Procollagen Type 1 N Propeptide Research Articles

Abnormal Bone Turnover Observed in Obese Children based on Puberty Stage-Specific Bone Turnover Marker Reference.

Childhood and adolescence are critical periods for lifelong bone health. The impact of obesity on these phases is controversial, which may be due to the lack of standards for age-, sex-, and puberty-specific bone turnover markers (BTMs) that could sensitively reflect bone metabolism. To generate age-, sex, and puberty stage-specific BTM reference curves in children and adolescents and to explore the effect of obesity on bone metabolism in the Chinese population. Our study was part of the Evaluation and Monitoring on School-based Nutrition and Growth in Shenzhen study. A total of 800 participants aged 6∼18 years with normal body mass index (BMI) were selected to establish BTM reference curves for boys and girls at different ages under different pubertal development stages. Additionally, 200 participants with obesity (BMI > 95th percentile) were matched with healthy children from the original cohort at a 1:1 ratio. All participants underwent bone mineral density assessment, and serum levels of procollagen type 1 N-propeptide (P1NP) and β-C-telopeptide of type I collagen (CTX) were measured. The BTM values presented significant age, sex, and puberty stage differences. Analysis of serum BTMs based on the established reference revealed a higher percentage of low-level P1NP in boys with obesity (P = .005); no significant difference was observed in girls. However, the obese group showed a significantly higher proportion of high β-CTX levels for girls, not boys (P = .022). We provide age-, sex-, and puberty stage-specific P1NP and β-CTX reference curves. According to these, obesity appeared to be a negative factor for bone formation in boys and for bone resorption in girls.

Pten knockout in mouse preosteoblasts leads to changes in bone turnover and strength.

Bone development and remodeling are controlled by the phosphoinositide-3-kinase (Pi3k) signaling pathway. We investigated the effects of downregulation of phosphatase and tensin homolog (Pten), a negative regulator of Pi3k signaling, in a mouse model of Pten deficiency in preosteoblasts. We aimed to identify mechanisms that are involved in the regulation of bone turnover and are linked to bone disorders. Femora, tibiae, and bone marrow stromal cells (BMSCs) isolated from mice with a conditional deletion of Pten (Pten cKO) in Osterix/Sp7-expressing osteoprogenitor cells were compared to Cre-negative controls. Bone phenotyping was performed by μCT measurements, bone histomorphometry, quantification of bone turnover markers CTX and procollagen type 1N propeptide (P1NP), and three-point bending test. Proliferation of BMSCs was measured by counting nuclei and Ki-67-stained cells. In vitro, osteogenic differentiation capacity was determined by ALP staining, as well as by detecting gene expression of osteogenic markers. BMSCs from Pten cKO mice were functionally different from control BMSCs. Osteogenic markers were increased in BMSCs derived from Pten cKO mice, while Pten protein expression was lower and Akt phosphorylation was increased. We detected a higher trabecular bone volume and an altered cortical bone morphology in Pten cKO bones with a progressive decrease in bone and tissue mineral density. Pten cKO bones displayed fewer osteoclasts and more osteoblasts (P = .00095) per trabecular bone surface and a higher trabecular bone formation rate. Biomechanical analysis revealed a significantly higher bone strength (P = .00012 for males) and elasticity of Pten cKO femora. On the cellular level, both proliferation and osteogenic differentiation capacity of Pten cKO BMSCs were significantly increased compared to controls. Our findings suggest that Pten knockout in osteoprogenitor cells increases bone stability and elasticity by increasing trabecular bone mass and leads to increased proliferation and osteogenic differentiation of BMSCs.

Variation of Bone Turnover Markers in Childhood and Adolescence.

