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

Proteomic Biomarkers Associated with Low Bone Mineral Density: A Systematic Review

Osteoporosis is a globally relevant public health issue. Our study aimed to summarize the knowledge on the proteomic biomarkers for low bone mineral density over the last years. We conducted a systematic review following the PRISMA guidelines; the scoured databases were PubMed, Web of Sciences, Scopus, and EBSCO, from inception to 2 June 2023. A total of 610 relevant studies were identified and 33 were assessed for eligibility. Finally, 29 studies met the criteria for this systematic review. The risk of bias was evaluated using the Joanna Briggs Institute Critical Appraisal Checklist tool. From the studies selected, 154 proteins were associated with changes of bone mineral density, from which only 10 were reported in at least two articles. The protein-protein network analysis indicated potential biomarkers involved in the skeletal system, immune system process, regulation of protein metabolic process, regulation of signaling, transport, cellular component assembly, cell differentiation, hemostasis, and extracellular matrix organization. Mass spectrometry-based proteomic profiling has allowed the discovery of new biomarkers with diagnostic potential. However, it is necessary to compare and validate the potential biomarkers in different populations to determine their association with bone metabolism and evaluate their translation to the clinical management of osteoporosis.

Bone metabolism and inflammatory biomarkers in radiographic and non-radiographic axial spondyloarthritis patients: a comprehensive evaluation

Introduction

Axial spondyloarthritis (axSpA) is a heterogeneous disease that can be represented by radiographic axSpA (r-axSpA) and non-radiographic axSpA (nr-axSpA). This study aimed to evaluate the relationship between the markers of inflammation and bone turnover in r-axSpA patients and nr-axSpA patients.

Methods

A cross-sectional study included 29 r-axSpA patients, 10 nr-axSpA patients, and 20 controls matched for age and sex. Plasma markers related to bone remodeling such as human procollagen type 1 N-terminal propeptide (P1NP), sclerostin, tartrate-resistant acid phosphatase 5b (TRACP5b), receptor activator of nuclear factor kappa B ligand (RANKL), and osteoprotegerin (OPG) were measured by an ELISA kit. A panel of 92 inflammatory molecules was analyzed by proximity extension assay.

Results

R-axSpA patients had decreased plasma levels of P1NP, a marker of bone formation, compared to controls. In addition, r-axSpA patients exhibited decreased plasma levels of sclerostin, an anti-anabolic bone hormone, which would not explain the co-existence of decreased plasma P1NP concentration; however, sclerostin levels could also be influenced by inflammatory processes. Plasma markers of osteoclast activity were similar in all groups. Regarding inflammation-related molecules, nr-axSpA patients showed increased levels of serum interleukin 13 (IL13) as compared with both r-axSpA patients and controls, which may participate in the prevention of inflammation. On the other hand, r-axSpA patients had higher levels of pro-inflammatory molecules compared to controls (i.e., IL6, Oncostatin M, and TNF receptor superfamily member 9). Correlation analysis showed that sclerostin was inversely associated with IL6 and Oncostatin M among others.

Conclusion

Altogether, different inflammatory profiles may play a role in the development of the skeletal features in axSpA patients particularly related to decreased bone formation. The relationship between sclerostin and inflammation and the protective actions of IL13 could be of relevance in the axSpA pathology, which is a topic for further investigation.

Team Approach: Bone Health Optimization in Orthopaedic Surgery

» Bone health optimization (BHO) has become an increasingly important consideration in orthopaedic surgery because deterioration of bone tissue and low bone density are associated with poor outcomes after orthopaedic surgeries.» Management of patients with compromised bone health requires numerous healthcare professionals including orthopaedic surgeons, primary care physicians, nutritionists, and metabolic bone specialists in endocrinology, rheumatology, or obstetrics and gynecology. Therefore, achieving optimal bone health before orthopaedic surgery necessitates a collaborative and synchronized effort among healthcare professionals.» Patients with poor bone health are often asymptomatic and may present to the orthopaedic surgeon for reasons other than poor bone health. Therefore, it is imperative to recognize risk factors such as old age, female sex, and low body mass index, which predispose to decreased bone density.» Workup of suspected poor bone health entails bone density evaluation. For patients without dual-energy x-ray absorptiometry (DXA) scan results within the past 2 years, perform DXA scan in all women aged 65 years and older, all men aged 70 years and older, and women younger than 65 years or men younger than 70 years with concurrent risk factors for poor bone health. All women and men presenting with a fracture secondary to low-energy trauma should receive DXA scan and bone health workup; for fractures secondary to high-energy trauma, perform DXA scan and further workup in women aged 65 years and older and men aged 70 years and older.» Failure to recognize and treat poor bone health can result in poor surgical outcomes including implant failure, periprosthetic infection, and nonunion after fracture fixation. However, collaborative healthcare teams can create personalized care plans involving nutritional supplements, antiresorptive or anabolic treatment, and weight-bearing exercise programs, resulting in BHO before surgery. Ultimately, this coordinated approach can enhance the success rate of surgical interventions, minimize complications, and improve patients' overall quality of life.

Osteoporosis: Investigations and Monitoring

Background

Osteoporosis is characterized by microarchitectural disruption of the bone, decrease in bone mineral density, and increased skeletal fragility and risk of fracture. Osteoporosis occurs due to the decoupling of bone formation and bone resorption, with a significant increase in resorption. This review article focuses on the role of laboratory investigations in the diagnosis and monitoring of treatment in patients with osteoporosis.

Methods

This review article collected literature from various databases using keywords such as 'Laboratory investigations', 'Osteoporosis', 'Diagnosis', 'Monitoring', and 'Bone turnover markers'.

Results and Discussion

Laboratory investigations, including serum calcium, alkaline phosphatase, vitamin D, and parathormone, are commonly performed tests to exclude secondary causes of osteoporosis and monitor the response to therapy. The biochemical markers of bone turnover are newly emerged tests for monitoring individual patients with osteoporosis. These markers are classified as bone formation and resorption markers, measurable in both serum and urine. The use of these markers is limited by biological and analytical variability. The International Federation of Clinical Chemistry and Laboratory Medicine and the International Osteoporosis Foundation recommend serum procollagen type 1 amino-terminal propeptide as the bone formation marker and β-form of C-terminal cross-linked telopeptide of type I collagen (β-CTx-1/β-CrossLaps) as the marker of choice, using standardized procedures. However, in specific cases, such as patients with chronic renal disease, CTx-1 is replaced by the resorption marker tartrate-resistant acid phosphatase 5b, as its levels are not affected by renal excretion.

Conclusion

Bone turnover markers have emerged as tools for the assessment of osteoporosis, using standardized procedures, and are useful in monitoring therapy and treatment compliance.

Artificial Intelligence Applications for Osteoporosis Classification Using Computed Tomography

Osteoporosis, marked by low bone mineral density (BMD) and a high fracture risk, is a major health issue. Recent progress in medical imaging, especially CT scans, offers new ways of diagnosing and assessing osteoporosis. This review examines the use of AI analysis of CT scans to stratify BMD and diagnose osteoporosis. By summarizing the relevant studies, we aimed to assess the effectiveness, constraints, and potential impact of AI-based osteoporosis classification (severity) via CT. A systematic search of electronic databases (PubMed, MEDLINE, Web of Science, ClinicalTrials.gov) was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A total of 39 articles were retrieved from the databases, and the key findings were compiled and summarized, including the regions analyzed, the type of CT imaging, and their efficacy in predicting BMD compared with conventional DXA studies. Important considerations and limitations are also discussed. The overall reported accuracy, sensitivity, and specificity of AI in classifying osteoporosis using CT images ranged from 61.8% to 99.4%, 41.0% to 100.0%, and 31.0% to 100.0% respectively, with areas under the curve (AUCs) ranging from 0.582 to 0.994. While additional research is necessary to validate the clinical efficacy and reproducibility of these AI tools before incorporating them into routine clinical practice, these studies demonstrate the promising potential of using CT to opportunistically predict and classify osteoporosis without the need for DEXA.

