Baseline Bone Turnover Markers Research Articles

Elevated bone turnover markers predict bone mineral density accrual in adolescents with 21-hydroxylase deficiency.

Prognostic biomarkers for monitoring bone health in adolescents with 21-hydroxylase deficiency (21OHD) are needed. To assess associations between concentrations of baseline bone turnover markers (BTMs) including osteocalcin (OC) and type-I collagen C-terminal telopeptide (CTX) and changes in lumbar spine bone mineral density (LSBMD) in adolescents with classic 21OHD. A retrospective-prospective study of 33 adolescents with classic 21OHD who had baseline data for LSBMD, bone age (BA), and BTM concentrations. BTM concentrations were converted into z-scores according to BA. We measured LSBMD at the follow-up study visit and calculated the annual percentage change in LSBMD (%∆LSBMD). At baseline, participants (55% female, 79% Tanner 5) had mean (±SD) age of 14.6 ± 3.6 years, BA 16.7 ± 2.9 years, and average glucocorticoid (GC) dose 17.3 ± 5.6 mg/m2 /day of hydrocortisone equivalent. The mean follow-up duration was 14.4 ± 5.6 months. Median (Q1-Q3) %∆LSBMD was 3.6% (0-8.5)/year. %∆LSBMD was similar among genders or 21OHD subtypes. Prednisolone versus hydrocortisone replacement resulted in lower %∆LSBMD (p = .004). %∆LSBMD was increased across tertiles of CTX z-score (p = .014). %∆LSBMD correlated negatively with GC dose (p = .01) and positively with CTX and OC z-scores (p < .01). In regression analyses, only CTX z-score positively associated with %∆LSBMD (p = .003), adjusting for sex, BA, body mass index, testosterone, 25-hydroxyvitamin D, and GC type and dose. Higher GC dose and the use of prednisolone were associated with decreased LSBMD accrual in adolescents with 21OHD. CTX z-score independently associated with LSBMD accrual, suggesting its potential for prognostic bone biomarker.

Effect of FLAVAnols on bone turnover markers in type 2 diabetes mellitus–post hoc analysis from a 3-month randomized placebo-controlled trial

BACKGROUND: Individuals with type 2 diabetes mellitus (T2DM) have increased fracture risk with high bone mineral density, possibly related to advanced glycation end products (AGEs) accumulation in bone. Flavanol supplementation in postmenopausal women reduced AGEs formation and decreased bone resorption markers. However, to date, these effects have not been investigated in T2DM. OBJECTIVE: We used a post hoc secondary analysis to determine the effect of monomeric and oligomeric flavanols supplementation on bone turnover markers (BTMs) in individuals with T2DM. METHODS: Eighty-three individuals with T2DM, aged 40–85 years, with microalbuminuria were enrolled from 4 trial centers in Rotterdam, the Netherlands, into a randomized, double-blind, placebo-controlled trial with renal vascular health as the primary outcome. Participants were randomized (1:1) to receive either a placebo or 200 mg of monomeric and oligomeric flavanols as intervention for three months. Serum alkaline phosphatase (ALP), type I collagen crosslinked beta C-telopeptide (β-CTx), and type I procollagen-N-propeptide (P1NP) were measured at baseline and three months. ANCOVA was performed on rank transformed BTMs at three months as the outcome, adjusting for baseline BTMs, group, age, sex, and BMI. RESULTS: Baseline characteristics did not differ between the two arms. The adjusted mean change in BTMs at three months was not different between the placebo vs. intervention arm: ALP –0.059 (–0.262–0.145) vs. 0.060 (–0.135–0.356), p = 0.41; β-CTx 0.013 (–0.205–0.231) vs. 0.100 (–0.109–0.310), p = 0.53 and P1NP 0.091 (–0.080–0.262) vs. 0.030 (–0.134–0.195), p = 0.61. There was no significant within-group change in BTMs after three months in both study arms. CONCLUSION: Supplementation with daily 200 mg of flavanols during three months, on top of usual care in individuals with T2DM, did not result in changes in BTMs compared to placebo. Future studies are needed to show whether long-term supplementation in higher dosages may positively affect BTMs in individuals with T2DM.

Baseline bone turnover marker levels can predict change in bone mineral density during antiresorptive treatment in osteoporotic patients: the Copenhagen bone turnover marker study.

