalities of calcium/phosphorus metabolism, and successfully treated by PTX. BMD gain at 1 year was considered significant if ≥0.030 g/cm(2) at one site or more, without any equivalent BMD loss at another site. A logistic regression analysis was performed to identify predictive factors of individual BMD gain.

RESULTS

Among the 55 PHPT patients included, 29 patients with hypercalcemia, 36 patients with normocalcemic PHPT, defined by normal pre-PTX serum total (albumin-corrected) calcium (tCa), including 15 patients with normal ionized calcium (iCa), were identified. At 1 year of PTX, an individual BMD gain was observed in 73.7 % of hypercalcemic, 44.4 % of normocalcemic, and 46 % of PHPT patients with both normal tCa and iCa. Site-specific BMD gains were most important at the spine and hip in all subgroups including patients with normal iCa. Alkaline phosphatase activity above median, which reflects high bone turnover, was predictive of individual BMD gain, both in the overall cohort (OR = 4.9, 95 % CI 1.3-18.9), and in the normocalcemic group: OR = 8.4, 95 % CI 1.4-56.6.

CONCLUSIONS

Successful PTX is followed at 1 year by a significant individual BMD gain in nearly half of normocalcemic PHPT patients with osteoporosis. ALP levels above median could contribute to the therapeutic decision in this context.

Follow-up of six patients with neurofibromatosis 1-related osteoporosis treated with alendronate for 23 months

This is the first prospective follow-up study to describe the effects of oral alendronate medication on neurofibromatosis 1 (NF1)-related osteoporosis. NF1 is a neurocutaneous skeletal syndrome associated with increased fracture risk and high frequency of osteopenia and osteoporosis. Alendronate is a bisphosphonate drug which inhibits the function of bone-resorbing osteoclasts, ultimately leading to an increase in bone mineral density (BMD) and reduction in fracture risk. However, in vitro studies have shown that NF1 osteoclasts display insensitivity to apoptotic signals caused by bisphosphonates. Our aim was to monitor the effects of alendronate medication in patients with NF1. Five men and one woman, aged 28-76 years, with NF1-related osteoporosis were enrolled to the study. Study participants did not have other conditions and were not taking any medication known to affect bone. The medication included a weekly dose of 70 mg alendronate and a daily 20 μg vitamin D supplementation. After 23 months of follow-up, BMD was increased in five out of six patients, but the increase was not statistically significant. Serum levels of the bone turnover markers CTX and PINP were reduced, suggesting slower bone remodeling, as expected. An unexpected result was that serum levels of the osteoclast activity marker TRAP5b did not change during the follow-up. One new stress fracture of the tibia was documented during the alendronate therapy. Even though the study group was small, the findings of the current study (one new fracture and one patient with decreased BMD) call for a larger study to assess the efficacy of bisphosphonates in NF1-related osteoporosis.

Bisphosphonates and bone quality

Bisphosphonates (BPs) are bone-avid compounds used as first-line medications for the prevention and treatment of osteoporosis. They are also used in other skeletal pathologies such as Paget's and metastatic bone disease. They effectively reduce osteoclast viability and also activity in the resorptive phase of bone remodelling and help preserve bone micro-architecture, both major determinants of bone strength and ultimately of the susceptibility to fractures. The chemically distinctive structure of each BP used in the clinic determines their unique affinity, distribution/penetration throughout the bone and their individual effects on bone geometry, micro-architecture and composition or what we call 'bone quality'. BPs have no clinically significant anabolic effects. This review will touch upon some of the components of bone quality that could be affected by the administration of BPs.

Comparative gastrointestinal safety of bisphosphonates in primary osteoporosis: a network meta-analysis

We completed a network meta-analysis of published papers to compare bisphosphonate gastrointestinal safety. We found that zoledronic acid had the highest chance of causing gastrointestinal adverse events. Etidronate had the highest chance of discontinuation due to an adverse event. No difference was found for serious adverse events.

INTRODUCTION

Bisphosphonates are first-line treatment for osteoporosis. Gastrointestinal (GI) adverse events (AE) are the primary reason for non-adherence. Little is known about the comparative GI safety of bisphosphonates.

PURPOSE

Leverage published clinical trial data to examine the comparative GI safety of bisphosphonates.

METHODS

We completed a systematic review of all English-language clinical trials that assessed bisphosphonate safety and/or efficacy in primary osteoporosis through to 2012. Randomized, blinded, and controlled studies were eligible. The primary outcome was any GI-related AE. Subanalyses were completed for upper GI symptoms, serious GI, nausea, esophageal-related events, and discontinuation due to AE. A Bayesian-based network meta-analysis was completed to allow for indirect comparisons. Results were reported as the probability that a specific drug had the highest number of events.

RESULTS

We identified 50 studies: 32 alendronate, 12 risedronate, 5 etidronate, and 7 zoledronic acid. Zoledronic acid had the highest probability of having the highest number of any GI AE (91%) and nausea (70%). Etidronate (70%) and zoledronic acid (28%) had the highest probability of having the greatest attrition due to AE. Etidronate had the highest probability (56%) of having the greatest number of upper GI symptoms among oral bisphosphonates.

CONCLUSION

Zoledronic acid had the highest probability of causing the greatest number of GI AE, possibly related to nausea. These results question the assumption that annual zoledronic acid will translate into better adherence. Little difference was found between alendronate and risedronate for serious AE. More research into real-world implications of the comparative safety of bisphosphonates is needed.

Study design considerations for a large simple trial of bisphosphonates

PURPOSE OF REVIEW

To evaluate design considerations for an osteoporosis large simple trial (LST).

RECENT FINDINGS

There is a growing need for more comparative effectiveness studies in osteoporosis. However, the design of such studies is challenged by issues surrounding study design, choosing comparator therapies, participant and outcome selection, data acquisition and data analysis.

SUMMARY

LSTs are real-world studies that can have high levels of generalizability, if designed properly. We propose novel approaches to LSTs focusing on some of the challenges associated with comparative effectiveness research in osteoporosis. In this review, we discuss these considerations in the context of bisphosphonate active comparator initiation and discontinuation trials, while presenting advantages and disadvantages of the various design aspects for such studies.

