Early changes in biochemical markers of bone formation during teriparatide therapy correlate with improvements in vertebral strength in men with glucocorticoid-induced osteoporosis

Denosumab, teriparatide and bisphosphonates for glucocorticoid-induced osteoporosis: a Bayesian network meta-analysis

Background: Several medications have been used for glucocorticoids-induced osteoporosis (GIO). However, the best therapeutic option for GIO is still controversial. A Bayesian network meta-analysis was conducted to compare the efficacy and safety of denosumab, teriparatide and bisphosphonates for patients with GIO. Methods: Relevant randomized controlled trials published in PubMed, Embase, Cochrane Library and ClinicalTrials.gov up to August 2023 were searched. The following efficiency and safety outcomes were extracted for comparison: bone mineral density (BMD) percentage changes in lumbar spine, femur neck and total hip, and incidences of adverse events (AEs), serious adverse events (SAEs), vertebrae and non-vertebrae fracture. Bayesian random effects models were used for multiple treatment comparisons. Results: 11 eligible RCTs involving 2,877 patients were identified. All the six medications including alendronate, risedronate, etidronate, zoledronate, teriparatide, and denosumab and were effective in increasing BMD. Teriparatide and denosumab were more effective in improving lumbar spine and femur neck BMD, and reducing vertebrae fracture. Alendronate and denosumab were more effective in improving total hip BMD. Alendronate and teriparatide had the lowest incidences of AEs and SAEs. Conclusion: Teriparatide denosumab and the bisphosphonates are all effective in improving BMD for GIO patients. Based on this network meta-analysis, teriparatide and denosumab have higher efficiency in improving lumbar spine and femur neck BMD, and reducing vertebrae fracture. Systematic Review Registration: 10.17605/OSF.IO/2G8YA, identifier CRD42023456305.

Comparison of Bisphosphonates Versus Teriparatide in Therapy of the Glucocorticoid-Induced Osteoporosis (GIOP): A Meta-Analysis of Randomized Controlled Trials

Osteoporosis (OP) is characterized as decreased bone mineral density (BMD) and increased risk of bone fracture. Secondary OP resulting from excess endogenous or exogenous glucocorticoid is defined as glucocorticoid-induced osteoporosis (GIOP). Current therapeutic strategies for GIOP are similar to menopausal osteoporosis, including calcium and vitamin D supplementation, bisphosphonates, and parathyroid hormone (PTH) analogues (teriparatide). Previously, several published meta-analyses compared anti-osteoporotic agents for the menopausal or aging-dependent OP. However, the physiopathologic bone metabolism of GIOP is different. In this study, we investigated the efficacy of BMD enhancement, bone fracture rate and safety of bisphosphonates versus teriparatide in the therapy of GIOP. We searched databases including PubMed, Embase, and the Cochrane Library until Jan 2023, and selected ten random clinical trials (RCT)s that compared the efficacy and/or safety of bisphosphonate versus teriparatide for GIOP patients. Teriparatide therapy increased lumber spinal BMD by 3.96% (95% CI 3.01-4.9%, p<0.00001), 1.23% (95% CI 0.36-2.1%, p=0.006) at total hip, and 1.45% (95% CI 0.31-2.58%, p=0.01) at femoral neck, respectively, compared to bisphosphonates at 18-month therapy for GIOP. Teriparatide also reduced bone fracture especially in vertebral bone (p=0.0001, RR 6.27, 95% CI 2.44-16.07), and increased bone formation and resorption marker levels. There was no difference in the incidence of adverse effects in bisphosphonate and teriparatide groups. Teriparatide showed better performance over bisphosphonate in BMD enhancement, bone fracture reduction, and bone remodeling improvement, without increasing the incidence of adverse effects.

Male osteoporosis

Osteoporosis, a disease classically attributed to postmenopausal women, is underappreciated, underdiagnosed, and undertreated in men. However, it is not uncommon for osteoporotic fractures to occur in men. About 40% of fractures occur in men with an incidence that has increased over the years. After a first fracture, the risk of a subsequent episode, as well as the risk of death, is higher in the male than in the female population. Despite these facts, only 10% of men with osteoporosis receive adequate treatment. Up to half of the cases of male osteoporosis have a secondary cause, the most common being hypogonadism, excessive alcohol consumption, and chronic use of glucocorticoids. The International Society for Clinical Densitometry (ISCD) recommends using the female database for the diagnosis of osteoporosis by DXA (T-score ≤ -2.5 in men over 50 years old). In addition, osteoporosis can also be diagnosed independently of the BMD if a fragility fracture is present, or if there is a high risk of fractures by FRAX. Treatment is similar to postmenopausal osteoporosis, because the data regarding changes in bone density track closely to those in women. Data concerning fracture risk reduction are not as certain because the clinical trials have included fewer subjects for shorter period of time. In men with symptomatic hypogonadism, testosterone replacement, if indicated, can improve BMD.