Caring for the Bone Health Among Liver Transplant Recipients

Liver transplant outcomes have improved over the years, and currently, the quality of life and long-term well-being of these patients needs to be improved. Improving bone health goes a long way toward achieving this objective. Poor bone health (osteopenia and osteoporosis) although prevalent, is often overlooked owing to its asymptomatic nature. It can be complicated by debilitating fracture affecting quality of life. It is recommended to assess and optimize bone health prior to liver transplant. Multiple factors contribute to poor bone health in a liver transplant recipient and it is vital to understand and ameliorate these. A careful and targeted approach with inputs from multidisciplinary team involving transplant physician, endocrinologist, occupational therapist, nutritionist, and nursing personnel may often be required. In this review, we aim to concisely discuss the various aspects related to prevalence, pathophysiology, evaluation, treatment, and follow-up of bone disease among liver transplant recipients.

Impact of Alcohol on Bone Health in People Living With HIV: Integrating Clinical Data From Serum Bone Markers With Morphometric Analysis in a Non-Human Primate Model

People living with HIV (PLWH) represent a vulnerable population to adverse musculoskeletal outcomes due to HIV infection, antiretroviral therapy (ART), and at-risk alcohol use. Developing measures to prevent skeletal degeneration in this group requires a grasp of the relationship between alcohol use and low bone mass in both the PLWH population and its constituents as defined by sex, age, and race. We examined the association of alcohol use with serum biochemical markers of bone health in a diverse cohort of PLWH enrolled in the New Orleans Alcohol Use in HIV (NOAH) study. To explore the effects of alcohol on bone in the context of HIV and ART and the role of estrogen, we conducted a parallel, translational study using simian immunodeficiency virus (SIV)+/ART+ female rhesus macaques divided into four groups: vehicle (Veh)/Sham; chronic binge alcohol (CBA)/Sham; Veh/ovariectomy (OVX); and CBA/OVX. Clinical data showed that both osteocalcin (Ocn) and procollagen type I N-propeptide (PINP) levels were inversely associated with multiple measures of alcohol consumption. Age (>50 years) significantly increased susceptibility to alcohol-associated suppression of bone formation in both female and male PLWH, with postmenopausal status appearing as an additional risk factor in females. Serum sclerostin (Scl) levels correlated positively with measures of alcohol use and negatively with Ocn. Micro-CT analysis of the macaque tibias revealed that although both CBA and OVX independently decreased trabecular number and bone mineral density, only OVX decreased trabecular bone volume fraction and impacted cortical geometry. The clinical data implicate circulating Scl in the pathogenesis of alcohol-induced osteopenia and suggest that bone morphology can be significantly altered in the absence of net change in osteoblast function as measured by serum markers. Inclusion of sophisticated tools to evaluate skeletal strength in clinical populations will be essential to understand the impact of alcohol-induced changes in bone microarchitecture. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Changes in Bone Turnover Markers after Osteoporotic Vertebral Compression Fractures in Males and Females

Background. To explore the normal changes in bone turnover markers (BTMs) and the correlations between the different BTMs after osteoporotic vertebral compression fracture (OVCF). Meanwhile, we explored the related differences that exist between sexes. Methods. A total of 130 OVCF patients were retrospectively reviewed. Using IBM SPSS 19.0 statistical software, the differences in the levels of BTMs and clinical parameters between sexes were assessed using Student’s unpaired $t$ test, and one-way ANOVA was used for the comparison of the three groups of samples. The correlations between P1NP, CTX, and clinical factors were assessed using Pearson’s correlation coefficient. Results. P1NP was 52.15 ng/ml within two weeks in male patients, and the level increased to 96.33 ng/ml after 12 weeks; in female patients, the increase was not as obvious as in male patients. CTX in male patients reached as much as approximately twice the initial value after 12 weeks. However, the situation in female patients was diverse. CTX was 0.58 ng/ml within two weeks and increased to 0.61 ng/ml within 2-12 weeks after the onset of OVCF. Subsequently, CTX decreased suddenly after 12 weeks. The increase in P1NP levels within 2 weeks after OVCF was significantly correlated with the levels of osteocalcin (OC) and bone-specific alkaline phosphatase (BAP). Changes in CTX within 2 weeks after OVCF were considerably related to phosphorus, 25 hydroxyvitamin D (25-OHD), OC, and BAP. Conclusion. The levels of P1NP and CTX increased differently in males and females after OVCF. The levels of OC and BAP were correlated with the levels of P1NP and CTX within 2 weeks of OVCF.

Pseudarthrosis of the Cervical Spine

Pseudarthrosis of the cervical spine represents a common and challenging problem for spine surgeons. Rates vary greatly from as low as 0%-20% to >60% and depend heavily on patient factors, approach, and number of levels. While some patients remain asymptomatic from pseudarthrosis, many require revision surgery due to instability, continued neck pain, or radiculopathy/myelopathy. We aimed to provide a practical, narrative review of cervical pseudarthrosis to address the following areas: (1) definitions, (2) incidence, (3) risk factors, (4) presentation and workup, (5) treatment decision-making, and (6) postoperative care. It is our hope the current review provides a concise summary for how to diagnose and treat challenging cervical nonunions.

Bone Phenotyping Approaches in Human, Mice and Zebrafish - Expert Overview of the EU Cost Action GEMSTONE ("GEnomics of MusculoSkeletal traits TranslatiOnal NEtwork")

A synoptic overview of scientific methods applied in bone and associated research fields across species has yet to be published. Experts from the EU Cost Action GEMSTONE ("GEnomics of MusculoSkeletal Traits translational Network") Working Group 2 present an overview of the routine techniques as well as clinical and research approaches employed to characterize bone phenotypes in humans and selected animal models (mice and zebrafish) of health and disease. The goal is consolidation of knowledge and a map for future research. This expert paper provides a comprehensive overview of state-of-the-art technologies to investigate bone properties in humans and animals - including their strengths and weaknesses. New research methodologies are outlined and future strategies are discussed to combine phenotypic with rapidly developing -omics data in order to advance musculoskeletal research and move towards "personalised medicine".

Exploring the Relationship of Bone Turnover Markers and Bone Mineral Density in Community-Dwelling Postmenopausal Women

Aims

To explore the relationships of procollagen type 1 N-terminal propeptide (P1NP) and β cross-linked C-telopeptide of type 1 collagen (β-CTX) with bone mineral density (BMD) in postmenopausal women.

Methods

All postmenopausal women were selected from a community-based case-control study. The anteroposterior L1-L4 and left proximal femur BMD were measured. P1NP and β-CTX were also collected and tested. The main correlation analysis was applied to explore the relationships of BMD, P1NP, and β-CTX.

Results

The total 1055 postmenopausal women were enrolled. The BMD at all sites kept a decrease continually with age (P < 0.01). In addition, the level of β-CTX increased significantly from 45 to 50 years old and remained at a high level in the later stage, while the level of P1NP changed little or even decreased with age. Logistic regression model showed that β-CTX has better ability to predict BMD than P1NP, as demonstrated by an area under the curve (AUC) of 0.63.

Conclusion

P1NP and β-CTX are important markers to monitor bone metabolism. This trial is registered with ChiCTR-SOC-17013090. The date of registration is Oct. 23, 2017.

Circulating miRNAs in bone health and disease

microRNAs have evolved as important regulators of multiple biological pathways essential for bone homeostasis, and microRNA research has furthered our understanding of the mechanisms underlying bone health and disease. This knowledge, together with the finding that active or passive release of microRNAs from cells into the extracellular space enables minimal-invasive detection in biofluids (circulating miRNAs), motivated researchers to explore microRNAs as biomarkers in several pathologic conditions, including bone diseases. Thus, exploratory studies in cohorts representing different types of bone diseases have been performed. In this review, we first summarize important molecular basics of microRNA function and release and provide recommendations for best (pre-)analytical practices and documentation standards for circulating microRNA research required for generating high quality data and ensuring reproducibility of results. Secondly, we review how the genesis of bone-derived circulating microRNAs via release from osteoblasts and osteoclasts could contribute to the communication between these cells. Lastly, we summarize evidence from clinical research studies that have investigated the clinical utility of microRNAs as biomarkers in musculoskeletal disorders. While previous reviews have mainly focused on diagnosis of primary osteoporosis, we have also included studies exploring the utility of circulating microRNAs in monitoring anti-osteoporotic treatment and for diagnosis of other types of bone diseases, such as diabetic osteopathy, bone degradation in inflammatory diseases, and monogenetic bone diseases.

Status of circulating bone turnover markers in elderly osteoporosis/osteopenia patients in comparison with healthy subjects

Background

In the aging individuals, osteoporosis is a major health problem. Due to the various limitations of dual X-ray absorptiometry (DEXA) for diagnosis osteoporosis, serum-based biochemical markers have been suggested for the discrimination between the patients and healthy subjects.