To determine the bone metabolic marker changes from childhood to adolescence and to provide reference values for monitoring bone development in children in Southwest China. We surveyed 703 participants attending physical examinations from April 2019 and August 2021. Twenty-eight participants were excluded for lack of laboratory tests, and 14 people were excluded for diseases that might affect bone metabolism. A total of 661 children were selected for the study. According to the main developmental periods, the children were divided into preschool, preadolescence, and adolescence groups. Serum bone turnover markers including β-isomerized C-terminal telopeptide of type I collagen (β-CTx), N-terminal midfragment of osteocalcin (N-MID), and procollagen type 1 N-propeptide (P1NP) as well as growth and development indices such as serum calcium (Ca), phosphorus (Pi), alkaline phosphatase (ALP), and vitamin D were measured. The changes in bone metabolism-related markers and the correlations between the indices were analyzed. During the development in boys, the levels of β-CTx and N-MID increased with age from preschool to adolescence, while the levels of P1NP decreased and then increased. In girls, the levels of β-CTx and N-MID plateaued in early adolescence and showed little change in subsequent adolescence, while the levels of P1NP exhibited a downward trend. The correlations between bone metabolism markers and vitamin D were not significant. The levels of bone metabolism markers differed between boys and girls. Reference intervals can be used as essential tools to examine the levels of bone metabolism markers reasonably.

Effect of Intravenous Iron Administration on Bone Mineral and Iron Homeostasis in Patients with Inflammatory Bowel Disease-Results of a Prospective Single-Centre Study.

Anaemia and bone metabolism alterations are common in inflammatory bowel disease (IBD), which is a heterogeneous group of diseases that include Crohn's disease (CD) and ulcerative colitis (UC) with a rich intestinal and extraintestinal symptomatology. All these make the diagnostic procedures complicated and difficult. The aim of this study was to assess the effect of parenteral iron administration on biomarkers of mineral and bone homeostasis over time. The study was a single-centre non-randomised prospective study. It was carried out between 2016 and 2020 in a group of patients in the Department of Internal Medicine and Gastroenterology Subunit of Inflammatory Bowel Diseases at the National Institute of Medicine of the Ministry of the Interior and Administration in Warsaw. At the first examination, the baseline disease severity, initial evaluation of anaemia (morphology, iron (Fe), total iron binding capacity (TIBC), ferritin, vitamin B12, folic acid) and bone mineral metabolism including C-reactive protein (CRP), albumins, alkaline phosphatase (ALP), Calcium, osteocalcin, phosphate in serum and in urine, parathyroid hormone (PTH), vitamin D3, fibroblast growth factor (iFGF23) and procollagen type 1N propeptide (P1NP) C-terminal telopeptide (CTX), was initially assessed. On the basis of peripheral blood counts, an appropriate dose of iron (iron derisomaltose or caboxymaltose) was administered. During the subsequent appointments on week 1, 4, and 12 morphology, iron (Fe), total iron binding capacity (TIBC), ferritin, vitamin B12, folic acid, C-reactive protein (CRP), albumins, alkaline phosphatase (ALP), Calcium, osteocalcin, phosphate in serum and in urine, parathyroid hormone (PTH), vitamin D3, fibroblast growth factor (iFGF23) and procollagen type 1N propeptide (P1NP) C-terminal telopeptide (CTX), were evaluated. A total of 56 patients were enrolled into the study: 24 women and 32 men. In the group, 32 patients had Crohn's disease (CD) and 24 had ulcerative colitis (UC). We found a statistically significant increase in the concentration of albumin (p = 0.031), haemoglobin (p < 0.001), haematocrit (p < 0.001), MCV (p < 0.001), MCHC (p = 0.001), iron (p < 0.001) and ferritin (p < 0.001) after the administration of parenteral iron. The influence of individual iron formulations on the analysed parameters (phosphate concentration in serum and in the urine, iFGF23, P1NP, PTH, vitamin D, haemoglobin and ferritin) was similar. Interestingly, an inverse correlation was found between the concentration of phosphorus in the blood and iFGF23 at certain time-points; however, in the study group they did not significantly affect the disturbances of calcium and phosphate metabolism. In the study group, transient and non-significant disorders of phosphate metabolism were found, which does not constitute a contraindication to treatment with parenteral iron in inflammatory bowel disease patients, which was safe and efficient.

Undercarboxylated Osteocalcin and Its Associations With Bone Mineral Density, Bone Turnover Markers, and Prevalence of Osteopenia and Osteoporosis in Chinese Population: A Cross-Sectional Study.

