Bone loss after discontinuation of denosumab: the devil is in the details

A 47-year-old postmenopausal woman with osteoporosis was treated with denosumab, which was discontinued due to side effects. She was therefore transitioned to a yearly intravenous infusion of zoledronic acid. An increase in bone turnover markers together with bone loss at the lumbar spine was observed before the second infusion, suggesting an overshooting of bone resorption due to denosumab discontinuation. On physical examination, the patient was restless and reported having lost about 10 kg since the last visit. A solitary left inferior thyroid nodule was noted on neck palpation. Circulating thyroid hormone levels were elevated, with suppressed thyroid-stimulating hormone. A thyroid scan showed increased uptake in the left inferior nodule with suppression of the remainder of the thyroid gland. A diagnosis of hyperthyroidism due to toxic adenoma was made. The patient was treated with radioactive iodine ablation, with consequent complete normalization of thyroid function. She continued yearly treatment with zoledronic acid. She remained clinically well with no further fractures. Bone turnover markers were appropriately suppressed and bone mineral density increased in the spine and hip. This case illustrates how the overshooting phenomenon following denosumab discontinuation may be compounded by the development of secondary conditions, which can result in suboptimal response to antiresorptive osteoporosis medications.

Risk Factors for Fragility Fractures in Chronic Lymphocytic Leukemia

Abnormal bone health and fragility fractures (FF) are more common in patients with chronic lymphocytic leukemia (CLL). We hypothesize that there may be risk factors in CLL patients with osteoporosis that increase the risk of FFs. We conducted a cohort study encompassing all patients diagnosed with CLL from January 1, 2000, to July 31, 2020, utilizing International Classification of Diseases (ICD) codes related to abnormal bone health (osteopenia, osteoporosis, and/or presence of FF) within a single tertiary care institution. Of the 89 patients included, 55 (62%) were female with a mean age of 68 ± 11 years at cohort entry. Fifty-nine (66%) had at least one FF present (pFF) and 30 (34%) did not have an FF (nFF). There were no differences in IGHV (Immunoglobulin heavy chain variable region gene) mutation status, chromosomal abnormalities, or the presence of a complex karyotype. The spine accounted for 81% of identified FF. T-score <-2.5 was more common in those without FF (pFF 38% vs. nFF 71%, P = 0.02). DXA evaluation was not conducted for 36 (40%) individuals within the cohort. Risk factors for fragility fractures included male sex (relative risk [RR] 8.1, 95% confidence interval [CI] 2.1-31.7), diabetes mellitus (RR 1.4, 95% CI 1.04-1.8), smoking (RR 1.3, 95% CI 1.02-1.8), Rai stage >0 (RR 1.4, 95% CI 1.04-1.9), and T-score >-2.5 (RR 1.8, 95% CI 1.1-3.1). There is a high frequency of vertebral FFs in people with CLL despite T-scores not being in the osteoporotic range. Increased awareness to screen and treat vertebral FFs in people with CLL is needed.

The role of bone modifying agents for secondary osteoporosis prevention and pain control in post-menopausal osteopenic breast cancer patients undergoing adjuvant aromatase inhibitors

Introduction

Hormonal therapy (HT) blocks the hormone-mediated growth signal dramatically reducing estrogenic levels with aromatase inhibitors (AIs) becoming a crucial component of the treatment mainstay in patients with early breast cancer (BC). Postmenopausal BC patients receiving HT present with a significant risk of secondary osteoporosis with AIs further reducing estrogen levels and ultimately leading to an accelerated rate of bone resorption and thus decreased bone mineral density (BMD). This was an observational retrospective clinical study that consecutively enrolled early BC patients with osteopenia to compare the impact of alendronate versus denosumab on secondary osteoporosis prevention and pain control.

Methods

We identified two groups of patients treated with denosumab 60 mg by subcutaneous injection once every six months or alendronate 70 mg orally once a week. All the patients underwent a baseline physiatric evaluation (T0) and underwent a follow-up visit after 18 months (T1) together with femoral and vertebral Dual-Energy X-ray Absorptiometry (DEXA) exam evaluating T-Score marks. From September 2015 to December 2019 a total of 50 early (stage I-III) BC patients were considered eligible and consecutively enrolled in our study if they met pre-specified inclusion criteria.

Results

In the entire observed population, the addition of treatment with alendronate or denosumab led to a significant T-score improvement at the lumbar spine level (-1.92 vs -1.52, p=0.03), with a comparable contribution from alendronate (-1.60 vs -1.45, p=0.07) and denosumab (-2.26 vs -1.58, p=0.07). Regarding the femoral region, neither alendronate (-0.98 vs -1.07, p=0.23) nor denosumab (-1.39 vs -1.34, p=0.81) were able to produce any statistically relevant effect. However, concerning pain control, BMAs had a significant impact on reducing NRS scoresin the general population (T1 3.94 vs. baseline 4.32, p=0.007), with a likelyspecific contribution from alendronate (T1 3.52 vs. baseline 3.88, p=0.004) compared to denosumab (T1 4.36 vs baseline 4.76, p=0.12), without any differences in analgesic therapy assumption over time (p=0.93).

Discussion

Both alendronate and denosumab significantly contributed to preventing secondary osteoporosis in early BC patients with low BMD undergoing AIs, mostly at the lumbar spine level. Moreover, alendronate seemed to significantly impact pain control in such patients further supporting alendronate as a cost-effective option in this frail setting, although BMAs particularities should be carefully considered on an individual basis according to specific clinical contexts.

Degree of Albuminuria is Associated With Increased Risk of Fragility Fractures Independent of Estimated GFR

Introduction

Fragility fractures are common in persons with chronic kidney disease (CKD); however, the association between fragility fractures and albuminuria is not well-studied. The primary objective of this study is to determine the association of albuminuria with incident risk of fragility fractures. The secondary objective is to examine the risk of fragility fracture by estimated glomerular filtration rate (eGFR) and Kidney Disease Improving Global Outcomes (KDIGO) risk categories.

Methods

Community dwelling adults residing in Alberta, Canada who had at least 1 creatinine and albuminuria measurement between April 1, 2008 and March 31, 2019 participated in the study (N = 2.72 million). Incident fragility fractures were identified using Canadian Chronic Disease Surveillance Systems Osteoporosis Working Group algorithms. Albuminuria was categorized as none/mild (albumin-to-creatinine ratio [ACR] <30 mg/g, protein-to-creatinine ratio [PCR] <150 mg/g, trace/negative dipstick); moderate (ACR 30-300 mg/g, PCR 150-500 mg/g, 1+ dipstick) or severe (ACR >300 mg/g, PCR >500 mg/g, ≥2+ dipstick). Multivariable analysis controlled for 42 variables.