Glucocorticoid-induced dose-related and site-specific bone remodelling, microstructure, and mechanical changes in cancellous and cortical bones

The study investigated the effects of long-term glucocorticoid (GC) administration on bone remodelling, microstructure, and biomechanical strength in cortical and cancellous (trabecular) bones. Thirty-one female Sprague-Dawley rats were randomly divided into three dexamethasone (Dex) dosage groups, 1.0, 2.5, and 5.0 mg/kg twice a week for 8 weeks, and one control group treated with saline. At the end of the experiment, the tibia of one side and the fourth lumbar vertebrae were processed into sections for a histomorphometric analysis, while the femur of the same side and the fifth vertebrae were isolated for a biomechanical test. A dose-dependent decline in bone formation was observed in both trabecular and cortical (periosteal and endosteal) bones. In contrast, bone resorption was inhibited only in cancellous bone in the two higher dose groups and not dose-related. The ratio of Node/Termini increased, while marrow star volume (MSV) decreased in all Dex groups in metaphyseal trabecular bones, both of which were dose-dependent. Subendosteal cortex porosity increased in parallel with non-uniform trabecular distribution, but cortical thickness remained unchanged. Interestingly, there were no significant changes in microstructure or mechanical strength in lumbar trabecular bone. The cortical elastic load was dose-independently reduced in all three Dex groups when compared with the control group. In summary, bone remodelling was dose-dependently inhibited in cancellous bones but enhanced in intracortical bones. The non-uniform distribution of trabecular bone and increased porosity in the inner edge of cortical bone were both in parallel with GC dosage, and the porosity increase was more likely to occur, leading to reduced cortical mechanical strength.

Restoration of the intravertebral stability in Kümmell's disease following the treatment of severe postmenopausal osteoporosis by 1-34PTH-a retrospective study

Following the 1-34PTH application for conservative treatment of Kümmell's disease, the intravertebral cleft was filled or bridged by the osseous tissue; the radiological evidence of further collapsing was absent. Pain and the neurological disorder were relieved; bone turnover markers, BMD as well as the health-related quality of life were improved.

INTRODUCTION

Kümmell's disease (KD) patients with severe osteoporosis were applied by the 1-34PTH; the fracture union and the increased bone mineral density (BMD) following this treatment were retrospectively reviewed.

METHODS

Twenty-one postmenopausal osteoporosis (PMOP) patients with KD received at least 6 months of 1-34PTH treatment. The medical records, including clinical evaluation symptoms, radiological evaluation for bone union and the stability of intravertebral vacuum cleft (IVC), BMD, and laboratory examination for osteoporosis recovery and health-related quality of life (HRQOL), were reviewed.

RESULTS

From baseline to month 12, visual analog scale decreased from 8.24 ± 0.54 to 1.71 ± 0.56 (P < 0.001) and the modified Japanese Orthopedic Association scores increased from 6.86 ± 1.77 to 10.43 ± 1.29 (P < 0.001). Sagittal CT demonstrated that the IVC was filled or bridged by the osseous tissue in all patients. Within the vertebra, the IVC area (IVCA) decreased from 4.50 ± 2.50 to 0 mm² (P = 0.001) and the mineralized bone area (MBA) increased from 170.91 ± 102.23 to 259.56 ± 98.60 mm² (P < 0.001). The area ratio of IVC to vertebra decreased from 0.97 ± 0.46 to 0% (P < 0.001), and the area ratio of mineral bone to vertebra was increased from 32.85 ± 14.51 to 54.97 ± 14.01% (P < 0.001). The kyphosis angle increment was 3.43 ± 1.80°, and the loss rate of anterior border height was 11.14 ± 4.82%. No differences were found in posterior border height and spinal canal diameter. The PINP, β-CTx, BMD, and Short Form-36 Health Survey scores markedly increased.

CONCLUSIONS

In KD patients with severe PMOP, 1-34PTH treatment could alleviate the clinical evaluation symptoms, facilitate the recovery of the intravertebral stability, ameliorate the BMD, and improve the HRQoL.

Glucocorticoids Enhanced Osteoclast Autophagy Through the PI3K/Akt/mTOR Signaling Pathway

Autophagy is an evolutionarily conserved dynamic process and present in variety of cells at basal levels to maintain homeostasis and to promote cell survival in response to stresses. The early bone loss with excessive glucocorticoids (GCs) was reported to be related with the extension of the life span of osteoclasts. However, the connection between GCs induced bone loss and osteoclast autophagy remains to be elucidated. Autophagy was detected in a Dexamethasone (Dex) induced osteoporotic mice model and primary osteoclast cultures by autophagosome detection kit, and autophagy-related proteins were assayed by Western blotting and Immunostaining. The bone morphology was examined by micro-CT and TRAP staining. The trabecular bone micro-architecture was deteriorated, and the osteoclast number and spread area were increased in the Dex-treated mice compared with the control group (P < 0.01). Meanwhile, autophagy in pre-osteoclasts was increased in mice under Dex administration evidenced by the increased number of autophagosome and up-regulation of autophagy-related protein levels. Further, the enhanced autophagy under Dex treatment was verified in primary cultured osteoclasts, as shown by the increased levels of Beclin 1 and LC3-II/LC3-I and the autophagy complex formation members including Atg1, Atg13, and Atg7. However, the expressions of PI3K, p-Akt and p-mTOR in primary cultured osteoclasts were inhibited under Dex induced autophagy. Using the selective PTEN inhibitor SF1670 to activate the PI3K/Akt/mTOR pathway reversed this osteoclast autophagy under Dex treatment. Our study suggests that osteoclast autophagy was enhanced in glucocorticoids induced bone loss, and the PI3K/Akt/mTOR signaling pathway mediated the increased autophagy in primary cultured osteoclasts under glucocorticoids treatment.

Updates in epidemiology, pathophysiology and management strategies of glucocorticoid-induced osteoporosis

INTRODUCTION

Endogenous or exogenous (corticosteroid-induced) glucocorticoids (GCs) excess represents, together with diabetes, the most common cause of secondary osteoporosis.