Effect of ONO-5334 on bone mineral density and biochemical markers of bone turnover in postmenopausal osteoporosis: 2-year results from the OCEAN study

Cathepsin K inhibitors, such as ONO-5334, are being developed for the treatment of postmenopausal osteoporosis. However, their relative effects on bone resorption and formation, and how quickly the effects resolve after treatment cessation, are uncertain. The aim of this study was to examine the efficacy and safety of 24-month treatment with ONO-5334 and to assess the effect of treatment cessation over 2 months. We studied 197 postmenopausal women with osteoporosis or osteopenia with one fragility fracture. Patients were randomized to ONO-5334 50 mg twice daily, 100 mg or 300 mg once daily, alendronate 70 mg once weekly (positive control), or placebo for 24 months. After 24 months, all ONO-5334 doses were associated with increased bone mineral density (BMD) for lumbar spine, total hip, and femoral neck (p < 0.001). ONO-5334 300 mg significantly suppressed the bone-resorption markers urinary (u) NTX and serum and uCTX-I throughout 24 months of treatment and to a similar extent as alendronate; other resorption marker levels remained similar to placebo (fDPD for ONO-5334 300 mg qd) or were increased (ICTP, TRAP5b, all ONO-5334 doses). Levels of B-ALP and PINP were suppressed in all groups (including placebo) for approximately 6 months but then increased for ONO-5334 to close to baseline levels by 12 to 24 months. On treatment cessation, there were increases above baseline in uCTX-I, uNTX, and TRAP5b, and decreases in ICTP and fDPD. There were no clinically relevant safety concerns. Cathepsin K inhibition with ONO-5334 resulted in decreases in most resorption markers over 2 years but did not decrease most bone formation markers. This was associated with an increase in BMD; the effect on biochemical markers was rapidly reversible on treatment cessation.

Comparable effects of alendronate and strontium ranelate on femur in ovariectomized rats

This study compared the effects of alendronate (ALN) and strontium ranelate (SR) on bone mineral density (BMD), bone histomorphometry, and biomechanics in ovariectomized (OVX) rats. We randomly assigned 48 3-month-old female Sprague-Dawley rats to four groups: sham, OVX, ALN, and SR. Rats in the OVX, ALN, and SR groups received bilateral OVX. Rats in the ALN and SR groups were orally administrated ALN (7 mg/kg/week) and SR (500 mg/kg/day). Rats in the sham and OVX groups were treated with saline. All treatments continued for 12 weeks. Femoral BMD examination, distal femoral bone histomorphometry analysis, and biomechanical tests at the femoral diaphysis and metaphysis were performed to evaluate the effects of treatments in OVX rats. Results showed that both ALN and SR significantly increased femoral BMD (total femur, diaphyseal BMD, and distal metaphyseal BMD), distal femoral bone histomorphometric parameters (BV/TV, Tb.N, and Tb.Th), and femoral biomechanical parameters (maximum load, failure load, stiffness) compared with the OVX group (P < 0.05). No differences were found between ALN and SR in increasing femoral BMD, distal femoral bone histomorphometric parameters (BV/TV, Tb.N, and Tb.Th), and femoral diaphysis biomechanical parameters (maximum load, failure load, stiffness) (P > 0.05). The SR group was inferior to the ALN group in femoral metaphysis biomechanical parameters (P < 0.05). In conclusion, ALN (7 mg/kg/week) and SR (500 mg/kg/day) have similar effects by increasing BMD, distal femoral bone histomorphometric parameters, and femoral metaphysis biomechanical properties. Although ALN has greater effects than SR on distal femoral metaphysis biomechanical properties, in general, ALN and SR have comparable effects on the femur in OVX rats.

Combination therapy with risedronate and teriparatide in male osteoporosis

Most studies of combination therapy with teriparatide and a bisphosphonate have not shown greater efficacy over monotherapy. The bisphosphonate risedronate, has not been studied in this context. The purpose of this proof-of-concept study was to assess whether combination risedronate and teriparatide increases bone mineral density (BMD) more than monotherapy with either drug alone. This was a randomized, double-blinded study of risedronate (35 mg weekly plus placebo injection), teriparatide (20 μg subcutaneously daily plus placebo tablet), or both risedronate plus teriparatide (combination) for 18 months in 29 men with low BMD. The primary endpoint was percentage change in lumbar spine (LS) BMD at 18 months. Secondary outcomes included changes in bone markers and BMD at other sites and interim time-points. All therapies increased LS BMD as compared with baseline (p < 0.05), but there were no between-group differences at 18 months. Total hip (TH) BMD increased to a greater extent in the combination group (mean ± SEM, 3.86 ± 1.1 %) versus teriparatide (0.29 ± 0.95 %) or risedronate (0.82 ± 0.95 %; p < 0.05 for both). Femoral neck (FN) BMD also increased more in the combination group (8.45 ± 1.8 %) versus risedronate (0.50 ± 1.7 %; p = 0.002), but was not different from teriparatide alone. In the combination group, P1NP and CTX increased rapidly, mirroring the teriparatide-alone arm. There were no between-group differences in adverse events. Combination teriparatide and risedronate increased BMD at the LS, TH as well as the FN and provided greater BMD increases at the TH than monotherapy. The results suggest combination risedronate and teriparatide therapy holds promise as a treatment for osteoporosis.

Zoledronic acid enhances bone-implant osseointegration more than alendronate and strontium ranelate in ovariectomized rats

This study was designed to compare the effects of alendronate (ALN), strontium ranelate (SR), and zoledronic acid (ZOL) on bone-implant osseointegration in ovariectomized rats. Histological examination and biomechanical tests show that ZOL, ALN, and SR enhance bone-implant osseointegration; ALN and SR have similar effects, while ZOL enhances bone-implant osseointegration more than ALN and SR INTRODUCTION: This study aims to compare the effects of ALN, SR, and ZOL on bone-implant osseointegration in ovariectomized rats.

METHODS

Sixty female Sprague-Dawley rats were included in this study. Of them, 48 rats were ovariectomized (OVX) and assigned to four groups: OVX (OVX + Veh), ALN (OVX + ALN), SR (OVX + SR), and ZOL (OVX + ZOL). And another 12 rats were sham-operated as a control group (Sham). Four weeks after ovariectomy, HA-coated titanium implants were inserted into the tibias bilaterally in all rats. Then the rats in groups ALN, SR, and ZOL were systemically administrated with alendronate (7 mg/kg/week, orally), strontium ranelate (500 mg/kg/day, orally), or a single injection of zoledronic acid (0.1 mg/kg, iv), respectively. Twelve weeks after implantation, all rats were sacrificed to get the femurs and tibias. Histological examination and biomechanical tests were used to evaluate bone-implant osseointegration in all groups.

RESULTS

ALN, SR, and ZOL significantly increased distal femoral BMD when compared with group OVX; ZOL increased BMD significantly more than ALN and SR (P < 0.05). Significant increase of bone-to-implant contact and peri-implant bone fraction were observed in groups ALN, SR, and ZOL when compared with group OVX (P < 0.05). Groups ALN and SR were inferior to groups ZOL and Sham (P < 0.05) in bone-to-implant contact and peri-implant bone fraction. Similar results were found in biomechanical testing (max pushout force).

CONCLUSIONS

In rats losing bone rapidly after ovariectomy, systemic administration of ZOL, ALN, and SR causes better bone-implant osseointegration when compared to OVX; ALN and SR have similar positive effects on osseointegration, while ZOL, that was given in a dose with more positive BMD effect than that of ALN or SR, causes better osseointegration than either ALN or SR.