In randomized, controlled trials of bisphosphonates, high pre-treatment levels of bone turnover markers (BTM) were associated with a larger increase in bone mineral density (BMD). The purpose of this study was to examine this correlation in a real-world setting. In this registry-based cohort study of osteoporosis patients (n = 158) receiving antiresorptive therapy, the association between pre-treatment levels of plasma C-telopeptide of type I Collagen (CTX) and/or N-terminal propeptide of type I procollagen (PINP) and change in bone mineral density (BMD) at lumbar spine, total hip, and femoral neck upon treatment was examined. Patients were grouped according to their pre-treatment BTM levels, defined as values above and below the geometric mean for premenopausal women. Pre-treatment CTX correlated with annual increase in total hip BMD, where patients with CTX above the geometric mean experienced a larger annual increase in BMD (p = 0.008) than patients with CTX below the geometric mean. The numerical pre-treatment level of CTX showed a similar correlation at all three skeletal sites (total hip (p = 0.03), femoral neck (p = 0.04), and lumbar spine (p = 0.0003)). A similar association was found for PINP where pre-treatment levels of PINP above the geometric mean correlated with a larger annual increase in BMD for total hip (p = 0.02) and lumbar spine (p = 0.006). Measurement of pre-treatment BTM levels predicts osteoporosis patients' response to antiresorptive treatment. Patients with high pre-treatment levels of CTX and/or PINP benefit more from antiresorptive treatment with larger increases in BMD than patients with lower pre-treatment levels.

Effects of bone turnover status on the efficacy and safety of denosumab among haemodialysis patients

Denosumab is reported to increase bone mineral density (BMD) among haemodialysis patients; however, hypocalcaemia is a serious adverse effect among chronic kidney disease (CKD) patients. Identifying which patients will show greater improvement in BMD is important. We enrolled 84 haemodialysis patients with osteoporosis in our study. 28 patients initiated denosumab treatment between October 2019 and October 2020. We assessed BMD changes and investigated the association between baseline bone turnover marker (BTM) levels and 6-month changes in BMD after denosumab treatment. BMD was increased at 6 months in denosumab-treated patients compared with patients not treated with denosumab (lumbar spine: 5.34% vs. − 0.49%; total hip: 2.43% vs. − 0.47%). Bone-specific alkaline phosphatase (BAP) and tartrate-resistant acid phosphatase-5b (TRACP-5b) at baseline were independently associated with increased BMD in the total hip (BAP: β = 0.472, p value = 0.004; TRACP-5b: β = 0.433, p value = 0.008) and lumbar spine (BAP: β = 0.591, p value = 0.001; TRACP-5b: β = 0.613, p value = 0.0008). BAP and TRACP-5b were also independent predictors of hypocalcaemic events (OR [95% CI] 1.747 [1.084–4.604] and 1.006 [1.000–1.015], respectively). BTMs may be associated with increased BMD and hypocalcaemic events after denosumab treatment. BTM measurement may be useful for assessing the effect of denosumab on BMD; however, careful monitoring of serum calcium levels is needed.

Effects of zoledronic acid therapy in fibrous dysplasia of bone: a single-center experience.

Fibrous dysplasia (FD) is a rare bone disorder that can involve any part of the skeleton, leading to bone pain, deformities, and fractures. Treatment with intravenous bisphosphonates has been used with variable results. Therefore, we aimed to evaluate the effects of zoledronic acid (ZA) therapy in patients with monostotic or polyostotic FD. The medical records of thirteen patients with FD evaluated between 2015 and 2020 were retrospectively analyzed. In the subgroup of patients treated with ZA (n = 7), data on pain relief, changes in bone turnover markers (BTMs), and adverse events following ZA infusions were retrieved. Moreover, radiological changes in response to treatment were recorded in patients who underwent radiological follow-up. Of the patients, 5 (38%) presented with monostotic whereas 8 (62%) had polyostotic FD. Bone pain was a common finding (69%), and most patients (62%) exhibited elevated baseline BTMs. Partial or complete pain relief was reported in 6 of 7 patients treated with ZA. BTMs, especially C-telopeptide of type I collagen (CTX), significantly decreased after therapy (change rate: -61.8% [IQR -71, -60%]), and median CTX levels were significantly lower than at baseline (0.296 ng/mL [0.216, 0.298] vs. 0.742 ng/mL [0.549, 0.907], respectively; P = 0.04). No radiological improvement was observed in cases with radiological follow-up (n = 3). No serious adverse effects of ZA were reported. ZA treatment was well tolerated and provided beneficial effects in relieving bone pain and reducing BTMs, especially CTX. Our data reinforce the role of ZA in the treatment of FD-related bone pain.