AREAS COVERED

We present a comprehensive overview about the pathophysiology, clinical management and treatment of GCs induced osteoporosis (GIOP). According to PRISMA guidelines, a literature search identifying articles about bone and GCs was done.

EXPERT OPINION

Despite the progress over the years and the increase in therapeutic options, there still are controversial issues about the management of GIOP. These mainly include the failure of BMD or FRAX to completely account for the rapid increase in fracture risk of most GC-treated patients, the understanding about the independent contribution on bone fragility of the underlying disease requiring GCs therapy, and the necessity of clearer information about the anti-fracture efficacy and long term-safety of most therapeutic options. Moreover, there are no specific indications for the management of bone fragility in endogenous hypercortisolism. Notwithstanding the above limitations there is a general consensus to recommend an assessment of fracture risk in all individuals >40 years committed to receive (or continuing) high dose (>7.5 mg of prednisone equivalent) GCs for ≥3 months and in all patients with fragility fracture history.

Treatment options for glucocorticoid-induced osteoporosis

INTRODUCTION

Glucocorticoid (GC) induced osteoporosis (GIOP) is the most common form of secondary osteoporosis. It develops in a dose and time dependent manner, due to a rapid and transient increase in bone resorption, followed by the inhibition of bone formation.

AREAS COVERED

In this review, the authors summarize the pathophysiology of GIOP and give discussion to the clinical management of patients taking GCs, focusing on the currently available drugs that have antiresorptive or anabolic activity on bone.

EXPERT OPINION

Despite the widespread use of GCs and their well-established detrimental skeletal effects, GIOP remains an under-diagnosed and under-treated condition. Indeed, the clinical management of GIOP is still debated, so that the recent guidelines differ in their indications for pharmacological intervention. Either bone mineral density (BMD) or algorithms such as FRAX do not completely account for the remarkable and rapid increase in fracture risk of most GC-treated patients. Moreover, while oral bisphosphonates remain the most used and cost-effective option, the potential increased benefits of more potent antiresorptive agents (e.g. denosumab and zoledronate) or anabolic compounds (e.g. teriparatide) warrant further investigation. Despite the above limitations, the assessment of fracture risk is recommended for all individuals committed to receiving oral GCs for 3 months or longer.

Update on the safety and efficacy of teriparatide in the treatment of osteoporosis

Following the completion of the Fracture Prevention Trial, teriparatide was approved by the United States Food and Drug Administration and the European Medicine Agency as the first therapeutic anabolic agent for the treatment of postmenopausal women with severe osteoporosis. It subsequently received additional approval for the treatment of osteoporosis in men, and for the treatment of osteoporosis associated with glucocorticoid therapy in men and women at risk of fracture. In this review, we summarize the most important data concerning PTH 1-34 therapy before 2016 in the treatment of osteoporosis, and report some outstanding results published in the last 2 years. New data on safety will also discussed, together with the state of art of nonclassical utilization. Finally, in view of the recent approval of biosimilars, possible future landscapes are discussed.

Anabolics in the management of glucocorticoid-induced osteoporosis: an evidence-based review of long-term safety, efficacy and place in therapy

Introduction

Glucocorticoid-induced osteoporosis is an underrecognized complication of chronic glucocorticoid therapy characterized by a decrease in new bone formation. Anabolic therapies, such as teriparatide, a recombinant human parathyroid hormone, combat the disease by promoting new bone growth.

Aims

This article outlines the pathophysiology of glucocorticoid-induced osteoporosis and details the evidence of efficacy, safety, and patterns of use of teriparatide and other future anabolic therapies.

Evidence review

In multiple clinical trials, teriparatide has been shown to significantly increase lumbar spine bone mineral density (BMD) in patients with glucocorticoid-induced osteoporosis when compared with placebo, alendronate, and risedronate. When compared with alendronate, significantly fewer vertebral fractures were noted in the teriparatide group. Adverse effects noted in clinical trials include nausea, insomnia, flushing, myalgias, and mild hypercalcemia/hyperuricemia. Early studies in rats noted an increased incidence of osteosarcoma; however, an increased rate beyond levels seen in general populations has not been noted in human studies or with long-term pharmacovigilance. Abaloparatide and romosozumab are newer anabolic therapies that have shown some benefit in postmenopausal osteoporosis but have not yet been studied in the chronic glucocorticoid population.

Place in therapy

Major specialty organizations continue to recommend bisphosphonates as first-line therapy in glucocorticoid-induced osteoporosis due to the proven benefit and relative affordability. However, the use of anabolics shows promise to improve outcomes by increasing BMD and reducing fracture-associated morbidity and mortality and has a role for selected populations at high fracture risk.

Update on the Comprehensive Approach to Fragility Fractures

The prevention and treatment of fragility fractures continuously evolve. Adequate fracture care should involve treating the fracture itself and the underlying bone disease. Although effective treatments of osteoporosis are available, a large proportion of patients with fragility fractures are not prescribed antiosteoporotic medications after their injury. Recent advances in diagnostic tools, medications, and implementation of Fracture Liaison Services allow for more effective and comprehensive treatment or fragility fractures. In the Fracture Liaison Service model, a physician and physician extenders coordinate care. This includes a thorough medical and surgical history, metabolic bone disease laboratory testing, dual-energy x-ray absorptiometry screening, treatment, and long-term follow-up. Treatment options include nonpharmacologic treatment with calcium and vitamin D and antiresorptive and anabolic agents. Antiresorptive agents such as bisphosphonates and denosumab are first-line treatments for osteoporosis and anabolic agents such as teriparatide are effective in reducing bone density loss and have implications in fracture healing. In addition, new anabolic agents including antisclerostin antibodies and parathyroid hormone-related protein show promise as potential treatments to increase bone density.

