The pathogenesis, epidemiology and management of glucocorticoid-induced osteoporosis

High Evening Cortisol Level Is Associated With Low TBS and Increased Prevalent Vertebral Fractures: OsteoLaus Study

CONTEXT

Increased evening cortisol levels have been implicated in bone mineral density (BMD) loss. The effect on bone microarchitecture and fracture risk has never been studied.

OBJECTIVE

To study the relationship between salivary cortisol circadian rhythm and (1) trabecular bone score (TBS) and (2) fracture prevalence.

DESIGN, SETTING, PATIENTS, AND INTERVENTIONS

Cross-sectional study including 608 women >50 years old (mean = 65.5) from the OsteoLaus cohort. Data included the FRAX© questionnaire, BMD, TBS and vertebral fracture (VFx) assessment by dual X-ray absorptiometry, and measures of salivary cortisol (awakening, 30 minutes thereafter, 11 am, and 8 pm).

RESULTS

In the multivariate model, participants in the highest tertile of 8 pm salivary cortisol (sc-8 pm) (mean = 5.7 ± 2.5 nmol/L) vs lowest tertile (1.7 ± 0.4 nmol/L) had lower TBS values (1.27 vs 1.29; P = 0.02), more prevalent VFx grades 2 and 3 (odds ratio = 5.34; P = 0.012), low-trauma fractures (odds ratio = 1.80; P = 0.036), and major osteoporotic fractures (odds ratio = 1.96; P = 0.042), without difference in lumbar spine BMD (0.91 vs 0.92 g/cm2; P = 0.431). VFx prevalence was associated with sc-8 pm and TBS independently of each other and of other risk factors. The cut-point for sc-8 pm correlating with the presence of >1 VFx was 3.62 nmol/L (sensitivity 0.74, specificity 0.66).

CONCLUSIONS

High sc-8 pm is associated with low TBS and an increased prevalence of radiologic VFx independently of other risk factors. Measurement of sc-8 pm may add relevant information in the assessment of fracture risk.

Effects of 1,25-dihydroxyvitamin D3 on the local bone renin-angiotensin system in a murine model of glucocorticoid-induced osteoporosis

Active vitamin D is closely related to the circulating renin-angiotensin system (RAS) in experimental animal models and humans; however, corresponding local bone data remain limited. The present study examined whether 1,25-dihydroxyvitamin D₃ supplementation altered local bone RAS elements in a murine model of glucocorticoid-induced osteoporosis (GIOP). A total of 36 8-week-old mice were randomized into three equal-sized groups: The sham, GIOP and 1,25-dihydroxyvitamin D₃ treatment groups. After 12 weeks, the cancellous bone microstructure of the third lumbar vertebra and left femur from the mice from each group were examined using micro-computed tomography. To access the impact of glucocorticoid use, the effect of 1,25-dihydroxyvitamin D₃ on cancellous bone microstructure, the expression of bone turnover markers, circulation and expression of the main RAS components was assessed. Results demonstrated that bone volume fraction, trabecular number and trabecular thickness of the treatment and sham groups were significantly higher than the GIOP group (P<0.05). Furthermore, the structure model index, trabecular separation and bone surface to bone volume ratio of the sham and treatment groups were significantly reduced compared with the GIOP group (P<0.05). All assessed parameters exhibited no significant differences between the treatment and sham groups. mRNA expression levels of local bone angiotensin type 1 and 2 receptors and receptor activator of nuclear factor-κB ligand were significantly lower in the treatment group than in the GIOP group (P<0.05); however, there were no significant differences in circulating protein levels between the groups (P>0.05). In conclusion, 1,25-dihydroxyvitamin D₃ may modulate bone metabolism by downregulating the local bone RAS in mice with GIOP.

Prevention and management of glucocorticoid-induced side effects: A comprehensive review: A review of glucocorticoid pharmacology and bone health

Systemic glucocorticoids are an essential therapy for a range of conditions, but their multiple side effects can produce significant morbidity for patients. The objective of this review is to discuss these side effects while addressing 3 questions: 1) What dose and duration of glucocorticoid therapy should prompt concern for individual side effects?; 2) How should clinicians counsel patients about these complications?; and 3) How can these problems be prevented or managed? To accomplish these objectives, we have created a series of tables and algorithms based on a review of relevant data to guide counseling, prophylaxis, and management of 11 glucocorticoid side effects. The first article in this 4-part continuing medical education series begins with a review of glucocorticoid pharmacology followed by a discussion of bone health (ie, osteoporosis and osteonecrosis).

Burden of Chronic Oral Corticosteroid Use by Adults with Persistent Asthma

BACKGROUND

Chronic oral corticosteroid (C-OCS) use in asthma is an indicator of disease severity, but its risk factors are largely unknown.

OBJECTIVE

To describe patient characteristics and disease burden associated with C-OCS use by adults with persistent asthma.

METHODS

We identified 9546 patients aged 18 to 64 years in a large managed care organization who met the Healthcare Effectiveness Data and Information Set 2-year criteria (2009-2010) for persistent asthma. A subgroup had blood eosinophil counts. We calculated cumulative OCS dispensed per patient in 2010 and examined the distribution of disease characteristics by average daily amounts of OCS dispensed. C-OCS use was defined as 2.5 mg/d or more. Baseline factors (2010) associated with C-OCS use during follow-up (2011) were investigated by multivariable Poisson regression.

RESULTS

At baseline, 782 (8.2%) patients were C-OCS users. Compared with patients who received no or less than 2.5 mg/d OCS, C-OCS users were older and more often female and ethnic minorities; and had more comorbidities, asthma specialist care, greater step-care level, controllers, asthma exacerbations, and greater blood eosinophil counts (all P < .01). Baseline factors significantly associated with C-OCS use in the follow-up year included (1) demographic characteristics: older age, females, blacks versus whites, and whites versus others/unknown ethnicities; (2) disease burden: more asthma emergency department or hospitalization visits, greater step-care level, excessive short-acting β₂-agonist dispensed, theophylline use, asthma specialist care, and nasal polyposis; (3) greater blood eosinophil counts; and (4) most strongly, C-OCS use.

CONCLUSIONS

C-OCS use was associated with more asthma burden, comorbidities, and greater blood eosinophil counts. Prior C-OCS use was the strongest predictor of future C-OCS use.

Asymptomatic vertebral fractures in patients with low bone mineral density

OBJECTIVE

Vertebral fracture assessment (VFA) is a test technique that can be used to detect asymptomatic vertebral fractures (AVF). It uses dual energy X-ray bsorptiometry (DXA) and can be performed concurrently with bone densitometry. This study aims to assess the prevalence of AVF in patients with low bone mass.

