Bone markers in osteoporosis

Does metabolic control of the disease related with bone turnover markers in children with type 1 diabetes mellitus in Turkey?

BACKGROUND

The aim was to evaluate the effect of metabolic control on bone biomarkers in children with type I diabetes.

MATERIALS AND METHODS

The children were divided into two groups according to their glycated hemoglobin (HbA1c) (%) levels: a group with HbA1c levels < 8% (n = 16) and: a group with HbA1c levels > 8% (n = 18). The serum total oxidative status (TOS) (µmol/L), total antioxidant status (TAS) (mmol/L), alkaline phosphatase (ALP) (IU/L), osteocalcin (OC) (ng/ml), procollagen type-1-N-terminal peptide (P1NP) (ng/ml), and vitamin D (IU) levels and food consumption frequencies were determined.

RESULTS

When patients were classified according to HbA1c (%) levels, those with HbA1c levels < 8% were found to have lower TOS (µmol/L) values (8.7 ± 6.16, 9.5 ± 5.60) and higher serum OC (ng/mL) (24.2 ± 16.92, 22.0 ± 6.21) levels than those with HbA1c levels > 8% (p < 0.05). Regardless of the level of metabolic control, there was a statistically significant association between serum TOS (µmol/L) and P1NP (ng/ml) (p < 0.05) levels, with no group-specific relationship (HbA1c levels <%8 or HbA1c levels >%8).

CONCLUSION

HbA1c and serum TOS levels had an effect on bone turnover biomarkers in individuals with type I diabetes.

ELISA array-based immunoassay for multiplex detection of osteoporosis-relevant biomarkers

Aim: This study aimed to develop an ELISA array-based immunoassay for the simultaneous detection of osteoporosis-relevant biomarkers. Methods: ELISA array was constructed and its performance was evaluated using commercial antigens. The validity was further confirmed using traditional ELISA. Results: The constructed ELISA array showed good repeatability. The linear ranges and limits of detection for the four markers mentioned above were 0.01-8 ng/ml (1 pg/ml), 5.0-1000 ng/ml (1 ng/ml), 0.5-400 ng/ml (0.1 ng/ml) and 1-100 ng/ml (1 ng/ml), respectively. The measured concentrations of serum samples by ELISA array showed high correlation with those from traditional ELISA. Conclusion: ELISA array-based immunoassay provided a feasible and productive method to multiplex measure markers for osteoporosis.

Changes in bone mineral density in unconscious immobile stroke patients from the acute to chronic phases of brain diseases

Objectives

Decreased bone mineral density (BMD) is observed in immobile stroke patients. But it is not clarified yet how rapidly BMD reduction occurs or what the most influencing factor to BMD loss is.

Methods

BMDs in the lumbar vertebrae and the proximal femur of the paralyzed side were measured in 100 immobile stroke patients at 1 week (0 month), 1 month, and 2 months after admission. The levels of serum calcium, phosphorous, 25-hydroxyvitamin D, and urine cross-linked N-telopeptide of type I collagen (NTx) were also measured.

Results

The average age of patients was 75.0 ± 11.4 years (31–94 years). No BMD reduction was identified in the lumbar vertebrae in 2 months; however, BMD in the femur significantly decreased in 2 months in female patients (P < 0.05). Serum calcium and phosphorous levels remained within the normal range during hospitalization, and 25-hydroxyvitamin D value rose in 2 months. Urine NTx significantly increased in both males and females in 2 months (male: P < 0.05, female: P < 0.01).

Conclusions

While there was no significant change in lumbar spine BMD in the 2 month period of immobilization after stroke, BMD in the proximal femur showed a significant reduction, particularly in women. The differential loss of BMD in the 2 regions of interest could possibly be due to the physical forces acting on different body parts during mobilization and nutritional factors. More studies are needed with larger study samples and prolonged follow-up to check the accuracy of these observations.

Secondary Osteoporosis and Metabolic Bone Diseases

Fragility fracture is a worldwide problem and a main cause of disability and impaired quality of life. It is primarily caused by osteoporosis, characterized by impaired bone quantity and or quality. Proper diagnosis of osteoporosis is essential for prevention of fragility fractures. Osteoporosis can be primary in postmenopausal women because of estrogen deficiency. Secondary forms of osteoporosis are not uncommon in both men and women. Most systemic illnesses and organ dysfunction can lead to osteoporosis. The kidney plays a crucial role in maintaining physiological bone homeostasis by controlling minerals, electrolytes, acid-base, vitamin D and parathyroid function. Chronic kidney disease with its uremic milieu disturbs this balance, leading to renal osteodystrophy. Diabetes mellitus represents the most common secondary cause of osteoporosis. Thyroid and parathyroid disorders can dysregulate the osteoblast/osteoclast functions. Gastrointestinal disorders, malnutrition and malabsorption can result in mineral and vitamin D deficiencies and bone loss. Patients with chronic liver disease have a higher risk of fracture due to hepatic osteodystrophy. Proinflammatory cytokines in infectious, autoimmune, and hematological disorders can stimulate osteoclastogenesis, leading to osteoporosis. Moreover, drug-induced osteoporosis is not uncommon. In this review, we focus on causes, pathogenesis, and management of secondary osteoporosis.