Results

Patients with severe albuminuria had an increased risk of hip fracture (odds ratio [OR] = 1.37; 95% confidence interval [CI] 1.28, 1.47]), vertebral fracture (OR = 1.31; 95% CI 1.21, 1.41) and any-type fracture (OR = 1.22; 95% CI 1.17, 1.28) compared with patients with none/mild albuminuria. Patients in the most severe KDIGO risk category had an increased risk of hip fracture (OR = 1.22; 95% CI 1.16, 1.29), vertebral fracture (OR = 1.18; 95% CI 1.09, 1.26) and any type of fracture (OR = 1.25; 95% CI 1.21, 1.30).

Conclusion

This study demonstrates the important role of albuminuria as a risk factor for fragility fractures in CKD and may help inform risk stratification and prevention strategies in this high-risk population category.

Trabecular Bone Score Significantly Influences Treatment Decisions in Secondary Osteoporosis

The trabecular bone score (TBS) can be determined in addition to the Dual Energy X-ray Absorptiometry (DXA) for bone mineral density (BMD) measurement to diagnose, evaluate, and stratify bone loss and decide on appropriate treatment in patients at risk. Especially in patients with secondary osteoporosis, TBS detects restricted bone quality. To investigate the influence of an additional evaluation of TBS on patients' treatment strategy decisions, we enrolled 292 patients, with a high proportion of patients with secondary osteoporosis, from one outpatient unit over one year. Patients eligible for BMD measurement had the option to opt-in for TBS measurement. We analyzed demographic data, leading diagnoses, bone metabolism parameters, and results of BMD and TBS measurements. More than 90% of patients consented to TBS measurement. TBS measurement influenced the decision in approximately 40% of patients with a treatment indication for anti-osteoporotic drugs. We demonstrate that depending on the underlying disease/risk spectrum, 21-25.5% of patients had an unremarkable BMD measurement with poor bone quality shown in the TBS measurement. In patients with secondary osteoporosis, the use of TBS supplementary to DXA seems useful to better assess fracture risk and, thus, to initiate therapy for osteoporosis in these patients in time.

Haemophilia and Fragility Fractures: From Pathogenesis to Multidisciplinary Approach

Haemophilia A (HA) and haemophilia B (HB) are X-linked inherited bleeding disorders caused by the absence or deficiency of coagulation factors VIII (FVIII) and IX (FIX), respectively. Recent advances in the development of effective treatments for haemophilia have led to a significant increase in life expectancy. As a result, the incidence of some comorbidities, including fragility fractures, has increased in people with haemophilia (PWH). The aim of our research was to perform a review of the literature investigating the pathogenesis and multidisciplinary management of fractures in PWH. The PubMed, Scopus and Cochrane Library databases were searched to identify original research articles, meta-analyses, and scientific reviews on fragility fractures in PWH. The mechanism underlying bone loss in PWH is multifactorial and includes recurrent joint bleeding, reduced physical activity with consequent reduction in mechanical load, nutritional deficiencies (particularly vitamin D), and FVIII and FIX deficiency. Pharmacological treatment of fractures in PWH includes antiresorptive, anabolic and dual action drugs. When conservative management is not possible, surgery is the preferred option, particularly in severe arthropathy, and rehabilitation is a key component in restoring function and maintaining mobility. Appropriate multidisciplinary fracture management and an adapted and tailored rehabilitation pathway are essential to improve the quality of life of PWH and prevent long-term complications. Further clinical trials are needed to improve the management of fractures in PWH.

Cerebral palsy and bisphosphonates - and what can be learned from other types of secondary osteoporosis in children: A scoping review

AIM

We aimed to improve bone health management of children with cerebral palsy (CP) by reviewing studies investigating bisphosphonate therapy in children with CP and other types of secondary osteoporosis.

METHODS

We included trials on bisphosphonate treatment reporting any direct bone measurement or fracture outcome. All studies of patients with CP were included. We also included all controlled trials of children with secondary bone fragility as well as observational studies with ≥20 participants or at least 3 years of follow-up. Studies were assessed according to PRISMA guidelines using the RoB2-tool and the Newcastle-Ottawa Scale.

RESULTS

We reviewed 1104 studies and found 37 eligible. Some studies were sufficiently homogeneous to include in a meta-analysis, and we found a 1-year effect on lumbar spine bone mineral density (BMD) Z-score of +0.65 after oral and + 1.21 after intravenous bisphosphonates in children with secondary osteoporosis. Further, data on adverse events and post-treatment follow-up were reviewed. Limitations were heterogeneity and small size of the included studies.

CONCLUSION

Meta-analysis consistently showed significant BMD increases with bisphosphonates in children with secondary osteoporosis. Direct evidence of the effect of bisphosphonates on reducing fractures is lacking. We found no reports of long-term adverse events yet longer studies are needed.

Resveratrol-Mediated Reversal of Doxorubicin-Induced Osteoclast Differentiation

Secondary osteoporosis has been associated with cancer patients undertaking Doxorubicin (DOX) chemotherapy. However, the molecular mechanisms behind DOX-induced bone loss have not been elucidated. Molecules that can protect against the adverse effects of DOX are still a challenge in chemotherapeutic treatments. We investigated the effect and mechanism of DOX in osteoclast differentiation and used the Sirt 1 activator resveratrol (RES) to counteract DOX-induced effects. RAW 264.7 cells were differentiated into osteoclasts under cotreatment with DOX and RES, alone or combined. RES treatment inhibited DOX-induced osteoclast differentiation, reduced the expression of osteoclast fusion marker Oc-stamp and osteoclast differentiation markers Rank, Trap, Ctsk and Nfatc1. Conversely, RES induced the upregulation of antioxidant genes Sod 1 and Nrf 2 while DOX significantly reduced the FoxM1 expression, resulting in oxidative stress. Treatment with the antioxidant MitoTEMPO did not influence DOX-induced osteoclast differentiation. DOX-induced osteoclastogenesis was studied using the cathepsin-K zebrafish reporter line (Tg[ctsk:DsRed]). DOX significantly increased ctsk signal, while RES cotreatment resulted in a significant reduction in ctsk positive cells. RES significantly rescued DOX-induced mucositis in this model. Additionally, DOX-exposed zebrafish displayed altered locomotor behavior and locomotory patterns, while RES significantly reversed these effects. Our research shows that RES prevents DOX-induced osteoclast fusion and activation in vitro and in vivo and reduces DOX-induced mucositis, while improving locomotion parameters.