METHODS

Cross-sectional study including 135 individuals with low bone mineral density (BMD) with a T-score < -2.0 standard deviation (SD) in a densitometry clinic located in the city of Blumenau (state of Santa Catarina). Anthropometric, clinical and lifestyle variables were obtained from history-taking and physical examination. Densitometric variables were obtained by bone mineral densitometry and VFA (Explorer, Hollogic®). Vertebral fractures were classified according to the Genant criteria. Student's t, chi-square and logistic regression were performed for statistical analysis.

RESULTS

AVFs occurred in 24.4% of the subjects. They were older compared to those without AVF (65±9.25 versus 60.1±8.66; p=0.005), and had a history of lowimpact fractures (38.24% versus 19.8%; OR 2.5; p=0.03). Half of the patients that reported steroid therapy had AVFs, compared to one fifth of those who did not use steroids (50% versus 21.49%; OR 3.6; p=0.01).

CONCLUSION

Asymptomatic vertebral fractures were present in approximately one fourth of patients. The risk factors associated were history of low-impact fracture, use of steroids and age > 61 years.

Trabecular Bone Score Reflects Trabecular Microarchitecture Deterioration and Fragility Fracture in Female Adult Patients Receiving Glucocorticoid Therapy: A Pre-Post Controlled Study

A recently developed diagnostic tool, trabecular bone score (TBS), can provide quality of trabecular microarchitecture based on images obtained from dual-energy X-ray absorptiometry (DXA). Since patients receiving glucocorticoid are at a higher risk of developing secondary osteoporosis, assessment of bone microarchitecture may be used to evaluate risk of fragility fractures of osteoporosis. In this pre-post study of female patients, TBS and fracture risk assessment tool (FRAX) adjusted with TBS (T-FRAX) were evaluated along with bone mineral density (BMD) and FRAX. Medical records of patients with (n = 30) and without (n = 16) glucocorticoid treatment were retrospectively reviewed. All patients had undergone DXA twice within a 12- to 24-month interval. Analysis of covariance was conducted to compare the outcomes between the two groups of patients, adjusting for age and baseline values. Results showed that a significant lower adjusted mean of TBS (p = 0.035) and a significant higher adjusted mean of T-FRAX for major osteoporotic fracture (p = 0.006) were observed in the glucocorticoid group. Conversely, no significant differences were observed in the adjusted means for BMD and FRAX. These findings suggested that TBS and T-FRAX could be used as an adjunct in the evaluation of risk of fragility fractures in patients receiving glucocorticoid therapy.

PKCβII-mediated cross-talk of TRPV1/CB2 modulates the glucocorticoid-induced osteoclast overactivity

In this study, we investigated the role of the endovanilloid/endocannabinoid system in the glucocorticoid-induced osteoclast overactivity. Receptorial and enzymatic component of the endovanilloid/endocannabinoid system are expressed in bone cells, and dysregulated when bone mass is reduced. Moreover, blockade or desensitization of vanilloid receptor 1 (TRPV1) and/or stimulation of cannabinoid receptor 2 (CB2) are beneficial for reducing number and activity of the bone cells modulating resorption, the osteoclasts. We have treated in vitro healthy woman derived osteoclasts with methylprednisolone in presence or not of CB2 or TRPV1 agonists/antagonists, analysing the effect on osteoclast function and morphology through a multidisciplinary approach. Moreover, a treatment with a protein kinase C inhibitor to evaluate osteoclast activity and endovanilloid/endocannabinoid component expression levels was performed in osteoclasts derived from healthy subjects in presence of not of methylprednisolone. Our results show, for the first time, that the endovanilloid/endocannabinoid system is dysregulated by the treatment with methylprednisolone, that the osteoclast activity is increased and that pharmacological compounds stimulating CB2 or inhibiting TRPV1 might reduce, possible inhibiting protein kinase C beta II, the methylprednisolone-induced osteoclast over-activation, suggesting their therapeutic use for protecting from the glucocorticoid-induced bone mass loss.

Effects of teriparatide on bone mineral density and quality of life in Duchenne muscular dystrophy related osteoporosis: a case report

Duchenne muscular dystrophy (DMD) is an X-linked recessive muscle disease characterized by secondary osteoporosis and increased fractures. We describe the case of a 20-year-old boy with DMD suffering from back pain due to multiple vertebral fractures who was treated with teriparatide. Improvement of bone density, pain, and quality of life was achieved. DMD is an X-linked recessive muscle disease with secondary osteoporosis and related frequently occurring fractures. To date, only bisphosphonates have been used to treat osteoporosis in DMD. Black bear parathyroid hormone has been previously reported to enhance bone mass in the dystrophin-deficient mouse. This study reports the positive effect of osteoanabolic treatment with once-daily recombinant human parathyroid hormone 1-34 (rhPTH 1-34, teriparatide) in a 20-year-old DMD boy suffering from multiple vertebral fractures causing back pain. Bone formation and resorption markers (osteocalcin and C-telopeptide of type I collagen, respectively), as expected, increased within 6 months and intensity of back pain early decreased, with no pain reported after 6 months at visual analog scale. Over a 18-month period of treatment with teriparatide, bone mineral density and quality of life, assessed by the 36-item short-form questionnaire, considerably improved and no side effects were reported. Further studies on large cohorts are warranted to test the efficacy of this promising treatment for DMD related osteoporosis.

1H NMR-based metabonomic study on the effects of Epimedium on glucocorticoid-induced osteoporosis

Glucocorticoids are widely used in clinical practice for the treatment of many immune-mediated and inflammatory diseases, and glucocorticoid-induced osteoporosis (GIO) is the most common type of secondary osteoporosis. Epimedium is one of the most commonly used traditional Chinese medicines for treating osteoporosis. In the present study, we systematically analysed the metabonomic characteristics of GIO model rats and elucidated the therapeutic effect of Epimedium by using a ¹H NMR-based metabonomic approach in conjunction with multivariate data analysis. Rats in treatment and model groups were injected with dexamethasone (0.1mg/kg/day) for 5 weeks. Simultaneously, two treatment groups were orally administered Epimedium (10g/kg/day) or Alendronate (1.2mg/kg/day) for 5 weeks. In GIO model rats, lipid and lactate levels in serum were increased, while creatine/creatinine, PC/GPC, taurine, glycine and β-glucose levels were decreased. In urine, GIO rats had higher levels of phenylacetylglycine but lower levels of 2-oxoglutarate, citrate, creatine/creatinine, taurine, PC/GPC and hippurate than controls. Epimedium reversed the aforementioned metabolic alterations in multiple metabolic pathways involved in energy, lipid, amino acid and phospholipid metabolism and gut microbiota derangement. Our results indicated that Epimedium had significant effects in the prevention and treatment of osteoporosis. It is concluded that ¹H NMR metabonomics is a useful method for studying the metabolic effects of traditional Chinese medicine from a systematic and holistic view.