ObjectiveUndercarboxylated osteocalcin (ucOC) is one form of osteocalcin lacking full carboxylation, which plays an important role in bone homeostasis, glucose homeostasis, and energy metabolism. Our aim is to obtain the profile of serum ucOC level according to gender and age and explore its associations with bone mineral density (BMD), bone turnover markers (BTMs), and prevalence of osteopenia and osteoporosis in the Chinese population.MethodsThis is a cross-sectional study with 900 subjects, composed of 431 men and 469 women. Clinical information was collected, and BMD values of the lumbar spine (L1–4), left femoral neck, and total hip were scanned. Biochemical markers including hepatic and renal function, serum calcium, serum phosphorus, procollagen type 1 N-propeptide (P1NP) β-CrossLaps of type I collagen-containing cross-linked C-telopeptide (β-CTX) intact parathyroid hormone (PTH), 25-hydroxyvitamin D (25OHD), and ucOC were measured.ResultsWe found that the median ucOC level was higher in men than women [men, 2.6 ng/ml; women, 1.6 ng/ml; p < 0.001]. The profile according to age showed that ucOC levels were the lowest at the age of 40–49 years in both men [2.55 ng/ml (95% CI = 1.96–3.13 ng/ml)] and women [1.57 ng/ml (95% CI = 1.12–2.03 ng/ml)]; in patients younger than 49 years, they decreased with age; then over 50 years, they quickly increased. Furthermore, we found that a higher ucOC level was correlated with lower BMD values at the lumbar spine (men, r = −0.128, p = 0.013; women, r = −0.321, p < 0.001), femoral neck (men, r = −0.095, p = 0.062; women, r = −0.260, p < 0.001), and total hip (men, r = −0.123, p = 0.015; women, r = −0.209, p < 0.001) and higher P1NP (men, r = 0.307, p < 0.001; women, r = 0.239, p < 0.001) and β-CTX (men, r = 0.169, p = 0.001; women, r = 0.354, p < 0.001) levels in both men and women. Furthermore, we also showed that a 1 − SD increase in ucOC was associated with an odds ratio (OR) of 1.63 and 1.70 for having osteopenia or osteoporosis in men and women, respectively (men, 95% CI = 1.25–2.13, p = 0.004; women, 95% CI = 1.19–2.42, p = 0.004).ConclusionsWe first revealed the profile of serum ucOC levels according to gender and age in the Chinese population and demonstrated the associations of ucOC with BMD and BTMs and the risk of prevalent osteopenia or osteoporosis. Our findings provide a clue to elucidate the function of ucOC in bone metabolism.

Vitamin D and Bone Health of Older Adults within Care Homes: An Observational Study.

Limited studies have reported vitamin D status and health outcomes in care home residents, a group at risk of vitamin D deficiency. This study investigated serum 25-hydroxyvitamin D (25-OHD) concentrations in older adults within care homes in Northern Ireland (NI) and its association with musculoskeletal health (ultrasound T-score, muscle strength, Timed Up & Go test (TUG)), bone turnover markers (BTMs), and immune function markers. A total of 87 participants were recruited with mean ± SD age 83.2 ± 7.9 years. Mean ± SD serum 25-OHD concentration (n 69) was 49.52 ± 35.58 nmol/L. Vitamin D deficiency (25-OHD <25 nmol/L) was observed in 34.8% (n 24) of participants with 17.4% (n 12) classified as insufficient (25-OHD 25–50 nmol/L) and 47.8% (n 33) as sufficient (25-OHD >50 nmol/L). 25-OHD concentration was not an independent predictor of T-score, muscle strength, TUG, or inflammatory cytokines. After adjusting for covariates, a significant negative association was observed between 25-OHD concentration and the BTMs; osteocalcin (β = −0.395; p = 0.001), procollagen type 1 N propeptide (P1NP) (β = −0.320; p = 0.012), and C-terminal telopeptide of type 1 collagen (CTX) (β = −0.377; p = 0.003). Higher 25-OHD concentration was positively associated with use of vitamin D ± calcium supplementation (β = 0.610; p < 0.001). Vitamin D deficiency and insufficiency were highly prevalent in this sample of care home residents in NI. Higher 25-OHD concentration was associated with greater supplement use and with reduced bone turnover, which in this population is linked with reduced bone loss. These findings emphasize the need for a mandatory vitamin D ± calcium supplementation policy specific for care home residents.

The Cortical Bone Metabolome of C57BL/6J Mice Is Sexually Dimorphic.