Effects of early estradiol valerate administration on bone turnover markers in surgically induced menopausal women

BackgroundCompared with a natural process, surgically induced menopausal women have a higher bone loss rate. This study aims to evaluate early treatment with estradiol valerate on bone turnover markers after surgically induced menopause.MethodsThis prospective study included 41 pre and perimenopausal women who underwent hysterectomy with oophorectomy for benign gynecologic conditions. Two weeks after the operation, all participants were assessed for menopausal hormone therapy (MHT) indications. Estrogen therapy was prescribed for those who had indications and accepted treatment (hormone treatment group). The others who had no MHT indication were allocated to the no-treatment group. Serum CTX and P1NP levels at preoperative and 12 weeks postoperative were measured and set as the primary outcome. Within the same group, serum CTX and P1NP before and after surgical menopause were analyzed using Wilcoxon signed-rank test. ANCOVA was used to compare serum CTX and P1NP at 12 weeks after surgical menopause between the two groups. Spearman's rank correlation coefficient analysis analyzed the correlation between age and baseline bone turnover markers. A p-value of < 0.05 was considered statistically significant.ResultsAt 12 weeks after surgery, there were no significant differences in serum CTX and P1NP levels in the hormone treatment group compared to baseline. In contrast, serum CTX and P1NP levels were significantly elevated among women who did not receive hormone treatment (p-value < 0.001 and 0.002, respectively). Serum CTX and P1NP at 12 weeks were significantly different between the two groups (p-value < 0.001 and 0.004, respectively).ConclusionEarly estrogen administration with oral estradiol valerate could significantly suppress the high bone remodeling in surgically induced menopausal women.Trial registration Thai Clinical Trial Registry identification number TCTR20190808004, retrospective registered since 2019-08-08. http://www.thaiclinicaltrials.org/show/TCTR20190808004.

Denosumab-Induced Hypocalcemia and Hyperparathyroidism in de novo Kidney Transplant Recipients

Introduction: Denosumab represents a realistic treatment option to increase bone mineral density in kidney transplant recipients (KTRs). It is still unknown how and at what extent posttransplantation bone disease and graft function influence the effects of denosumab on mineral metabolism indexes. In this study, we analyze risk factors of hypocalcemia and parathyroid hormone (PTH) increase after denosumab administration in eighteen de novo KTRs and its management before and after this treatment. Methods: We conducted a monocentric, observational, prospective study on de novo KTRs. All KTRs enrolled received a single 60 mg subcutaneous dose of denosumab every 6 months. Before kidney transplantation, no patients were treated with calcio-mimetic. After kidney transplantation and before antiresorptive therapy, no patients were treated with calcio-mimetic drugs and/or vitamin D receptor agonists, while all patients received nutritional vitamin D supplementation (from 1,000 IU to 1,500 IU daily). Results: Hypocalcemia was related to the degree of lumbar osteoporosis (p = 0.047); the increase in the PTH level was correlated to baseline bone turnover markers (bone alkaline phosphatase, serum osteocalcin, and β-C-terminal telopeptide), the 25 OH status, and eGFR. The introduction of calcitriol, after the PTH increase, in addition to cholecalciferol was necessary to ensure an adequate control of serum calcium and PTH during a follow-up of 15 months. Following the treatment with denosumab, it was observed an improvement of areal bone mineral density both at lumbar and femoral sites with a mean percentual increase of 1.74% and 0.25%, respectively. Conclusions: Denosumab is an effective treatment for bone disease in KTRs. In our study, the increase in PTH is not a transient event but prolonged throughout the follow-up period and requires continuous supplementation therapy with calcitriol.

Bone turnover markers are associated with the PTH levels in different subtypes of pseudohypoparathyroidism type 1 patients.