Protection From Glucocorticoid-Induced Osteoporosis by Anti-Catabolic Signaling in the Absence of Sost/Sclerostin

Excess of glucocorticoids, either due to disease or iatrogenic, increases bone resorption and decreases bone formation and is a leading cause of osteoporosis and bone fractures worldwide. Improved therapeutic strategies are sorely needed. We investigated whether activating Wnt/β-catenin signaling protects against the skeletal actions of glucocorticoids, using female mice lacking the Wnt/β-catenin antagonist and bone formation inhibitor Sost. Glucocorticoids decreased the mass, deteriorated the microarchitecture, and reduced the structural and material strength of bone in wild-type (WT), but not in Sost^-/- mice. The high bone mass exhibited by Sost^-/- mice is due to increased bone formation with unchanged resorption. However, unexpectedly, preservation of bone mass and strength in Sost^-/- mice was due to prevention of glucocorticoid-induced bone resorption and not to restoration of bone formation. In WT mice, glucocorticoids increased the expression of Sost and the number of sclerostin-positive osteocytes, and altered the molecular signature of the Wnt/β-catenin pathway by decreasing the expression of genes associated with both anti-catabolism, including osteoprotegerin (OPG), and anabolism/survival, such as cyclin D1. In contrast in Sost^-/- mice, glucocorticoids did not decrease OPG but still reduced cyclin D1. Thus, in the context of glucocorticoid excess, activation of Wnt/β-catenin signaling by Sost/sclerostin deficiency sustains bone integrity by opposing bone catabolism despite markedly reduced bone formation and increased apoptosis. This crosstalk between glucocorticoids and Wnt/β-catenin signaling could be exploited therapeutically to halt resorption and bone loss induced by glucocorticoids and to inhibit the exaggerated bone formation in diseases of unwanted hyperactivation of Wnt/β-catenin signaling. © 2016 American Society for Bone and Mineral Research.

Coracoid Process Avulsion Fracture at the Coracoclavicular Ligament Attachment Site in an Osteoporotic Patient with Acromioclavicular Joint Dislocation

Coracoid fractures are uncommon, mostly occur at the base or neck of the coracoid process (CP), and typically present with ipsilateral acromioclavicular joint (ACJ) dislocation. However, CP avulsion fractures at the coracoclavicular ligament (CCL) attachment with ACJ dislocation have not been previously reported. A 59-year-old woman receiving glucocorticoid treatment fell from bed and complained of pain in her shoulder. Radiographs revealed an ACJ dislocation with a distal clavicle fracture. Three-dimensional computed tomography (3D-CT) reconstruction showed a small bone fragment at the medial apex of the CP. She was treated conservatively and achieved a satisfactory outcome. CP avulsion fractures at the CCL attachment can occur in osteoporotic patients with ACJ dislocations. Three-dimensional computed tomography is useful for identifying this fracture type. CP avulsion fractures should be suspected in patients with ACJ dislocations and risk factors for osteoporosis or osteopenia.

Molecular Actions of Glucocorticoids in Cartilage and Bone During Health, Disease, and Steroid Therapy

Cartilage and bone are severely affected by glucocorticoids (GCs), steroid hormones that are frequently used to treat inflammatory diseases. Major complications associated with long-term steroid therapy include impairment of cartilaginous bone growth and GC-induced osteoporosis. Particularly in arthritis, GC application can increase joint and bone damage. Contrarily, endogenous GC release supports cartilage and bone integrity. In the last decade, substantial progress in the understanding of the molecular mechanisms of GC action has been gained through genome-wide binding studies of the GC receptor. These genomic approaches have revolutionized our understanding of gene regulation by ligand-induced transcription factors in general. Furthermore, specific inactivation of GC signaling and the GC receptor in bone and cartilage cells of rodent models has enabled the cell-specific effects of GCs in normal tissue homeostasis, inflammatory bone diseases, and GC-induced osteoporosis to be dissected. In this review, we summarize the current view of GC action in cartilage and bone. We further discuss future research directions in the context of new concepts for optimized steroid therapies with less detrimental effects on bone.

Fracture risk in oral glucocorticoid users: a Bayesian meta-regression leveraging control arms of osteoporosis clinical trials

Little data exist on the frequency of fracture among oral glucocorticoid users. We examined the effect of oral glucocorticoids on fracture incidence using data from randomized controlled trials. Patients starting glucocorticoids had a higher probability of fracture and decline in bone mineral density compared to chronic glucocorticoid users.

INTRODUCTION

Oral glucocorticoids (GCs) are the leading cause of secondary osteoporosis. However, there have been few studies that quantify the rate of fracture among GC users. We sought to provide a pooled estimate of fracture risk from randomized controlled trials (RCTs) of GC-treated patients.

METHODS

We updated a MEDLINE search published by the American College of Rheumatology through to March 2015 and identified RCTs of osteoporosis therapies that reported fracture and bone mineral density (BMD) among oral GC users. We restricted the analysis to placebo or control arms. RCT arms were stratified by GC exposure at enrolment to GC initiators (≤6 months) and chronic GC users (>6 months). Bayesian meta-regression was used to estimate the annual probability of vertebral fracture (primary), non-vertebral fracture and percentage change in lumbar spine and femoral neck BMD.

RESULTS

The annual incidence of vertebral and non-vertebral fracture was 5.1 % (95 % CrI = 2.8-8.2) and 2.5 % (95 % CrI = 1.2--4.2) among GC initiators, and 3.2 % (95 % CrI = 1.8-5.0) and 3.0 % (95 % CrI = 0.8-5.9) among chronic GC users. Our meta-regression identified a non-significant effect of group-level variables (mean age, mean BMD, mean GC daily dose, patients with previous vertebral fractures, proportion of women and adjuvant used) on vertebral fracture rate.

CONCLUSION

Our study found higher vertebral fracture incidence among GC initiators, yet a relative decline in fracture incidence with longer exposure. Our findings suggest that fracture incidence among oral GC users may be more common than previously estimated. Optimizing GC-induced osteoporosis management during early exposure to GC is essential to prevent fractures.

Management of severe osteoporosis

INTRODUCTION

Severe osteoporosis represents a disease of high mortality and morbidity. Recognition of what constitutes and causes severe osteoporosis and aggressive intervention with pharmacological agents with evidence to reduce fracture risk are outlined in this review.

AREAS COVERED

This review is a blend of evidence obtained from literature searches from PubMed and The National Library of Medicine (USA), clinical experience and the author's opinions. The review covers the recognition of what constitutes severe osteoporosis, and provides up-to-date references on this sub-set of high risk patients.

EXPERT OPINION

Severe osteoporosis can be classified by using measurements of bone densitometry, identification of prevalent fractures, and, knowledge of what additional risk factors contribute to high fracture risk. Once recognized, the potential consequences of severe osteoporosis can be mitigated by appropriate selection of pharmacological therapies and modalities to reduce the risk for falling.