Comparison of Bone Mineral Density and Markers of Bone Turnover in Osteoporotic Women after 6-Month Treatment with Alendronate or Bazedoxifene: A Randomized Controlled Trial

Background

In a randomized controlled trial, we compared the bone mineral densities (BMDs) and blood markers of bone turnover during short-term treatment of osteoporotic women with bisphosphonate alendronate or bazedoxifene, a selective estrogen receptor modulator.

Methods

Ten and eleven patients were randomized to the alendronate and bazedoxifene groups, respectively. BMDs were measured before and after 6 months of treatment. Blood tests were used to measure the levels of osteocalcin (OC), C-terminal telopeptide of type I collagen (CTX), vitamin D3, and parathyroid hormone pretreatment and after 3 and 6 months of treatment. The variables were compared statistically.

Results

The alendronate group showed decreases in blood levels of both OC and CTX during the study period (P<0.001 and P=0.002, respectively), while the bazedoxifene group had a decrease only in OC levels (P=0.012). After 6 months of treatment, BMDs significantly increased in the alendronate group at multiple bone sites, including the L1–4 lumbar vertebrae, femur trochanter, and total femur. However, there was no significant increase in BMD in the bazedoxifene group. BMDs were not significantly different between the 2 groups.

Conclusions

Patients treated with alendronate showed more rapid suppression of markers of bone turnover and higher BMD than those treated with bazedoxifene during a short-term regime. Considering the effects and complications of each medication, the relationship between bone turnover rate and bone quality will need to be investigated in future studies.

Relationship between bone turnover markers and oxidative stress in children with type 1 diabetes mellitus

BACKGROUND

Oxidative stress in children with type 1 DM (T1DM) may negatively affect the bone.

METHODS

This study included 40 children with T1DM as the patient group and 40 healthy children of matched age and sex as the control group. Plasma alkaline phosphatase, procollagen type-1 amino-terminal propeptide (P1NP), and urinary deoxypyridinoline (DPD) were measured to assess bone turnover. Glutathione, superoxide dismutase (SOD), and malondialdehyde (MDA) were measured to assess oxidative stress.

RESULTS

Patients with T1DM had a significantly lower P1NP level but a significantly higher urinary DPD level compared to the control group. Moreover, there were significantly lower glutathione and SOD levels with significantly higher MDA levels in patients with T1DM. We found a significant positive correlation between P1NP level and both glutathione and SOD levels but a significant negative correlation between P1NP and MDA in patients with T1DM. There was a significant negative correlation between DPD levels and both glutathione and SOD levels and a significant positive correlation between DPD and MDA. Moreover, glutathione was a significant predictor for both P1NP and DPD levels, while MDA was a significant predictor for P1NP levels.

CONCLUSIONS

There is an association between oxidative stress and bone turnover markers in children with T1DM.

IMPACT

Oxidative stress can negatively affect bone but the exact relationship between oxidative stress and bone turnover in T1DM has not been previously studied in pediatrics. For the best of our knowledge, our study was the first to assess the relationship between oxidative stress and bone turnover in children with T1DM. We revealed that increased oxidative stress in children and adolescents with T1DM may be involved in the impairment of bone turnover process, so treatment strategies toward better glycemic control and decreasing oxidative stress may be beneficial in preventing and treating diabetic bone disease in these children.

Effects of androgen excess and glucocorticoid exposure on bone health in adult patients with 21-hydroxylase deficiency

CONTEXT

This study aimed to determine the role of modifiable predictors on bone health in congenital adrenal hyperplasia (CAH).

DESIGN

Cross-sectional, single center study, including 97 patients (N = 42 men) with classic CAH due to 21-hydroxylase deficiency (N = 65 salt wasting, N = 32 simple virilizing).

MAIN OUTCOME MEASURES

Treatment-related predictors of bone health.

RESULTS

Average T scores (-0.9 ± 1.4 vs. -0.4 ± 1.4; p = 0.036) as well as Z scores (-1.0 ± 1.3 vs. -0.1 ± 1.4; p = 0.012) at the spine in patients with CAH were significantly lower in men than women. While osteoporosis was rare in women, it was documented in 9.1% of men with CAH. There was a significant positive correlation of Z scores at the spine with advancing age in women with CAH (R² = 0.178; p = 0.003). In multivariate analysis, the intake of conventional hydrocortisone (HC) instead of synthetic glucocorticoids was independently associated with a higher bone mineral density (BMD) at the hip region in both sexes. In women, there was a positive association with vitamin D concentrations. Interestingly, higher sodium levels were associated with a lower BMD independent of renin levels and fludrocortisone dosage. Neither in men nor in women, markers of androgen control were predictive for BMD at any site. Markers of bone turnover indicated low bone turnover. No pathological fractures were documented.