ABSTRACTCortical bone quality, which is sexually dimorphic, depends on bone turnover and therefore on the activities of remodeling bone cells. However, sex differences in cortical bone metabolism are not yet defined. Adding to the uncertainty about cortical bone metabolism, the metabolomes of whole bone, isolated cortical bone without marrow, and bone marrow have not been compared. We hypothesized that the metabolome of isolated cortical bone would be distinct from that of bone marrow and would reveal sex differences. Metabolite profiles from liquid chromatography–mass spectrometry (LC‐MS) of whole bone, isolated cortical bone, and bone marrow were generated from humeri from 20‐week‐old female C57Bl/6J mice. The cortical bone metabolomes were then compared for 20‐week‐old female and male C57Bl/6J mice. Femurs from male and female mice were evaluated for flexural material properties and were then categorized into bone strength groups. The metabolome of isolated cortical bone was distinct from both whole bone and bone marrow. We also found sex differences in the isolated cortical bone metabolome. Based on metabolite pathway analysis, females had higher lipid metabolism, and males had higher amino acid metabolism. High‐strength bones, regardless of sex, had greater tryptophan and purine metabolism. For males, high‐strength bones had upregulated nucleotide metabolism, whereas lower‐strength bones had greater pentose phosphate pathway metabolism. Because the higher‐strength groups (females compared with males, high‐strength males compared with lower‐strength males) had higher serum type I collagen cross‐linked C‐telopeptide (CTX1)/procollagen type 1 N propeptide (P1NP), we estimate that the metabolomic signature of bone strength in our study at least partially reflects differences in bone turnover. These data provide novel insight into bone bioenergetics and the sexual dimorphic nature of bone material properties in C57Bl/6 mice. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Bone turnover and mineral metabolism in adult patients with hypophosphatasia treated with asfotase alfa

SummaryThere is limited understanding of how asfotase alfa affects mineral metabolism and bone turnover in adults with pediatric-onset hypophosphatasia. This study showed that adults with hypophosphatasia treated with asfotase alfa experienced significant changes in biochemical markers of bone and mineral metabolism, possibly reflecting enhanced bone remodeling of previously osteomalacic bone.IntroductionHypophosphatasia (HPP), due to a tissue nonspecific alkaline phosphatase (TNSALP) deficiency, can cause impaired bone mineralization and turnover. Although HPP may be treated with asfotase alfa, an enzyme replacement therapy, limited data are available on how treatment with asfotase alfa affects mineral metabolism and bone turnover in adults with HPP.MethodsALP substrates, bone turnover and mineral metabolism markers, and bone mineral density (BMD) data from EmPATHY, a single-center, observational study of adults (≥ 18 years) with pediatric-onset HPP treated with asfotase alfa (NCT03418389), were collected during routine clinical care and analyzed from baseline through 24 months of treatment.ResultsData from 21 patients showed significantly increased ALP activity and reduced urine phosphoethanolamine (PEA)/creatinine (Cr) ratios after baseline through 24 months of asfotase alfa treatment. There were significant transient increases in parathyroid hormone 1-84 (PTH), osteocalcin, and procollagen type 1 N-propeptide (P1NP) levels at 3 and 6 months and in tartrate-resistant acid phosphatase 5b (TRAP5b) levels at 3 months, with a significant decrease in N-terminal telopeptide of type 1 collagen (NTX) levels at 24 months. Lumbar spine BMD T scores continuously increased during treatment.ConclusionSignificant changes in bone turnover and mineral metabolism markers after asfotase alfa treatment suggest that treatment-mediated mineralization may enable remodeling and bone turnover on previously unmineralized surfaces. Urine PEA/Cr ratios may be a useful parameter in monitoring treatment during routine care.

Bone metabolic marker concentrations across the menstrual cycle and phases of combined oral contraceptive use.