Comparison of the efficacy of three once-weekly bisphosphonates on bone mineral density gains in Korean women

Objective

To assess the efficacies of once-weekly bisphosphonates on bone mineral density (BMD) gains in Korean women aged 50 years or more.

Methods

We selected 166 patients who received: alendronate 70 mg (n=48), alendronate 70 mg + cholecalciferol 2,800 IU (n=31) or risedronate 35 mg (n=87) for one year. The baseline BMD and the % changes of BMD at one-year were compared among the three medication groups.

Results

The menopausal status and number of women with osteoporosis was not different among the three groups, but mean age of women was significantly lower in alendronate group. Baseline BMD at L1-4 and femur neck (FN) was similar, but baseline BMD at femur total (FT) was significantly lower in alendronate group. After one-year use, the median % changes of BMD at three sites were similar among the three groups; however, the median values were highest in alendronate + cholecalciferol group (L1-4: 4.48%, 6.74%, and 4.50%; FT: 2.09%, 3.70%, and 2.31%; FN: 3.05%, 3.79%, and 2.03%).

Conclusion

Among three once-weekly bisphosphonates, BMD gains were highest after one-year use of alendronate+cholecalciferol, although statistically not significant.

Distribution of serum βCTX in a population-based study of postmenopausal women taking into account different anti-osteoporotic therapies (the FRODOS Cohort)

This cross-sectional study evaluated the distribution of serum cross-linked C-telopeptides of collagen type I (βCTXs) in postmenopausal women, the characteristics of bone remodeling, and the factors influencing this bone marker, especially the use of anti-osteoporotic drugs. Women (n = 4,175) aged 59-70 years randomly selected from the community were invited to participate, measuring βCTXs and lumbar and femoral bone mineral density at recruitment. Risk factors for osteoporosis and the use of anti-osteoporotic treatment were collected with a structured questionnaire. We evaluated the percentage of women with increased (βCTXs >0.620 ng/mL) and decreased bone turnover (βCTXs <0.100 ng/mL) and those reaching the so-called treatment target (values of βCTXs within the lower half of the reference range for healthy young premenopausal women). Two thousand nine hundred sixty-eight women (70 %) participated (2,405 non-treated and 563 treated). Increased and decreased bone turnover was observed in 16.4 and 1.8 %, respectively, of non-treated women with significant differences compared with treated women (9.7 and 14.2 %, respectively, p < 0.001); 28 % of non-treated osteoporotic individuals had increased bone turnover versus 14 % of osteopenic participants and 8.8 % of women with normal bone density (p < 0.001). Women receiving bisphosphonates presented the highest percentages of decreased bone turnover (27 %) and βCTXs (43 %) within the treatment target. Increased bone turnover is observed in 16.4 % of non-treated postmenopausal women and is more frequent in individuals with osteoporosis, whereas decreased bone turnover is unusual. Most participants taking bisphosphonates had values within the treatment target, but nearly one quarter had decreased bone turnover.

Treatment of postmenopausal osteoporosis with delayed-release risedronate 35 mg weekly for 2 years

Bone mineral density response to once weekly delayed-release formulation of risedronate, given before or following breakfast, was non-inferior to that seen with traditional immediate-release risedronate given daily before breakfast. Delayed-release risedronate is a convenient dosing regimen for oral bisphosphonate therapy that might avoid poor compliance.

INTRODUCTION

This 2-year, randomized, controlled, non-inferiority study assessed the efficacy and safety of a delayed-release (DR) 35-mg weekly oral formulation of risedronate that allows subjects to take their weekly risedronate dose before or immediately after breakfast. Results from the first year of the study were published previously (McClung et al. Osteoporos Int 23(1):267-276, 2012); we now report the final results after 2 years.

METHODS

Women with postmenopausal osteoporosis were randomly assigned to receive risedronate 5 mg immediate-release (IR) daily (n = 307) at least 30 min before breakfast, or risedronate 35 mg DR weekly, either immediately following breakfast (FB, n = 307) or at least 30 min before breakfast (BB, n = 308). Bone mineral density (BMD), bone turnover markers (BTMs), fractures, adverse events, and bone histomorphometry were evaluated.

RESULTS

A total of 248 subjects (80.8 %) in the IR daily group, 234 subjects (76.2 %) in the DR FB weekly group, and 240 subjects (77.9 %) in the DR BB weekly group completed the 2-year study. After 2 years of treatment, BMD increases at the lumbar spine and total hip with the weekly DR doses similar to or greater than that with the IR daily dose. Decreases in BTMs were similar or significantly lower in the DR groups. Bone histomorphometry results did not differ among the DR weekly and the IR daily formulations. The three regimens were similarly well tolerated.

CONCLUSIONS

Risedronate 35 mg DR weekly is as effective and as well tolerated as risedronate 5 mg IR daily, and will allow subjects to take their weekly risedronate dose immediately after breakfast.

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

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Use of bone turnover markers in clinical practice

PURPOSE OF REVIEW

To describe the modalities and interest of the use of bone turnover markers (BTMs) in clinical practice for osteoporosis management.

RECENT FINDINGS

Serum procollagen type I N-terminal propeptide and serum collagen type I crosslinked C-telopeptide are respectively the formation and resorption markers recommended to use as references for bone remodelling assessment in clinical studies.

SUMMARY

Biochemical BTMs reflect changes in bone metabolism. In clinical practice, many factors influencing BTMs, variability needs to be integrated during all of the dosage process. They include sample collection and storage conditions, patient's characteristics and lifestyle habits, recent fracture. The reference intervals are also affected by the type of automated assays used to assess BTMs. Appropriate references measured with the same assay method must be used for the optimum interpretation of results. BTMs have been extensively used as indicators in the diagnosis and monitoring of osteoporosis. However, their interest was mainly demonstrated to reflect changes in bone metabolism under antiosteoporotic treatments in clinical studies. Significant reductions in BTMs associated with fracture risk reduction needs to be determined in the management of osteoporosis. The standardization of BTMs, assays with international reference standards should provide conditions to state on the applications of BTMs in routine clinical practice.

Clinical role of bisphosphonate therapy

Bisphosphonates (BPs) are synthetic analogues of pyrophosphate. They inhibit bone resorption and are therefore widely used in disorders where there are increases or disruptions in bone resorption. This includes postmenopausal osteoporosis, glucocorticoid-induced osteoporosis, Paget's disease of bone, and malignancy-related bone loss. To best understand the clinical application of BPs, an understanding of their pharmacokinetics and pharmacodynamics is important. This review describes the structure, pharmacology and mode of action of BPs, focusing on their role in clinical practice. Controversies and side effects surrounding their use will also be discussed.