CONCLUSIONS

Men with CAH are particularly prone to low bone density, while women seem to be relatively protected by androgen excess compared to the general female population. The use of HC instead of synthetic GCs for hormone replacement may translate into better bone health.

Effects of sodium glucose cotransporter 2 inhibitors on mineral metabolism in type 2 diabetes mellitus

Purpose of review

Sodium glucose cotransporter 2 (SGLT2) inhibitors are relatively novel antidiabetic drugs that improve glycemic control and reduce cardiovascular outcomes as well as renal function decline. SGLT2 inhibitors act by inhibiting glucose reabsorption in the proximal tubule of the kidney. Emerging data suggest that these drugs may also influence bone and mineral metabolism. This review summarizes clinical trial data on bone and mineral outcomes, and discusses potential underlying mechanisms.

Recent findings

Three large randomized controlled trials documented cardiovascular and renal protective effects of SGLT2 inhibitors. Recent studies indicate that SGLT2 inhibitors influence renal phosphate reabsorption and calciuria. Although the CANVAS trial suggested an increased fracture risk associated with canagliflozin compared with placebo, the vast majority of trials and meta-analyses did not demonstrate an increased fracture risk associated with SGLT2 inhibitor use.

Summary

SGLT2 inhibitors have shown clinically relevant cardiovascular and renal protective effects. The long-term implications for bone health, in particular in the context of chronic kidney disease, are still incompletely understood and warrant further investigation.

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.

Osteoglycin and Bone-a Systematic Review

PURPOSE OF REVIEW

Bone turnover is a regulated process. Osteoglycin is suggested to have an important impact on bone function but may also affect cardiovascular and metabolic functions. This review investigates the action of osteoglycin in bone as well as its potential endocrine effects.

RECENT FINDINGS

Osteoglycin is expressed by several tissues including bone and muscle. Some studies suggest that osteoglycin increases osteoblast differentiation whereas others suggest that osteoglycin decreases osteoblast differentiation. Thus, findings on the influence of osteoglycin in bone are conflicting. A recent study found increased bone mass in osteoglycin deficient mice. Another study reported that osteoglycin is a marker of low bone mineral density and vertebral fractures in women with type 2 diabetes. Furthermore, clinical studies link osteoglycin to insulin resistance and cardiovascular disease. Osteoglycin may be a novel marker of a muscle, pancreatic, and bone axis. However, current evidence is limited and further research investigating osteoglycin in both a pre-clinical and a clinical setting is needed.

Treatment of osteoporosis with recombinant parathyroid hormone, utilisation of total body DXA to observe treatment effects on total body composition and factors determining response to therapy

PURPOSE

Recombinant parathyroid hormone (rPTH) increases bone mineral density (BMD). However, certain other potential effects of rPTH remain to be studied. The aim of this study is to identify whether bone turnover markers, relevant biochemical parameters or total body fat and muscle composition affect the response to rPTH and to establish if these parameters in particular change during treatment.

METHODS

One hundred seventy-two participants were treated with rPTH, and 128 subjects who fully complied with the therapy and completed their investigations including biochemical bone markers and total body composition at baseline, 6 months and 1 year of the treatment were divided into responder and non-responder groups. A total body dual-energy X-ray absorptiometry (DXA) scanner was used to assess the body muscle, fat and bone composition.

RESULTS

rPTH significantly increased BMD spine at 1 year (p = 0.000). Twenty-four-hour urinary calcium was significantly increased at 6 months in the responder group (p = 0.00). There was a trend to an increase in the fat and muscle mass (p = 0.52 and 0.45, respectively), and it was not negatively affected by rPTH. Bone turnover markers (P1NP and OC) did not show statistically significant difference over time between responders and non-responders (p = 0.74 and p = 0.19, respectively).

CONCLUSIONS

Hypercalciuria which is a frequent feature in osteoporotic population may predict non-responders at 6 months of rPTH, and it may help to optimise individual patient's treatment. Unlike endogenous PTH in pathological conditions, rPTH is anabolic to bone and has no detrimental effects on the body fat and muscle composition.

Association of bone turnover markers with glucose metabolism in Chinese population