Use of bone turnover markers in postmenopausal osteoporosis

Bone turnover comprises two processes: the removal of old bone (resorption) and the laying down of new bone (formation). N-terminal propeptide of type I procollagen (PINP) and C-telopeptide of type I collagen (CTX-I) are markers of bone formation and resorption, respectively, that are recommended for clinical use. Bone turnover markers can be measured on several occasions in one individual with good precision. However, these markers are subject to several sources of variability, including feeding (resorption decreases) and recent fracture (all markers increase for several months). Bone turnover markers are not used for diagnosis of osteoporosis and do not improve prediction of bone loss or fracture within an individual. In untreated women, very high bone turnover marker concentrations suggest secondary causes of high bone turnover (eg, bone metastases or multiple myeloma). In people with osteoporosis, bone turnover markers might be useful to assess the response to anabolic and antiresorptive therapies, to assess compliance to therapy, or to indicate possible secondary osteoporosis. Much remains to be learnt about how bone turnover markers can be used to monitor the effect of stopping bisphosphonate therapy (eg, to identify a threshold above which restarting therapy should be considered). More studies are needed to investigate the use of bone turnover markers for assessment of the bone safety of new medications.

New anabolic therapies for osteoporosis

Osteoporosis is characterized by low bone mass and qualitative structural abnormalities of bone tissue, leading to increased bone fragility that results in fractures. Pharmacological therapy is aimed at decreasing the risk of fracture, mainly correcting the imbalance between bone resorption and formation at the level of bone remodeling units. Anabolic therapy has the capability to increase bone mass to a greater extent than traditional antiresorptive agents. The only currently available drug licensed is parathyroid hormone 1-34 (teriparatide); new drugs are on the horizon, targeting the stimulation of bone formation, and therefore improving bone mass, structure and ultimately skeletal strength. These are represented by abaloparatide (a 34-amino acid peptide which incorporates critical N-terminal residues, shared by parathyroid hormone and parathyroid hormone-related protein, followed by sequences unique to the latter protein) and romosozumab (an antibody to sclerostin). In the future, the availability of new anabolic treatment will allow a more extensive utilization of additive and sequential approach, with the goal of both prolonging the period of treatment and, more importantly, avoiding the side effects consequent to long-term use of traditional drugs.

Bone Turnover Markers After Sleep Restriction and Circadian Disruption: A Mechanism for Sleep-Related Bone Loss in Humans

CONTEXT

Sleep abnormalities are associated with low bone mineral density. Underlying mechanisms are unknown.

OBJECTIVE

Investigate the impact of sleep restriction with circadian disruption on bone biomarkers.

DESIGN

Intervention study.

PARTICIPANTS AND METHODS

Four bone biomarkers [C-terminal cross-linked telopeptide of type I collagen (CTX) = bone resorption, N-terminal propeptide of type I procollagen (P1NP) = bone formation, sclerostin and fibroblast growth factor 23 = osteocyte function] were measured in bihourly serum samples over 24 hours at baseline and after ∼3 weeks of sleep restriction (5.6 hours sleep/24 hours) with concurrent circadian disruption (recurring 28-hour "day" in dim light) in 10 men (age groups: 20 to 27 years, n = 6; 55 to 65 years, n = 4). The effects of sleep/circadian disruption and age on bone biomarker levels were evaluated using maximum likelihood estimation in a mixed model for repeated measures.

RESULTS

P1NP levels were lower after intervention compared with baseline (P < 0.001); the decrease in P1NP was greater for younger compared with older men (28.0% vs 18.2%, P < 0.001). There was no change in CTX (Δ = 0.03 ± 0.02 ng/mL, P = 0.10). Sclerostin levels were higher postintervention in the younger men only (Δ = 22.9% or 5.64 ± 1.10 pmol/L, P < 0.001).

CONCLUSIONS

These data suggest that 3 weeks of circadian disruption with concurrent sleep restriction can lead to an uncoupling of bone turnover wherein bone formation is decreased but bone resorption is unchanged. Circadian disruption and sleep restriction may be most detrimental to bone in early adulthood.

Measurement and Clinical Utility of βCTX in Serum and Plasma

Biochemical markers of bone turnover (BTM) are released during bone remodeling and can be measured in blood or urine as noninvasive surrogate markers for the bone remodeling rate. The C-terminal cross-linked telopeptide of type I collagen (βCTX) is released during bone resorption and is specific to bone tissue. Assays have been developed to measure βCTX in blood and in urine; most current use of βCTX measurement for research and in clinical practice is performed on a blood sample. Method-specific differences for serum and plasma βCTX have led to initiatives to standardize or harmonize βCTX commercial assays. βCTX demonstrates significant biological variation due to circadian rhythm and effect of food which can be minimized by standardized sample collection in the fasting state in the morning. While βCTX predicts fracture risk independent of bone mineral density, lack of data has precluded its inclusion in fracture risk calculators. The changes seen in βCTX with antiresorptive therapies have been well characterized and this has led to its widespread use for monitoring therapy in osteoporosis. However, more fracture-based data on appropriate treatment goals for monitoring need to be developed. Evidence is lacking for the use of βCTX in managing "drug holidays" of bisphosphonate treatment in osteoporosis or risk stratifying those at increased risk of developing osteonecrosis of the jaw. βCTX is useful as an adjunct to imaging techniques for the diagnosis of Paget's disease of bone and for monitoring therapy and detecting recurrence. βCTX also shows promise in the management of metastatic bone disease.