Efficacy of intravenously administered ibandronate in postmenopausal Korean women with insufficient response to orally administered bisphosphonates

We investigated rates of insufficient and over-responsiveness to orally administered bisphosphonates in postmenopausal women, and tested the efficacy of intravenous ibandronate in patients with insufficient response to orally administered bisphosphonates. Postmenopausal women were treated with either alendronate (70 mg/week; n = 88) or risedronate (35 mg/week; n = 84) for 1 year, and their response to orally administered bisphosphonates was assessed using serum C-telopeptide (CTX) levels. Insufficient responders were changed to once-quarterly intravenous ibandronate 3 mg injection (n = 13) or maintained on orally administered bisphosphonates (n = 19), according to patients' preference, for an additional 1 year. There was no significant difference in baseline characteristics between two orally administered bisphosphonate groups except the bone mineral density values at the lumbar spine. Insufficient rate was higher in the risedronate group (19.0 %) than in the alendronate group (8.0 %), using the premenopausal serum CTX median as a cut-off (P = 0.043). The over-response rate among the alendronate group (59.1 %) was significantly higher than that in the risedronate group (38.1 %), based on a serum CTX cut-off value of 0.100 ng/ml (P = 0.006). Intravenous ibandronate suppressed serum CTX levels to a significantly greater degree at 7 days after the second dosing (0.191 ± 0.110 ng/mL; P < 0.001) and 3 months after the fourth dosing (0.274 ± 0.159 ng/mL; P = 0.004) among insufficient responders, compared with post-oral/pre-intravenous levels (0.450 ± 0.134 ng/mL). Rates of insufficient and over-responsiveness to orally administered bisphosphonates were considerable, and a change to intravenous bisphosphonates may be considered in patients showing an insufficient response to orally administered bisphosphonates.

Bone effects of rosiglitazone in HIV-infected patients with lipoatrophy

OBJECTIVES

Thiazoledinediones increase limb fat in HIV+ patients with lipoatrophy. However, their use in the general population has been associated with bone loss and fracture. We sought to determine the effects of rosiglitazone on bone metabolism in HIV-infected patients.

METHODS

HIV+ patients with lipoatrophy were randomized to rosiglitazone versus placebo for 48 weeks in a double-blind, placebo-controlled trial. Limb fat, bone mineral density (BMD), bone formation markers (procollagen type 1 amino-terminal propeptide [P1NP], osteocalcin [OC]) and bone resorption markers (C-terminal telopeptide of type I collagen [CTX]) were measured, along with receptor activator for nuclear factor kappa β ligand (RANKL), osteoprotegerin (OPG), and inflammatory cytokines.

RESULTS

Seventy-one subjects were randomized to rosiglitazone or placebo: 17% female and 51% white. Total BMD did not change significantly in either group. In the rosiglitazone group, P1NP showed statistically significant decreases at 24 and 48 weeks; however, changes compared to placebo were only significant at 24 weeks. OC decreased significantly in the rosiglitazone group at 24 weeks, but there were no between-group differences. CTX, RANKL, or OPG did not change for either group. Multivariable regression within the rosiglitazone arm showed P1NP changes were inversely associated with limb fat changes, protease inhibitors, and tenofovir use.

CONCLUSION

Rosiglitazone use was associated with decreased bone formation, but it did not alter bone resorption or total BMD. The increase in limb fat that accompanies rosiglitazone use appears to be associated with decreased osteoblast activity. Further studies are needed to determine the effect of thiazoledinediones on bone health in HIV-infected persons.

Regional bone metabolism at the lumbar spine and hip following discontinuation of alendronate and risedronate treatment in postmenopausal women

The aim of this study was to examine the effects of bisphosphonate discontinuation on bone metabolism at the spine and hip measured using (18) F-fluoride PET. Bone metabolism at the spine remained stable following discontinuation of alendronate and risedronate at 1 year but increased in the hip in the alendronate group only.

INTRODUCTION

Bisphosphonates such as alendronate (ALN) or risedronate (RIS) have persistent effects on spine BMD following discontinuation.

METHODS

Positron emission tomography (PET) was used to examine regional bone metabolism in 20 postmenopausal women treated with ALN (n = 11) or RIS (n = 9) for a minimum of 3 years at screening (range 3-9 years, mean 5 years for both groups). Subjects underwent a dynamic scan of the lumbar spine and a static scan of both hips at baseline and 6 and 12 months following treatment discontinuation. (18) F-fluoride plasma clearance (K(i)) at the spine was calculated using a three-compartment model. Standardised uptake values (SUV) were calculated for the spine, total hip, femoral neck and femoral shaft. Measurements of BMD and biochemical markers of bone turnover were also performed.

RESULTS

With the exception of a significant decrease in spine BMD in the ALN group, BMD remained stable. Bone turnover markers increased significantly from baseline by 12 months for both study groups. Measurements of K(i) and SUV at the spine and femoral neck did not change significantly in either group. SUV at the femoral shaft and total hip increased significantly but in the ALN group only, increasing by 33.8% (p = 0.028) and 24.0% (p = 0.013), respectively.

CONCLUSIONS

Bone metabolism at the spine remained suppressed following treatment discontinuation. A significant increase in SUV at the femoral shaft and total hip after 12 months was observed but for the ALN group only. This study was small, and further clinical studies are required to fully evaluate the persistence of BP treatment.

Bone turnover markers: use in osteoporosis

Biochemical markers of bone turnover (bone turnover markers, BTMs) can be used to study changes in bone remodelling in osteoporosis. Investigators and clinicians should be aware of the appropriate sample collection and storage conditions for optimum measurements of these markers. Improvements in the variability of BTM measurements have resulted from the development of assays for automated analysers, and from international consensus regarding their use. Appropriate reference intervals should be used for the optimum interpretation of results. BTMs can provide information that is useful for the management of patients with osteoporosis, for both the initial clinical assessment and for guiding and monitoring of treatment. BTMs are clinically useful to determine possible causes of secondary osteoporosis by identifying patients with high bone turnover and rapid bone loss. In the follow-up of treatment response, BTM levels respond rapidly to both anabolic and antiresorptive treatments. BTM changes can also be used for understanding the mechanism of action of drugs in development and identifying the correct dose; they are also potentially useful as surrogate biomarkers for fracture.

Osteoporosis in men: an Endocrine Society clinical practice guideline

OBJECTIVE

The aim was to formulate practice guidelines for management of osteoporosis in men.

EVIDENCE

We used the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system to describe the strength of recommendations and evidence quality.

CONSENSUS PROCESS

Consensus was guided by systematic evidence reviews, one in-person meeting, and multiple conference calls and e-mails. Task Force drafts were reviewed successively by The Endocrine Society's Clinical Guidelines Subcommittee and Clinical Affairs Core Committee; representatives of ASBMR, ECTS, ESE, ISCD; and members at large. At each stage, the Task Force received written comments and incorporated needed changes. The reviewed document was approved by The Endocrine Society Council before submission for peer review.