The association between type 2 diabetes (T2DM) and bone metabolism has been discussed previously but is controversial. In this study we aimed to evaluate the association of bone turnover markers with glucose metabolism in Chinese population, in which 919 males and 4171 postmenopausal females in a region of Shanghai were recruited. Anthropometric and biochemical traits related to glucose and bone metabolism were analyzed. Participants were classified according to their glucose tolerance as normal glucose tolerance (NGT), impaired glucose regulation (IGR) or T2DM. Males and females were analyzed separately, and then associations between bone turnover markers (BTMs) and glucose metabolism were evaluated. The results showed that in females, the serum levels of N-terminal osteocalcin (N-MID), N-terminal procollagen of type I collagen (PINP) and β-cross-linked C-telopeptide of type I collagen (β-CTX) were significantly decreased in the T2DM group compared to the NGT group (P<0.01). When age, body mass index, serum lipids, fat percentage, visceral fat area, subcutaneous fat area, anti-diabetic medicines, PINP, N-MID and β-CTX were included in one logistic model, N-MID (OR [95% CI]: 0.954 [0.932; 0.976]; P=0.0001) was significantly associated with T2DM in females. In females, N-MID was associated with insulin sensitivity and HOMA-β. PINP was significantly associated with HOMA-β, GUTT-ISI, Stumvoll first-phase insulin secretion index (STU-1) and Stumvoll second-phase insulin secretion index (STU-2), but β-CTX was associated only with HOMA-β (β±SE: 0.1331±0.0311; P=1.95×10^-5) and GUTT-ISI (β±SE: 0.0727±0.0229; P=0.0015). In males, N-MID was significantly correlated with HOMA-β (β±SE: 0.3439±0.0633; P=7.75×10^-8), GUTT-ISI (β±SE: 0.1601±0.0531; P=0.0027) and STU-1 (β±SE: 0.2529±0.1033; P=0.0146). Significant associations were also detected between β-CTX and HOMA-β (β±SE: 0.2736±0.0812; P=0.0009). This study reveals that BTMs are highly associated with T2DM, insulin sensitivity and beta cell function in both Chinese males and postmenopausal females.

Pharmacological treatment options for low Bone Mineral Density and secondary osteoporosis in Anorexia Nervosa: A systematic review of the literature

OBJECTIVE

Although there are several evidence-based treatments available to increase Bone Mineral Density (BMD) and reduce fracture risk in aging men and women, there are still uncertainties regarding which treatments are efficacious in reducing lifetime fracture risk in women with Anorexia Nervosa (AN).

METHODS

Medline, PsychInfo, Embase and the Cochrane Database were searched for English Language Studies. Inclusion criteria were studies of females of any age with AN who received pharmacological treatment with the primary aim to increase BMD or reduce fracture risk. Data were extracted from each study regarding pharmacological treatment and dosage used, BMD and bone formation marker outcomes; and participant characteristics including age, Body Mass Index (BMI), duration of AN, and duration of amenorrhea.

RESULTS

675 studies were reviewed, of which 19 fit the inclusion criteria and were included in the final review, investigating a total of 1119 participants; 10 of the 19 included studies were double-blind RCTs. The remaining studies consisted of prospective observational studies, a retrospective cohort study, a case-control study and five non-randomised control trials. Bisphosphonates were effective in increasing BMD in adult women with AN, while estrogen administered transdermally resulted in significant increases in BMD in mature adolescents with AN. Administration of oral contraceptives (OC) did not significantly increase BMD in randomised or controlled trials, however, lifetime OC use was associated with higher spinal BMD.

CONCLUSION

Future research should clarify the safety of long-term bisphosphonate use in adult women with AN, and verify that transdermal estrogen replacement increases BMD in women with AN.

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.

The association between bone turnover markers and kyphosis in community-dwelling older adults

PURPOSE

Hyperkyphosis, accentuated curvature of the thoracic spine, is often attributed to osteoporosis, yet its underlying pathophysiology is not well understood. Bone turnover markers (BTM) reflect the dynamic process of bone formation and resorption. This study examined the association between serum BTM levels and kyphosis in community-dwelling older adults.

METHODS

Between 2003 and 2006, 760 men and women in the Rancho Bernardo Study age 60 and older had blood drawn and kyphosis measured. Fasting serum was assayed for N-telopeptide (NTX) and procollagen type 1 n-terminal propeptide (P1NP), markers of bone resorption and formation, respectively. Participants requiring two or more 1.7 cm blocks under their head to achieve a neutral supine position were classified as having accentuated kyphosis. Analyses were stratified by sex and use of estrogen therapy (ET). Odds of accentuated kyphosis were calculated for each standard deviation increase in log-transformed BTM.

RESULTS

Mean age was 75 years. Overall, 51% of 341 non-ET using women, 41% of 111 ET-using women, and 75% of 308 men had accentuated kyphosis. In adjusted models, higher P1NP and NTX were associated with decreased odds of accentuated kyphosis in non-ET using women (P1NP: OR = 0.78 [95% CI, 0.58-0.92]; NTX: OR = 0.68 [95% CI, 0.54-0.86]), but not in men or ET-using women (p > 0.05).

CONCLUSIONS

The selective association of higher bone turnover with reduced odds of accentuated kyphosis in non-ET using women suggests that elevated BTM were associated with a lower likelihood of hyperkyphosis only in the low estrogen/high BTM environment characteristic of postmenopausal women who are not using ET.