Sclerostin antibody and interval treadmill training effects in a rodent model of glucocorticoid-induced osteopenia

Glucocorticoids have a beneficial anti-inflammatory and immunosuppressive effect, but their use is associated with decreased bone formation, bone mass and bone quality, resulting in an elevated fracture risk. Exercise and sclerostin antibody (Scl-Ab) administration have both been shown to increase bone formation and bone mass, therefore the ability of these treatments to inhibit glucocorticoid-induced osteopenia alone or in combination were assessed in a rodent model. Adult (4 months-old) male Wistar rats were allocated to a control group (C) or one of 4 groups injected subcutaneously with methylprednisolone (5mg/kg/day, 5 days/week). Methylprednisolone treated rats were injected subcutaneously 2 days/week with vehicle (M) or Scl-Ab-VI (M+S: 25mg/kg/day) and were submitted or not to treadmill interval training exercise (1h/day, 5 days/week) for 9 weeks (M+E, M+E+S). Methylprednisolone treatment increased % fat mass and % apoptotic osteocytes, reduced whole body and femoral bone mineral content (BMC), reduced femoral bone mineral density (BMD) and osteocyte lacunae occupancy. This effect was associated with lower trabecular bone volume (BV/TV) at the distal femur. Exercise increased BV/TV, osteocyte lacunae occupancy, while reducing fat mass, the bone resorption marker NTx, and osteocyte apoptosis. Exercise did not affect BMC or cortical microarchitectural parameters. Scl-Ab increased the bone formation marker osteocalcin and prevented the deleterious effects of M on bone mass, further increasing BMC, BMD and BV/TV to levels above the C group. Scl-Ab increased femoral cortical bone parameters at distal part and midshaft. Scl-Ab prevented the decrease in osteocyte lacunae occupancy and the increase in osteocyte apoptosis induced by M. The addition of exercise to Scl-Ab treatment did not result in additional improvements in bone mass or bone strength parameters. These data suggest that although our exercise regimen did prevent some of the bone deleterious effects of glucocorticoid treatment, particularly in trabecular bone volume and osteocyte apoptosis, Scl-Ab treatment resulted in marked improvements in bone mass across the skeleton and in osteocyte viability, resulting in decreased bone fragility.

Risk factors for osteoporosis in inflammatory bowel disease patients

Inflammatory bowel disease (IBD) patients exhibit higher risk for bone loss than the general population. The chronic inflammation causes a reduction in bone mineral density (BMD), which leads to osteopenia and osteoporosis. This article reviewed each risk factor for osteoporosis in IBD patients. Inflammation is one of the factors that contribute to osteoporosis in IBD patients, and the main system that is involved in bone loss is likely RANK/RANKL/osteoprotegerin. Smoking is a risk factor for bone loss and fractures, and many mechanisms have been proposed to explain this loss. Body composition also interferes in bone metabolism and increasing muscle mass may positively affect BMD. IBD patients frequently use corticosteroids, which stimulates osteoclastogenesis. IBD patients are also associated with vitamin D deficiency, which contributes to bone loss. However, infliximab therapy is associated with improvements in bone metabolism, but it is not clear whether the effects are because of inflammation improvement or infliximab use. Ulcerative colitis patients with proctocolectomy and ileal pouches and Crohn’s disease patients with ostomy are also at risk for bone loss, and these patients should be closely monitored.

Giant cell arteritis: Current treatment and management

Glucocorticoids remain the cornerstone of medical therapy in giant cell arteritis (GCA) and should be started immediately to prevent severe consequences of the disease, such as blindness. However, glucocorticoid therapy leads to significant toxicity in over 80% of the patients. Various steroid-sparing agents have been tried, but robust scientific evidence of their efficacy and safety is still lacking. Tocilizumab, a monoclonal IL-6 receptor blocker, has shown promising results in a number of case series and is now being tested in a multi-centre randomized controlled trial. Other targeted treatments, such as the use of abatacept, are also now under investigation in GCA. The need for surgical treatment is rare and should ideally be performed in a quiescent phase of the disease. Not all patients follow the same course, but there are no valid biomarkers to assess therapy response. Monitoring of disease progress still relies on assessing clinical features and measuring inflammatory markers (C-reactive protein and erythrocyte sedimentation rate). Imaging techniques (e.g., ultrasound) are clearly important screening tools for aortic aneurysms and assessing patients with large-vessel involvement, but may also have an important role as biomarkers of disease activity over time or in response to therapy. Although GCA is the most common form of primary vasculitis, the optimal strategies for treatment and monitoring remain uncertain.

Local renin-angiotensin system is associated with bone mineral density of glucocorticoid-induced osteoporosis patients

The local renin-angiotensin system (RAS) is closely related to bone metabolism. However, it is unknown whether the local RAS is related to bone mineral density (BMD) in glucocorticoid-induced osteoporosis (GIOP). Here, we revealed that the two main characteristics of GIOP might inhibit bone formation and enhance bone resorption.

INTRODUCTION

The aim of this study is to assess the expression of the main RAS components in the trabecular bone of lumbar vertebrae in GIOP and analyze the relationship between the major RAS components and BMD.

METHODS

We collected 96 inpatient cases of lumbar disc herniation from patients who underwent dual-energy X-ray absorptiometry examinations followed by surgical treatment in our hospital. Patients were divided into the GIOP group (n = 48) and control group (n = 48). The circulating and local expression levels of the main RAS components were examined. The correlation between the main RAS components and BMD was then analyzed.

RESULTS

The mRNA expression of local bone angiotensin type 1 and 2 receptors (AT1R and AT2R, respectively) and RANKL was higher in the GIOP group compared with the control group (p < 0.001), but there was no difference in the circulating protein levels between groups (p > 0.05). Multiple logistic regression analysis revealed that AT1R and AT2R expression and the RANKL/OPG ratio in local bone were negatively associated with BMD (p < 0.001, odds ratio (OR) 1.236, 95 % confidence interval (CI) 1.207-1.333; p < 0.001, OR 1.971, 95% CI 1.809-2.233; and p < 0.001, OR 1.676, 95% CI 1.546-1.845, respectively).

CONCLUSION

This study provides evidence that the role of local RAS is related to BMD in GIOP patients, and suggests that local RAS might influence RANKL/OPG signaling to modulate bone metabolism.

Evaluation of the discriminative potential of a novel biomarker for estradiol treatments in bovine animals

The endogenous occurrence of natural hormones obstructs the application of classical targeted methods as confirmatory options. In the case of estradiol, the ultimate confirmation of its exogenous administration relies on gas chromatography coupled to combustion/isotope ratio mass spectrometry (GC-C/IRMS). A serum dipeptide composed of pyroglutamic acid and phenylalanine was identified as a potential biomarker of estradiol treatments in adult cows. To evaluate its potential to pinpoint suspicious samples, samples from prepubertal females under different estrogenic treatments have been analyzed. The results confirmed the up-regulation of the dipeptide in adult bovines. The 2-week-old females exhibited short-lasting responses only in a few animals. The 6-month-old female showed a delayed but clear increase on the biomarker level. The composition of the anabolic preparations, the dose, and/or the administration route are possible additional reasons for the reduced response in young animals. A comparison to previous results reported by various researchers is included.