Objective

To investigate the serum levels of bone turnover markers in elderly osteoporosis patients.

Methods

The serum samples from elderly subjects (osteoporosis (n = 28), osteopenia (n = 28), and healthy ones (n = 28) were collected from Amirkola Health and Ageing Project study. Furthermore, serum levels of bone formation and bone resorption markers as well as estrogen and progesterone were measured by enzyme-linked immunosorbent assay. Kruskal–Wallis test and receiver operating characteristic curve analysis were used for statistical analysis using SPSS.

Results

Levels of bone alkaline phosphatase (B-ALP) and procollagen type I N-terminal propeptide (PINP) differed between groups (P = 0.003 and 0.009, respectively). Furthermore, PINP and B-ALP levels had the best area under the curve, sensitivity, and specificity for the discrimination between patients with osteoporosis and healthy individuals.

Conclusion

In conditions in which we are not able to assess the bone mineral density by DEXA, analysis of the B-ALP and PINP levels may be a helpful tool.

Variation of urinary and serum bone turnover marker reference values among pre and postmenopausal women in Asia: a systematic review

PURPOSE

Bone turnover markers (BTMs) are not widely used in clinical decision-making partly due to the wide variation of the reference values. This paper describes the geographical variation in BTMs reported from Asian countries.

METHOD

A systematic search was conducted using the PubMed, EMBASE, and Ovid. We searched for BTMs or individual BTMs in Asia or different countries in the Asian region. Original research which published BTM values were included while reviews, comments, and meta-analyses were excluded.

RESULTS

Of 650 articles, 23 fulfilled the selection criteria and were considered for this study. Among premenopausal women, mean intact OC ranged from 3.35 in Japan to 7.38 ng/mL (55%) in Thailand while it ranged between 3.35 and 5.8 ng/mL (42%) within Japan. Mean BALP varied from 15.9 in India to 41.2 U/L (61%) in Japan whereas in India, it ranged between 15.9 and 53.7 U/L (70%). Mean sP1NP ranged from 29.5 in Japan to 38.02 ng/mL in China (22%) whereas sCTX varied from 0.26 in Thailand to 0.099 ng/mL (62%) in Japan. Among postmenopausal women, mean total OC ranged from 10.02 in India to 29.8 ng/mL (66%) in Japan and intact OC ranged between 2.69 and 9.49 ng/mL (72%) within China. Mean BALP ranged from 20.9 in Japan to 60.28 U/L (65%) in China, and within China, it ranged from 28.2 to 60.28 U/L (53%). Mean sP1NP ranged from 40.11 in China to 56.4 ng/mL (29%) in Japan whereas it ranged within China from 40.11 to 53.76 ng/mL (25%). Mean sCTX varied from 0.25 to 0.433 ng/mL (42%) between the same countries respectively while within China, it varied from 0.25 to 0.395 ng/mL (37%). Urinary BTMs showed a lesser variation.

CONCLUSION

A wide inter-country and intra-country variation of serum BTMs was observed among pre and postmenopausal women in Asia. Differences in selection criteria of subjects and those inherited to analytical methods may have contributed to these differences.

Effects of post exercise protein supplementation on markers of bone turnover in adolescent swimmers

BACKGROUND

This study examined the effects of whey protein supplementation, compared with an isocaloric carbohydrate beverage and water, consumed immediately following an intense swimming trial on bone turnover in adolescent swimmers.

METHODS

Fifty-eight (31 female, 27 male) swimmers (14.1 ± 0.4 years) were stratified into three groups matched for age, sex and body mass. The protein and carbohydrate groups consumed two isocaloric post-exercise beverages each containing 0.3 g.kg- 1 of whey protein (with ~ 6 mg of calcium) or maltodextrin while the control group consumed water. Participants provided a morning, fasted, resting blood sample, then performed an intense swimming trial consisting of a maximal 200 m swim followed by a high intensity interval swimming protocol (5x100m, 5x50m and 5x25m; 1:1 work-to-rest ratio). Following swimming, they consumed their first respective post-exercise beverage, and 2 h later, they performed a second maximal swim immediately followed by the second beverage. Approximately 3 h after the second beverage, two post-consumption blood samples were collected at 8 h and 24 h from baseline. Procollagen type 1 intact N-terminal propeptide (PINP) and carboxy-terminal collagen crosslinks (CTXI) were measured in serum. The multiples of medians of PINP and CTXI were also used to calculate bone turnover rate and balance.

RESULTS

No significant changes were observed in PINP. CTXI increased (+ 11%) at 8 h in all groups, but then significantly decreased (- 22%) at 24 h in the protein group only. The protein group also had a significantly higher calculated rate of bone turnover at 8 h and 24 h compared to baseline, which was not observed in the other groups.

CONCLUSIONS

These results shed light on the potential importance of protein consumed shortly after intense swimming in promoting positive bone turnover responses up to 24 h following exercise in adolescent athletes.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov PRS; NCT04114045. Registered 1 October 2019 - Retrospectively registered.

Effect of Collagen Peptide, Alone and in Combination with Calcium Citrate, on Bone Loss in Tail-Suspended Rats

Oral administration of bovine collagen peptide (CP) combined with calcium citrate (CC) has been found to inhibit bone loss in ovariectomized rats. However, the protective effects of CP and CP–CC against bone loss have not been investigated in a tail-suspension simulated microgravity (SMG) rat model. Adult Sprague-Dawley rats (n = 40) were randomly divided into five groups (n = 8): a control group with normal gravity, a SMG control group, and three SMG groups that underwent once-daily gastric gavage with CP (750 mg/kg body weight), CC (75 mg/kg body weight) or CP–CC (750 and 75 mg/kg body weight, respectively) for 28 days. After sacrifice, the femurs were analyzed by dual-energy X-ray absorptiometry, three-point bending mechanical tests, microcomputed tomography, and serum bone metabolic markers. Neither CP nor CP–CC treatment significantly inhibited bone loss in SMG rats, as assessed by dual-energy X-ray absorptiometry and three-point bending mechanical tests. However, both CP and CP–CC treatment were associated with partial prevention of the hind limb unloading-induced deterioration of bone microarchitecture, as demonstrated by improvements in trabecular number and trabecular separation. CP–CC treatment increased serum osteocalcin levels. Dietary supplementation with CP or CP–CC may represent an adjunct strategy to reduce the risk of fracture in astronauts.

Osteoporosis in South-East Asian Countries

Osteoporosis (OP) is a condition where there is low bone density and microarchitectural deterioration which can predispose to fragility fractures. There is a wealth of literature on OP from the developed countries, but less so from Asia. This review will explore the field of OP research in South-East Asia with regard to the epidemiology, the diagnosis of OP and the role of laboratory tests in the management of OP, with emphasis on 25-dihydroxyvitamin D and bone turnover markers.

Bone metabolic biomarkers and bone mineral density in male patients with early-stage Alzheimer's disease

PURPOSE

Alzheimer's disease (AD), osteoporosis, and osteopenia are the most common diseases in older individuals and share some similar pathophysiological processes of degeneration. The aim of this study is to investigate the association between bone metabolic biomarkers, bone mineral density (BMD), and early-stage AD in men.

METHODS

Forty-two male early-stage AD patients and 40 age-matched healthy older volunteers were enrolled. Serum calcium, osteocalcin, 1,25(OH)₂D₃, urine deoxypyridinoline/creatinine (DPD/Cr) ratio, urine calcium/creatinine (Ca/Cr) ratio, and BMD were measured. The correlation between early-stage AD and bone quality was evaluated.

RESULTS

The urine DPD/Cr, urine Ca/Cr, and serum osteocalcin levels in the early-stage AD patients were significantly higher than those in the healthy control (HC) group (P < 0.05). The BMD data showed that the cortical and total BMD at 38% of the tibial length in the early-stage AD patients were lower than those in the HC group (P < 0.05). Furthermore, there was a negative correlation between the Montreal Cognitive Assessment score and serum osteocalcin or urine DPD/Cr levels. Abnormal urine DPD/Cr, urine Ca/Cr, and cortical BMD levels were independent risk factors in male patients with early-stage AD.