Regular Supplementation with Antioxidants Rescues Doxorubicin-Induced Bone Deformities and Mineralization Delay in Zebrafish

Osteoporosis is characterized by an abnormal bone structure with low bone mass and degradation of microarchitecture. Oxidative stress induces imbalances in osteoblast and osteoclast activity, leading to bone degradation, a primary cause of secondary osteoporosis. Doxorubicin (DOX) is a widely used chemotherapy drug for treating cancer, known to induce secondary osteoporosis. The mechanism underlying DOX-induced bone loss is still not fully understood, but one of the relevant mechanisms is through a massive accumulation of reactive oxygen and nitrogen species (i.e., ROS and NOS) leading to oxidative stress. We investigated the effects of antioxidants Resveratrol and MitoTEMPO on DOX-induced bone impairment using the zebrafish model. DOX was shown to increase mortality, promote skeletal deformities, induce alterations on intestinal villi, impair growth and mineralization and significantly downregulate osteoblast differentiation markers osteocalcin 2 and osterix/sp7. Lipid peroxidation was significantly increased in DOX-supplemented groups as compared to control and antioxidants, suggesting ROS formation as one of the key factors for DOX-induced bone loss. Furthermore, DOX affected mineral contents, suggesting an altered mineral metabolism. However, upon supplementation with antioxidants, DOX-induced effects on mineral content were rescued. Our data show that supplementation with antioxidants effectively improves the overall growth and mineralization in zebrafish and counteracts DOX-induced bone anomalies.

Efficacy and safety of bisphosphonates on childhood osteoporosis secondary to chronic illness or its treatment: a meta-analysis

Background:

Bisphosphonates are a type of medication that prevents the loss of bone density. Secondary childhood osteoporosis reduces bone strength and results in an increased risk of fragility fracture. This meta-analysis aims to explore the efficacy and safety of bisphosphonates on secondary childhood osteoporosis.

Methods:

We performed a systematic search of PubMed, Cochrane library, and Web of Science databases up to 31 July 2022 to screen for random clinical trials (RCTs) on bisphosphonate treatment for childhood secondary osteoporosis. Data from selected studies, mainly changes in lumbar spine (LS) bone mineral density (BMD), changes in LS BMD Z-scores, fracture events, and adverse events (AEs), were extracted and analyzed.

Results:

Nine RCTs (n = 429 in total) were included in our meta-analysis. The meta-analysis indicated that bisphosphonates improved the changes in LS BMD [mean difference (MD) = 0.04, 95% confidence intervals (CIs) = 0.01–0.07, p < 0.01] and LS BMD Z-scores [MD = 0.52, 95% CI = 0.23–0.81, p < 0.01]. Use of bisphosphonates did not increase the risk of AEs [odds ratio (OR) = 1.61, 95% CI = 0.87–2.99, p = 0.13]. Subgroup analysis showed that routes of administration, but not causes of secondary osteoporosis, might influence the efficacy of bisphosphonates. IV bisphosphonates close to significantly improved the incidence of fracture (OR = 0.34, 95% CI: 0.11–1.08, p = 0.07).

Conclusions:

The use of bisphosphonates improves LS BMD without increasing AE rates, which supports the clinical use of bisphosphonates in secondary childhood osteoporosis. Further large RCTs are still warranted, especially for their long-term effects on fracture rates.

Bone Health in Children with Rheumatic Disorders: Focus on Molecular Mechanisms, Diagnosis, and Management

Bone is an extremely dynamic and adaptive tissue, whose metabolism and homeostasis is influenced by many different hormonal, mechanical, nutritional, immunological and pharmacological stimuli. Genetic factors significantly affect bone health, through their influence on bone cells function, cartilage quality, calcium and vitamin D homeostasis, sex hormone metabolism and pubertal timing. In addition, optimal nutrition and physical activity contribute to bone mass acquisition in the growing age. All these factors influence the attainment of peak bone mass, a critical determinant of bone health and fracture risk in adulthood. Secondary osteoporosis is an important issue of clinical care in children with acute and chronic diseases. Systemic autoimmune disorders, like juvenile idiopathic arthritis, can affect the skeletal system, causing reduced bone mineral density and high risk of fragility fractures during childhood. In these patients, multiple factors contribute to reduce bone strength, including systemic inflammation with elevated cytokines, reduced physical activity, malabsorption and nutritional deficiency, inadequate daily calcium and vitamin D intake, use of glucocorticoids, poor growth and pubertal delay. In juvenile arthritis, osteoporosis is more prominent at the femoral neck and radius compared to the lumbar spine. Nevertheless, vertebral fractures are an important, often asymptomatic manifestation, especially in glucocorticoid-treated patients. A standardized diagnostic approach to the musculoskeletal system, including prophylaxis, therapy and follow up, is therefore mandatory in at risk children. Here we discuss the molecular mechanisms involved in skeletal homeostasis and the influence of inflammation and chronic disease on bone metabolism.

Case report: Clinical characteristics and treatment of secondary osteoporosis induced by X-linked congenital adrenal dysplasia

OBJECTIVE

To summarize the clinical features and bone complications in a patient from a large family with X-linked congenital adrenocortical hypoplasia (AHC) and evaluate the efficacy of different treatment regimens on the prognosis of secondary osteoporosis caused by AHC at a 5-year follow-up.

METHODS

A large family with AHC was recruited, and the causative gene mutation was identified by Sanger sequencing in the proband. Clinical features as well as radiological examinations and laboratory indices of osteoporosis secondary to AHC were analyzed in this study. Meanwhile, the proband was treated with classical antiresorptive drugs (bisphosphonates) for 2 years and switched to a vitamin K₂ analogue for another 3 years, during which the efficacy of the drugs was evaluated.

RESULTS

The proband was identified as carrying a homozygous insertion mutation (p. Thr193GlyfsX13) in the NR0B1 (nuclear receptor subfamily 0, group B, member 1) gene, resulting in a premature stop codon due to a frameshift mutation. During treatment and follow-up, the proband did not respond well to bisphosphonate and developed atypical femoral fractures. Vitamin K₂ improved clinical symptoms. In terms of bone mineral density (BMD), there is no evidence of any effect of vitamin K₂ on the neck of femur, though some minor effects on spinal BMD cannot be excluded.

CONCLUSIONS

Secondary osteoporosis induced by AHC deserves clinical attention. Unlike in primary osteoporosis, the curative effect of bisphosphonates was unsatisfactory and was more likely to cause atypical femoral fractures in long-term treatment. It is suggested that bone anabolic drugs may be better alternatives.

Is vitamin K2 a treatment choice for atypical femoral fractures in patients with secondary osteoporosis?