Mechanism and Treatment Strategy of Osteoporosis after Transplantation

Osteoporosis (OP) has emerged as a frequent and devastating complication of organ solid transplantation process. Bone loss after organ transplant is related to adverse effects of immunosuppressants on bone remodeling and bone quality. Many factors contribute to the pathogenesis of OP in transplanted patients. Many mechanisms of OP have been deeply approached. Drugs for OP can be generally divided into "bone resorption inhibitors" and "bone formation accelerators," the former hindering bone resorption by osteoclasts and the latter increasing bone formation by osteoblasts. Currently, bisphosphonates, which are bone resorption inhibitors drugs, are more commonly used clinically than others. Using the signaling pathway or implantation bone marrow stem cell provides a novel direction for the treatment of OP, especially OP after transplantation. This review addresses the mechanism of OP and its correlation with organ transplantation, lists prevention and management of bone loss in the transplant recipient, and discusses the recipients of different age and gender.

Medication-induced osteoporosis: screening and treatment strategies

Drug-induced osteoporosis is a significant health problem and many physicians are unaware that many commonly prescribed medications contribute to significant bone loss and fractures. In addition to glucocorticoids, proton pump inhibitors, selective serotonin receptor inhibitors, thiazolidinediones, anticonvulsants, medroxyprogesterone acetate, aromatase inhibitors, androgen deprivation therapy, heparin, calcineurin inhibitors, and some chemotherapies have deleterious effects on bone health. Furthermore, many patients are treated with combinations of these medications, possibly compounding the harmful effects of these drugs. Increasing physician awareness of these side effects will allow for monitoring of bone health and therapeutic interventions to prevent or treat drug-induced osteoporosis.

Managing osteoporosis in ulcerative colitis: something new?

The authors revise the latest evidence in the literature regarding managing of osteoporosis in ulcerative colitis (UC), paying particular attention to the latest tendency of the research concerning the management of bone damage in the patient affected by UC. It is wise to assess vitamin D status in ulcerative colitis patients to recognize who is predisposed to low levels of vitamin D, whose deficiency has to be treated with oral or parenteral vitamin D supplementation. An adequate dietary calcium intake or supplementation and physical activity, if possible, should be guaranteed. Osteoporotic risk factors, such as smoking and excessive alcohol intake, must be avoided. Steroid has to be prescribed at the lowest possible dosage and for the shortest possible time. Moreover, conditions favoring falling have to been minimized, like carpets, low illumination, sedatives assumption, vitamin D deficiency. It is advisable to assess the fracture risk in all UC patient by the fracture assessment risk tool (FRAX(®) tool), that calculates the ten years risk of fracture for the population aged from 40 to 90 years in many countries of the world. A high risk value could indicate the necessity of treatment, whereas a low risk value suggests a follow-up only. An intermediate risk supports the decision to prescribe bone mineral density (BMD) assessment and a subsequent patient revaluation for treatment. Dual energy X-ray absorptiometry bone densitometry can be used not only for BMD measurement, but also to collect data about bone quality by the means of trabecular bone score and hip structural analysis assessment. These two indices could represent a method of interesting perspectives in evaluating bone status in patients affected by diseases like UC, which may present an impairment of bone quality as well as of bone quantity. In literature there is no strong evidence for instituting pharmacological therapy of bone impairment in UC patients for clinical indications other than those that are also applied to the patients with osteoporosis. Therefore, a reasonable advice is to consider pharmacological treatment for osteoporosis in those UC patients who already present fragility fractures, which bring a high risk of subsequent fractures. Therapy has also to be considered in patients with a high risk of fracture even if it did not yet happen, and particularly when they had long periods of corticosteroid therapy or cumulative high dosages. In patients without fragility fractures or steroid treatment, a medical decision about treatment could be guided by the FRAX tool to determine the intervention threshold. Among drugs for osteoporosis treatment, the bisphosphonates are the most studied ones, with the best and longest evidence of efficacy and safety. Despite this, several questions are still open, such as the duration of treatment, the necessity to discontinue it, the indication of therapy in young patients, particularly in those without previous fractures. Further, it has to be mentioned that a long-term bisphosphonates use in primary osteoporosis has been associated with an increased incidence of dramatic side-effects, even if uncommon, like osteonecrosis of the jaw and atypical sub-trochanteric and diaphyseal femoral fractures. UC is a long-lasting disease and the majority of patients is relatively young. In this scenario primary prevention of fragility fracture is the best cost-effective strategy. Vitamin D supplementation, adequate calcium intake, suitable physical activity (when possible), removing of risk factors for osteoporosis like smoking, and avoiding falling are the best medical acts.

Glucocorticoid induced osteoblast apoptosis by increasing E4BP4 expression via up-regulation of Bim

It is well known that glucocorticoid (GC)-induced bone loss is caused primarily by hypofunction and apoptosis of osteoblasts. However, the precise molecular events underlying the effect of GC on osteoblast apoptosis are not fully understood. Recent studies implicated an important role of E4BP4 in the regulation of osteoblast apoptosis and differentiation. Furthermore, E4BP4 is a GC-regulated gene required for GC-induced apoptosis in many cells. Therefore, we hypothesize that E4BP4 may be implicated in the process of GC-induced osteoblast apoptosis. Western blot, reverse-transcription-PCR, flow cytometry, and Hoechst 33258 staining were employed to investigate the role of E4BP4 in dexamethasone (DEX)-induced osteoblast apoptosis. We found that the expression of E4BP4 is significantly up-regulated in osteoblasts exposed to DEX. Furthermore, the depletion of E4BP4 significantly decreased DEX-induced osteoblast apoptosis. In addition, E4BP4 plays a crucial role in GC-evoked apoptosis of osteoblasts by enabling induction of Bim. On the basis of these results above, we can draw the conclusion that E4BP4 may contribute to the process of DEX-induced osteoblast apoptosis.

Glucocorticoids and bone: local effects and systemic implications

Glucocorticoids (GCs) are highly effective in the treatment of inflammatory and autoimmune conditions but their therapeutic use is limited by numerous adverse effects. Recent insights into the mechanisms of action of both endogenous and exogenous GCs on bone cells have unlocked new approaches to the development of effective strategies for the prevention and treatment of GC-induced osteoporosis. Furthermore, topical studies in rodents indicate that the osteoblast-derived peptide, osteocalcin, plays a central role in the pathogenesis of GC-induced diabetes and obesity. These exciting findings mechanistically link the detrimental effects of GCs on bone and energy metabolism. In this article we review the physiology and pathophysiology of GC action on bone cells, and discuss current and emerging concepts regarding the molecular mechanisms underlying adverse effects of GCs such as osteoporosis and diabetes.