Bone responsiveness to parathyroid hormone (PTH) in different subtypes of pseudohypoparathyroidism type 1 (PHP1) remains controversial. We aimed to investigate this phenomenon using bone turnover markers (BTMs) in a large cohort of PHP1 patients. Retrospective study. Sixty-three PHP1 patients diagnosed by molecular analysis were used as subjects, and 48 sex- and age-matched patients with nonsurgical hypoparathyroidism (NS-HP) were used for comparison. Bone turnover markers, alkaline phosphatase (ALP), C-terminal telopeptide of type I collagen (β-CTX) and related parameters in PHP1 were compared among different subtypes and with NS-HP. Among all the PHP1 patients (15 PHP1A, 14 familial 1B and 34 sporadic 1B), 23.8% had elevated baseline BTM levels. No significant difference was found in the β-CTX levels among different subtypes. The β-CTX level was positively correlated with the PTH level for all PHP1, PHP1B and PHP1A patients (B=0.001, 0.001 and 0.004, respectively; all p<.05). The BTM levels of PHP1 patients were significantly higher than those of NS-HP patients (β-CTX: 0.56ng/ml vs. 0.20ng/ml, p=.001; ALP: 105 U/L vs. 72 U/L, p=.001). The serum β-CTX levels in different PHP1 subtypes were all significantly higher than those in NS-HP patients in adults. Among the 22 followed up patients, changes in BTMs were associated with changes in PTH (β-CTX: r=.507, p=.023; ALP: r=.475, p=.034). Bone tissues respond to PTH in different PHP1 subtypes, and it is reasonable to monitor and normalize PTH and BTMs in addition to the serum and urinary calcium levels in the follow-up of PHP1 patients.

Acute Hyperinsulinemia Alters Bone Turnover in Women and Men With Type 1 Diabetes.

ABSTRACTType 1 diabetes (T1D) increases fracture risk across the lifespan. The low bone turnover associated with T1D is thought to be related to glycemic control, but it is unclear whether peripheral hyperinsulinemia due to dependence on exogenous insulin has an independent effect on suppressing bone turnover. The purpose of this study was to test the bone turnover marker (BTM) response to acute hyperinsulinemia. Fifty‐eight adults aged 18 to 65 years with T1D over 2 years were enrolled at seven T1D Exchange Clinic Network sites. Participants had T1D diagnosis between age 6 months to 45 years. Participants were stratified based on their residual endogenous insulin secretion measured as peak C‐peptide response to a mixed meal tolerance test. BTMs (CTX, P1NP, sclerostin [SCL], osteonectin [ON], alkaline phosphatase [ALP], osteocalcin [OCN], osteoprotegerin [OPG], osteopontin [OPN], and IGF‐1) were assessed before and at the end of a 2‐hour hyperinsulinemic‐euglycemic clamp (HEC). Baseline ON (r = −0.30, p = .022) and OCN (r = −0.41, p = .002) were negatively correlated with age at T1D diagnosis, but baseline BTMs were not associated with HbA1c. During the HEC, P1NP decreased significantly (−14.5 ± 44.3%; p = .020) from baseline. OCN, ON, and IGF‐1 all significantly increased (16.0 ± 13.1%, 29.7 ± 31.7%, 34.1 ± 71.2%, respectively; all p < .001) during the clamp. The increase in SCL was not significant (7.3 ± 32.9%, p = .098), but the decrease in CTX (−12.4 ± 48.9, p = .058) neared significance. ALP and OPG were not changed from baseline (p = .23 and p = .77, respectively). Baseline ON and SCL were higher in men, but OPG was higher in women (all p ≤ .029). SCL was the only BTM that changed differently in women than men. There were no differences in baseline BTMs or change in BTMs between C‐peptide groups. Exogenous hyperinsulinemia acutely alters bone turnover, suggesting a need to determine whether strategies to promote healthy remodeling may protect bone quality in T1D. © 2020 American Society for Bone and Mineral Research © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Assessment of baseline bone turnover marker levels and response to risedronate treatment: Data from a Japanese phase III trial

BackgroundRisedronate increases bone mineral density (BMD) and reduces fracture risk, but treatment response may depend on the baseline state of bone turnover. Data regarding the selection of therapeutic drugs or the prediction of therapeutic effects with baseline levels of bone turnover markers (BTMs) as a reference are insufficient. We hypothesized that when the baseline levels of BTMs are higher, baseline BMD might be lower, changes in BMD at 12 months after risedronate treatment might be higher, and the reduction of fracture incidence might be greater. This study aimed to analyze the data of a phase III clinical trial of risedronate from Japan to investigate the relationships between baseline BTM levels and (1) baseline BMD, (2) changes in BMD at 12 months after the start of treatment, and (3) the incidence of new vertebral fractures. MethodsThis post-hoc analysis included 788 postmenopausal women with osteoporosis whose baseline BTM levels as well as baseline and endpoint BMDs were measured. Relationships between baseline BTM levels and BMD at baseline and 12 months after risedronate treatment and new vertebral fractures were examined. One-way analysis of variance, two-tailed Student's t-test, and Fisher's exact test were used to analyze the data. ResultsBaseline BMD showed a significant upward trend when baseline BTM levels were lower in the analysis by tertiles. New vertebral fractures tended to occur in patients with prevalent vertebral fractures, but the relationship between new fractures and BTM levels was not statistically significant. Regardless of BTM types, BMD percentage increments (%) and increments (g/cm2) with the 12-month treatment were high when pretreatment BTM levels were high (P < 0.0001), and a >5.0% increase in BMD was observed even if baseline BTM levels were within the normal range. A new vertebral fracture occurred in only six patients (0.77%), and there was not enough statistical power to clarify the relationship between baseline BTM levels and fracture risk reduction. ConclusionsWhen pretreatment BTM levels increased, baseline BMD tended to be lower and the increase in BMD with 12-month risedronate treatment was higher. However, BMD could still be increased even if the baseline BTM levels are within the normal range. Combined with available evidence, baseline BTMs may not have an important role in deciding the optimal therapy. To elucidate the relationship between baseline BTM levels and long-term fracture risk, it will be necessary to conduct more large-scale studies with a longer follow-up period in severe osteoporotic patients with a high fracture risk. Mini abstractWe evaluated the significance of baseline bone turnover markers in the response to risedronate treatment. The increase in the bone mineral density (BMD) with the 12-month treatment may be higher when the state of bone turnover at baseline is higher, and BMD could still be increased even if the baseline bone turnover is within the normal range.