Aggravation of spinal cord compromise following new osteoporotic vertebral compression fracture prevented by teriparatide in patients with surgical contraindications

Patients with spinal cord deficits following new unstable osteoporotic compression fracture and surgical contraindications were considered to receive conservative treatment. Teriparatide was better than alendronate at improving bone mineral density and bone turnover parameters, as well as preventing aggravation of spinal cord compromise.

INTRODUCTION

This study compared the preventive effects of teriparatide and alendronate on aggravation of spinal cord compromise following new unstable osteoporotic vertebral compression fracture (OVCF) in patients with surgical contraindications.

METHODS

This was a 12-month, randomized, open-label study of teriparatide versus alendronate in 49 patients with new unstable OVCF and surgical contraindications. Neurological function was evaluated using modified Japanese Orthopedic Association (mJOA) score (11-point scale, the maximum score of 11 implies normalcy). Visual analog scale (VAS) scores, kyphotic angles, anterior-border heights and diameters of the spinal canal of the fractured vertebrae, any incident of new OVCFs (onset of OVCF during follow-up), spine bone mineral density (BMD), and serum markers of bone resorption and bone formation were also examined at baseline and 1, 3, 6, and 12 months after initiation of the medication regimen.

RESULTS

At 12 months, mean mJOA score had improved in the teriparatide group and decreased in the alendronate group. Mean concentrations of bone formation and bone resorption biomarkers, mean spine BMD, and mean anterior-border height and spinal canal diameter of the fractured vertebrae were significantly greater in the teriparatide group than in the alendronate group. Mean VAS score, mean kyphotic angle of the fractured vertebrae, and incidence of new OVCFs were significantly smaller in the teriparatide group than in the alendronate group.

CONCLUSIONS

In patients with neurological deficits following new unstable OVCF and with surgical contraindications, teriparatide was better than alendronate at improving the BMD and the bone turnover parameters, as well as preventing aggravation of spinal cord compromise.

A retrospective analysis of nonresponse to daily teriparatide treatment

Some patients with osteoporosis do not respond to teriparatide treatment. Prior bisphosphonate use, lower bone turnover marker (BTMs) concentrations, and lower early increases in BTMs were significantly associated with a blunted lumbar spine (LS) bone mineral density (BMD) response to daily treatment with teriparatide, although the impact was limited.

INTRODUCTION

Some osteoporosis patients do not respond to teriparatide treatment. To better understand the factors underlying treatment nonresponses, we compared nonresponders' and responders' characteristics.

METHODS

We retrospectively analyzed 354 male and female patients with osteoporosis who were administered teriparatide (20 μg/day) for 24 months. The patients were categorized as responders (≥3 % lumber spine (LS) bone mineral density (BMD) increase) or nonresponders (<3 % LS BMD increase), and the groups were compared.

RESULTS

The univariate analyses determined that prior bisphosphonate use, a lower baseline procollagen type I N-terminal propeptide (PINP) concentration and a lower urinary N-telopeptide of type I collagen (uNTX) concentration at baseline were significantly associated with teriparatide nonresponses, but these factors were not significant following multivariate analysis. Diminished early increases in the bone turnover markers (BTMs) were also related to nonresponses after teriparatide treatment began. In the nonresponders, the mean (standard deviation (SD)) absolute LS and femoral neck (FN) BMD changes were -0.002 g/cm(2) (0.032) and -0.010 g/cm(2) (0.045), respectively. In the responders, the mean (SD) absolute LS and FN BMD changes were 0.118 g/cm(2) (0.056) and 0.021 g/cm(2) (0.046), respectively. The serum PINP and uNTX levels increased rapidly in both groups, but the responders showed higher early absolute serum PINP and uNTX increases.

CONCLUSIONS

The factors associated with nonresponses were prior bisphosphonate use, lower baseline BTM levels, and lower early increases in the BTMs after starting teriparatide treatment, but the impact of these factors on achieving a ≥3 % LS BMD increase at 24 months was limited.

Improvement of cancellous bone microstructure in patients on teriparatide following alendronate pretreatment

An increase in procollagen type I amino-terminal propeptide (PINP) early after teriparatide initiation was shown to correlate with increased lumbar spine areal BMD and is a good predictor of the anabolic response to teriparatide. Few data exist correlating PINP and bone microstructure, and no data exist in patients on teriparatide following prior potent antiresorptive treatment. This exploratory analysis aimed to investigate the effects of teriparatide on cancellous bone microstructure and correlations of bone markers with microstructure in alendronate-pretreated patients. This was a post hoc analysis of changes in bone markers and three-dimensional indices of bone microstructure in paired iliac crest biopsies from a prospective teriparatide treatment study in postmenopausal women with osteoporosis who were either treatment-naïve (TN, n=16) or alendronate-pretreated (ALN, n=29) at teriparatide initiation. Teriparatide (20μg/day) was given for 24months; biopsies were taken at baseline and endpoint, and serum concentrations of PINP and type 1 collagen cross-linked C-telopeptide (βCTX) were measured at intervals up to 24months. In the TN and ALN groups, respectively, mean (SD) increases in three-dimensional bone volume/tissue volume were 105 (356)% (P=0.039) and 55 (139)% (P<0.005) and trabecular thickness 30.4 (30)% (P<0.001) and 30.8 (53)% (P<0.001). No significant changes were observed in trabecular number or separation. In the ALN patients, 3-month change of neither PINP nor βCTX correlated with indices of cancellous bone microstructure. However, 12-month changes in biochemical bone markers correlated significantly with improvements in bone volume/tissue volume, r=0.502 (P<0.01) and r=0.378 (P<0.05), trabecular number, r=0.559 (P<0.01) and r=0.515 (P<0.01), and reduction of trabecular separation, r=-0.432 (P<0.05) and r=-0.530 (P<0.01), for PINP and βCTX, respectively. We conclude that cancellous bone microstructure improved with teriparatide therapy irrespective of prior antiresorptive use.