There is a need to further understand the impact of the menstrual cycle and phase of combined oral contraceptive (COC) use on the pre-analytical variability of markers of bone metabolism in order to improve standardisation procedures for clinical practice and research. The aim of this study was to assess bone metabolism marker concentrations across the menstrual cycle and phases of COC use. Carboxy-terminal cross-linking telopeptide of type I collagen (β-CTX), procollagen type 1N propeptide (P1NP) and Bone alkaline phosphatase (Bone ALP) concentrations were assessed in eumenorrheic women (n=14) during the early follicular, ovulatory and mid-luteal phases of the menstrual cycle and in COC (Microgynon®) (n=14) users on day 2-3 of pill consumption (PC1), day 15-16 pill consumption (PC2) and day 3-4 of the pill free interval (PFI). β-CTX was significantly (-16%) lower at PC2 compared to PC1 (P=0.015) in COC users and was not affected by menstrual cycle phase (P>0.05). P1NP and Bone ALP were not significantly different across either menstrual cycle phase or phase of COC use (all P>0.05). There was no difference in pooled bone marker concentrations between eumenorrheic women and COC users (P>0.05). In contrast to some previous studies, this study showed that bone marker concentrations do not significantly fluctuate across the menstrual cycle. Furthermore, bone resorption markers are significantly affected by phase of COC use, although bone formation markers do not significantly vary by COC phase. Therefore, the phase of COC use should be considered in clinical practice and research when assessing markers of bone metabolism as this can impact circulating concentrations of bone metabolic markers yet is not currently considered in existing guidelines for best practice.

Propranolol Promotes Bone Formation and Limits Resorption Through Novel Mechanisms During Anabolic Parathyroid Hormone Treatment in Female C57BL/6J Mice.

Although the nonselective β-blocker, propranolol, improves bone density with parathyroid hormone (PTH) treatment in mice, the mechanism of this effect is unclear. To address this, we used a combination of in vitro and in vivo approaches to address how propranolol influences bone remodeling in the context of PTH treatment. In female C57BL/6J mice, intermittent PTH and propranolol administration had complementary effects in the trabecular bone of the distal femur and fifth lumbar vertebra (L5 ), with combination treatment achieving microarchitectural parameters beyond that of PTH alone. Combined treatment improved the serum bone formation marker, procollagen type 1 N propeptide (P1NP), but did not impact other histomorphometric parameters relating to osteoblast function at the L5 . In vitro, propranolol amplified the acute, PTH-induced, intracellular calcium signal in osteoblast-like cells. The most striking finding, however, was suppression of PTH-induced bone resorption. Despite this, PTH-induced receptor activator of nuclear factor κ-B ligand (RANKL) mRNA and protein levels were unaltered by propranolol, which led us to hypothesize that propranolol could act directly on osteoclasts. Using in situ methods, we found Adrb2 expression in osteoclasts in vivo, suggesting β-blockers may directly impact osteoclasts. Consistent with this, we found propranolol directly suppresses osteoclast differentiation in vitro. Taken together, this work suggests a strong anti-osteoclastic effect of nonselective β-blockers in vivo, indicating that combining propranolol with PTH could be beneficial to patients with extremely low bone density. © 2022 American Society for Bone and Mineral Research (ASBMR).

SUN-386 Treatment Outcomes of Intravenous Zoledronic Acid vs Oral Alendronate in Postmenopausal Women with Osteoporosis

In real practice, many patients with osteoporosis are poorly compliant with oral bisphosphonate, partly due to gastrointestinal side effects and partly due to medication procedure leading to premature termination of treatment. Once yearly intravenous zoledronic acid is well tolerated; little or no gastrointestinal effects and effective drug in treatment of postmenopausal osteoporosis with favourable dosing regimen to improve compliance of patients. So this study aims to study treatment outcomes of intravenous zoledronic acid vs oral alendronate in postmenopausal women with osteoporosis. This study was a randomized open label comparative study and included 94 postmenopausal women with osteoporosis. In this study, once yearly zoledronic acid (ZOL) infusion provided a greater reduction of serum procollagen type 1 N propeptide (P1NP) at 3 months than once weekly oral alendronate (ALN). Percentages of P1NP change in ZOL group was -70.25±17.51% and ALN group was -60.61±18.87% (P= 0.012). A decrease of P1NP ≥40% was observed in the majority of patients in both groups (89.4% in ZOL group and 85.1% in ALN group) (P= 0.536). ZOL was non-inferior to ALN in terms of BMD change at lumbar spine (4.8±5.5% in ZOL versus 4.9±4.5% in ALN treated patients) with P value of 0.922 and also at total hip (3.8±8.0% in ZOL versus 3.8±7.5% in ALN group) (P= 0.970). Two cases (4.3%) of new fractures was observed in ZOL group whereas 4 cases (8.5%) of new fractures occurred in ALN group over one year of study. The overall frequencies of treatment related adverse effects were similar between ZOL group (57.4%) and ALN group (42.6%) (P= 0.149). ZOL group showed significantly increased frequencies of musculoskeletal pain (57.4%) and acute phase reaction (12.8%) and 12.8% of participants in ALN group complained of heartburn. The overall preference to continue current medication was higher in ZOL group than ALN group (P= 0.002). The participants treated with ZOL were tend to have more satisfaction (P= 0.026) and willing to receive it longer period (P< 0.001).Compared to weekly oral alendronate therapy in treatment of postmenopausal osteoporosis, yearly infusion of 5 mg zoledronic acid infusion produced a significant greater response in serum P1NP at 3 months and similar change in BMD at one year of treatment and overall frequencies of adverse effects were similar between two treatment groups with excellent patient preference and satisfaction after zoledronate treatment. Reference: (1) Al-Bogami et al (2015) Favorable therapeutic response of osteoporotic patients to treatment with intravenous zoledronate compared with oral alendronate. Saudi Med J. 36(11):1305-1311. (2) Saag et al (2007) A single zoledronic acid infusion reduces bone resorption markers more rapidly than weekly oral alendronate in postmenopausal women with low bone mineral density. Bone. 40:1238-1243.