Correlation between Bone Turnover Markers and Bone Mineral Density in Patients Undergoing Long-Term Anti-Osteoporosis Treatment: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis aimed to evaluate the correlations between the bone turnover markers (BTMs) and the bone mineral density (BMD) in patients treated for primary osteoporosis and to identify promising BTMs for the prediction of future BMD changes. The PubMed, EMBASE, Cochrane Library, and Web of Science databases were searched for relevant studies that investigated the relationship between the BTMs and the BMD changes in patients treated for osteoporosis. All significant correlation coefficients of the baseline BTMs or changes in BTMs from baseline with the BMD changes from baseline under different interventions from eligible studies were used for systematic review and the subgroup analyses. The correlations were analyzed in terms of bone sites, intervention, time duration of BTMs measurements, and time duration of BMD measurements. Twenty-two records reporting correlation coefficients and the corresponding p-values were included, 13 of which were enrolled in the further subgroup analyses. The combined results from the systematic review and meta-analyses indicated that the changes in osteocalcin (OC), procollagen type I N propeptide (PINP), and urine N-terminal crosslinking telopeptide of type I collagen (U-NTX), or the PINP at baseline tended to be useful in evaluating the long-term BMD changes after drug intervention.

Bone Status in Obese, Non-diabetic, Antipsychotic-Treated Patients, and Effects of the Glucagon-Like Peptide-1 Receptor Agonist Exenatide on Bone Turnover Markers and Bone Mineral Density.

Background: Low bone mineral density (BMD) may constitute an underestimated comorbidity in schizophrenia patients undergoing long-term antipsychotic treatment. Glucagon-like peptide 1 (GLP-1) receptor agonists are antidiabetic drugs, which may also affect bone turnover.Methods: In planned secondary analyses of a 3 months, double-blind, randomized, placebo-controlled trial (n = 45), we explored effects of the GLP-1 receptor agonist exenatide 2 mg once-weekly (n = 23), or placebo (n = 22) on bone turnover markers (BTMs) and BMD in chronic, obese, antipsychotic-treated patients with schizophrenia spectrum disorder. Baseline BTMs were compared to sex- and age-adjusted reference values from a Danish population cohort, and T- and Z-scores were calculated for BMD.Results: In women (n = 24), all baseline BTM measurements of procollagen type I N-terminal propeptide (PINP) and C-terminal cross-linking telopeptide of type I collagen (CTX) were within reference values. In men (n = 21), 5% displayed lower PINP and 14% displayed lower CTX. One patient displayed BMD Z-score < −2, and 23% of patients (17% of women and 29% of men) displayed −2.5 < T-scores < –1 indicating osteopenia, but none had osteoporosis. After treatment, PINP decreased at trend level significance (P = 0.05), and body mass index BMD increased for L2–L4 (P = 0.016). No changes in bone markers were significant after correction for mean prolactin levels.Conclusions: Sex- and age-adjusted measures of bone status in chronic, obese, antipsychotic-treated patients appeared comparable to the reference population. Subtle changes in bone markers during 3 months exenatide treatment may suggest beneficial effects of GLP-1 receptor agonists on bone status in antipsychotic-treated patients, and further studies should consider the potential influence of prolactin.

Factors associated with inadequate responses to risedronate in Japanese patients with osteoporosis.