An atypical femoral fracture (AFF) is a rare complication associated with excessive inhibition of osteoclast expression during treatment of osteoporosis. We herein describe a patient who had been treated with alendronate for more than 10 years and subsequently developed an AFF that healed after treatment with vitamin K₂ (VK2). We also discuss the potential beneficial effects of VK2 on the healing of AFFs. A 48-year-old Asian man with secondary osteoporosis was treated with alendronate for more than 10 years. The patient underwent surgical treatment for a complete AFF of the right femur. Six months postoperatively, he complained of pain in his left thigh. X-ray examination revealed an incomplete AFF of the left femoral shaft. He was then treated with VK2. After 4 months of VK2 treatment, the patient reported that the pain in his left thigh had decreased, and follow-up X-ray examination demonstrated healing of the left AFF line. This case report indicates that VK2 may be a potential direction for pharmacological treatment of AFFs in future research.

Longitudinal Evolution of Bone Microarchitecture and Bone Strength in Type 2 Diabetic Postmenopausal Women With and Without History of Fragility Fractures-A 5-Year Follow-Up Study Using High Resolution Peripheral Quantitative Computed Tomography

Introduction

Diabetic bone disease is characterized by an increased fracture risk which may be partly attributed to deficits in cortical bone quality such as higher cortical porosity. However, the temporal evolution of bone microarchitecture, strength, and particularly of cortical porosity in diabetic bone disease is still unknown. Here, we aimed to prospectively characterize the 5-year changes in bone microarchitecture, strength, and cortical porosity in type 2 diabetic (T2D) postmenopausal women with (DMFx) and without history of fragility fractures (DM) and to compare those to nondiabetic fracture free controls (Co) using high resolution peripheral quantitative computed tomography (HR-pQCT).

Methods

Thirty-two women underwent baseline HR-pQCT scanning of the ultradistal tibia and radius and a FU-scan 5 years later. Bone microarchitectural parameters, including cortical porosity, and bone strength estimates via µFEA were calculated for each timepoint and annualized. Linear regression models (adjusted for race and change in BMI) were used to compare the annualized percent changes in microarchitectural parameters between groups.

Results

At baseline at the tibia, DMFx subjects exhibited the highest porosity of the three groups (66.3% greater Ct.Po, 71.9% higher Ct.Po.Volume than DM subjects, p < 0.022). Longitudinally, porosity increased significantly over time in all three groups and at similar annual rates, while DMFx exhibited the greatest annual decreases in bone strength indices (compared to DM 4.7× and 6.7× greater decreases in failure load [F] and stiffness [K], p < 0.025; compared to Co 14.1× and 22.2× greater decreases in F and K, p < 0.020).

Conclusion

Our data suggest that despite different baseline levels in cortical porosity, T2D women with and without fractures experienced long-term porosity increases at a rate similar to non-diabetics. However, the annual loss in bone strength was greatest in T2D women with a history of a fragility fractures. This suggests a potentially non-linear course of cortical porosity development in T2D bone disease: major porosity may develop early in the course of disease, followed by a smaller steady annual increase in porosity which in turn can still have a detrimental effect on bone strength-depending on the amount of early cortical pre-damage.

Meta-regression analysis of the efficacy of alendronate for prevention of glucocorticoid-induced fractures

BACKGROUND

What affects the efficacy of alendronate for prevention of glucocorticoid-induced (GI) fractures remains unclear. We aimed to explore the factors affecting alendronate's efficacy, and further identify subgroup effects of alendronate in preventing GI fractures.

METHODS

We searched 3 databases. Random-effects meta-analysis was conducted to synthesize risk ratio (RR) and 95% confidence interval (CI) for each endpoint. Meta-regression analysis was used to explore sources of heterogeneity, and subgroup analysis was used to address heterogeneity and evaluate subgroup effects. We detected publication bias using funnel plots and Egger tests.

RESULTS

We included 13 papers from 12 unique studies involving 46431 participants. Glucocorticoid (GC) dosage (P = .053) and proportion of previous vertebral fracture (PVF) (P = .047) were probably 2 sources of heterogeneity in meta-analysis for vertebral fractures, while GC duration (P = .020) was probably 1 for nonvertebral fractures. Alendronate reduced vertebral fractures in the high dosage subgroup (RR 0.61, 95% CI 0.44-0.86), but didn't in the low dosage subgroup (RR 1.56, 95% CI 0.20-12.02). Alendronate reduced vertebral fractures (RR 0.53, 95% CI 0.40-0.68) in the subgroup of PVF proportion <5%, but didn't (RR 0.76, 95% CI 0.42-1.37) in the subgroup of this proportion ≥5%. Alendronate reduced nonvertebral and hip fractures, whether in primary or in secondary prevention subgroup.

CONCLUSIONS

The findings in our study support that alendronate is used for the primary and secondary prevention of GI fractures, but do not support that alendronate is recommended as a first-line agent for patients receiving a low dose of GCs or patients with PVF.

Lactobacillus Fermentum ZS40 prevents secondary osteoporosis in Wistar Rat

Using retinoic acid to inducer, we successfully established a rat model of secondary osteoporosis and verified the preventive effect of Lactobacillus fermentum ZS40 (ZS40) on secondary osteoporosis. Serum biochemical indicators showed that ZS40 can effectively slow down bone resorption caused by retinoic acid, increase blood content of calcium, phosphorus, bone alkaline phosphatase, bone gla protein, and insulin-like growth factor 1, and decrease blood content of tartrate-resistant acid phosphatase (TRAP) 5b. qRT-PCR results showed that ZS40 could upregulate mRNA expressions of β-catenin, Wnt10b, Lrp5, Lrp6, Runx2, ALP, RANKL, and OPG, and downregulate mRNA expression of DKK1, RANK, TRACP, and CTSK in the rats' spinal cord. Results following TRAP staining showed that ZS40 could slow down retinoic acid-induced formation of osteoclasts. Micro-CT results showed that ZS40 could reduce Tb.Sp, increase BV/TV, Tb.N, Tb.Th, and ultimately increase bone mineral density of rats in vivo. These findings indicate that ZS40 might have a potential role in preventing retinoic acid-induced secondary osteoporosis in vivo.

Osteoporosis in Premenopausal Women: A Clinical Narrative Review by the ECTS and the IOF

CONTEXT

Consensus regarding diagnosis and management of osteoporosis in premenopausal women (PW) is still lacking due to few studies carried out in this population.

DESIGN

The European Calcified Tissue Society and the International Osteoporosis Foundation convened a working group to produce an updated review of literature published after 2017 on this topic.