Effect of glucocorticoid withdrawal on glucocorticoid inducing bone impairment

Glucocorticoid (GC) withdrawal after a short-term use was common in clinical practice like immediate post-transplant period. However, previous studies without setting age-control group failed to determine whether the BMD recovery was sufficient and whether it is necessary to accept anti-osteoporosis therapy after GC withdrawal. The aim of this study was to investigate the effect of GC withdrawal on bone impairment in glucocorticoid-induced osteoporosis (GIOP) rats. Twenty-four female Sprague-Dawley rats (3 months' old) were randomly divided into two treatment groups: an untreated age-control group (Con, n = 12); another group receiving a dexamethasone injection (DEXA, n = 12). Animals in the Con group were euthanized at 3rd month (M3) and 6th month (M6), respectively. Six rats in the DEXA group were euthanized at 3rd month (M3), whereas GC intervention was withdrew in the remaining animals of DEXA group, which were euthanized at the end of 6th month (M6). Bone mass, bone microarchitecture, biomechanical properties of vertebrae, morphology, serum levels of PINP and β-CTX were evaluated. Compared with the Con(M3) group, the Con(M6) group showed significantly better bone quantity, morphology and quality. Compared with the Con(M3) group, the DEXA (M3) group showed significantly lower BMC, BMD, BS/TV, BV/TV, Tb.N, Tb.Th, vBMD, bone strength, compressive displacement, energy absorption capacity, PINP levels, β-CTX levels, and damaged trabecular morphology. And the same change trend was observed in the comparison between the Con(M6) group and DEXA (M6) group. Compared with the DEXA (M3) group, the DEXA (M6) group showed significantly higher BMC, BMD and AREA, but no significant difference in BS/TV, BV/TV, SMI, Tb.N, Tb.Th, Tb.Sp, vBMD, bone strength, bone stiffness, compressive displacement, energy absorption capacity, PINP levels, β-CTX levels, and improvement in trabecular morphology was observed. These results indicate that the reverse effect of GC withdrawal for 3 months on bone impairment in GIOP rats was insufficient, which implied that related anti-osteoporosis treatment might be still necessitated after GC withdrawal in clinical setting.

The role of biochemical of bone turnover markers in osteoporosis and metabolic bone disease: a consensus paper of the Belgian Bone Club

The exact role of biochemical markers of bone turnover in the management of metabolic bone diseases remains a topic of controversy. In this consensus paper, the Belgian Bone Club aimed to provide a state of the art on the use of these biomarkers in different clinical or physiological situations like in postmenopausal women, osteoporosis in men, in elderly patients, in patients suffering from bone metastasis, in patients with chronic renal failure, in pregnant or lactating women, in intensive care patients, and in diabetics. We also gave our considerations on the analytical issues linked to the use of these biomarkers, on potential new emerging biomarkers, and on the use of bone turnover biomarkers in the follow-up of patients treated with new drugs for osteoporosis.

[Male osteoporosis]

BACKGROUND

Osteoporosis in men is an important public health problem with more than 1 million cases in Germany. Although osteoporotic fractures have a much higher mortality in men than in women, male patients are still underdiagnosed and undertreated.

OBJECTIVE

Epidemiology of male osteoporosis and current treatment situation, pathophysiological aspects at the hormonal level, risk factors, diagnostic work-up and therapeutic options.

MATERIAL AND METHODS

Overview of data concerning male osteoporosis, recommendations for diagnostic work-up and presentation of the study situation on pharmaceutical therapies.

RESULTS

As risk factors for osteoporosis are present in 50-70 % of male patients, a detailed patient history is necessary for assessment of the risk factors. Radiological imaging of the spine is primarily recommended to identify individuals with prevalent vertebral fractures, as approximately 10 % of males above the age of 50 years have suffered a vertebral fracture. Laboratory testing of relevant parameters helps to rule out other metabolic bone diseases. In Germany, specific medications available for the treatment of male osteoporosis comprise the active vitamin D analogue alfacalcidol, the oral bisphosphonates alendronate and risedronate, the intravenous biphosphonate zoledronic acid, the anti- receptor activator of NF-κB ligand (RANKL) antibody denosumab, which can be given as intravenous injection and strontium ranelate, a drug with a complex mode of action. Teriparatide, a recombinant form of the 34 N-terminal amino acid sequence of parathyroid hormone is the only anabolic agent approved for male osteoporosis.

CONCLUSION

Osteoporosis in men is increasingly being recognized as an important public health problem and affected patients need to be adequately diagnosed and treated. Nowadays, a broad spectrum of well-proven therapeutic options with different modes of action allow individual treatment strategies for male osteoporosis patients.