CONCLUSION

Bone metabolic biomarkers and BMD are closely associated with early-stage AD in male patients. Our data indicated that the measurement of bone metabolic biomarkers and BMD may provide an alternative approach for screening AD patients at the early stage.

Effects of alendronate and calcifediol compared to alendronate and cholecalciferol in osteoporotic patients

BACKGROUND

Several formulations of vitamin D and alendronate are available for the treatment of osteoporosis. The objective of this study was to examine efficacy and safety of calcifediol (25(OH)D) compared to cholecalciferol (vitamin D3) and also the relationship between different formulations of alendronate and adverse reactions.

METHODS

We observed a population of women diagnosed with postmenopausal osteoporosis or osteopenia treated with alendronate 70 mg weekly associated to vitamin D3 or 25(OH)D at monthly total dose of 625 µg. Data collected both at baseline (T0) and at follow-up after at least 12 months of therapy (T1) were: demographic characteristics, BMI, full medical history, lumbar T-score, femur T-score, calcium, osteocalcin, alkaline phosphatase, PTH and vitamin D blood level.

RESULTS

A total of 362 patients were enrolled in the study. Alendronate 70 mg + calcifediol (A+25(OH)D) group consisted of 202 patients while 160 patients were treated with alendronate 70 mg + cholecalciferol (A+D3). In the A+25(OH)D group, we observed a significant increase in lumbar T-score value (0.26±0.35 vs. 0.13±0.3) and serum vitamin D (20.64±20.71 vs. 6.07±7.61 ng/mL) levels compared to the A+D3 group (P<0.05). The lowest incidence of gastrointestinal adverse reactions was observed among patients taking alendronate 70 mg in drinkable solution form (P<0.05).

CONCLUSIONS

Alendronate 70 mg with calcifediol gives a better outcome in the treatment of osteoporosis according to lumbar T-score and vitamin D serum level observed at one-year follow-up compared to alendronate 70 mg with cholecalciferol. Both vitamin D formulations did not show to cause hypercalcemia in this study. Alendronate 70 mg in drinkable solution form is also associated with lowest incidence of gastrointestinal adverse reactions.

Western Osteoporosis Alliance Clinical Practice Series: Treat-to-Target for Osteoporosis

Patients often start treatment to reduce fracture risk because of a bone mineral density T-score consistent with osteoporosis (≤ -2.5). Others with a T-score above -2.5 may be treated when there is a history of fragility fracture or when a fracture risk algorithm categorizes them as having a high risk for fracture. It is common to initiate therapy with a generic oral bisphosphonate, unless contraindicated, and continue therapy if the patient is responding as assessed by stability or an increase in bone mineral density. However, some patients may respond well to an oral bisphosphonate, yet remain with an unacceptably high risk for fracture. Recognition of this occurrence has led to the development of an alternative strategy: treat-to-target. This involves identifying a biological marker (treatment target) that represents an acceptable fracture risk and then initiating treatment with an agent likely to reach this target. If the patient is on a path to reaching the target with initial therapy, treatment is continued. If it appears the target will not be reached with initial therapy, treatment is changed to an agent more likely to achieve the goal.

Associations Between Serum Bone Biomarkers in Early Breast Cancer and Development of Bone Metastasis: Results From the AZURE (BIG01/04) Trial

Background

Adjuvant therapies can prevent/delay bone metastasis development in breast cancer. We investigated whether serum bone turnover markers in early disease have clinical utility in identifying patients with a high risk of developing bone metastasis.

Methods

Markers of bone formation (N-terminal propeptide of type-1 collagen [P1NP]) and bone resorption (C-telopeptide of type-1 collagen [CTX], pyridinoline cross-linked carboxy-terminal telopeptide of type-1 collagen [1-CTP]) were measured in baseline (pretreatment blood samples from 872 patients from a large randomized trial of adjuvant zoledronic acid (AZURE-ISRCTN79831382) in early breast cancer. Cox proportional hazards regression and cumulative incidence functions (adjusted for factors having a statistically significant effect on outcome) were used to investigate prognostic and predictive associations between recurrence events, bone marker levels, and clinical variables. All statistical tests were two-sided.

Results

When considered as continuous variables (log transformed), P1NP, CTX, and 1-CTP were each prognostic for future bone recurrence at any time (P = .006, P = .009, P = .008, respectively). Harrell’s c-indices were a P1NP of 0.57 (95% confidence interval [CI] = 0.51 to 0.63), CTX of 0.57 (95% CI = 0.51 to 0.62), and 1-CTP of 0.57 (95% CI = 0.52 to 0.63). In categorical analyses based on the normal range, high baseline P1NP (>70 ng/mL) and CTX (>0.299 ng/mL), but not 1-CTP (>4.2 ng/mL), were also prognostic for future bone recurrence (P = .03, P = .03, P = .10, respectively). None of the markers were prognostic for overall distant recurrence; that is, they were bone metastasis specific, and none of the markers were predictive of treatment benefit from zoledronic acid.

Conclusions

Serum P1NP, CTX, and 1-CTP are clinically useful, easily measured markers that show good prognostic ability (though low-to-moderate discrimination) for bone-specific recurrence and are worthy of further study.

Relationships of social support, health-promoting lifestyles, glycemic control, and bone turnover among adults with type 2 diabetes

AIM

There is increasing evidence that hyperglycemia, oxidative stress, and the accumulation of advanced glycation end products in type 2 diabetes mellitus (T2DM) can lead to the deterioration of bone remodeling. The purpose of this study was to explore relationships of social support, health-promoting lifestyles, glycated hemoglobin (HbA1c) levels, and serum bone turnover markers (BTMs, including procollagen type I amino-terminal propeptide [PINP] and β-isomerised carboxy-terminal cross-linking telopeptide of type I collagen [β-CTX]) among individuals with T2DM.

METHODS

A total of 175 subjects were recruited by convenience sampling and divided into three groups based on their HbA1c levels. Statistical strategies of Spearman's correlation coefficient and multiple linear regression were used in this cross-sectional study.

RESULTS

There was a positive association between PINP and β-CTX, whereas the HbA1c level was inversely correlated with BTMs. Moreover, scores of both PINP and β-CTX were different in genders, males having lower levels of BTMs than females after adjustment for weight. Furthermore, both social support and health-promoting lifestyles were negatively correlated with HbA1c levels, whereas they did not significantly relate to declines in PINP and β-CTX.

CONCLUSION

High HbA1c levels detrimentally influence bone formation and bone resorption, and males with T2DM might be more susceptible to osteoporosis because of their relatively lower levels of BTMs. However, social support and health-promoting lifestyles could contribute to better glycemic control.

Tight control: a new therapeutic strategy in the management of osteoporotic patients

BMD changes in patients under tight control (monitored at 3-month intervals with adjustment of therapy guided by bone turnover markers) and routine management (controlled once a year) were compared. After 1 year, the femoral neck BMD increased significantly in the tight control compared to the routine management group.

INTRODUCTION

We intended to ascertain whether tight control (i.e., follow-up visits and bone turnover markers/BTM/and parathyroid hormone/PTH/monitoring at 3-month intervals) strategy achieves a statistically greater increase in bone mineral density over the observation period than standard follow-up care (i.e., bone densitometry at 1-year intervals, without BTM monitoring).

METHODS

We studied involutional osteoporotic patients newly enrolled into chronic care. One hundred and eleven patients underwent tight control, while another 113 received routine treatment (with follow-up visits scheduled at > 1-year intervals). We compared the changes in bone mineral density reflected by the results of bone mineral density (BMD) measurements of the lumbar spine and of the left femoral neck. Statistical analyses were performed with version 22 of the SPSS software package.

RESULTS

In the group of patients under tight control, baseline and follow-up median BMD values were 0.842/0.881 g/cm² at the L_1-4 vertebrae and 0.745/0.749 g/cm² at the femoral neck. In the group under routine care, the corresponding values were 0.903/0.915 g/cm² and 0.742/0.72 g/cm², respectively. The relative changes of the bone mineral density of the femoral neck was significantly (p = 0.041) higher in patients under tight control than in those receiving routine care; however, BMD changes in the lumbar spine were not statistically different.

CONCLUSION

Our findings suggest that adopting tight control as a new therapeutic strategy might be justified in the osteoporosis management. In fact, a greater improvement of BMD can be achieved by treatment according to these principles.