Sclerostin as a novel marker of bone turnover in athletes

Sclerostin is a protein secreted by osteocytes that acts as an inhibitor of bone formation. It has been shown that physical activity affects sclerostin concentration and thus bone remodelling. The aim of the study was to evaluate serum concentrations of sclerostin, selected bone turnover markers (PTH, P1NP), 25(OH)D3 and the intake of calcium and vitamin D in physically active versus sedentary men. A total of 59 healthy men aged 17-37 were enrolled in the study (43 athletes and 16 non-athletes). The mean sclerostin concentration in the group of athletes (A) was significantly higher than in non-athletes (NA) (35.3±8.9 vs 28.0±5.6 pmol·l^-1, p= 0.004). A compared with NA had higher concentrations of P1NP (145.6±77.5 vs 61.2±22.3 ng·ml^-1, p= <0.0001) and 25(OH)D3 (16.9±8.4 vs 10.3±4.3 ng·ml^-1, p= 0.004) and lower concentrations of PTH (25.8±8.3 vs 38.2±11.5 pg·ml^-1, p= <0.0001). Vitamin D deficiency was found in 77% of A and 100% of NA. A and NA had similar daily energy intake. They did not differ as to the intake of calcium and vitamin D. We observed a negative correlation between the serum concentrations of sclerostin and calcium in the studied subjects. Our results suggest that regular, long-lasting physical training may be associated with higher concentration of sclerostin. It seems that increased sclerostin is not related to other bone turnover markers (PTH, P1NP).

Osteoporotic risk and physeal closure in prepubertal ovariohysterectomized cats

We aimed to examine the early effects of prepubertal ovariohysterectomy (P-OHE) on bone loss and proximal physeal closure in cats. Fourteen kittens randomly underwent P-OHE or sham operations (S-OP) at three months (mo) of age and were allocated to group I and group II. Each mo between four and nine mo of age, dual-energy X-ray absorptiometry (DEXA) scans were performed to determine the total body bone mineral density (BMD) and bone mineral content (BMC). Proximal radial physeal closure and radial length were determined by radiography. Bone-specific alkaline phosphatase (BAP), carboxy-terminal collagen teleopeptide (CTX), 17-β estradiol, progesterone, calcium (Ca) and phosphorus (P) were measured in the serum samples. No significant differences were observed between the groups in terms of BMD, BMC, BAP, BAP/CTX, P, progesterone and body weight (BW) (between 4 and 9mo) and for Ca (between 5 and 9mo) and for CTX levels (between 4 and 8mo). The 17-β estradiol was significantly higher at 6, 8 and 9mo of age in the S-OP group due to puberty (P=0.02, P=0.03 and P=0.02 respectively). Although there was a significant difference (P=0.0002) between the P-OHE and S-OP groups in terms of the proximal radial physeal closure times (7.43±0.20mo and 6.14±0.14mo, respectively), no significant difference was observed for the mean radius length (10.59±0.10cm and 10.06±0.27cm, respectively) at the last evaluation time. In conclusion, prepubertal ovariohysterectomized cats do not have any osteoporotic risks until nine mo of age and exhibit a delayed physeal closure time without a change in radius length.

Effect of weight loss on bone health in overweight/obese postmenopausal breast cancer survivors

Current guidelines recommend weight loss in obese cancer survivors. Weight loss, however, has adverse effects on bone health in obese individuals without cancer but this has not been evaluated in breast cancer survivors. We investigated the associations of intentional weight loss with bone mineral density (BMD) and bone turn-over markers in overweight/obese postmenopausal breast cancer survivors. Participants were overweight/obese breast cancer survivors (N = 81) with stage I, II or IIIA disease enrolled in the St. Louis site of a multi-site Exercise and Nutrition to Enhance Recovery and Good health for You (ENERGY) study; a randomized-controlled clinical trial designed to achieve a sustained ≥7 % loss in body weight at 2 years. Weight loss was achieved through dietary modification with the addition of physical activity. Generalized estimating equations were used to assess differences in mean values between follow-up and baseline. Mean weight decreased by 3 and 2.3 % between baseline and 6-month follow-up, and 12-month follow-up, respectively. There were decreases in osteocalcin (10.6 %, p value < 0.001), PINP (14.5 %, p value < 0.001), NTx (19.2 % p value < 0.001), and RANK (48.5 %, p value < 0.001), but not BALP and CTX-1 levels between baseline and 12-month follow-up. No significant changes occurred in mean T-scores, pelvis and lumbar spine BMD between baseline and 12-month follow-up. A 2.3 % weight loss over 12 months among overweight/obese women with early-stage breast cancer does not appear to have deleterious effect on bone health, and might even have beneficial effect. These findings warrant confirmation, particularly among breast cancer survivors with a larger magnitude of weight loss.

Novel assessment tools for osteoporosis diagnosis and treatment

This review describes new technologies for the diagnosis and treatment, including fracture risk prediction, of postmenopausal osteoporosis. Four promising technologies and their potential for clinical translation and basic science studies are discussed. These include reference point indentation (RPI), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and magnetic resonance imaging (MRI). While each modality exploits different physical principles, the commonality is that none of them require use of ionizing radiation. To provide context for the new developments, brief summaries are provided for the current state of biomarker assays, fracture risk assessment (FRAX), and other fracture risk prediction algorithms and quantitative ultrasound (QUS) measurements.