Sclerostin-antibody treatment of glucocorticoid-induced osteoporosis maintained bone mass and strength

This study was to determine if antibody against sclerostin (Scl-Ab) could prevent glucocorticoid (GC)-induced osteoporosis in mice. We found that Scl-Ab prevented GC-induced reduction in bone mass and bone strength and that the anabolic effects of Scl-Ab might be partially achieved through the preservation of osteoblast activity through autophagy.

INTRODUCTION

Glucocorticoids (GCs) inhibit bone formation by altering osteoblast and osteocyte cell activity and lifespan. A monoclonal antibody against sclerostin, Scl-Ab, increased bone mass in both preclinical animal and clinical studies in subjects with low bone mass. The objectives of this study were to determine if treatment with the Scl-Ab could prevent loss of bone mass and strength in a mouse model of GC excess and to elucidate if Scl-Ab modulated bone cell activity through autophagy.

METHODS

We generated reporter mice that globally expressed dsRed fused to LC3, a protein marker for autophagosomes, and evaluated the dose-dependent effects of GCs (0, 0.8, 2.8, and 4 mg/kg/day) and Scl-Ab on autophagic osteoblasts, bone mass, and bone strength.

RESULTS

GC treatment at 2.8 and 4 mg/kg/day of methylprednisolone significantly lowered trabecular bone volume (Tb-BV/TV) at the lumbar vertebrae and distal femurs, cortical bone mass at the mid-shaft femur (FS), and cortical bone strength compared to placebo (PL). In mice treated with GC and Scl-Ab, Tb-BV/TV increased by 60-125 %, apparent bone strength of the lumbar vertebrae by 30-70 %, FS-BV by 10-18 %, and FS-apparent strength by 13-15 %, as compared to GC vehicle-treated mice. GC treatment at 4 mg/kg/day reduced the number of autophagic osteoblasts by 70 % on the vertebral trabecular bone surface compared to the placebo group (PL, GC 0 mg), and GC + Scl-Ab treatment.

CONCLUSIONS

Treatment with Scl-Ab prevented GC-induced reduction in both trabecular and cortical bone mass and strength and appeared to maintain osteoblast activity through autophagy.

Bisphosphonates and glucocorticoid-induced osteoporosis: cons

During the use of glucocorticoids (GCs), both vertebral and nonvertebral fracture risk are increased, due to the direct and indirect negative effects of GCs on bone, muscles, and the activity of the underlying inflammatory diseases. Inhibition of bone formation and increased apoptosis of osteocytes play a consistent and crucial role in the pathogenesis of glucocorticoid-induced osteoporosis (GIO), while changes in bone resorption during GC-use are variable. To prevent fractures, important general measures include using the lowest possible dose of GCs, treating the underlying disease adequately, a healthy life style, adequate calcium and vitamin D supplementation, and regular exercise. Although it has been shown that bisphosphonates reduce vertebral fractures during the first 2 years of GC-treatment, there are no data on long-term use of bisphosphonates during GC-treatment. Of some concern in GIO, bisphosphonates reduce bone turnover, including bone formation, which is already downregulated by GCs. In contrast, the use of the anabolic agent teriparatide is more effective in reducing vertebral fractures than alendronate. In summary, bisphosphonates remain the first choice in the first two years of treatment in GC-treated patients with high fracture risk, but their long-term effects on bone quality and fracture risk reduction remain uncertain.

Clinical Use of Quantitative Computed Tomography-Based Finite Element Analysis of the Hip and Spine in the Management of Osteoporosis in Adults: the 2015 ISCD Official Positions-Part II

The International Society for Clinical Densitometry (ISCD) has developed new official positions for the clinical use of quantitative computed tomography (QCT)-based finite element analysis of the spine and hip. The ISCD task force for QCT reviewed the evidence for clinical applications and presented a report with recommendations at the 2015 ISCD Position Development Conference. Here we discuss the agreed upon ISCD official positions with supporting medical evidence, rationale, controversy, and suggestions for further study. Parts I and III address the clinical use of QCT of the hip, and the clinical feasibility of existing techniques for opportunistic screening of osteoporosis using CT scans obtained for other diagnosis such as colonography was addressed.

Management of glucocorticoid-induced osteoporosis: clinical data in relation to disease demographics, bone mineral density and fracture risk

INTRODUCTION

Glucocorticoid-induced osteoporosis (GIOP) is the most common type of secondary osteoporosis. Patient selection and the treatment choice remain to be controversial. None of the proposed management guidelines are widely accepted. We evaluate the available clinical data, the efficacy of current medication and we propose an overall algorithm for managing GIOP.

AREAS COVERED

This article provides a critical review of in vivo and clinical evidence regarding GIOP and developing evidence-based algorithm of treatment. Data base used includes MEDLINE® (1950 to May 2014).

EXPERT OPINION

Patient-specific treatment is the gold standard of care. Glucocorticoid (GC)-treated patients must comply with a healthy lifestyle and receive 1000 mg of calcium and at least 800 mg of Vitamin D daily. Bisphosphonate (BP) therapy is the current standard of care for prevention and treatment of GIOP. Most of bisphosphonates demonstrated benefit in lumbar bone mineral density (BMD) and some in hip BMD. Alendronate, risedronate and zoledronate showed vertebral anti-fracture efficacy in postmenopausal women and men. Scarce data however when compared head to head with BP efficacy. In post-menopausal women, early antiresorptive BP treatment appears to be efficient and safe. In premenopausal women and patients at high risk of fracture receiving long-term GC therapy however, teriparitide may be advised alternatively.