Factors associated with an inadequate response (IR) to bisphosphonates have been reported in many countries, but not in Japan, where the approved dose is half the global dose. We analyzed factors associated with IR to risedronate in Japanese patients with osteoporosis. This was a post hoc analysis of 1261 Japanese osteoporosis patients who received risedronate for 1year in phase III trials. IR was defined as more than one new vertebral fracture (VF) and/or negative change in lumbar spine bone mineral density (BMD) at 1year. Various baseline and follow-up variables were examined for potential contribution to IR. Of the 1261 subjects, 118 exhibited an IR. At baseline, IR was associated with a higher BMD, lower levels of bone turnover markers (BTM) (serum bone-specific alkaline phosphatase, urinary N-terminal telopeptide of type 1 collagen and C-terminal telopeptide of type 1 collagen), and serum 25-hydroxyvitamin D [25(OH)D] below 16ng/mL. BTM changes were blunted at 6months in subjects with IR. On simple regression analysis, all the above variables and poor drug adherence were associated with an IR. On multivariate regression analysis, factors associated with IR were high BMD, vitamin D deficiency at baseline and low BTM at baseline, or a decreased BTM response at 6months. Low serum 25(OH)D and BTM as well as high BMD at baseline were independent predictors of an IR to risedronate in Japan. These results emphasize the importance of the assessment of serum 25(OH)D and BTM in the management of osteoporosis with bisphosphonates.

The relationship between bone turnover and insulin sensitivity and secretion: Cross-sectional and prospective data from the RISC cohort study.

Bone metabolism appears to influence insulin secretion and sensitivity, and insulin promotes bone formation in animals, but similar evidence in humans is limited. The objectives of this study are to explore if bone turnover markers were associated with insulin secretion and sensitivity and to determine if bone turnover markers predict changes in insulin secretion and sensitivity. The study population encompassed 576 non-diabetic adult men with normal glucose tolerance (NGT; n=503) or impaired glucose regulation (IGR; n=73). Baseline markers of bone resorption (CTX) and formation (P1NP) were determined in the fasting state and after a 2-h hyperinsulinaemic, euglycaemic clamp. An intravenous glucose tolerance test (IVGTT) and a 2-h oral glucose tolerance test (OGTT) were performed at baseline, and the OGTT was repeated after 3years. There were no differences in bone turnover marker levels between NGT and IGR. CTX and P1NP levels decreased by 8.0% (p<0.001) and 1.9% (p<0.01) between baseline and steady-state during the clamp. Fasting plasma glucose was inversely associated with CTX and P1NP both before and after adjustment for recruitment centre, age, BMI, smoking and physical activity. However, baseline bone turnover markers were neither associated with insulin sensitivity (assessed using hyperinsulinaemic euglycaemic clamp and OGTT) nor with insulin secretion capacity (based on IVGTT and OGTT) at baseline or at follow-up. Although inverse associations between fasting glucose and markers of bone turnover were identified, this study cannot support an association between insulin secretion and sensitivity in healthy, non-diabetic men.

DIAGNOSIS OF ENDOCRINE DISEASE: Bone turnover markers: are they clinically useful?

Bone turnover markers (BTMs) are useful in clinical practice as they are inexpensive, and they have proven useful for treatment monitoring and identification of poor adherence. BTMs cannot be used in individual patients for identifying accelerated bone loss or an increase in fracture risk or in deciding on the optimal therapy. They are useful for monitoring both anti-resorptive and anabolic treatment. Response can be defined as a result that exceeds an absolute target, or by a change greater than the least significant change; if such a response is not present, then poor compliance or secondary osteoporosis are likely causes. A baseline BTM measurement is not always made; in that case, a value of BTM on anti-resorptive treatment that is low or low normal or above the reference interval for anabolic therapy may be taken to indicate a satisfactory response. We provide an approach to using these bone turnover markers in clinical practice by describing algorithms for anti-resorptive and anabolic therapy and describing the changes we observe in the clinical practice setting.