Osteoporosis, fractures, and diabetes

It is well established that osteoporosis and diabetes are prevalent diseases with significant associated morbidity and mortality. Patients with diabetes mellitus have an increased risk of bone fractures. In type 1 diabetes, the risk is increased by ∼6 times and is due to low bone mass. Despite increased bone mineral density (BMD), in patients with type 2 diabetes the risk is increased (which is about twice the risk in the general population) due to the inferior quality of bone. Bone fragility in type 2 diabetes, which is not reflected by bone mineral density, depends on bone quality deterioration rather than bone mass reduction. Thus, surrogate markers and examination methods are needed to replace the insensitivity of BMD in assessing fracture risks of T2DM patients. One of these methods can be trabecular bone score. The aim of the paper is to present the present state of scientific knowledge about the osteoporosis risk in diabetic patient. The review also discusses the possibility of problematic using the study conclusions in real clinical practice.

Biochemical markers of bone turnover in diabetes patients--a meta-analysis, and a methodological study on the effects of glucose on bone markers

This study examined whether markers of bone turnover differ between individuals with and without diabetes. Bone markers showed heterogeneity between studies and were discrepant for markers of bone creation and markers of bone degradation. Bone markers may be of lesser value in diabetes due to heterogeneity.

INTRODUCTION

The aim of this meta-analysis was to compare existing literature regarding changes in bone markers among diabetics compared to healthy controls. To exclude that blood glucose levels among diabetes patients could influence the assays used for determining bone turnover markers, a methodological study was performed.

METHODS

Medline at Pubmed Embase, Cinahl, Svemed+, Cochrane library, and Bibliotek.dk was searched in August 2012. The studies should examine biochemical bone turnover among diabetes patients in comparison to controls in an observational design. In the methodological study, fasting blood samples were drawn from two individuals. Glucose was added to the blood samples in different concentrations and OC, CTX, and procollagen type 1 amino terminal propeptide were measured after 0, 1, 2, and 3 h.

RESULTS

Twenty-two papers fulfilled the criteria for the meta-analysis. From the pooled data in the meta-analysis, the bone markers osteocalcin (OC) (-1.15 ng/ml [-1.78,-0.52]) and C-terminal cross-linked telopeptide (CTX) (-0.14 ng/ml [-0.22, -0.05]) were significantly lower among diabetes patients than non-diabetes patients, however other markers did not differ. All markers displayed very high heterogeneity by I2 statistics. In the methodological study, the addition of glucose did not significantly change the bone markers neither by level of glucose nor with increasing incubation time.

CONCLUSION

The dissociative pattern of biochemical bone markers of bone formation and bone resorption present in diabetes patients is thus not caused by glucose per se but may be modulated by unknown factors associated with diabetes mellitus.

Bone disease in patients with Gaucher disease

Gaucher disease is an inborn error of metabolism due to a deficiency of the lysosomal enzyme glucocerebrosidase. As a result of this deficiency, the substrate glucocerebroside accumulates in the liver, spleen, bone and bone marrow. Bone involvement can lead to abnormalities in bone growth, bone remodeling, bone infarcts, aseptic necrosis, osteonecrosis, increased fracture risk and lytic bone lesions. Patients may experience bone pain and bone crises related to bone infarcts. There is evidence of abnormal bone metabolism in both bone resorption and bone formation based upon biochemical abnormalities found in patients. In addition, both immunological and coagulation abnormalities have in part been implicated in the causation of bone disease. Treatment with enzyme replacement therapy and substrate reduction therapy has led to improvement in both the symptoms and the radiographic abnormalities seen in these patients. It is unknown whether these treatments lower fracture risk.

Odanacatib, a selective cathepsin K inhibitor to treat osteoporosis: safety, tolerability, pharmacokinetics and pharmacodynamics--results from single oral dose studies in healthy volunteers

AIMS

To evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of odanacatib (ODN), a cathepsin K inhibitor, in humans.

METHODS

Two double-blind, randomized, placebo-controlled, single oral dose studies were performed with ODN (2-600 mg) in 44 healthy volunteers (36 men and eight postmenopausal women).

RESULTS

Adverse experiences (AEs) with single doses of ODN were transient and mild to moderate, with the exception of one severe AE of gastroenteritis. Headache was the most frequent AE. After absorption of ODN (initial peak concentrations 4-6 h postdose), plasma concentrations exhibited a monophasic decline, with an apparent terminal half-life of ∼40-80 h. The area under the curve0-24 hours (AUC(0-24 h)), concentration at 24 hours (C(24 h)) and maximum concentration (C(max,overal)) increased in a less than dose-proportional manner from 2 to 600 mg. Administration of ODN with a high-fat meal led to ∼100% increases in AUC(0-24 h), C(max,day1), C(max,overall) and C(24 h) relative to the fasted state, while administration with a low-fat meal led to a ∼30% increase in those parameters. Reduction of biomarkers of bone resorption, the C- and N-telopeptides of cross-links of type I collagen, (CTx and NTx, respectively), was noted at 24 h for doses ≥5 mg and at 168 h postdose for ≥10 mg. In postmenopausal women administered 50 mg ODN, reductions in serum CTx of -66% and urine NTx/creatinine (uNTx/Cr) of -51% relative to placebo were observed at 24 h. At 168 h, reductions in serum CTx (-70%) and uNTx/Cr (-78%) were observed relative to baseline. Pharmacokinetic/pharmacodynamic modeling characterized the ODN concentration/uNTx/Cr relation, with a modeled EC50 value of 43.8 nM and ∼80% maximal reduction.