Risk factors and management of osteoporosis in inflammatory bowel disease

PURPOSE OF REVIEW

To provide a synopsis on established and new research evaluating bone disease in patients with inflammatory bowel disease (IBD).

RECENT FINDINGS

Persons with IBD, including Crohn's disease and ulcerative colitis are believed to be at high risk for osteoporosis and fracture. As osteoporosis is clinically silent and persons with IBD are not universally screened, the burden of bone disease in IBD has been difficult to accurately assess. It is also unclear whether bone disease is due to inflammatory activity, medication use, poor nutrient intake/absorption, or body habitus characteristics. Recent studies using population-wide databases of bone mineral density (BMD) analyses suggest that Crohn's disease is responsible for a small effect on BMD after adjusting for other risk factors for low BMD, whereas ulcerative colitis does not appear to confer an independent risk. Furthermore, IBD does not appear to be a risk for overall fracture once controlling for factors which are associated with both IBD and fracture risk. The ability to assess BMD on incidentally performed computed tomography scans may allow detection of low BMD in IBD patients.

SUMMARY

Although reduced BMD and fracture are more common in persons with IBD, the precise burden is not well characterized. Also, the relative impact of IBD-associated factors and IBD-specific inflammation on bone health is still uncertain.

Glucocorticoid-induced osteoporosis: an update on effects and management

Glucocorticoids remain a cornerstone of guideline-based management of persistent asthma and allergic diseases. Glucocorticoid-induced osteoporosis (GIO) is the most common iatrogenic cause of secondary osteoporosis and an issue of concern for physicians treating patients with inhaled or oral glucocorticoids either continuously or intermittently. Patients with GIO experience fragility fractures at better dual-energy x-ray absorptiometry T-scores than those with postmenopausal or age-related osteoporosis. This might be explained, at least in part, by the effects of glucocorticoids not only on osteoclasts but also on osteoblasts and osteocytes. Effective options to detect and manage GIO exist, and a management algorithm has been published by the American College of Rheumatology to provide treatment guidance for clinicians. This review will summarize GIO epidemiology and pathophysiology and assess the role of inhaled and oral glucocorticoids in asthmatic adults and children, with particular emphasis on the effect of such therapies on bone health. Lastly, we will review the American College of Rheumatology GIO guidelines and discuss diagnostic and therapeutic strategies to mitigate the risk of GIO and fragility fractures.

A rare presentation of subclinical Cushing's syndrome as a pubic fracture

Osteoporosis and bone fractures are commonly seen in patients with Cushing's syndrome (CS). Fractures usually occur in the vertebrae and ribs whereas pubic fractures are less common. Similar to obvious hypercortisolemia, subclinical hypercortisolemia can increase the risk of fractures. However, in subclinical cases, bone fractures are very rarely seen as the presenting symptom. We herein report the case of a 62-year-old postmenopausal woman who was presented with a pubic fracture. During the evaluation of the fracture, thoracoabdominal magnetic resonance imaging of the patient demonstrated an adrenal mass. Although the patient did not show any signs of overt hypercortisolism, an endocrinologic evaluation revealed hypercortisolism due to an adrenal tumor. Adrenalectomy was performed, which resulted in a cure of the disease. During the orthopedic follow-up, the patient's pubic area pain gradually improved, and the pubic fracture healed without any accompanying new bone fractures. One year after the surgery, a remarkable improvement was detected in the patient's bone density in spite of the lack of administration of any medications for osteoporosis. Subclinical CS can present as a pubic fracture, and awareness of this relationship can help physicians to diagnose the disease.

The intelligent use of systemic glucocorticoids in rheumatoid arthritis

Glucocorticoids (GC) have potent anti-inflammatory and immunomodulatory effects and are widely used in the management of rheumatoid arthritis in combination with other disease-modifying anti-rheumatoid drugs. Concern about the risk of adverse effects may be to some extent misplaced as low to moderate doses of GC have different mechanisms of action and risk profiles compared with high doses. This review discusses the current understanding about the different modes of action of GC, their strong disease-modifying properties and the efforts at improving the therapeutic ratio of GC through the development of new drugs which promise greater safety such as selective GC receptor agonists, liposomal GC and modified-release (MR) prednisone.

EULAR evidence-based and consensus-based recommendations on the management of medium to high-dose glucocorticoid therapy in rheumatic diseases

To develop recommendations for the management of medium to high-dose (ie, >7.5 mg but ≤100 mg prednisone equivalent daily) systemic glucocorticoid (GC) therapy in rheumatic diseases. A multidisciplinary EULAR task force was formed, including rheumatic patients. After discussing the results of a general initial search on risks of GC therapy, each participant contributed 10 propositions on key clinical topics concerning the safe use of medium to high-dose GCs. The final recommendations were selected via a Delphi consensus approach. A systematic literature search of PubMed, EMBASE and Cochrane Library was used to identify evidence concerning each of the propositions. The strength of recommendation was given according to research evidence, clinical expertise and patient preference. The 10 propositions regarded patient education and informing general practitioners, preventive measures for osteoporosis, optimal GC starting dosages, risk-benefit ratio of GC treatment, GC sparing therapy, screening for comorbidity, and monitoring for adverse effects. In general, evidence supporting the recommendations proved to be surprisingly weak. One of the recommendations was rejected, because of conflicting literature data. Nine final recommendations for the management of medium to high-dose systemic GC therapy in rheumatic diseases were selected and evaluated with their strengths of recommendations. Robust evidence was often lacking; a research agenda was created.