RESULTS

Fragility fractures in PW are rare and mostly due to secondary osteoporosis (ie, in presence of an underlying disease such as hormonal, inflammatory, or digestive disorders). In absence of another disorder, low bone mineral density (BMD) together with fragility fractures qualifies as idiopathic osteoporosis. In contrast, low BMD alone does not necessarily represent osteoporosis in absence of bone microarchitectural abnormalities. BMD increases in PW with osteoporosis when the underlying disease is treated. For example, in celiac disease, an increase of 9% in radius trabecular volumetric density was achieved after 1 year of gluten-free diet, while anti-tumor necrosis factor alpha improved BMD in PW with inflammatory bowel diseases. In amenorrhea, including anorexia nervosa, appropriately delivered estrogen replacement therapy can also improve BMD. Alternatively, antiresorptive or anabolic therapy has been shown to improve BMD in a variety of conditions, the range of improvement (3%-16%) depending on skeletal site and the nature of the secondary cause. No studies were powered to demonstrate fracture reduction. The effects of bisphosphonates in childbearing women have been scantly studied and caution is needed.

CONCLUSION

The majority of PW with osteoporosis have an underlying disease. Specific therapy of these diseases, as well as antiresorptive and anabolic drugs, improve BMD, but without evidence of fracture reduction.

Evaluation of the fracture risk assessment tool for determining bone disease and the impact of secondary causes of osteoporosis in people living with HIV

BACKGROUND

Among HIV-infected individuals, screening for bone disease is encouraged to assess reversible risk factors and plan therapeutic interventions.

OBJECTIVE

We assessed the usefulness of Fracture Risk Assessment (FRAX) tool to identify candidates for dual X-ray absorptiometry (DXA) scan, or individuals with bone loss progression. We further explored how secondary causes of osteoporosis are reflected on FRAX.

METHODS

Longitudinal study of 217 consecutive individuals (mean, 45.8 years, 24% females) included after DXA scan. FRAX was calculated without/with femoral neck bone mineral density (BMD), checking the box of "secondary osteoporosis" for all the individuals.

RESULTS

Low BMD was observed in 133/217 (61%) individuals, of whom 98.5% had not been selected as candidates for DXA by current FRAX thresholds. Specifically, 23% of individuals aged <50 had low BMD but none was candidate for DXA. Adding BMD data, FRAX results increased by 50-100%, with 2/217 individuals (1%) above the thresholds. Classical and HIV-related secondary causes of osteoporosis (observed in 98% overall) correlated with low BMD, modifying significantly FRAX results (HCV coinfection, +124%; longer time of HIV infection, +93%; longer time on antiretroviral therapy, +147%; tenofovir exposure +36%). Individuals with lower BMD and higher FRAX results at inclusion had less bone decline in a follow-up DXA after a median of 3.5 years.

CONCLUSIONS

Currently recommended FRAX thresholds are not useful to select candidates for DXA scan, which could delay its performance in a population with a high prevalence of secondary factors for low BMD. Classical and HIV-related factors alter BMD and fracture risk estimation.

A Primary Care Provider's Guide to Bone Health in Spinal Cord-Related Paralysis

Individuals with spinal cord injury/disorder (SCI/D) are at high risk for developing secondary osteoporosis. Bone loss after neurologic injury is multifactorial and is dependent on the time from and extent of neurologic injury. Most bone loss occurs in the first year after complete motor paralysis, and fractures occur most commonly in the distal femur and proximal tibia (paraplegic fracture). The 2019 International Society for Clinical Densitometry Position Statement in SCI establishes that dual-energy X-ray absorptiometry (DXA) can be used to both diagnose osteoporosis and predict lower extremity fracture risk in individuals with SCI/D. Pharmacologic treatments used in primary osteoporosis have mixed results when used for SCI/D-related osteoporosis. Ambulation, standing, and electrical stimulation may be helpful at increasing bone mineral density (BMD) in individuals with SCI/D but do not necessarily correlate with fracture risk reduction. Clinicians caring for individuals with spinal cord-related paralysis must maintain a high index of suspicion for fragility fractures and consider referral for surgical evaluation and management.

Systemic mastocytosis: a rare cause of osteoporosis

A 61-year old female patient who was referred to the endocrine clinic for evaluation of an elevated alkaline phosphatase. She was originally referred to gastroenterology (GI), however no GI causes of elevated alkaline phosphatase was found. Upon fractionation, it was noted that she had elevation in bone specific alkaline phosphatase. Past history was significant for hypertension, atrial fibrillation and menopause 6 years ago. She was also noted to have multiple drug allergies manifesting as urticaria and flushing. Review of the past records revealed a persistently elevated alkaline phosphatase over the last two years. She had no history of falls or fractures. Computed tomography (CT) abdomen done to rule out biliary pathology, revealed osteosclerotic and osteolytic lesion in the pelvis concerning neoplastic disease. Bone marrow biopsy however, was negative for cancer but consistent with systemic mastocytosis (SM). Dual Energy X-ray absorbimetery (DEXA) scan revealed osteoporosis Serum tryptase levels were elevated; further genetic analysis showed a positive CKIT D816 mutation. She was started on bisphosphonates (initially alendronate and then ibandronate). Upon follow up at two years she had not experienced any fractures and her bone mineral density also had improved significantly.

Tools for Enhancement and Quality Improvement of Peer Assessment and Clinical Care in Endocrinology and Metabolism

Members of the College of Physicians and Surgeons of Ontario Endocrinology and Metabolism Peer Review Network have been involved in a quality improvement project to help standardize the peer assessment of physicians practicing in endocrinology and metabolism. This has included developing state-of-the-art summaries of common endocrine problems by Canadian experts in endocrinology and metabolism. These tools have been developed in response to the educational needs, as identified by peer reviewers, of practicing endocrinologists in Ontario. These pedagogical tools aim not only to standardize the documentation of the clinical performance of endocrinologists but also to make the process more transparent and to improve the quality of patient care in Ontario. This article summarizes the project and also provides the tools developed for the endocrinology and metabolism section of the College of Physicians and Surgeons of Ontario.