CONCLUSIONS

Odanacatib was well tolerated and has a pharmacokinetic and pharmacodynamic profile suitable for once weekly dosing.

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

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

Diabetes, biochemical markers of bone turnover, diabetes control, and bone

Diabetes mellitus is known to have late complications including micro vascular and macro vascular disease. This review focuses on another possible area of complication regarding diabetes; bone. Diabetes may affect bone via bone structure, bone density, and biochemical markers of bone turnover. The aim of the present review is to examine in vivo from humans on biochemical markers of bone turnover in diabetics compared to non-diabetics. Furthermore, the effect of glycemic control on bone markers and the similarities and differences of type 1- and type 2-diabetics regarding bone markers will be evaluated. A systematic literature search was conducted using PubMed, Embase, Cinahl, and SveMed+ with the search terms: "Diabetes mellitus," "Diabetes mellitus type 1," "Insulin dependent diabetes mellitus," "Diabetes mellitus type 2," "Non-insulin dependent diabetes mellitus," "Bone," "Bone and Bones," "Bone diseases," "Bone turnover," "Hemoglobin A Glycosylated," and "HbA1C." After removing duplicates from this search 1,188 records were screened by title and abstract and 75 records were assessed by full text for inclusion in the review. In the end 43 records were chosen. Bone formation and resorption markers are investigated as well as bone regulating systems. T1D is found to have lower osteocalcin and CTX, while osteocalcin and tartrate-resistant acid are found to be lower in T2D, and sclerostin is increased and collagen turnover markers altered. Other bone turnover markers do not seem to be altered in T1D or T2D. A major problem is the lack of histomorphometric studies in humans linking changes in turnover markers to actual changes in bone turnover and further research is needed to strengthen this link.

Assessment of temporomandibular joint disease

The diagnosis of temporomandibular joint (TMJ) disorders consists of clinical (Reaserch Diagnostic Criteria for Temporomandibular Disorders, RDC/TMD) and additional (computer tomography, CT or magnetic resonance imaging, and MRI) examinations. Due to the growing knowledge of pathologic changes within the TMJ, the researches become more aware of the difficulty in detection the early symptoms of disorders using conventional examination. Therefore, it is now expected that the collected samples of synovial fluid, serum, or urine samples could enable easier identification of inflammatory process course, and degenerative cartilage changes state.

Effect of gender, season, and vitamin D status on bone biochemical markers in Saudi diabetes patients

Biochemical bone turnover markers (BTMs) provide important information on the diagnosis, therapy and monitoring of metabolic bone diseases. They are evident before measurable changes in bone mineral density (BMD) take place. A total of 35 adult Saudi patients (23 males; 12 females) with type 2 diabetes and diagnosed to be vitamin D deficient were recruited in this prospective study. Here we investigated the effects of gender, season, and vitamin D status on bone biochemical markers of bone remodeling. Anthropometry and blood samples were collected at different intervals. Metabolic parameters and bone biomarkers were measured routinely and by ELISA. Both males and females had a significant increase in their vitamin D status over time, but no significant changes in the bone biomarkers were observed in females. In males there was a significant increase in circulating levels of corrected calcium and OPN (p = 0.004 and 0.01 respectively) and a significant decrease in crosslaps (p = 0.005). In all subjects there was a modest but significant positive relationship between vitamin D status and OC (R = 0.34; p = 0.04). In conclusion, our study demonstrates that changes in bone remodeling markers are affected by season, gender, and possibly vitamin D status. This gender difference may well reflect the physiologic pathway responsible for the higher peak bone mass achieved in males compared to females.

Reduction of urinary levels of N-telopeptide correlates with treatment compliance in women with postmenopausal osteoporosis receiving alendronate

OBJECTIVE

The aim of this study was to assess the factors associated with the effectiveness of treatment with alendronate (ALN) quantified by a reduction in urinary excretion of N-telopeptide (NTx).

METHODS

The study is an observational, prospective, multicenter trial, with a 6-month follow-up. Postmenopausal osteoporotic women (densitometric criteria), who initiated treatment with ALN (70 mg/weekly) without previous treatment with antiresorptive agents (12 month) and calcitonin (6 month), were included. The assessment of NTx levels (nmol bone collagen equivalents/mmol creatinine) in the urine was performed at baseline and after completion of follow-up. A logistic regression model included "achieving a reduction in urinary NTx of at least 30% (minimal clinically significant change [MCSC])" as a dichotomous dependent variable and the following as independent variables: baseline urinary NTx levels, treatment compliance, years since diagnosis of menopause, ALN treatment duration, and treatment with calcium and vitamin D. Treatment compliance was assessed as the percentage of days of medication prescribed as a function of the time between the beginning and end of treatment. Good compliance was defined as a percentage between 80% and 120%.