Comparative effects of teriparatide and risedronate in glucocorticoid-induced osteoporosis in men: 18-month results of the EuroGIOPs trial

Data on treatment of glucocorticoid-induced osteoporosis (GIO) in men are scarce. We performed a randomized, open-label trial in men who have taken glucocorticoids (GC) for ≥3 months, and had an areal bone mineral density (aBMD) T-score ≤ -1.5 standard deviations. Subjects received 20 μg/d teriparatide (n = 45) or 35 mg/week risedronate (n = 47) for 18 months. Primary objective was to compare lumbar spine (L1 -L3 ) BMD measured by quantitative computed tomography (QCT). Secondary outcomes included BMD and microstructure measured by high-resolution QCT (HRQCT) at the 12th thoracic vertebra, biomechanical effects for axial compression, anterior bending, and axial torsion evaluated by finite element (FE) analysis from HRQCT data, aBMD by dual X-ray absorptiometry, biochemical markers, and safety. Computed tomography scans were performed at 0, 6, and 18 months. A mixed model repeated measures analysis was performed to compare changes from baseline between groups. Mean age was 56.3 years. Median GC dose and duration were 8.8 mg/d and 6.4 years, respectively; 39.1% of subjects had a prevalent fracture, and 32.6% received prior bisphosphonate treatment. At 18 months, trabecular BMD had significantly increased for both treatments, with significantly greater increases with teriparatide (16.3% versus 3.8%; p = 0.004). HRQCT trabecular and cortical variables significantly increased for both treatments with significantly larger improvements for teriparatide for integral and trabecular BMD and bone surface to volume ratio (BS/BV) as a microstructural measure. Vertebral strength increases at 18 months were significant in both groups (teriparatide: 26.0% to 34.0%; risedronate: 4.2% to 6.7%), with significantly higher increases in the teriparatide group for all loading modes (0.005 < p < 0.015). Adverse events were similar between groups. None of the patients on teriparatide but five (10.6%) on risedronate developed new clinical fractures (p = 0.056). In conclusion, in this 18-month trial in men with GIO, teriparatide showed larger improvements in spinal BMD, microstructure, and FE-derived strength than risedronate.

Glucocorticoid-induced changes in the geometry of osteoclast resorption cavities affect trabecular bone stiffness

Bone fracture risk can increase through bone microstructural changes observed in bone pathologies, such as glucocorticoid-induced osteoporosis. Resorption cavities present one of these microstructural aspects. We recently found that glucocorticoids (GCs) affect the shape of the resorption cavities. Specifically, we found that in the presence of GC osteoclasts (OCs) cultured on bone slices make more trenchlike cavities, compared to rather round cavities in the absence of GCs, while the total eroded surface remained constant. For this study, we hypothesized that trenchlike cavities affect bone strength differently compared to round cavities. To test this hypothesis, we cultured OCs on bone slices in the presence and absence of GC and quantified their dimensions. These data were used to model the effects of OC resorption cavities on bone mechanical properties using a validated beam-shell finite element model of trabecular bone. We demonstrated that a change in the geometry of resorption cavities is sufficient to affect bone competence. After correcting for the increased EV/BV with GCs, the difference to the control condition was no longer significant, indicating that the GC-induced increase in EV/BV, which is closely related to the shape of the cavities, highly determines the stiffness effect. The lumbar spine was the anatomic site most affected by the GC-induced changes on the shape of the cavities. These findings might explain the clinical observation that the prevalence of vertebral fractures during GC treatment increases more than hip, forearm and other nonvertebral fractures.

Monoclonal antibodies for the treatment of osteoporosis

INTRODUCTION

Osteoporosis is a systemic skeletal disorder that weakens bones and increases the risk of fractures. It is caused by perturbations of bone remodeling, the coupled process whereby bone is continually resorbed and formed in small discrete units. Despite the availability of cost-effective pharmacological agents that reduce fracture risk, many patients who could benefit from treatment are not receiving it. Advances in the understanding of the molecular regulators of bone remodeling have led to the identification of new targets for therapeutic intervention. Monoclonal antibodies directed to these targets have recently been developed, providing new ways of modulating bone remodeling that may provide additional benefits beyond previously available therapy.

AREAS COVERED

An approved fully human monoclonal antibody to receptor activator of nuclear factor-κB ligand, the principal regulator of osteoclastic bone resorption, reduces the risk of fractures in postmenopausal women with osteoporosis. Monoclonal antibodies in development include inhibitors of sclerostin and Dickhopf1, with osteoanabolic activity that may be beneficial in the treatment of osteoporosis.

EXPERT OPINION

Monoclonal antibodies to molecular regulators of bone remodeling represent a new class of compounds for the management of osteoporosis and other skeletal disorders associated with an imbalance of bone resorption and formation.

Longitudinal change in bone mineral density in a population-based cohort of patients with inflammatory bowel disease

Persons with inflammatory bowel disease (IBD) are reported to have a high prevalence of osteoporosis and reduced bone mineral density (BMD) and to be at higher risk of fracture. The course of BMD loss over time is poorly characterized in persons with IBD. Eighty-six persons, stratified by age, were enrolled from a population-based longitudinal IBD cohort study to undergo BMD testing at baseline, with final BMD testing a mean of 4.3 years later. The proportion of subjects with significant change in BMD at the lumbar spine, total hip, and femoral neck was assessed, as were clinical, biochemical, and anthropomorphic changes. Vertebral radiographs were also obtained at baseline and at the end of follow-up in those aged 50 years and above to detect vertebral fractures. The change in BMD seen in this cohort of IBD patients was similar to the expected rate of BMD loss in the general population. Age >50 years, decreasing body mass index (BMI), and corticosteroid use were most notably correlated with BMD loss. Subjects aged <50 years did not have statistically significant declines in BMD. IBD symptom activity scores correlated poorly with BMD loss. Vertebral fractures were uncommon, with only two subjects out of 41 >50 years old developing a definite radiographic fracture over the course of follow-up. No major nonvertebral fractures were observed. Patients with IBD do not appear to have significantly accelerated BMD loss. Older age, decreasing BMI, and corticosteroid use may identify IBD patients at greater risk for BMD loss.

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.

Cortisol secretion, bone health, and bone loss: a cross-sectional and prospective study in normal non-osteoporotic women in the early postmenopausal period

OBJECTIVE

The aim of the study was to evaluate the relationship between cortisol secretion, bone health, and bone loss in a cohort of normal women in the early postmenopausal period.

METHODS

We measured lumbar and hip bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA) and heel ultrasound parameters in 82 healthy, nonosteoporotic (lumbar T-score ≥-2.0) women (median age 52.5 years, range 42-61). These women were examined in two sessions, 1 year apart, in the early postmenopausal period (onset of menopause between 6 and 60 months). Parameters of the hypothalamic-pituitary-adrenal (HPA) axis function were morning serum cortisol, morning and midnight salivary cortisol, 24-h urinary free cortisol (UFC), serum cortisol after 0.5 and 1 mg overnight dexamethasone, and DHEA-S.

RESULTS

In multiple regression analyses, the following significant inverse correlations were found: i) lumbar BMD and either 24-h UFC (P<0.005) or morning serum cortisol (P<0.05), ii) total femur and femoral neck BMD with morning serum cortisol (P=0.05 and P<0.05), and iii) heel ultrasound stiffness index and midnight salivary cortisol (P<0.005). The annual rate of change in lumbar and femoral BMD did not correlate with any of the above-mentioned hormonal variables. No difference was found in the parameters of HPA axis function in slow (loss of BMD <1%) vs fast (loss of BMD ≥3%) bone losers.

CONCLUSIONS

HPA axis may contribute to postmenopausal bone health, but differences in cortisol secretion do not influence the differential rate of bone loss between slow and fast bone losers in the early postmenopausal period, at least in healthy women.