Effect of cabozantinib on bone turnover markers (BTM) and bone metastases (BM) in radioiodine refractory (RAIR)-differentiated thyroid cancer (DTC).

e17580 Background: Cabozantinib is a small molecule multiple-receptor tyrosine kinase inhibitor that primarily targets MET and vascular endothelial growth factor receptor 2 (VEGFR2). We evaluated the effect of cabozantinib on BTM in RAIR DTC. We also assessed the response of BM to cabozantinib using 18F Sodium Fluoride (NaF) PET and radionuclide bone scans. Methods: This prospective analysis was performed as part of a multicenter International Thyroid Oncology Group phase II study of cabozantinibin patients with RAIR DTC who progressed on prior VEGFR-targeted therapy (NCT01811212). BTM [serum C-telopeptide (CTx), osteocalcin, N-telopeptide (NTx), procollagen type 1 (Pc1) and urinary NTx] and NaF PET or Tc-MDP scans were done at baseline and after 8 weeks of therapy. A paired t-test was used between baseline and week 8 BTM. Results: Primary study results were presented elsewhere (Shah, et al. 2015, International Thyroid Congress) showing a response rate of 36% with cabozantinib. Of 25 patients (pts) enrolled, 21 had BM, 10 of whom were on bone-modifying agents (BMA) prior to week 8. Only 2 pts had elevated BTM at baseline. In all pts who had paired BTM, there was a statistically significant decline in all BTM except NTx by week 8 (table). Pts not on BMA also had a significant decline in CTx (p 0.0003), urine NTx (p 0.0300), and Pc1 (p 0.0030) compared to baseline. 19 pts were evaluable for overall response and there was no correlation between BTM and response rate. 6/21 patients underwent paired NaF PET scans and 4/6 had minor reduction in lesion uptake at 8 weeks. Conclusions: Interestingly, most of our patients had normal baseline BTM despite BM. Cabozantinib was associated with a strikingly significant reduction in all BTM (even when BTM were within normal limits at baseline) except NTx by week 8. Minor decreases in bone lesion uptake was noted on NaF PET in 4/6 evaluable patients. Clinical trial information: NCT01811212. [Table: see text]

A retrospective analysis of nonresponse to daily teriparatide treatment.

Some patients with osteoporosis do not respond to teriparatide treatment. Prior bisphosphonate use, lower bone turnover marker (BTMs) concentrations, and lower early increases in BTMs were significantly associated with a blunted lumbar spine (LS) bone mineral density (BMD) response to daily treatment with teriparatide, although the impact was limited. Some osteoporosis patients do not respond to teriparatide treatment. To better understand the factors underlying treatment nonresponses, we compared nonresponders' and responders' characteristics. We retrospectively analyzed 354 male and female patients with osteoporosis who were administered teriparatide (20μg/day) for 24months. The patients were categorized as responders (≥3% lumber spine (LS) bone mineral density (BMD) increase) or nonresponders (<3% LS BMD increase), and the groups were compared. The univariate analyses determined that prior bisphosphonate use, a lower baseline procollagen type I N-terminal propeptide (PINP) concentration and a lower urinary N-telopeptide of type I collagen (uNTX) concentration at baseline were significantly associated with teriparatide nonresponses, but these factors were not significant following multivariate analysis. Diminished early increases in the bone turnover markers (BTMs) were also related to nonresponses after teriparatide treatment began. In the nonresponders, the mean (standard deviation (SD)) absolute LS and femoral neck (FN) BMD changes were -0.002g/cm(2) (0.032) and -0.010g/cm(2) (0.045), respectively. In the responders, the mean (SD) absolute LS and FN BMD changes were 0.118g/cm(2) (0.056) and 0.021g/cm(2) (0.046), respectively. The serum PINP and uNTX levels increased rapidly in both groups, but the responders showed higher early absolute serum PINP and uNTX increases. The factors associated with nonresponses were prior bisphosphonate use, lower baseline BTM levels, and lower early increases in the BTMs after starting teriparatide treatment, but the impact of these factors on achieving a ≥3% LS BMD increase at 24months was limited.

Hypocalcaemia in patients with metastatic bone disease treated with denosumab

BackgroundThis analysis was performed to further characterise treatment-emergent hypocalcaemia in patients with bone metastases receiving denosumab. MethodsLaboratory abnormalities and adverse events of hypocalcaemia in patients with metastatic bone disease were analysed using data from three identically designed phase 3 trials of subcutaneous denosumab 120mg (n=2841) versus intravenous zoledronic acid 4mg (n=2836). ResultsThe overall incidence of laboratory events of hypocalcaemia grade ⩾2 was higher with denosumab (12.4%) than with zoledronic acid (5.3%). Hypocalcaemia events were primarily grade 2 in severity and usually occurred within the first 6months of treatment. Patients who reported taking calcium and/or vitamin D supplements had a lower incidence of hypocalcaemia. Prostate cancer or small-cell lung cancer, reduced creatinine clearance and higher baseline bone turnover markers of urinary N-telopeptide of type I collagen (uNTx; >50 versus ⩽50nmol/mmol) and bone-specific alkaline phosphatase (BSAP; >20.77μg/L [median] versus ⩽20.77μg/L) values were important risk factors for developing hypocalcaemia. The risk associated with increased baseline BSAP levels was greater among patients who had >2 bone metastases at baseline versus those with ⩽2 bone metastases at baseline. ConclusionHypocalcaemia was more frequent with denosumab versus zoledronic acid, consistent with denosumab’s greater antiresorptive effect. Low serum calcium levels and potential vitamin D deficiency should be corrected before initiating treatment with a potent osteoclast inhibitor, and corrected serum calcium levels should be monitored during treatment. Adequate calcium and vitamin D intake appears to substantially reduce the risk of hypocalcaemia.