Combining information from multiple bone turnover markers as diagnostic indices for osteoporosis using support vector machines

CONTEXT

Osteoporosis (OP) is a progressive systemic bone disease. Dual-energy X-ray absorptiometry (DXA) is routinely employed and is considered the gold standard method for the diagnosis of OP.

OBJECTIVE

We aimed to investigate the potential use of combined information from multiple bone turnover markers (BTMs) as a clinical diagnostic tool for OP.

MATERIALS AND METHODS

A total of 9053 Chinese postmenopausal women (2464 primary OP patients and 6589 healthy controls) were recruited. Serum levels of six common BTMs, including BAP, BSP, CTX, OPG, OST and sRANKL were assayed. Models based on support vector machine (SVM) were constructed to explore the efficiency of different combinations of multiple BTMs for OP diagnosis.

RESULTS

Increasing the number of BTMs used in generating the models increased the predictive power of the SVM models for determining the disease status of study subjects. The highest kappa coefficient for the model with one BTM (BAP) compared to DXA was 0.7783. The full model incorporating all six BTMs resulted in a high kappa coefficient of 0.9786.

CONCLUSION

Our findings showed that although single BTMs were not sufficient for OP diagnosis, appropriate combinations of multiple BTMs incorporated into the SVM models showed almost perfect agreement with the DXA.

Clinical utility of bone markers in various diseases

Measurements of bone markers (BMs) in peripheral blood or urine are a pivotal part of bone research within modern clinical medicine. In recent years the use of BMs increased substantially as they can be useful either to diagnose bone (related) disease and to follow its natural history, but also to monitor the effects of interventions. However, the use of BMs is still complicated mainly due to (pre)analytical variability of these substances, limited accessibility of assays, variable cut-off values in different countries and laboratories and heterogeneous results with regard to clinical implications of measuring BMs in several studies. This review will provide the clinician with a practical guide, based on current evidence, in which circumstances to test which bone markers for optimal diagnostic purposes, in order to improve patient care in different areas of bone diseases including Paget's disease, primary osteoporosis, tumor induced osteomalacia, hypophosphatemic rickets, van Buchem disease, chronic kidney disease, rheumatoid arthritis, neoplasma/multiple myeloma, type 2 diabetes mellitus and primary hyperparathyroidism. The clinician should consider fasting state, recent fractures, aging, menopausal status, concomitant liver and kidney disease when ordering and interpreting BM measurements as these factors might result in misleading BM concentrations. We found that BMs are clearly useful in the current diagnosis of tumor induced osteomalacia, van Buchem disease, Paget's disease and hypophosphatemic rickets. In addition, BMs are useful to monitor disease activity in chronic kidney disease, Paget's disease and are useful to monitor treatment adherence in osteoporosis.

Osteoporosis: Current Concepts

Osteoporosis is a worldwide disease characterized by reduction of bone mass and alteration of bone architecture resulting in increased bone fragility and increased fracture risk. Causes of osteoporosis include increasing age, female sex, postmenopausal status, hypogonadism or premature ovarian failure, low body mass index, ethnic background, rheumatoid arthritis, low bone mineral density (BMD), vitamin D deficiency, low calcium intake, hyperkyphosis, current smoking, alcohol abuse, immobilization, and long-term use of certain medications. The diagnosis of osteoporosis is established by measurement of BMD of the hip and spine using dual energy X-ray absorptiometry. According to the World Health Organization criteria, osteoporosis is defined as a BMD that lies 2.5 standard deviation or more below the average value for young healthy women. Bone turnover biomarker detection may be useful in monitoring osteoporosis treatment and assessing fracture risk but not for diagnosis of osteoporosis. Management of osteoporosis consists of nonpharmacological interventions, which are recommended for all subjects, and pharmacological therapy in all postmenopausal women who have had an osteoporotic fracture or have BMD values consistent with osteoporosis.

A role for bone turnover markers β-CrossLaps (CTX) and amino-terminal propeptide of type I collagen (PINP) as potential indicators for disease progression from MGUS to multiple myeloma

Multiple myeloma (MM) is characterized by bone lesions arising due to unbalanced bone remodeling. Changes in the bone formation marker amino-terminal propeptide of type I collagen (PINP) and the bone resorption marker β-CrossLaps (CTX) reflect physiologic bone turnover. Whether PINP and CTX have a role in disease progression from monoclonal gammopathy of undetermined significance (MGUS) to MM is unknown. In this cross-sectional follow-up study, 241 patients with MM or MGUS were included. Serum levels of PINP and CTX were significantly higher in MM patients compared to MGUS. Moreover, increasing concentrations of PINP and CTX were observed in those MGUS patients progressing to MM, whereas PINP and CTX levels remained unchanged in MGUS patients with stable disease. In conclusion, these data indicate a potential role of PINP and CTX as biomarkers for the progression of MGUS to MM.

Osteoporosis in patients with erythropoietic protoporphyria

BACKGROUND

Erythropoietic protoporphyria (EPP) is a rare metabolic disease with painful photosensitivity due to protoporphyrin IX accumulation.

OBJECTIVES

To evaluate bone mineral density (BMD) and known osteoporosis risk factors in patients with EPP.

METHODS

Patients with EPP attending the Erasmus MC outpatient clinic who had undergone BMD measurements were included. Plasma 25 hydroxy (OH) vitamin D, alkaline phosphatase, parathyroid hormone and total protoporphyrin IX levels were measured; information on lifestyle, sunlight exposure and a bone-relevant physical exercise index [Bone Physical Activity Questionnaire (BPAQ) score] was obtained via questionnaires. BMD scores and the prevalence of osteopenia and osteoporosis in the EPP population were compared with a reference population.

RESULTS

Forty-four patients with EPP (23 female, 21 male; mean age 37·6 years) were included. The mean SDs of the T-scores were -1·12 for the lumbar spine and -0·82 for the femoral neck (both P < 0·001). Osteopenia was present in 36%; osteoporosis in 23%. Based on the reference population the expected prevalence was 15% and 1%, respectively. Prevalence of vitamin D deficiency was 50% (defined as a 25-OH vitamin D level < 50 nmol L^-1 ). Mean self-reported BPAQ score was 19·4 units (reference interval 19-24). Multiple linear regression analysis showed a significant influence of vitamin D deficiency and bone-relevant physical exercise score on BMD in patients with EPP.

CONCLUSIONS

The prevalence of osteoporosis and osteopenia is greatly increased in patients with EPP. Alkaline phosphatase (related to vitamin D deficiency) and amount of weight-bearing exercise are significantly correlated with low BMD in this population.

Osteoporosis, obesity, and sarcopenia on abdominal CT: a review of epidemiology, diagnostic criteria, and management strategies for the reporting radiologist

Abdominal computed tomography (CT) is a widely performed examination, with many indications. Assessment of bone, fat, and muscle on abdominal CT can be performed in a quantitative manner. Published studies have developed diagnostic cutoffs for osteoporosis, obesity, and sarcopenia, which are summarized with pictorial examples. The epidemiological and prognostic significance of these disease states are outlined. Further diagnostic steps and treatment strategies are outlined to inform both the managing clinician and reporting radiologist. This article summarizes an unglamorous yet information-rich field, which is ripe for assessment in the dawning era of personalized medicine, and one in which the radiologist is well placed to add value to patient care.

Bone mineral density in people living with HIV: a narrative review of the literature

Bone health status is largely absent in South Africa, the main reasons being the absence and cost-effectiveness of specific screening equipment for assessing bone mineral density (BMD). Various risk factors seem to play a role, some of which can be modified to change bone health status. Urbanisation is also a public health concern. Changing nutritional, as well as social behaviour, play integral roles in the prevalence and incidence of decreased BMD. Furthermore, human immunodeficiency virus (HIV) specifically, has a negative impact on BMD and although highly active antiretroviral therapy increases the prognosis for HIV-infected individuals, BMD still seem to decrease further. Dual energy X-ray absorptiometry is considered the gold standard for BMD assessment; however, recent developments have provided more cost-effective screening methods, among which heel quantitative ultrasound appears to be the most widely used in resource limited countries such as South Africa.