RESULTS

The variables that reached statistical significance were baseline urinary NTx values (odds ratio, 1.052; 95% CI, 1.025-1.079) and compliance (odds ratio, 3.9; 95% CI, 1.5-10.1). Therefore, the women with good treatment compliance were almost 4 times more likely to achieve an MCSC in NTx levels, and the raise in one unit of urinary NTx baseline values increased by 5% of the probability of achieving MCSC.

CONCLUSIONS

Treatment with ALN (70 mg/week) in women with postmenopausal osteoporosis effectively reduces the urinary excretion of the bone turnover biomarker NTx. The probability of achieving a clinically significant reduction is greater in those women with higher baseline levels of NTx and in women who comply with treatment.

Physical training increases osteoprotegerin in postmenopausal women

The purpose of this study was to explore whether mechanical loading by exercise over a 1-year period in postmenopausal women had an effect on the receptor activator for nuclear factor kappa B ligand/osteoprotegerin (RANKL/OPG) system or the levels of the Wnt-signaling antagonist sclerostin. A total of 112 postmenopausal were randomized to either sedentary life (controls) or physical activity (training group). Ninety-two women fulfilled the study protocol. The training program consisted of three fast 30-min walks and one or two 1-h aerobic training sessions per week. The effect on the bone mineral density of the hip assessed with dual X-ray absorptiometry was positive as reported earlier. Blood samples were taken from participants at baseline and after 1 year and serum levels of OPG, RANKL and sclerostin were quantified together with the bone metabolism markers C-terminal telopeptide of collagen type I (CTX) and bone-specific alkaline phosphatase (BALP). The results were analyzed using an analysis of covariance model using baseline values as the covariate. The training group displayed a clear mean increase of OPG +7.55 pg/ml compared to controls (p = 0.007). The mean changes for RANKL +0.19 pg/ml (square-root transformed data) and sclerostin +0.62 pmol/l were non-significant (p = 0.13 and p = 0.34). The changes in bone turnover markers CTX and BALP showed a tendency to decrease in the training group versus controls but the changes were small and non-significant. Although our study is limited in number of participating women, we have been able to show an OPG-associated, and RANKL- and sclerostin-independent, training-induced inhibition of postmenopausal bone loss.

[2011 Up-date of the consensus statement of the Spanish Society of Rheumatology on osteoporosis]

OBJECTIVE

Due to increasing improvement in the diagnosis, evaluation and management of osteoporosis and the development of new tools and drugs, the Spanish Society of Rheumatology (SER) has promoted the development of recommendations based on the best evidence available. These recommendations should be a reference to rheumatologists and other health professionals involved in the treatment of patients with osteoporosis.

METHODS

Recommendations were developed following a nominal group methodology and based on a systematic review. The level of evidence and degree of recommendation were classified according to the model proposed by the Center for Evidence Based Medicine at Oxford. The level of agreement was established through Delphi technique. Evidence from previous consensus and available clinical guidelines was used.

RESULTS

We have produced recommendations on diagnosis, evaluation and management of osteoporosis. These recommendations include the glucocorticoid-induced osteoporosis, premenopausal and male osteoporosis.

CONCLUSIONS

We present the SER recommendations related to the biologic therapy risk management.

Markers of bone turnover are elevated in patients with antiretroviral treatment independent of the substance used

OBJECTIVES

Osteoporosis and bone fractures are correlated to antiretroviral treatment. It is not clear whether some substances comprise greater risks of bone loss than others.

METHODS

We measured pyridinoline, deoxypyridinoline crosslinks, and bone-specific alkaline phosphatase in 113 HIV-positive patients. We compared patients with and without antiretroviral treatment. We then compared patients with versus without tenofovir and patients with protease inhibitor versus nonnucleoside reverse transcriptase inhibitor use.

RESULTS

Bone-specific alkaline phosphatase, pyridinoline, and deoxypyridinoline crosslinks were significantly higher in patients with antiretroviral treatment compared with patients without antiretroviral treatment: 24.5 versus 13.04 pg/L (P < 0.001), 82.73 versus 51.93 nmol/mmol (P < 0.001), and 16.56 versus 9.94 nmol/mmol (P < 0.001), respectively. In contrast, no difference was found between patients with and without tenofovir: 25.38 versus 20.02 pg/l (P = 0.1); 79.85 versus 83.95 nmol/mmol (P = 0.64), and 19.12 versus 14.00 nmol/mmol (P = 0.14), respectively. Comparison between patients with protease inhibitor versus nonnucleoside reverse transcriptase inhibitor yielded no difference either: 23.07 versus 27.18 pg/L (P = 0.24), 92.96 versus 80.73 nmol/mmol (P = 0.36), and 18.22 versus 16.39 nmol/mmol (P = 0.55).

CONCLUSION

Markers for bone turnover are higher in treated compared with untreated patients. No difference concerning tenofovir use or protease inhibitor versus nonnucleoside reverse transcriptase inhibitor use could be found.