WNT16 overexpression partly protects against glucocorticoid-induced bone loss

Therapeutic use of glucocorticoids (GCs) is a major cause of secondary osteoporosis, but the molecular mechanisms responsible for the deleterious effects of GCs in bone are only partially understood. WNT16 is a crucial physiological regulator of bone mass and fracture susceptibility, and we hypothesize that disturbed WNT16 activity might be involved in the deleterious effects of GC in bone. Twelve-week-old female Obl-Wnt16 mice (WNT16 expression driven by the rat procollagen type I α1 promoter) and wild-type (WT) littermates were treated with prednisolone (7.6 mg·kg^-1·day^-1) or vehicle for 4 wk. We first observed that GC treatment decreased the Wnt16 mRNA levels in bone of female mice (-56.4 ± 6.1% compared with vehicle, P < 0.001). We next evaluated if WNT16 overexpression protects against GC-induced bone loss. Dual-energy X-ray absorptiometry analyses revealed that GC treatment decreased total body bone mineral density in WT mice (-3.9 ± 1.2%, P = 0.028) but not in Obl-Wnt16 mice (+1.3 ± 1.4%, nonsignificant). Microcomputed tomography analyses showed that GC treatment decreased trabecular bone volume fraction (BV/TV) of the femur in WT mice ( P = 0.019) but not in Obl-Wnt16 mice. Serum levels of the bone formation marker procollagen type I N-terminal propeptide were substantially reduced by GC treatment in WT mice (-50.3 ± 7.0%, P = 0.008) but not in Obl-Wnt16 mice (-3.8 ± 21.2%, nonsignificant). However, the cortical bone thickness in femur was reduced by GC treatment in both WT mice and Obl-Wnt16 mice. In conclusion, GC treatment decreases Wnt16 mRNA levels in bone and WNT16 overexpression partly protects against GC-induced bone loss.

Risk of secondary osteoporosis due to lobular cholestasis in non-cirrhotic primary biliary cholangitis

BACKGROUND AND AIM

It remains unclear whether primary biliary cholangitis (PBC) represents a risk factor for secondary osteoporosis.

METHODS

A case-control study was conducted to examine bone mineral density and bone turnover markers in middle-aged postmenopausal PBC patients without liver cirrhosis. We compared the incidence of low bone mineral density between propensity-score matched subgroups of PBC patients and healthy controls and investigated the mechanisms underlying unbalanced bone turnover in terms of the associations between bone turnover markers and PBC-specific histological findings.

RESULT

Our analysis included 128 consecutive PBC patients, all postmenopausal women aged in their 50s or 60s, without liver cirrhosis or fragility fracture at the time of PBC diagnosis. The prevalence of osteoporosis was significantly higher in the PBC group than in the control group (26% vs 10%, P = 0.015, the Fisher exact probability test). In most PBC patients (95%), the level of bone-specific alkaline phosphatase was above the normal range, indicating increased bone formation. On the other hand, the urine type I collagen-cross-linked N-telopeptide showed variable levels among our PBC patients, indicating unbalanced bone resorption. Advanced fibrosis was associated with low bone turnover. Lobular cholestasis, evaluated as aberrant keratin 7 expression in hepatocytes, showed significant negative correlations with bone formation and resorption, indicating low bone turnover.

CONCLUSION

Our results show that, compared with healthy controls, even non-cirrhotic PBC patients have significantly higher risk of osteoporosis. Moreover, lobular cholestasis was associated with low bone turnover, suggesting this feature of PBC may itself cause secondary osteoporosis in PBC patients.

Use of Trabecular Bone Score (TBS) as a Complementary Approach to Dual-energy X-ray Absorptiometry (DXA) for Fracture Risk Assessment in Clinical Practice

Osteoporosis is a common bone disease characterized by low bone mass and altered bone microarchitecture, resulting in decreased bone strength with an increased risk of fractures. In clinical practice, physicians can assess the risk of fracture for a patient based on several risk factors. Some such as age, weight, and history of fractures after 50 years of age, parental fracture, smoking status, and alcohol intake are incorporated into FRAX, an assessment tool that estimates the 10-year probability of hip fracture and major osteoporotic fractures based on the individual's risk factors profile. The diagnosis of osteoporosis is currently based on bone mineral density (BMD) assessed by dual-energy X-ray absorptiometry scans. Among other widely recognized limitations of BMD is that BMD considers only the density of the bone and fails in measuring bone microarchitecture, for which novel techniques, such as trabecular bone score (TBS), have been developed. TBS is a texture parameter related to bone microarchitecture that may provide skeletal information that is not captured from the standard BMD measurement. Several studies have examined the value of TBS on predicting osteoporotic fractures. Our study aimed to summarize a review of the current scientific literature with focus on fracture risk assessment and to present both its findings and its conclusions regarding how and when TBS should be used. The existing literature indicates that low lumbar spine TBS is associated with a history of fracture and the incidence of new fracture. The effect is largely independent of BMD and of sufficient magnitude to enhance risk stratification with BMD. The TBS effect is also independent of FRAX, with likely greatest utility for those individuals whose BMD levels lie close to an intervention threshold. The clinical and scientific evidence supporting the use of TBS, with the ability of this technology to be seamlessly integrated into a daily workflow, makes TBS an attractive and useful clinical tool for physicians to improve patient management in osteoporosis. Further research is ongoing and necessary to further clarify the role of TBS in additional specific disorders.

Ethnic Differences in Osteoporosis After Cardiac Transplantation

Cardiac transplantation is associated with a high risk of fracture. African Americans (AAs) are believed to have a lower risk of osteoporosis than Caucasians, but it is not clear whether they are also protected from osteoporosis resulting from the use of glucocorticoids and/or organ transplantation. We examined possible ethnic differences in 33 cardiac transplant recipients (16 AAs) in a cross-sectional analysis. In addition to bone mineral density and vertebral fracture assessment, we also compared biochemical variables, trabecular bone score, total body dual-energy X-ray absorptiometry, and disability. Overall fracture rates were low in both groups, with only 6 total subjects with fractures on vertebral fracture assessment or history of fracture. While T-scores were similar between groups, Z-scores were lower in AA with the difference reaching statistical significance when controlling for important covariates. The trabecular bone score was also lower in AAs than in Caucasians even when adjusting for age and tissue thickness (1.198 ± 0.140 vs 1.312 ± 0.140, p = 0.03). While AAs are generally thought to be protected from osteoporosis, our study instead suggests that AAs may be at higher risk of bone deterioration after cardiac transplantation and may need to be managed more aggressively than suggested by current guidelines.

Understanding the effect of acromegaly on the human skeleton

Acromegaly, caused in most cases by Growth Hormone (GH)-secreting pituitary adenomas, is characterized by increased skeletal growth and enlargement of the soft tissue, because GH and its effector Insulin-like Growth factor-1 are important regulators of bone homeostasis and have a central role in the longitudinal bone growth and maintenance of bone mass. Areas covered: Despite the anabolic effect of these hormones is well known, as a result of the stimulation of bone turnover and especially of bone formation, many acromegalic patients are suffering from a form of secondary osteoporosis with increased risk of fractures. Expert commentary: In this review, we summarize the pathophysiology, diagnosis, clinical picture, disease course and management of skeletal complications of acromegaly, focusing in particular on secondary osteoporosis and fracture risk in acromegaly.