Prednisone affects inflammation, glucose tolerance, and bone turnover within hours of treatment in healthy individuals

OBJECTIVE

Use of glucocorticoids for anti-inflammatory efficacy is limited by their side effects. This study examined, in the same individuals, prednisone's acute, dose-dependent effects on inflammation as well as biomarkers of glucose regulation and bone homeostasis.

DESIGN

In this randomized, double-blind, parallel-design trial of healthy adults demonstrating cutaneous allergen-induced hypersensitivity, patients received placebo or prednisone 10, 25 or 60 mg daily for 7 days.

METHODS

Effects on peripheral white blood cell (WBC) count, ex vivo whole blood lipopolysaccharide (LPS)-stimulated TNF-α release and response to cutaneous allergen challenge were assessed concurrently with biomarkers for glucose tolerance and bone turnover.

RESULTS

Differential peripheral WBC counts changed significantly within hours of prednisone administration. Ex vivo, LPS-stimulated TNF-α was significantly reduced by all prednisone doses on days 1 and 7. The late phase cutaneous allergen reaction was significantly reduced with prednisone 60 mg vs placebo on days 1 and 7. Oral glucose tolerance tests revealed significant increases in glycaemic excursion on days 1 and 7, whereas increases in insulin and C-peptide excursions were more notable on day 7 with all doses of prednisone. The bone formation markers osteocalcin, and procollagen I N- and C-terminal peptides decreased significantly on days 1 and 7 vs placebo.

CONCLUSIONS

In healthy young adults after single doses as low as 10 mg, prednisone treatment has significant effects on glucose tolerance and bone formation markers within hours of treatment, in parallel with anti-inflammatory effects.

The effects of the organopollutant PCB 126 on bone density in juvenile diamondback terrapins (Malaclemys terrapin)

Bone is a dynamic tissue with diverse functions including growth, structural support, pH balance and reproduction. These functions may be compromised in the presence of organopollutants that can alter bone properties. We exposed juvenile diamondback terrapins (Malaclemys terrapin) to 3,3',4,4',5-pentachlorobiphenyl (PCB 126), a ubiquitous anthropogenic organochlorine, and measured organic content, apparent bone mineral density (aBMD) using radiography and computed tomography, and quantified bone microstructure using histological preparations of femora. PCB-exposed terrapins were smaller in total size. Skulls of exposed animals had a higher organic content and a skeletal phenotype more typical of younger animals. The femora of exposed individuals had significantly reduced aBMD and significantly more cortical area occupied by non-bone. Because bone is an integral component of physiology, the observed skeletal changes can have far-reaching impacts on feeding and locomotor performance, calcium reserves and ultimately life history traits and reproductive success. Additionally, we caution that measurements of bone morphology, density, and composition from field-collected animals need to account not only for relatedness and age, but also environmental pollutants.

Bisphosphonates and glucocorticoid osteoporosis in men: results of a randomized controlled trial comparing zoledronic acid with risedronate

BACKGROUND

We studied 265 men (mean age 56.4 years; range 18-83 years), among patients enrolled in two arms of a double-blind, 1-year study comparing the effects of zoledronic acid (ZOL) with risedronate (RIS) in patients either commencing (prednisolone 7.5 mg/day or equivalent) (prevention arm, n=88) or continuing glucocorticoid therapy (treatment arm, n=177).

METHODS

Patients received either a single ZOL 5 mg infusion or RIS 5 mg oral daily at randomization, along with calcium (1000 mg) and vitamin D (400-1200 IU). Primary endpoint: difference in percentage change from baseline in bone mineral density (BMD) at the lumbar spine (LS) at 12 months. Secondary endpoints: percentage changes in BMD at total hip (TH) and femoral neck (FN), relative changes in bone turnover markers (β-CTx and P1NP), and overall safety.

FINDINGS

In the treatment subpopulation, ZOL increased LS BMD by 4.7% vs. 3.3% for RIS and at TH the percentage changes were 1.8% vs. 0.2%, respectively. In the prevention subpopulation, bone loss was prevented by both treatments. At LS the percentage changes were 2.5% vs. -0.2% for ZOL vs. RIS and at TH the percentage changes were 1.1% vs. -0.4%, respectively. ZOL significantly increased lumbar spine BMD more than RIS at Month 12 in both the prevention population (p=0.0024) and the treatment subpopulation (p=0.0232) in men. In the treatment subpopulation, ZOL demonstrated a significantly greater reduction in serum β-CTx and P1NP relative to RIS at all time-points. In the prevention subpopulation, ZOL significantly reduced β-CTx at all time-points, and P1NP at Month 3 (p=0.0297) only. Both treatments were well tolerated in men, albeit with a higher incidence of influenza-like illness and pyrexia events post-infusion with ZOL.

INTERPRETATION

Once-yearly ZOL preserves or increases BMD within 1 year to a greater extent than daily RIS in men receiving glucocorticoid therapy.

A reappraisal of generic bisphosphonates in osteoporosis

The competitive price of generic bisphosphonates has had a marked effect on practice guidelines, but an increasing body of evidence suggests that they have more limited effectiveness than generally assumed.

INTRODUCTION

The purpose of this study is to review the impact of generic bisphosphonates on effectiveness in the treatment of osteoporosis.

METHODS

This study is a literature review.

RESULTS

A substantial body of evidence indicates that many generic formulations of alendronate are more poorly tolerated than the proprietary preparations which results in significantly poorer adherence and thus effectiveness. Poorer effectiveness may result from faster disintegration times of many generics that increase the likelihood of adherence of particulate matter to the oesophageal mucosa. Unfortunately, market authorisation, based on the bioequivalence of generics with a proprietary formulation, does not take into account the potential concerns about safety. The poor adherence of many generic products has implications for guideline development, cost-effectiveness and impact of treatment on the burden of disease.

CONCLUSIONS

The impact of generic bisphosphonates requires formal testing to re-evaluate their role in the management of osteoporosis.

[Bone density measurements on growing skeletons and the clinical consequences]

The measurement of bone mineral density (BMD) was established to judge the fracture risk in an individual. The most commonly used densitometric technique DXA is a two-dimensional method and reports BMD (bone mass/projection area), which increases during growth. Bone mineral density (in g/cm(3)), however, is almost stable and does not change with age or height. To analyze the data special pediatric references including data on age, sex and ethnicity are necessary as well as correction for height. Bone forms a unit with muscle. Bone responds to mechanical loading with increase in bone size and therefore adapts to the biomechanical needs. Therefore, interpretation of bone development data requires data on muscle development.The indication for bone mineral density measurement and result reporting should be made by and together with a pediatric specialist. The diagnosis of osteoporosis should not be made based solely on densitometric measurements. History of low trauma fracture is an important aspect for the definition. Besides DXA there exist further methods with advantages and disadvantages.