CONCLUSIONS

Osteoporosis in men causes significant morbidity and mortality. We recommend testing higher risk men [aged ≥70 and men aged 50-69 who have risk factors (e.g. low body weight, prior fracture as an adult, smoking, etc.)] using central dual-energy x-ray absorptiometry. Laboratory testing should be done to detect contributing causes. Adequate calcium and vitamin D and weight-bearing exercise should be encouraged; smoking and excessive alcohol should be avoided. Pharmacological treatment is recommended for men aged 50 or older who have had spine or hip fractures, those with T-scores of -2.5 or below, and men at high risk of fracture based on low bone mineral density and/or clinical risk factors. Treatment should be monitored with serial dual-energy x-ray absorptiometry testing.

Effects of alendronate and risedronate on bone material properties in actively forming trabecular bone surfaces

We used Raman and Fourier transform infrared microspectroscopy (FTIRM) analysis to examine the intrinsic bone material properties at actively bone-forming trabecular surfaces in iliac crest biopsies from women with postmenopausal osteoporosis (PMO) who were treated with either alendronate (ALN) or risedronate (RIS). At eight study sites, women were identified who had postmenopausal osteoporosis (PMO), were at least 5 years postmenopause, and had been on long-term therapy (either 3-5 years or >5 years) with daily or weekly ALN or RIS. Following standard tetracycline labeling, biopsies were collected from 102 women (33 treated with ALN for 3-5 years [ALN-3], 35 with ALN for >5 years [ALN-5], 26 with RIS for 3-5 years [RIS-3], and 8 with RIS for >5 years [RIS-5]) and were analyzed at anatomical areas of similar tissue age in bone-forming areas (within the fluorescent double labels). The following outcomes were monitored and reported: mineral to matrix ratio (corresponding to ash weight), relative proteoglycan content (regulating mineralization commencement), mineral maturity (indicative of the mineral crystallite chemistry and stoichiometry, and having a direct bearing on crystallite shape and size), and the ratio of two of the major enzymatic collagen cross-links (pyridinoline/divalent). In RIS-5 there was a significant decrease in the relative proteoglycan content (-5.83% compared to ALN-5), while in both RIS-3 and RIS-5 there was significantly lower mineral maturity/crystallinity (-6.78% and -13.68% versus ALN-3 and ALN-5, respectively), and pyridinoline/divalent collagen cross-link ratio (-23.09% and -41.85% versus ALN-3 and ALN-5, respectively). The results of the present study indicate that ALN and RIS exert differential effects on the intrinsic bone material properties at actively bone-forming trabecular surfaces.

Bone turnover, osteoprotegerin/RANKL and inflammation with antiretroviral initiation: tenofovir versus non-tenofovir regimens

BACKGROUND

Bone mineral density decreases with antiretroviral therapy (ART) initiation, although the pathogenesis, including the role of tenofovir (TDF), is unclear. This study assessed changes in bone-turnover markers, osteoprotegerin (OPG), soluble receptor activator for nuclear factor-κβ ligand (sRANKL), and inflammation in subjects initiating TDF- versus non-TDF-containing regimens, and determined the relationship between bone turnover, OPG/sRANKL and inflammation.

METHODS

This was a longitudinal observational study comparing levels of bone turnover markers (C-terminal telopeptide of type I collagen [CTX] and osteocalcin [OC]), OPG, sRANKL and inflammatory cytokines (soluble tumour necrosis factor [TNF]-α receptor [sTNFR]-I, sTNFR-II and interleukin-6) prior to ART and 6-12 months after ART initiation with a TDF- versus non-TDF-containing regimen in HIV-infected subjects 18-50 years old.

RESULTS

A total of 87 subjects were enrolled (TDF n=44 and non-TDF n=43). Groups were similar except subjects on TDF had a lower CD4(+) T-cell nadir (P<0.01) and were more likely to receive a protease inhibitor (PI; P=0.03). At pre-ART, 35% and 1% of subjects had CTX and OC above the normal range, respectively. Both increased with ART initiation, whereas OPG, sRANKL and inflammatory markers significantly decreased. In multivariate models, increases in OC were associated with TDF use, PI use and pre-ART levels of sTNFR-I, whereas increases in CTX were associated with CD4(+) T-cell nadir <50 cell/mm³. Increases in bone markers were unrelated to pre-ART levels of OPG/sRANKL and changes in OPG/sRANKL after ART initiation.

CONCLUSIONS

TDF use, PI use, TNF-α activity and advanced HIV disease are associated with changes in bone turnover markers, underscoring the complicated interaction between ART, bone turnover, inflammation and immune status, which extend beyond the OPG/RANKL system.

Current recommendations for laboratory testing and use of bone turnover markers in management of osteoporosis

Osteoporosis is a major health problem worldwide, and is projected to increase exponentially due to the aging of the population. The absolute fracture risk in individual subjects is calculated by the use of algorithms which include bone mineral density (BMD), age, gender, history of prior fracture and other risk factors. This review describes the laboratory investigations into osteoporosis which include serum calcium, phosphate, creatinine, alkaline phosphatase and 25-hydroxyvitamin D and, additionally in men, testosterone. Parathyroid hormone (PTH) is measured in patients with abnormal serum calcium to determine its cause. Other laboratory investigations such as thyroid function testing, screening for multiple myeloma, and screening for Cushing's syndrome, are performed if indicated. Measurement of bone turnover markers (BTMs) is currently not included in algorithms for fracture risk calculations due to the lack of data. However, BTMs may be useful for monitoring osteoporosis treatment. Further studies of the reference BTMs serum carboxy terminal telopeptide of collagen type I (s-CTX) and serum procollagen type I N-terminal propeptide (s-PINP) in fracture risk prediction and in monitoring various treatments for osteoporosis may help expedite their inclusion in routine clinical practice.

Extraskeletal benefits and risks of calcium, vitamin D and anti-osteoporosis medications

Drugs used for the prevention and the treatment of osteoporosis exert various favourable and unfavourable extra-skeletal effects whose importance is increasingly recognized notably for treatment selection.

INTRODUCTION

The therapeutic armamentarium for the prevention and the treatment of osteoporosis is increasingly large, and possible extra-skeletal effects of available drugs could influence the choice of a particular compound.

METHODS

The present document is the result of a national consensus, based on a systematic and critical review of the literature.

RESULTS

Observational research has suggested an inverse relationship between calcium intake and cardiovascular diseases, notably through an effect on blood pressure, but recent data suggest a possible deleterious effect of calcium supplements on cardiovascular risk. Many diverse studies have implicated vitamin D in the pathogenesis of clinically important non-skeletal functions or diseases, especially muscle function, cardiovascular disease, autoimmune diseases and common cancers. The possible effects of oral or intravenous bisphosphonates are well-known. They have been associated with an increased risk of oesophageal cancer or atrial fibrillation, but large-scale studies have not found any association with bisphosphonate use. Selective oestrogen receptor modulators have demonstrated favourable or unfavourable extra-skeletal effects that vary between compounds. Strontium ranelate has a limited number of non-skeletal effects. A reported increase in the risk of venous thromboembolism is not found in observational studies, and very rare cases of cutaneous hypersensitivity reactions have been reported. Denosumab has been introduced recently, and its extra-skeletal effects still have to be assessed.