Established and forthcoming drugs for the treatment of osteoporosis

PURPOSE OF REVIEW

The aim of treatment in patients at high risk for fractures is to reduce the risk of a first or a subsequent fracture. New data are available on the antifracture effects and side-effects of antiresorptive and osteoanabolic drugs, and new emerging therapies with new modes of action are on the horizon.

RECENT FINDINGS

Calcium and vitamin D intake should be sufficient, but not too high. Vertebral, nonvertebral (including hip fracture) prevention with antiresorptive drugs such as bisphosphonates (alendronate, risedronate and zoledronic acid) and denosumab exceeds the risk of rare side-effects such as atypical femur fracture and osteonecrosis of the jaw. Teriparatide is an osteoanabolic drug that improves quality of life in severe osteoporosis. Strontium ranelate decreases dynamic parameters of bone formation during the first year of treatment, and could increase the risk of cardiovascular events in high-risk patients. Initiation of and adherence to fracture prevention drugs are still low. New potential developments in antiresorptive drugs include odanacatib, a selective inhibitor of cathepsin K, and, in osteoanabolic drugs, monoclonal antibodies against sclerostin.

SUMMARY

These recent data indicate that fracture prevention with antiresorptives and teriparatide is effective with a reasonable safety profile. Odanacatib and antisclerostin are promising new drugs with new mechanisms of action, as they are able to disconnect the normal coupling between bone resorption and bone formation.

Glucocorticoid-induced osteoporosis: who to treat with what agent?

Among the adverse events of glucocorticoid treatment are bone loss and fractures. Despite available, effective preventive measures, many patients receiving or initiating glucocorticoid therapy are not appropriately evaluated and treated for bone health and fracture risk. Populations with, or at risk of, glucocorticoid-induced osteoporosis (GIOP) to target for these measures are defined on the basis of dose and duration of glucocorticoid therapy and bone mineral density. That patients with GIOP should be treated as early as possible is generally agreed upon; however, diversity remains in intervention thresholds and management guidelines. The FRAX(®) algorithm provides a 10-year probability of fracture that can be adjusted according to glucocorticoid dose. There is no evidence that GIOP and postmenopausal osteoporosis respond differently to treatments. Available anti-osteoporotic therapies such as anti-resorptives including bisphosphonates and the bone anabolic agent teriparatide are effective for the management of GIOP. Prevention with calcium and vitamin D supplementation is less effective than specific anti-osteoporotic treatment. Anti-osteoporotic treatment should be stopped at the time of glucocorticoid cessation, unless the patient remains at increased risk of fracture.

PINP as a biological response marker during teriparatide treatment for osteoporosis

Postmenopausal women with severe osteoporosis may require treatment with the bone anabolic drug teriparatide. While changes in bone mineral density (BMD) are one measure of response, BMD changes often require a minimum of one year to observe measureable changes. Biochemical markers of bone turnover change within 1 to 3 months of initiating osteoporosis therapy. Monitoring with a marker such as procollagen type I N propeptide (PINP), an osteoblast-derived protein, during teriparatide treatment may provide clinically useful information for managing patients with osteoporosis. Clinical trials have shown consistent increases in PINP within 3 months of initiating teriparatide, increases that are significantly greater than placebo and significantly different from baseline. Increases in PINP concentrations during teriparatide treatment correlate well with increases in skeletal activity assessed by radioisotope bone scans and quantitative bone histomorphometry parameters. Individuals treated with teriparatide in clinical trials usually experienced an increase in PINP > 10 mcg/L from baseline, while those given placebo usually did not. In the clinical setting, patients experiencing a significant increase in PINP > 10 mcg/L after initiating teriparatide therapy may receive an earlier confirmation of anabolic effect, while those who do not may be assessed for adherence, proper injection technique, or undetected secondary conditions that might mitigate an anabolic response. PINP monitoring may provide information supplemental to BMD monitoring and be a useful aid in managing patients receiving anabolic osteoporosis treatment in the same way that biochemical markers of bone resorption are useful in monitoring antiresorptive therapy. This review examines PINP as a biological response marker during teriparatide treatment for osteoporosis.

Determinants associated with bone mineral density increase in response to daily teriparatide treatment in patients with osteoporosis

INTRODUCTION

Several factors associated with bone mineral density (BMD) increase are reported with daily teriparatide treatment, but there has been no systematic analysis to summarize these associations. The purpose of this study was to investigate the clinical determinants associated with BMD increase to daily teriparatide treatment.

METHODS

This was a retrospective study. We performed an analysis of 306 patients diagnosed with osteoporosis. Teriparatide was administered at 20μg/day for 12months. The primary efficacy measure was a change in lumbar spine (LS) BMD from baseline at 12months. To determine the response variables of BMD changes, we investigated the clinical determinants using univariate and multivariate analyses.

RESULTS

There was a 9.8±8.2% increase in LS BMD after 12months. Prior bisphosphonate treatment and baseline procollagen type I N-terminal propeptide (PINP) concentration were significantly associated with LS BMD absolute response by univariate analyses. In the multiple regression model, patients with higher baseline PINP concentration had a significantly greater LS BMD absolute increase. Prior bisphosphonate use lost its correlation in the multiple regression models.

CONCLUSION

Our results showed that baseline PINP concentration was a useful predictor of LS BMD absolute increase regardless of prior treatment.