Menopause transition promotes distinct modulation of mRNAs and miRNAs expression in calvaria and bone marrow osteoblastic cells

Investigation on functional genome research may contribute to the knowledge of functional roles of different mRNAs and miRNAs in bone cells of osteoporotic animals. Currently, few studies indicate the changes in gene modulation that osteoporosis causes in osteoblastic cells from different sites. Thus, the purpose of this investigation was to evaluate cell viability, alkaline phosphatase activity and modulation of mRNAs/miRNAs in osteoblastic cells from calvaria and bone marrow by means of microarray technology. Wistar female rats were divided in sham operated and ovariectomized groups. After 150 days of ovariectomy, cells were isolated from both sites to perform cell culture. Results showed that calvaria cells from ovariectomized rats had a decrease in viability when compared to control groups and to bone marrow cells from osteoporotic rats after 3 days. Alkaline phosphatase activity decreased in calvaria cells from ovariectomized rats whereas it was increased in bone marrow osteoblastic cells in the same group. Microarray data analysis showed 5447 differentially expressed mRNAs and 82 differentially expressed miRNAs in calvaria cells. The same way, 4399 mRNAs and 54 miRNAs were expressed in bone marrow cells. mRNAs associated with bone metabolism such as Anxa5, Sp7, Spp1, Notch1 were distinctively modulated in both sites, as well as miRNAs such as miR-350, miR-542-3p, miR-204-5p, and miR-30e-3p. The RNA species identified in this study could be further used as targets for treatment or prevention of osteoporosis.

Role of vitamin D in energy and bone metabolism in postmenopausal women with type 2 diabetes mellitus: A 6-month follow-up evaluation

AIMS/INTRODUCTION

Resting energy expenditure was associated with a serum bone turnover marker in postmenopausal women with type 2 diabetes (T2DMPW) in the present cross-sectional study. To clarify the fundamental pathological factor for the correlation of bone metabolism and basal metabolism in type 2 diabetes, a 6-month prospective follow-up study was carried out with supplementation of vitamin D.

MATERIALS AND METHODS

A total of 44 T2DMPW were enrolled. The following factors were evaluated at the beginning and the end of the summer: procollagen type 1 N-terminal propeptide, carboxy-terminal collagen crosslinks-1, intact parathyroid hormone and 25-hydroxyvitamin D (25[OH]D), as well as diabetic complications, body composition, respiratory quotient and resting energy expenditure. A total of 23 patients with low 25(OH)D levels (˂20 ng/mL) were instructed to increase vitamin D levels by lifestyle change. Among them, 15 patients with osteoporosis were also administered alfacalcidol.

RESULTS

Serum 25(OH)D increased in 25 patients and decreased in 19 patients. Patients who did not receive the study intervention at the start tended to have a decreased 2525(OH)D level; therefore, the average 25(OH)D level of all patients was not changed. Changes in resting energy expenditure were positively correlated with those of procollagen type 1 N-terminal propeptide/carboxy-terminal collagen crosslinks-1. Changes in the respiratory quotient correlated with the mean glycated hemoglobin levels; procollagen type 1 N-terminal propeptide levels positively correlated with serum 25(OH)D after the intervention. These correlations were prominent in patients with increased 25(OH)D and those with alfacalcidol supplementation.

CONCLUSIONS

Restoration of vitamin D level might be a prerequisite for a normal correlation between bone and basal metabolism in T2DMPW. Lifestyle intervention for retention of vitamin D level is important even in summer, in T2DMPW.

Significance of the ionized calcium measurement to assess calcium status in osteopenic/osteoporosis postmenopausal outpatients

INTRODUCTION

Evaluation of calcium status is important in the osteoporotic risk assessment. Although guidelines indicate total calcium (tCa) as first-line measurement, directly measured ionized calcium (m-iCa), considered as the gold standard, is more and more often required. Aim of this study is to evaluate the agreement between m-iCa, tCa and iCa calculated from a formula based on total calcium and albumin (c-iCa) in osteopenic/osteoporotic postmenopausal outpatients.

METHODS

A total of 140 postmenopausal outpatients, 41 osteopenic (OPN) and 99 osteoporotic (OP) were enrolled. Levels of tCa, m-iCa, c-iCa, total protein and albumin, vitamin D (25-OHD), parathyroid hormone 1-84 (PTH), bone alkaline phosphatase, osteocalcin and serum collagen type 1 cross-linked C-telopeptide (CTX) were also measured.

RESULTS

There were no statistically significant differences between OPN and OP groups regarding values of tCa, m-iCa, and c-iCa, 25-OHD and PTH. However, OP women had lower levels of CTX (p < 0.05). A significant direct correlation between m-iCa and tCa (r = 0.60, p < 0.001) and c-iCa (r = 0.61, p < 0.001) was found. Women with isolated hyper-m-iCa had similar DEXA parameter levels respect to the other patients. However, one patient with confirmed primary hyperparathyroidism presented hyper-m-iCa versus normal tCa and c-iCa values.

CONCLUSIONS

The use of tCa could be sufficient to characterize the calcium status in postmenopausal outpatients, but reflexive calcium testing strategy for m-iCa test is necessary to women presenting the low or high extremes of tCa levels, or in women with suspected PHPT.

Osteoporosis: a discussion on the past 5 years

PURPOSE OF THE REVIEW

The purposes of this study are to examine the literature within the past 5 years regarding osteoporosis and offer a discussion on new topics and controversies.

RECENT FINDINGS

Patient compliance with therapy remains an issue. The effectiveness of Vitamin D and calcium are being called into question Atypical femur fractures have been associated with bisphosphonate and denosumab use. Treatment is both surgical and pharmaceutical. A multidisciplinary approach to osteoporotic fractures is important and having some form of fracture liaison service (FLS) improves the efficacy of osteoporotic care and decreases secondary fractures. Screening for osteoporosis remains low. Ultrasound may be cost-effective for diagnosis. Understanding of osteoporosis has come a long way in the medical community, but the translation to the lay community has lagged behind. Patients often take a laissez-faire attitude toward osteoporosis that can affect compliance. Information read by patients often focuses on complications, such as atypical femur fractures and myocardial infarctions. It is essential for providers to be able to discuss these issues with patients. Newer medications and more cost-effective diagnostic tests exist, but availability may be limited. FLS are effective, but the most cost-effective model for therapy still eludes us. Areas for further investigation include FLS models, the effectiveness of vitamin supplementation, and more ubiquitous and cost-effective diagnostic tools.

Osteoporosis: Treat-to-Target

PURPOSE OF REVIEW

Treat-to-target (goal-directed therapy) has been proposed as a strategy to assist clinicians in selecting the most appropriate initial treatment for osteoporosis and guiding subsequent decisions to continue, change, or stop treatment. This is a review of the current medical evidence regarding treatment targets and potential clinical applications in managing patients with osteoporosis.

RECENT FINDINGS

Analyses of randomized placebo-controlled trials of approved agents to treat osteoporosis have generally shown that larger increases in bone mineral density are associated with greater reduction in fracture risk. Achievement of T-scores > -2.5 to -2.0 with treatment appears to provide little additional fracture protection. The paradigm of treat-to-target is aimed at enhancing and individualizing the care of patients with osteoporosis. Based on the best available data, the most promising target is T-score > -2.5. More data are needed to validate the clinical utility of treat-to-target for osteoporosis.

Effects of obesity treatments on bone mineral density, bone turnover and fracture risk in adults with overweight or obesity

BACKGROUND

New evidence suggests that obesity is deleterious for bone health, and obesity treatments could potentially exacerbate this.

MATERIALS AND METHODS

This narrative review, largely based on recent systematic reviews and meta-analyses, synthesizes the effects on bone of bariatric surgery, weight loss pharmaceuticals and dietary restriction.

RESULTS AND CONCLUSIONS

All three obesity treatments result in statistically significant reductions in hip bone mineral density (BMD) and increases in bone turnover relative to pre-treatment values, with the reductions in hip BMD being strongest for bariatric surgery, notably Roux-en Y gastric bypass (RYGB, 8%-11% of pre-surgical values) and weakest for dietary restriction (1%-1.5% of pre-treatment values). Weight loss pharmaceuticals (orlistat or the glucagon-like peptide-1 receptor agonist, liraglutide) induced no greater changes from pre-treatment values than control, despite greater weight loss. There is suggestive evidence that liraglutide may increase bone mineral content (BMC) - but not BMD - and reduce fracture risk, but more research is required to clarify this. All three obesity treatments have variable effects on spine BMD, probably due to greater measurement error at this site in obesity, suggesting that future research in this field could focus on hip rather than spine BMD. Various mechanisms have been proposed for BMD loss with obesity treatments, notably reduced nutritional intake/absorption and insufficient exercise, and these are potential avenues for protection against bone loss. However, a pressing outstanding question is whether this BMD reduction contributes to increased fracture risk, as has been observed after RYGB, and whether any such increase in fracture risk outweighs the risks of staying obese (unlikely).