CONCLUSION

Several non-skeletal effects of bone drugs are well demonstrated and influence treatment choices.

Bisphosphonate therapy for osteoporosis: combining optimal fracture risk reduction with patient preference

OBJECTIVE

To review current use of bisphosphonates as first-line therapy for osteoporosis, with an emphasis on the importance of patient compliance and persistence.

METHODS

The US National Library of Medicine was used to obtain the relevant information on current bisphosphonate treatment for osteoporosis management, and patient compliance and persistence with treatment.

RESULTS

Bisphosphonates have demonstrated efficacy in fracture risk reduction, although differences may exist with respect to both onset of action and the site of fracture risk reduction. Good compliance and persistence with osteoporosis therapy is needed to reduce fracture risk, but currently the willingness of patients to conform to their prescribed course of treatment is suboptimal. Intermittent dosing schedules have been developed to facilitate ease of medication-taking in order to help improve rates of compliance and persistence. When primary care physicians provide patients with information about the established efficacy and safety of medications, as well as clarifying the crucial link between continued, consistent treatment and fracture risk reduction, patients are more likely to understand the importance of taking their medications consistently in order to maximize the effectiveness of the therapy.

CONCLUSIONS

A therapy that provides vertebral and nonvertebral efficacy, is well-tolerated, and offers a flexible dosing regimen is likely to enhance patient compliance and persistence, and provide optimal fracture protection. Numerous studies have consistently demonstrated that medication compliance and persistence are well-correlated with fracture risk reduction.

Effects of one year daily teriparatide treatment on trabecular bone material properties in postmenopausal osteoporotic women previously treated with alendronate or risedronate

In the present work we examined the effect of teriparatide administration following bisphosphonate treatment on bone compositional properties by Raman and Fourier Transform Infrared Imaging (FTIR) microspectroscopic analysis. Thirty two paired iliac crest biopsies (before and after 1 year teriparatide) from sixteen osteoporotic women previously treated with either Alendronate (ALN) or Risedronate (RIS) and subsequently treated 12 months with teriparatide (TPTD) were analyzed at anatomical areas of similar tissue age in bone forming areas (within the fluorescent double labels). The outcomes that were monitored and reported were mineral to matrix ratio (corresponding to ash weight), mineral maturity (indicative of the mineral crystallite chemistry and stoichiometry, and having a direct bearing on crystallite shape and size), relative proteoglycan content (regulating mineralization commencement), and the ratio of two of the major enzymatic collagen cross-links (pyridinoline/divalent). Significant differences in mineral/matrix, mineral maturity/crystallinity, and collagen cross-link ratio bone quality indices after TPTD treatment were observed, indicating a specific response of these patients to TPTD treatment. Moreover differences between ALN and RIS treated patients at baseline in the collagen cross-link ratio were observed. Since tissue areas of similar tissue age were analyzed, these differences may not be attributed to differences in bone turnover.

Use of Bone Turnover Markers in Clinical Osteoporosis Assessment in Women: Current Issues and Future Options

Monitoring bone turnover of the adult and aging skeleton is essential for optimal treatment of bone metabolic diseases, such as postmenopausal osteoporosis. Diagnosis of osteoporosis is based solely on dual-emission x-ray absorptiometry-based measurements of bone mineral density. However, within the last 20 years, biochemical markers of bone turnover have been implemented to a larger degree, and especially within the field of drug development. Numerous clinical studies have underscored that the markers have promise in terms of predicting patients at high risk of losing bone, future fracture events and importantly also the fracture efficacy of drugs in development. Furthermore, while classical methods often require years to monitor the changes, the bone turnover markers do so within a shorter time span. The aims of this article are to provide an update on the different biochemical markers of bone turnover, and to give an overview of their applications in epidemiological and clinical research especially in women. The main emphasis will be on their utility in clinical trials testing the efficacy of drugs for the treatment of osteoporosis, and their ability to supplement bone mass measurements. Finally, recent evidence suggests that biochemical markers may provide information on bone age that may indirectly relate to bone quality, and this is discussed together with future possibilities for measuring bone quality using bone turnover markers. In summary, a more targeted use of biomarkers could assist in the identification of high-risk patients, the process of drug discovery and monitoring of the efficacy of osteoporosis treatment in clinical settings.

Diagnostic thresholds in osteoporosis: how are they used in clinical trials?

Clinical trials are used to determine the efficacy and safety of a medication prior to approval for commercial use and to influence the prescribing habits of clinicians. The lack of uniformity in the diagnostic thresholds used in clinical trials on osteoporosis makes it difficult to compare the results of these trials. The use of placebo, different anatomical sites, T-score cutoff points, and risk factors precludes any meaningful comparison being made between the outcomes of clinical trials. Finally, the lack of uniform reporting format makes it difficult to retrieve important information to compare one medication to another. Because the diagnostic thresholds used affect the outcomes of these trials, health care providers need to be aware of these criteria to determine whether the results of a particular clinical trial can be applied to a particular patient.

Corticosteroid exposure not associated with long-term bone mineral density in pediatric liver transplantation

OBJECTIVES

The aim of the study was to examine the association of corticosteroid exposure and other skeletal risk factors with bone mineral density (BMD) and fractures following pediatric liver transplantation (LT) at a large single center.

PATIENTS AND METHODS

Lumbar spine BMD, measured using dual-energy x-ray absorptiometry (DXA), was corrected for bone age in 52 ambulatory children ages 4 to 18 years, at least 1 year post-LT. Potential risk factors for skeletal health such as corticosteroid exposure, dietary and lifestyle factors, and growth and fracture occurrence, were related to BMD using univariate and multivariate regression analyses.

RESULTS

The prevalence of low BMD (z score <-2) and post-LT fractures was 3 of 52 (5.8%) and 11 of 52 (21%), respectively. Univariate analysis revealed age >10 years at LT and body mass index (BMI) < 85th percentile at time of DXA were significantly associated with BMD (both P = 0.02). BMD did not correlate with corticosteroid dosage in the first year post-LT, the year before DXA or cumulative lifetime exposure. A cholestatic primary LT indication, acute rejection episodes, and fractures post-LT were not associated with BMD. Extracurricular physical activity, vitamin D, and calcium intake were not associated with BMD or fractures. Multivariate linear regression revealed increased time post-LT (P = 0.04) and higher BMI z score at time of DXA (P = 0.02) as the strongest independent variables associated with greater BMD.

CONCLUSIONS

Neither corticosteroid exposure nor a cholestatic primary indication for LT influenced BMD, which was largely normal in this ambulatory group. Children and adolescents undergoing LT after the age of 10 years and those with low BMI post-LT may be at greatest risk of poor skeletal health later in life, and thus a potential target patient population to benefit from preventive interventions.