Rare causes of osteoporosis

Osteoporosis is a metabolic bone disease characterized by loss of bone mass and strength, resulting in increased risk of fractures. It is classically divided into primary (post-menopausal or senile), secondary and idiopathic forms. There are many rare diseases, that cause directly or indirectly osteoporosis. The identification and classification of most of these rare causes of osteoporosis is crucial for the specialists in endocrinology and not, in order to prevent this bone complication and to provide for an early therapy. Several pathogenic mechanisms are involved, including various aspects of bone metabolism such as: decreased bone formation, increased bone resorption, altered calcium, phosphorus and/or vitamin D homeostasis, and abnormal collagen synthesis. In this review, less common forms of primary and secondary osteoporosis are described, specifying, if applicable: genetic causes, epidemiology, clinical features, and pathogenic mechanisms causing osteoporosis. A greater awareness of all rare causes of osteoporosis could reduce the number of cases classified as idiopathic osteoporosis and allow the introduction of appropriate and timely treatments.

Osteoporosis in pituitary diseases: lessons for the clinic

Osteoporosis is a systemic disease characterized by bone mass and density loss leading to fragility fractures. Osteoporosis due to endocrine disorders is an example of secondary osteoporosis. The harmful effects on bones are common in patients harboring pituitary tumors (acromegaly, prolactinoma, Cushing's disease) and suffering from hypopituitarism. Increased fracture risk and high healthcare costs of fractured patients are their consequences. The coexistence of some of these disorders and hypogonadism results in severe osteoporosis. The influence of the certain diseases, their activity and therapy and accompanying hypogonadism on bone turnover, bone mineral density and fracture incidence is presented.

Bilateral Adrenal Adenoma Presented As Multiple Metatarsal And Phalangeal Fractures

INTRODUCTION

Symptomatic adrenal adenoma usually presents with systemic symptoms. Depending on the function of the adenoma, the patient can present with pheochromocytoma-like symptoms; primary hyperaldosteronism and Cushing syndrome (weight gain, weakness, depression, and bruising).

CASE REPORT

A 41 year-old lady presented with multiple metatarsal and phalangeal fractures of the both feet without significant injury. DEXA scan showed evidence of osteoporosis. Investigations showed that the picture was compatible with adrenal Cushing syndrome. Computed tomogram showed bilateral adrenal adenoma. Adrenal cortex scintigraphy with NP-59 scan showed hyperfunctioning right adrenal adenoma. Laproscopic R adrenalectomy was performed and histological study confirmed adrenal cortical adenoma with adjacent cortical atrophy suggestive of a functioning adenoma. Post-operatively, she was put on hydrocortisone replacement and recovered well.

CONCLUSION

Adrenal adenoma can present with insufficiency fractures of the feet.

Secondary osteoporosis: pathophysiology & diagnosis

Osteoporosis is a skeletal disease characterized by decreased bone mass and microarchitectural changes in bone tissue that increase the susceptibility to fracture. Secondary osteoporosis is loosely defined as low bone mineral density or increased risk of fragility fracture caused by any factor other than aging or postmenopausal status. The purpose of this review is to discuss the current understanding of the pathophysiology and contribution to fracture risk of many of the more common causes of secondary osteoporosis, as well as diagnostic considerations, outlined by organ system. While not comprehensive, included are a wide array of diseases, conditions, and medications that have been associated with bone loss and susceptibility to fractures. The hope is to highlight the importance to the general clinician of screening for and treating the osteoporosis in these patients, so to limit the resultant increased morbidity associated with fractures.

Current and future treatments of secondary osteoporosis

Osteoporosis is commonly associated with menopause and ageing. It can, however, also be caused by diseases, lifestyle, genetic diseases, drug therapies and other therapeutic interventions. In cases of secondary osteoporosis, a common rule is the management of the underlying condition. Healthy habits and calcium and vitamin D supplementation are also generally advised. In cases of high risk of fracture, specific antiosteoporosis medications should be prescribed. For most conditions, the available evidence is limited. Special attention should be paid to possible contraindications of drugs used for the treatment of postmenopausal or senile osteoporosis. Bisphosphonates are the most widely used drugs in secondary osteoporosis, and denosumab or teriparatide have been also assessed in some cases. Important research is needed to develop more tailored strategies, specific to the peculiarities of the different types of secondary osteoporosis.

[The role of vitamin D3 in the regulation of the mineral metabolism in experimental type 1 diabetes]

Diabetes was shown to be associated with a considerable lowering of 25(OH)D3 in blood serum of mice. Vitamin D3 deficiency was correlated with impaired mineral metabolism in bone tissue, indicating the development of secondary osteoporosis. A decrease in weight, length and diameter (diaphysis, proximal metaepiphysis) of tibia in diabetic animals was observed as compared with control. Diabetes caused hypocalcemia, hypophosphatemia and increased enzymatic activity of alkaline phosphatase (ALP) and its isoenzymes in serum. This changes were accompanied by the impairments of vitamin D3 25-hydroxylase isoforms (CYP27A1 and CYP2R1) expression, which are the main enzymes of cholecalciferol biotransformation to 25(OH)D3 - precursor of hormonally active form of vitamin D3. A decrease in bone resorption processes was established after vitamin D3 administration as it is evident from normalization of bone morphometrical parameters and mineral metabolism in diabetic mice. Vitamin D3 ability to counter diabetes-induced alterations in bone tissue can be ascribed, at least in part, to its positive effects on the formation of vitamin D3 hormonally active forms.

Chronic obstructive pulmonary disease and low bone mass: A case-control study

Background and Objective:

Low bone mass (osteopenia and osteoporosis) is one of the effects associated with chronic obstructive pulmonary disease (COPD). There is very little data from Saudi Arabia on COPD and low bone mass. This retrospective study was done to assess the prevalence of osteoporosis and osteopenia in COPD patients attending King Fahd Hospital of the University (KFHU), Alkhobar.

Patients and Methods:

After obtaining the ethical approval from the research committee, all patients seen between at the King Fahd Hospital of the University between January 2010 and December 2012 were included. The inclusion criteria included a follow up of a minimum 2 years, and the Medical Records should have the details of forced expiratory volume in one second (FEV₁), blood bone profile and bone biomarkers and dual-energy X-ray absorptiometry (DEXA) scan. Patients were labeled as osteopenia if the T score was -<1 to <-2.5 and osteoporosis of <-2.5 as per the WHO definition of osteopenia and osteoporosis.