Circulating microRNAs Correlated with Bone Loss Induced by 45 Days of Bed Rest

The purpose of this study was to find the circulating microRNAs (miRNAs) co-related with bone loss induced by bed rest, and testify whether the selected miRNAs could reflect the bone mineral status of human after bed-rest. We analyzed plasma miRNA levels of 16 subjects after 45 days of −6° head-down tilt bed rest, which is a reliable model for the simulation of microgravity. We characterize the circulating miRNA profile in individuals after bed rest and identify circulating miRNAs which can best reflect the level of bone loss induced by bed rest. Expression profiling of circulating miRNA revealed significant downregulation of 37 miRNAs and upregulation of 2 miRNAs, while only 11 of the downregulated miRNAs were further validated in a larger volunteer cohort using qPCR. We found that 10 of these 11 miRNAs (miR-103, 130a, 1234, 1290, 151-5p, 151-3p, 199a-3p, 20a, 363, and 451a) had ROC curve that distinguished the status after bed rest. Importantly, significant positive correlations were identified between bone loss parameters and several miRNAs, eventually miR-1234 showed clinical significance in detecting the bone loss of individuals after 45 days of bed rest.

The use of biomarkers in clinical osteoporosis

Osteoporosis is a disease of ascending character in the world population; in this context, bone biomarkers are being increasingly studied in order to aid in the diagnosis and monitoring of these patients. The main objective of this study was a literature review of articles whose main theme was the use of biomarkers for bone formation and degradation, and to evaluate their possible applicability in clinical practice. Literature review was performed through articles indexed and published in the last five years in the PubMed database. The findings of this study showed that most of the previously selected articles were published in the last two years, and the most cited markers were bone resorption, C-terminal collagen telopeptide (CTX), showing the highest correlation with the dynamics of bone, and the biomarker of bone formation, bone-specific alkaline phosphatase (BAP), which is increased in the event of fracture or may suggest another bone disease. There was an increase in published articles, associating different bone biomarkers and their clinical applicability, especially for treatment control. Our findings suggest that in recent years there has been significant increase in publications evaluating the use of bone turnover biomarkers for bone formation and resorption and their possible clinical applicability, especially in the monitoring of treatment. Still, we believe that further studies need to be conducted to confirm these findings, given the advantages that bone biomarkers can deliver in the clinical management of the disease.

Serum 25-hydroxyvitamin D and bone turnover markers in Palestinian postmenopausal osteoporosis and normal women

This study evaluated the association of vitamin D and bone markers with the development osteoporosis in Palestinian postmenopausal women. Even though vitamin D deficiency was very high for the recruited subjects, it was not associated with osteoporosis except for bones of the hip. Age and obesity were the strongest determining factors of the disease.

PURPOSE

The purpose of this study was to investigate the association of bone mineral density (BMD) with serum vitamin D levels, parathyroid hormone (PTH), calcium, obesity, and bone turnover markers in Palestinian postmenopausal women.

METHODS

Three hundred eighty-two postmenopausal women (≥45 years) were recruited from various women clinics for BMD assessment (131 women had osteoporosis and 251 were normal and served as controls). Blood samples were obtained for serum calcium, PTH, 25(OH)D, bone formation (N-terminal propeptide (PINP)), and bone resorption (serum C-terminal telopeptide of type I collagen (CTX1)) markers.

RESULTS

Women with osteoporosis had statistically significant lower mean weight, height, body mass index (BMI), and serum calcium (p < 0.05) compared to controls. No significant differences were detected between the mean values of bone turnover markers (CTX and PINP), 25(OH)D, and PTH of the two groups. Women with vitamin D deficiency (severe and insufficiency) represented 85.9% of the study subjects. Multiple and logistic regression showed that age and BMI significantly affected BMD and vitamin D had a significant association with BMD only at the lumbar spine. BMI was positively correlated with BMD and PTH but negatively correlated with vitamin D. Logistic regression showed that the odds ratio (OR) for having osteoporosis decreased with increasing BMI (overweight OR = 0.11, p = 0.053; obese OR = 0.05, p = 0.007).

CONCLUSIONS

There was no direct correlation between BMD and PTH, bone turnover markers, and vitamin D except at the lumbar spine. A negative correlation between BMD and age and a positive correlation with BMI were observed. The protective effect of obesity on osteoporosis was complicated by the effect of obesity on vitamin D and PTH.

In Situ Sensor Advancements for Osteoporosis Prevention, Diagnosis, and Treatment

Osteoporosis is still a serious issue in healthcare, and will continue to increase due to the aging and growth of the population. Early diagnosis is the key to successfully treating many diseases. The earlier the osteoporosis is diagnosed, the more quickly people can take action to stop bone deterioration. Motivated by this, researchers and companies have begun developing smart in situ bone sensors in order to dramatically help people to monitor their bone mass density (BMD), bone strain or bone turnover markers (BTMs); promptly track early signs of osteoporosis; and even monitor the healing process following surgery or antiresorptive therapy. This paper focuses on the latest advancements in the field of bone biosensing materials and sensor technologies and how they can help now and in the future to detect disease and monitor bone health.

Effect of Intravenous Glucose Tolerance Test on Bone Turnover Markers in Adults with Normal Glucose Tolerance

Background

It is well known that enteral nutrients result in acute suppression of bone turnover markers (BTMs), and incretin hormones are believed to play a significant role in this physiological skeletal response. However, there is limited research exploring the impact of parenteral nutrients on BTMs. Our aim was to assess the influence of intravenous glucose on BTMs in adults with normal glucose tolerance (NGT).

Material/Methods

We conducted 1-h intravenous glucose tolerance test (IVGTT) in 24 subjects with NGT. Blood samples were collected before and 5, 10, 15, 20, 30, 60 min after administration of glucose, then serum levels of bone formation marker procollagen type I N-terminal propeptide (P1NP) and resorption marker C-terminal cross-linking telopeptides of collagen type I (CTX) were measured.

Results

During IVGTT, the fasting CTX level fell gradually and reached a nadir of 80.4% of the basal value at 60 min. Conversely, the fasting P1NP level decreased mildly and reached a nadir of 90.6% of the basal value at 15 min, then gradually increased and reached 96.6% at 60 min. The CTX-to-P1NP ratio increased slightly and reached a peak of 104.3% of the basal value at 10 min, then fell gradually and reached a nadir of 83% at 60 min.

Conclusions

Our study indicates that intravenous glucose results in an acute suppression of BTMs in the absence of incretin hormones. The mechanism responsible for this needs further investigation.

Vitamin D3 supplementation, bone health and quality of life in adults with diabetes and chronic kidney disease: Results of an open label randomized clinical trial

BACKGROUND

Adults with diabetes (DM) and chronic kidney disease (CKD) are at risk for vitamin D (vitD) insufficiency, suboptimal bone health and reduced quality of life (QoL) due to limited sunlight exposure, poor vitD intake and CKD.

AIMS

This open-labeled, randomized clinical trial, compared the impact of daily (2000 IU/D) verses monthly (40,000 IU/month) vitD₃ supplementation over six months on markers of vitD status, bone health and QoL in adults with DM and CKD (stages: 1-4).

METHODS

Participants (18-80 years) were randomized to daily (n = 60) or monthly (n = 60) vitD₃ for six months. Primary outcomes included: vitD status (25-hydroxyvitD [25(OH)D], 1, 25-dihydroxyvitD [1,25(OH)₂D], bone health (bone mineral density [BMD] and serum concentrations of bone-specific alkaline phosphatase [BSAP], osteocalcin [OC], N-telopeptide-type 1-collagen [NTx]) and Fibroblast Growth Factor-23 (FGF-23). Secondary outcomes included QoL (Short Form-36 questionnaire).

RESULTS

Adherence by dose allocation over six months was 95.0 ± 5.7% (daily) and 94.1 ± 4.1% (monthly), respectively (p = 0.44); resulting in an overall median [95% CI] increase in serum 25(OH)D of 19 (12-26) nmol/L (p < 0.001). Serum 25(OH)D increased at three (p < 0.001) and six months (p < 0.001) in the daily and monthly groups, respectively. No significant differences over six months between groups were observed in serum concentrations of 1,25(OH)₂D, FGF-23, OC and NTx, BMD and QoL measures (p > 0.05). Serum 25(OH)D ≥ 75 nmol/L was associated with significant reductions in BSAP (p = 0.01) and improved physical functioning vs those with concentrations < 75 nmol/L (62.5 ± 26.8 vs 52.7 ± 26.3; p = 0.03) in the monthly and daily groups, respectively.