MON-180 EVEROLIMUS ASSOCIATED OSTEONECROSIS OF THE JAW IN KIDNEY TRANSPLANT RECIPIENT

Mammalian target of rapamycin (mTOR) inhibitors, used in kidney transplant recipients, inhibit T-cell activation and vascular endothelial growth factor (VEGF) pathways, thereby exerting antiproliferative and antiangiogenic effects. Osteonecrosis of the jaw (ONJ) is a serious side-effect of antiresorptive and anti-angiogenic therapies. We report a unique case of osteonecrosis of the jaw associated with use of everolimus in a kidney transplant recipient. A 65-year-old man with polycystic kidney disease and subtotal parathyroidectomy for tertiary hyperparathyroidism, received a deceased donor kidney transplant in 2015 with basiliximab, tacrolimus, mycophenolate and prednisolone immunosuppression. He suffered non-immune delayed graft function and recovered with a 12-month serum creatinine of 230umol/L (eGFR 25ml/min/1.73sq.m). Tacrolimus was changed to everolimus to optimise renal function and retard interstitial fibrosis secondary to CNI use. In November 2017, he presented with swollen gums and left maxillary tenderness with gingival inflammation, exposed maxilla and purulent discharge, indicating infective periodontal disease. He was managed conservatively with antibiotics and dental extractions. His renal function was stable on everolimus 1mg BD with a trough level (C0) at 3.0-4.0 ng/ml. Six months later, he had progressive severe pain limiting oral intake, with 10kg weight loss. A CT head showed progressive bony destruction of maxilla, erosion of the maxillary sinus floor and an oro-antral fistula, consistent with ONJ. Bone biopsy ruled out malignancy, showing necrotic bony trabeculae filled with bacteria. He had never received bisphosphonate, denosumab or radiotherapy. He was on everolimus 0.75mg BD (C0= 3.0ng/ml). Tests revealed relatively low bone turnover markers in the context of active osteonecrosis: parathyroid hormone (PTH) <1.1pmol/L (1.6-6.0pmol/L), procollagen type 1 N propeptide (P1NP) 17ug/L(15-80ug/L), alkaline phosphatase (ALP) 69 U/L (30-110U/L), and C-telopeptide (CTX) 432ng/L (100-600ng/L). In view of its anti-proliferative and possible inhibitory effects on bone turnover, everolimus was ceased. He underwent surgical exploration of the sinuses, debridement of the palate with full upper dental clearance. He was treated with teriparatide 20ug monthly to stimulate bone turnover. Four-months later, the osteonecrotic process had abated, the exposed bone was stable and there were signs of healing. His nutrition status improved and he gained back his lost weight. This is the first case of everolimus associated ONJ in a kidney transplant recipient, despite being on relatively low dose therapy. The suppression of bone resorption via parathyroidectomy and additional inhibitory effect of everolimus resulted in the uncoupling of bone resorption and formation processes. This case not only underlies the importance of considering the potential of ONJ with everolimus in transplant recipients, particularly in those with poor dentition, malignancy, hypoparathyroidism or previous parathyroidectomy, and renal bone disease but also indicates possible therapeutic role of teriparatide in this situation.