Bisphosphonates for postmenopausal osteoporosis

Bisphosphonates are effective in reducing bone turnover, increasing BMD and reducing fracture risk in postmenopausal women with osteoporosis. The licensed bisphosphonates exhibit some differences in potency and speed of onset and offset of action. These differences mean that different agents may be more advantageous in different situations. Uncertainties still exist around the optimum duration of treatment and treatment holidays, how best to use bisphosphonates with anabolic treatments, and the benefits of treatment in patients who do not have a BMD T-score below -2.5.

Greater magnitude of turnover suppression occurs earlier after treatment initiation with risedronate than alendronate

Clinical data suggest that reductions in fractures associated with osteoporosis may occur sooner in patients treated with risedronate (RIS) compared to those treated with alendronate (ALN). This could be explained by differences in the time course of turnover suppression between these two bisphosphonates. To determine if differences in the onset of turnover suppression exist between RIS and ALN, female New Zealand white rabbits (total n=32) were treated with clinically relevant doses of RIS or ALN and then administered different fluorochrome labels weekly for four weeks in order to allow histological assessment of the time-course of turnover suppression. By the third week of treatment vertebral trabecular bone formation rate (BFR/BS) was significantly suppressed with RIS-treatment compared to both VEH and ALN. By the 4th week of treatment, turnover rates in RIS-treated animals remained significantly lower than in VEH-treated animals and were also lower than ALN; at this time-point ALN was significantly lower than VEH. There was no significant reduction in intra-cortical remodeling in the tibial mid-diaphysis at any time point for either RIS or ALN. This greater effect on turnover suppression with RIS early in treatment compared to ALN is likely the result of both risedronate's greater potency on osteoclast inhibition and its lower binding affinity. Together with studies showing more rapid return toward baseline turnover following withdrawal of RIS compared to ALN, this pre-clinical study provides evidence of the differences between bisphosphonates with respect to onset and recovery of bone turnover suppression.

Safety of bisphosphonates

Bisphosphonates are one of the most well studied groups of medications and they are bone specific. This tissue specificity is a rare property for a drug introduced into clinical practice as long as 40 years ago. Over the years, the therapeutic boundaries of bisphosphonates were explored and their safety profile has withstood the challenges of the harsh clinical reality and widespread use. Certainly, the esophageal or gastric irritation caused by the oral preparations is an established adverse effect, the risk of which can be reduced by the recommended routine of taking the medication. From the other reported associations with adverse events, osteonecrosis of the jaw (ONJ) and subtrochanteric fractures have attracted most of the attention mainly because their pathophysiology remains unclear. However, overall, only a very small proportion of patients treated with bisphosphonates, especially with the oral formulations, experience adverse events and the overall benefits have consistently outweighed their potential risks. Furthermore, bisphosphonates improve the quality of life in patients with metastatic bone cancer and delay the development of adverse skeletal effects.

Pharmacology of bisphosphonates

Four decades of preclinical and clinical research of the pharmacology of bisphosphonates have generated data and concepts that have considerably improved their clinical use. However, despite this progress several pharmacological aspects relevant to bisphosphonate action on bone are still incompletely understood. This is mainly due to the complex, unique pharmacological properties of bisphosphonates. We review here the pharmacokinetic and pharmacodynamic data of bisphosphonates that are relevant for their clinical application and for the potential choice of a given compound, focusing on uncertainties that still exist.

Bisphosphonate effects on bone turnover, microdamage, and mechanical properties: what we think we know and what we know that we don't know

The bisphosphonates (BPs) have been useful tools in our understanding of the role that bone remodeling plays in skeletal health. The purpose of this paper is to outline what we know, and what is still unknown, about the role that BPs play in modulating bone turnover, how this affects microdamage accumulation, and ultimately what the effects of these changes elicited by BPs are to the structural and the material biomechanical properties of the skeleton. We know that BPs suppress remodeling site-specifically, probably do not have a direct effect on formation, and that the individual BPs vary with respect to speed of onset, duration of effect and magnitude of suppression. However, we do not know if these differences are meaningful in a clinical sense, how much remodeling is sufficient, the optimal duration of treatment, or how long it takes to restore remodeling to pre-treatment levels following withdrawal. We also know that suppression is intimately tied to microdamage accumulation, which is also site-specific, that BPs impair targeted repair of damage, and that they can reduce the energy absorption capacity of bone at the tissue level. However, the BPs are clearly effective at preventing fracture, and generally increase bone mineral density and whole bone strength, so we do not know whether these changes in damage accumulation and repair, or the mechanical effects at the tissue level, are clinically meaningful. The mechanical effects of BPs on the fatigue life of bone, or BP effects on bone subject to an impact, are entirely unknown. This paper reviews the literature on these topics, and identifies gaps in knowledge that can be addressed with further research.

Safety and efficacy of the cathepsin K inhibitor ONO-5334 in postmenopausal osteoporosis: the OCEAN study

Osteoporosis occurs when there is an imbalance between resorption and formation of bone, with resorption predominating. Inhibitors of cathepsin K may rebalance this condition. This is the first efficacy study of a new cathepsin K inhibitor, ONO-5334. The objective of the study was to investigate the efficacy and safety of ONO-5334 in postmenopausal osteoporosis. This was a 12-month, randomized, double-blind, placebo- and active-controlled parallel-group study conducted in 13 centers in 6 European countries. Subjects included 285 postmenopausal women aged 55 to 75 years with osteoporosis. Subjects were randomized into one of five treatment arms: placebo; 50 mg twice daily, 100 mg once daily, or 300 mg once daily of ONO-5334; or alendronate 70 mg once weekly. Lumbar spine, total hip, and femoral neck BMD values were obtained along with biochemical markers of bone turnover and standard safety assessments. All ONO-5334 doses and alendronate showed a significant increase in BMD for lumbar spine, total hip (except 100 mg once daily), and femoral neck BMD. There was little or no suppression of ONO-5334 on bone-formation markers compared with alendronate, although the suppressive effects on bone-resorption markers were similar. There were no clinically relevant safety concerns. With a significant increase in BMD, ONO-5334 also demonstrated a new mode of action as a potential agent for treating osteoporosis. Further clinical studies are warranted to investigate long-term efficacy as well as safety of ONO-5334.