CONCLUSIONS

Daily (2000 IU/D) and monthly (40,000 IU/month) vitD₃ supplementation for six months in adults with DM and CKD was safe, and resulted in equivalent adherence and improvements in overall vitD status, but only modest changes in markers of bone health and QoL.

Secondary osteoporosis

Secondary osteoporosis is less common than primary osteoporosis. It may be suspected in patients who present with a fragility fracture despite having no risk factors for osteoporosis. In addition, secondary osteoporosis should be considered if the bone density Z-score is -2.5 or less. Consider the fracture site and presence of other clinical clues to guide investigations for an underlying cause. The tests to use are those that are indicated for the suspected cause. Baseline investigations include tests for bone and mineral metabolism (calcium, phosphate, alkaline phosphatase, 25-hydroxyvitamin D, parathyroid hormone), liver and kidney function, full blood count and thyroid-stimulating hormone. More detailed testing may be required in patients with severe osteoporosis.

Assessment of vitamin D status and serum CrossLaps levels in adults with primary lactose malabsorption

BACKGROUND/OBJECTIVES

Primary adult-type lactose malabsorption (PALM) is a widespread inherited autosomal recessive condition, which is considered to be associated with osteoporosis. This prospective study aimed at assessing the 25-hydroxy-vitamin D (25(OH)D) status and serum CrossLaps levels in individuals with PALM and normal controls.

SUBJECTS/METHODS

All participants (n=210) underwent genotyping for the LCT C/T-13910 polymorphism, 25(OH)D and CrossLaps measurements and clinical examinations. In addition, the anthropometric data (that is, height, weight and body mass index) were determined.

RESULTS

Fifty-five individuals with PALM (that is, LCT C/C-13910 homozygotes) showed lower 25(OH)D (mean: 24.95±10.04 vs 28.59±9.56 ng/ml, P=0.018) and higher CrossLaps serum levels (mean: 0.46±0.31 vs 0.43±0.49 ng/ml, P=0.251) compared with 155 normal controls (that is, LCT C/T-13910 hetero- or T/T-13910 homozygotes). Anthropometric data were similar between PALM probands and controls.

CONCLUSIONS

Individuals with PALM were found to have lower 25(OH)D and higher CrossLaps serum levels compared with normal controls. In order to preserve life-long bone health, routine 25(OH)D and CrossLaps serum measurements should be performed in individuals with PALM.

Moving toward a prevention strategy for osteoporosis by giving a voice to a silent disease

A major unmet challenge in developing preventative treatment programs for osteoporosis is that the optimal timing of treatment remains unknown. In this commentary we make the argument that the menopausal transition (MT) is a critical period in a woman's life for bone health, and that efforts aimed at reducing fracture risk later in life may benefit greatly from strategies that treat women earlier with the intent of keeping bones strong as long as possible. Bone strength is an important parameter to monitor during the MT because engineering principles can be applied to differentiate those women that maintain bone strength from those women that lose bone strength and are in need of early treatment. It is critical to understand the underlying mechanistic causes for reduced strength to inform treatment strategies. Combining measures of strength with data on how bone structure changes during the MT may help differentiate whether a woman is losing strength because of excessive bone resorption, insufficient compensatory bone formation, trabeculae loss, or some combination of these factors. Each of these biomechanical mechanisms may require a different treatment strategy to keep bones strong. The technologies that enable physicians to differentially diagnose and treat women in a preventive manner, however, have lagged behind the development of prophylactic treatments for osteoporosis. To take advantage of these treatment options, advances in preventive treatment strategies for osteoporosis may require developing new technologies with imaging resolutions that match the pace by which bone changes during the MT and supplementing a woman's bone mineral density (BMD)-status with information from engineering-based analyses that reveal the structural and material changes responsible for the decline in bone strength during the menopausal transition.

Natural Products from Chinese Medicines with Potential Benefits to Bone Health

Osteoporosis is a progressive, systemic bone disorder characterized by loss of bone mass and microstructure, leading to reduced bone strength and increased risk of fracture. It is often associated with reduced quality of life and other medical complications. The disease is common in the aging population, particularly among postmenopausal women and patients who receive long-term steroidal therapy. Given the rapid growth of the aging population, increasing life expectancy, the prevalence of bone loss, and financial burden to the healthcare system and individuals, demand for new therapeutic agents and nutritional supplements for the management and promotion of bone health is pressing. With the advent of global interest in complementary and alternative medicine and natural products, Chinese medicine serves as a viable source to offer benefits for the improvement and maintenance of bone health. This review summarizes the scientific information obtained from recent literatures on the chemical ingredients of Chinese medicinal plants that have been reported to possess osteoprotective and related properties in cell-based and/or animal models. Some of these natural products (or their derivatives) may become promising leads for development into dietary supplements or therapeutic drugs.

Development and Validation of Osteoporosis Risk-Assessment Model for Korean Men

PURPOSE

The aim of the present study was to develop an osteoporosis risk-assessment model to identify high-risk individuals among Korean men.

MATERIALS AND METHODS

The study used data from 1340 and 1110 men ≥50 years who participated in the 2009 and 2010 Korean National Health and Nutrition Examination Survey, respectively, for development and validation of an osteoporosis risk-assessment model. Osteoporosis was defined as T score ≤-2.5 at either the femoral neck or lumbar spine. Performance of the candidate models and the Osteoporosis Self-assessment Tool for Asian (OSTA) was compared with sensitivity, specificity, and area under the receiver operating characteristics curve (AUC). A net reclassification improvement was further calculated to compare the developed Korean Osteoporosis Risk-Assessment Model for Men (KORAM-M) with OSTA.

RESULTS

In the development dataset, the prevalence of osteoporosis was 8.1%. KORAM-M, consisting of age and body weight, had a sensitivity of 90.8%, a specificity of 42.4%, and an AUC of 0.666 with a cut-off score of -9. In the validation dataset, similar results were shown: sensitivity 87.9%, specificity 39.7%, and AUC 0.638. Additionally, risk categorization with KORAM-M showed improved reclassification over that of OSTA up to 22.8%.

CONCLUSION

KORAM-M can be simply used as a pre-screening tool to identify candidates for dual energy X-ray absorptiometry tests.

Collagen and tissue turnover as a function of age: Implications for fibrosis

BACKGROUND & AIMS

The extracellular matrix (ECM) is the backbone of all tissues. It is a complex grid consisting of multiple structural proteins which each play a vital role for the function and maintenance of normal tissue function. In development and growth, tissue is being formed and elaborated (tissue modeling), while in adult life, tissues are being maintained and remodeled. These processes involve likely different mechanisms. During tissue modeling and remodeling, small fragments of proteins are released into the circulation, where they may be used as biomarkers for tissue turnover. The aim of the study was to investigate ECM turnover in rodents as a function of age.

METHODS

Serum of rats of 1, 2, 3, 4, 5, 6, 10 and 12months of age was profiled for 15 markers of ECM turnover, including: fragments of type I, II, III, IV, V and VI collagen formation (P1NP, P4NP-7S, Pro-C5, Pro-C6) and degradation (C1M, C2M, C2M-beta, C3M, C4M, C5M, C6M); biglycan (BGM) and elastin (ELM7) degradation; and the type I and II collagen telopeptides CTX-I and CTX-II.

RESULTS

Type I and II collagen turnover was up to 93% and 97% downregulated in old (one year) compared to young (one month) old animals (p<0.0001), while type IV and V collagen and biglycan turnover was upregulated 2.5-, 2- and 2-fold, respectively (p<0.0001). Type III and VI collagen and elastin turnover was not influenced significantly by age.

CONCLUSIONS

ECM turnover rates were consistently different in young vs. old animals, up to 30 fold. This appears to be due to body growth, a different ECM composition and a higher regenerative capability of connective tissues in young vs. old animals. These changes have to be accounted for in translational science. Both in measuring serum levels of ECM biomarkers and in the development of therapies to speed up wound healing or inhibit fibrogenesis.