Results:

Seventy-three patients were being followed in the clinics and 49 patients satisfied the inclusion criteria. The average age was 60.6 ± 10.47 years; males were 43 and females 6. Three (6.1%) were normal and the remaining 46 (93.9%) were with low bone mass. Thirty-two (65.3%) were osteoporotic and 14 (28.57%) were osteopenic. The average duration of COPD was 4.5 ± 6.2 years. Majority (n = 36, 73.4%) of patients were in the Global Initiative for COPD (GOLD) class II and III. FEV₁ was significantly lower in the patients with low bone mass 1.66 ± 0.60 versus 3.61 ± 0.58 (P < 0.001).

Conclusions:

Our study shows that over 90% of Saudi Arabian patients with COPD suffer from osteopenia and osteoporosis and unfortunately they remain under-diagnosed and undertreated.

The value of laboratory tests in diagnosing secondary osteoporosis at a fracture and osteoporosis outpatient clinic

BACKGROUND

As more and more patients meeting the criteria for osteoporosis are referred to a fracture and osteoporosis outpatient clinic (FO clinic), the laboratory costs to screen for secondary osteoporosis also increases. This study was conducted to determine the value of screening on underlying diseases at an FO clinic by obtaining a standard set of laboratory tests.

METHODS

We included all 541 patients ≥50 years with a fracture referred to our FO clinic, during the period January 2005 to January 2007. The bone mineral density (BMD) was measured by dual energy x-ray absorptiometry and expressed as a T score. A standard set of laboratory tests was obtained to screen on underlying diseases.

RESULTS

Laboratory results were as often abnormal in patients with a normal BMD compared to patients with a low BMD. Underlying diseases were infrequently diagnosed. However, the prevalence of secondary osteoporosis in men was quite high, up to 18.2%. The costs to diagnose 1 patient with an underlying disease did vary between €92 and €972 depending on the group of patients described.

CONCLUSION

Screening all patients, referred to an FO clinic, for underlying diseases by obtaining a standard set of laboratory tests is probably not useful since laboratory tests are as often abnormal in patients with a normal BMD compared to patients with a low BMD. Moreover, the prevalence of secondary osteoporosis is low, while laboratory costs are substantial.

An unusual case of hypercortisolism with multiple weight-bearing bone fractures

Glucocorticoid excess, either from exogenous exposure or through endogenous overproduction, is a common cause of secondary osteoporosis. We report a 52-year-old woman presenting with multiple stress fractures of the lower extremities, despite various osteoporosis therapeutic regimens. Investigations led to the diagnosis of hypercortisolism of pituitary origin. Pituitary surgery was unsuccessful, justifying a treatment of ketoconazole. In the absence of densitometric osteoporosis, assessment of bone microstructure using high resolution peripheral quantitative computed tomography revealed alterations of both the cortical and trabecular compartments. This case illustrates that hypercortisolism may cause bone fragility in the absence of marked changes in areal bone mineral density.

Guidance for the diagnosis, prevention and therapy of osteoporosis in Italy

Osteoporosis poses a significant public health issue. In recent years, International and National Societies have developed Guidelines for the diagnosis and treatment of this disorder, with an effort of adapting specific tools for risk assessment on the peculiar characteristics of a given population. The Società Italiana dell'Osteoporosi, del Metabolismo Minerale e delle Malattie dello Scheletro (SIOMMMS) has recently revised the previously published Guidelines on the diagnosis, risk-assessment, prevention and management of idiopathic postmenopausal osteoporosis, also focusing on male and secondary osteoporosis. These recommendations are based on systematic reviews of the best available evidence and explicit consideration of cost effectiveness. When minimal evidence is available, recommendations are based on leading experts' experience and opinion, and on good clinical practice. Nonetheless, the practical management of osteoporosis is greatly influenced by economic reimbursement policies, particularly for secondary forms of osteoporosis. The refinement of risk assessment, the long-term treatment of osteoporosis and the prevention and management of disease-associated bone loss constitute open issues.

Japanese 2011 guidelines for prevention and treatment of osteoporosis--executive summary

INTRODUCTION

In 1998, the first Japanese practice guidelines on osteoporosis was published. It has been updated several times, with the most recent being the full-scale 2011 edition and its abridged edition. The present guidelines provide information for the managements of primary osteoporosis in postmenopausal women and men over 50 years old, a summary of the evidence for the treatment of secondary osteoporosis, and a summary of the evidence for the prevention of osteoporosis in younger people.

METHOD

The present Executive Summary is primarily based on the content of the 2011 Japanese abridged edition. One of the key changes is revision of the criteria for initiation of pharmacological treatment, along with an introduction of the fracture risk factors used in FRAX®. Key figures and tables were selected from the Japanese abridged edition and a reference list was added.

RESULT AND CONCLUSIONS

The essential points of the Japanese practice guidelines on osteoporosis were translated into English for the first time. It is hoped that the content of the guidelines becomes known throughout the world.

The efficacy of calcitriol therapy in the management of bone loss and fractures: a qualitative review

Osteoporosis, a skeletal disorder characterized by a reduction in bone strength, increases fracture risk. Primary osteoporosis is usually a result of reduced bone mineral density as a consequence of natural aging. Secondary osteoporosis is usually a result of a disease, such as cystic fibrosis, or medical treatment, such as corticosteroids or cancer treatment.

INTRODUCTION

Currently, ten million Americans are osteoporotic and an additional 34 million have the precursor condition, osteopenia. Osteoporosis leads to 1.5 million fractures and 500,000 hospitalizations annually. Osteoporosis-related fractures increase mortality and reduce quality of life. Calcitriol, the active form of vitamin D, regulates intestinal calcium absorption, among other actions. During the past four decades, many clinical trials investigating the effect of calcitriol on bone loss have been performed.

METHODS

We conducted a systematic qualitative review of clinical trials that assessed calcitriol for the treatment of osteoporosis and bone loss. In these clinical trials, calcitriol was used as a monotherapy and in combination with other therapeutic bone agents.

RESULTS AND CONCLUSION

Studies using calcitriol monotherapy, although not conclusive, found that calcitriol slowed the rate of bone loss in a variety of populations. Calcitriol in combination with other therapeutic bone agents was shown to have additional bone-preserving effects when compared to the use of therapeutic bone agents alone. A common side-effect of calcitriol therapy was hypercalcemia and hypercalciuria, but the degree of hypercalcemia was mild. Recent research found that intermittent dosing can reduce hypercalcemia rates. Calcitriol, alone or in combination with other agents, should be considered for the therapy of osteoporosis.