Biochemical markers of bone turnover as predictors of osteoporosis and osteoporotic fractures in men and women: 10-year follow-up of the Taiji cohort

We aimed to assess the capacity of biochemical markers of bone turnover (BTMs) to predict bone loss, osteoporosis (OP), and osteoporotic fractures. We randomly selected 400 individuals (age 40-79 years in 1993; 50 of each gender and age stratum) from a list of registered residents. In the years 1993, 1996, 2000, and 2003, bone mineral density (BMD) of the spine and hip were measured by dual-energy X-ray absorptiometry. The BTMs assessed at baseline were serum intact osteocalcin (OC), total OC, bone-specific alkaline phosphatase, C-terminal propeptide of type I procollagen, N-terminal propeptide of type I procollagen (PINP), C-terminal cross-linking telopeptide of type I collagen generated by matrix metalloproteinase, C-terminal cross-linking telopeptide of type I collagen (beta-CTX), N-terminal cross-linking telopeptide of type I collagen (NTX), urinary pyridinoline, and deoxypyridinoline (DPD). For 307 completers, multivariate analysis after adjusting for confounders revealed that serum PINP levels in men [hazard ratio (HR) 2.80, P < 0.05] and serum PINP (HR 1.65, P < 0.05), beta-CTX (HR 1.80, P < 0.001), NTX (HR 1.96, P < 0.01), and urinary DPD levels (HR 1.40, P < 0.05) in women were significantly related to the occurrence of spinal OP. In addition to adjustment for the baseline status of BMD, i.e., osteopenia or normal range, PINP, beta-CTX, and NTX in women could significantly predict the future occurrence of spinal OP. BTMs were not significant predictors of bone loss, femoral OP, or osteoporotic fractures. In conclusion, various BTMs in women can predict the occurrence of spinal OP.

Effects of intravenous zoledronic acid plus subcutaneous teriparatide [rhPTH(1-34)] in postmenopausal osteoporosis

Clinical data suggest concomitant therapy with bisphosphonates and parathyroid hormone (PTH) may blunt the anabolic effect of PTH; rodent models suggest that infrequently administered bisphosphonates may interact differently. To evaluate the effects of combination therapy with an intravenous infusion of zoledronic acid 5 mg and daily subcutaneous recombinant human (rh)PTH(1-34) (teriparatide) 20 µg versus either agent alone on bone mineral density (BMD) and bone turnover markers, we conducted a 1-year multicenter, multinational, randomized, partial double-blinded, controlled trial. 412 postmenopausal women with osteoporosis (mean age 65 ± 9 years) were randomized to a single infusion of zoledronic acid 5 mg plus daily subcutaneous teriparatide 20 µg (n = 137), zoledronic acid alone (n = 137), or teriparatide alone (n = 138). The primary endpoint was percentage increase in lumbar spine BMD (assessed by dual-energy X-ray absorptiometry [DXA]) at 52 weeks versus baseline. Secondary endpoints included change in BMD at the spine at earlier time points and at the total hip, trochanter, and femoral neck at all time points. At week 52, lumbar spine BMD had increased 7.5%, 7.0%, and 4.4% in the combination, teriparatide, and zoledronic acid groups, respectively (p < .001 for combination and teriparatide versus zoledronic acid). In the combination group, spine BMD increased more rapidly than with either agent alone (p < .001 versus both teriparatide and zoledronic acid at 13 and 26 weeks). Combination therapy increased total-hip BMD more than teriparatide alone at all times (all p < .01) and more than zoledronic acid at 13 weeks (p < .05), with final 52-week increments of 2.3%, 1.1%, and 2.2% in the combination, teriparatide, and zoledronic acid groups, respectively. With combination therapy, bone formation (assessed by serum N-terminal propeptide of type I collagen [PINP]) increased from 0 to 4 weeks, declined minimally from 4 to 8 weeks, and then rose throughout the trial, with levels above baseline from 6 to 12 months. Bone resorption (assessed by serum β-C-telopeptide of type I collagen [β-CTX]) was markedly reduced with combination therapy from 0 to 8 weeks (a reduction of similar magnitude to that seen with zoledronic acid alone), followed by a gradual increase after week 8, with levels remaining above baseline for the latter half of the year. Levels for both markers were significantly lower with combination therapy versus teriparatide alone (p < .002). Limitations of the study included its short duration, lack of endpoints beyond DXA-based BMD (e.g., quantitative computed tomography and finite-element modeling for bone strength), lack of teriparatide placebo, and insufficient power for fracture outcomes. We conclude that while teriparatide increases spine BMD more than zoledronic acid and zoledronic acid increases hip BMD more than teriparatide, combination therapy provides the largest, most rapid increments when both spine and hip sites are considered.

Markers of bone turnover for the prediction of fracture risk and monitoring of osteoporosis treatment: a need for international reference standards

The International Osteoporosis Foundation (IOF) and the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) recommend that a marker of bone formation (serum procollagen type I N propeptide, s-PINP) and a marker of bone resorption (serum C-terminal telopeptide of type I collagen, s-CTX) are used as reference analytes for bone turnover markers in clinical studies.

INTRODUCTION

Bone turnover markers (BTM) predict fracture risk, and treatment-induced changes in specific markers account for a substantial proportion of fracture risk reduction. The aims of this report were to determine their clinical potential in the prediction of fracture risk and for monitoring the treatment of osteoporosis and to set an appropriate research agenda.

METHODS

Evidence from prospective studies was gathered through literature review of the PUBMED database between the years 2000 and 2010 and the systematic review of the Agency for Healthcare Research and Quality up to 2001.

RESULTS

High levels of BTMs may predict fracture risk independently from bone mineral density in postmenopausal women. They have been used for this purpose in clinical practice for many years, but there is still a need for stronger evidence on which to base practice. BTMs provide pharmacodynamic information on the response to osteoporosis treatment, and as a result, they are widely used for monitoring treatment in the individual. However, their clinical value for monitoring is limited by inadequate appreciation of the sources of variability, by limited data for comparison of treatments using the same BTM and by inadequate quality control. IOF/IFCC recommend one bone formation marker (s-PINP) and one bone resorption marker (s-CTX) to be used as reference markers and measured by standardised assays in observational and intervention studies in order to compare the performance of alternatives and to enlarge the international experience of the application of markers to clinical medicine.

CONCLUSION

BTM hold promise in fracture risk prediction and for monitoring treatment. Uncertainties over their clinical use can be in part resolved by adopting international reference standards.

Osteoporosis therapies: evidence from health-care databases and observational population studies

Osteoporosis is a well-recognized disease with severe consequences if left untreated. Randomized controlled trials are the most rigorous method for determining the efficacy and safety of therapies. Nevertheless, randomized controlled trials underrepresent the real-world patient population and are costly in both time and money. Modern technology has enabled researchers to use information gathered from large health-care or medical-claims databases to assess the practical utilization of available therapies in appropriate patients. Observational database studies lack randomization but, if carefully designed and successfully completed, can provide valuable information that complements results obtained from randomized controlled trials and extends our knowledge to real-world clinical patients. Randomized controlled trials comparing fracture outcomes among osteoporosis therapies are difficult to perform. In this regard, large observational database studies could be useful in identifying clinically important differences among therapeutic options. Database studies can also provide important information with regard to osteoporosis prevalence, health economics, and compliance and persistence with treatment. This article describes the strengths and limitations of both randomized controlled trials and observational database studies, discusses considerations for observational study design, and reviews a wealth of information generated by database studies in the field of osteoporosis.