Bisphosphonate-associated atypical sub-trochanteric femur fractures: Paired bone biopsy quantitative histomorphometry before and after teriparatide administration

ObjectivesBisphosphonate-associated atypical sub-trochanteric femur fractures (ASFF) may be seen with long-term bisphosphonate use, though these fractures are also seen in patients never exposed to bisphosphonates. One theory for the mechanism of action whereby bisphosphonates may induce these ASFF is over-suppression of bone turnover. Bisphosphonates suppress bone turnover, but in bisphosphonate clinical trials, over-suppression defined whether by maintaining the biochemical markers of bone turnover below the defined reference range or by quantitative bone histomorphometry, has not been observed. MethodsWe studied 15 clinic patients referred to The Colorado Center for Bone Research (CCBR) after they had a bisphosphonate-associated ASFF and performed quantitative bone histomorphometry both before and after 12 months of teriparatide (20µg SQ/day). All patients had been on long-term alendronate (mean = 7 years, range: 6–11 years) and had already had intramedullary rods placed when first seen (6 weeks to 7 months after rod placement). Alendronate had been discontinued in all patients at the time of their first clinic visit to CCBR. All of the fractures fulfilled The American Society for Bone and Mineral Research major radiological criteria for ASFF. ResultsThree key dynamic histomorphometric features show that 7 of the 15 patients had unmeasurable bone formation, mineralizing surface, and mineral apposition, while the other 8 patients had measurable dynamic parameters; although for all 15 patients, the mean values for all 3 dynamic parameters was far below the average for the published normal population. Administration of teriparatide was associated with an increase in all 3 dynamic histomorphometric parameters. Baseline bone turnover markers did not correlate with the baseline histomorphometry. While there is heterogeneity in the bone turnover in patients with bisphosphonate ASFF, there is a large portion in this uncontrolled series that had absent bone turnover at the standard biopsy site (iliac crest). Discontinuation of the bisphosphonate and administration of the anabolic agent, teriparatide was associated with improvement in bone turnover. ConclusionsWhile our study does not establish causality or address the ability of teriparatide to prevent progression of early stress fracture to displaced fractures, it does suggest that teriparatide may improve bone formation in these patients. Our study should stimulate other investigations using larger sample sizes and early stress fractures to see if anabolic agents can reverse these fractures from becoming displaced.

Failure to Suppress Markers of Bone Turnover on First-Line Hormone Therapy for Metastatic Prostate Cancer Is Associated With Shorter Time to Skeletal-Related Event

BackgroundElevated markers of bone turnover are prognostic for shorter survival in castration-resistant prostate cancer. We aimed to determine the prognostic value of bone turnover markers in metastatic hormone-sensitive prostate cancer. Patients and MethodsMarkers of bone turnover (urine deoxypyridinoline [DPD] and N-telopeptide, serum bone alkaline phosphatase (AP), and osteocalcin [OC]) from baseline and after 6 months of study were assessed in men enrolled in a prospective metastatic prostate cancer trial with androgen deprivation therapy (ADT) with or without risedronate (ClinicalTrials.gov, NCT00216060). ResultsSerum samples were collected from 63 patients with bone involvement and a median follow-up of 39.7 months. A multivariate model using Cox regression—which included prostate-specific antigen (PSA) nadir, bisphosphonate treatment, and extent of metastases—showed that suppression of bone turnover markers after 6 months of therapy compared with baseline was significantly associated with longer skeletal-related event (SRE)-free survival. ADT without bisphosphonate therapy was also associated with a decline in markers of bone turnover, presumably resulting from direct anticancer activity. Elevated baseline bone turnover markers were not prognostic. ConclusionFailure to suppress bone turnover while receiving ADT, even when otherwise responding to therapy, may identify patients with hormone-sensitive metastatic prostate cancer who are destined for a shorter time to SREs and progression.