2444-PUB: Bone Mineral Density and Bone Biomarkers in Women with Type 2 Diabetes Mellitus of Buryat Ethnic Group

There is a difference of bone tissue state of women belonging to various ethnic groups. We have conducted a study of bone tissue state among postmenopausal women of Buryat origin. Buryats are a main northern group of Mongolians, they are a core population of Siberia with a compact residence close to Lake Baikal. We have examined the associations between bone mineral density (BMD), trabecular bone score (TBS) and bone biomarkers in 17 postmenopausal women with T2D (59 years, diabetes duration 5.2 years, A1c &amp;lt;8.0%) and 21 postmenopausal women without diabetes (56 years). Collagen type 1 cross-linked C-telopeptide (CTX), 25-hydroxyvitamin D, ionized calcium (iCa), femoral neck BMD were similar between two groups. T2D postmenopausal women had lower osteocalcin (OC), procollagen type 1 N propeptide (P1NP), TBS and higher BMD total hip, BMD lumbar spine 1-4 (L1-L4) compared to the controls (Table). Total hip BMD in women with T2D was associated with body mass index (BMI). TBS was positively correlated with iCa. Twenty-five-hydroxyvitamin D was associated with lower OC, P1NP and CTX. Total hip BMD and BMD L1-L4 were positively correlated with BMI in women without diabetes. Femoral neck BMD was positively correlated with P1NP and inversely correlated with women’s age. T2D in Buryat women is associated with low levels of osteosynthesis markers, TBS and higher BMD. TBS was positively correlated only with iCa. Disclosure T. Bardymova: None. M. Mistiakov: None. M. Berezina: None. S. Tsyretorova: None. V. Velm: None.

Consensus Statement on the Use of Bone Turnover Markers for Short-Term Monitoring of Osteoporosis Treatment in the Asia-Pacific Region

Osteoporosis is a major health issue. By 2050, a greater than 2-fold increase in patients number with hip fractures will occur in Asia representing 50% of all hip fractures worldwide. For the Asia-Pacific (AP) region, more efforts on controlling osteoporosis and the subsequent fractures are crucial. Bone mineral density (BMD) by dual energy X-ray absorptiometry (DXA) is commonly used to diagnose osteoporosis and monitor osteoporosis treatment. However, the inconvenience, cost, limited availability of DXA and the delay in detection of BMD changes after treatment initiation support an important role for bone turnover markers (BTMs), as short-term tools to monitor therapy. With regards to low adherence rates of medical treatment of osteoporosis, the experts reached consensus on the use of BTMs for both raising awareness and short-term monitoring of osteoporosis treatment in the AP region. The experts endorse the use of BTMs, especially serum C-terminal telopeptide of type 1 collagen (CTX) and serum procollagen type 1 N propeptide (P1NP), as short-term monitoring tools to help clinicians assess the responses to osteoporosis therapies and appropriately adjust treatment regimens earlier than BMD. Either the absolute values or the degree of change from baseline in BTMs can be used to monitor the potential efficacy of osteoporosis therapies. The use of BTMs can be incorporated in osteoporosis care programs, such as fracture liaison service (FLS), to improve patient adherence and treatment outcomes. Encouraging sufficient reimbursement from health care systems may facilitate widespread use of BTMs in clinical practice in the AP region.

Serum procollagen type 1 N propeptide: A novel diagnostic test for diabetic foot osteomyelitis - A case-control study.

Background:The objective of the study was to determine whether serum levels of procollagen type 1 N propeptide (P1NP), a bone formation turnover marker, differs between diabetic foot ulcer with osteomyelitis (DFO) and diabetic foot ulcers without osteomyelitis serving as controls. It was also aimed to assess the usefulness of P1NP in diagnosing DFO compared to other common inflammatory markers.Materials and Methods:A case–control study was designed comparing the aforementioned groups. Patients were classified as osteomyelitis and controls based on the International Working Group diagnostic criteria. Serum P1NP and three other inflammatory markers, namely, C-reactive protein (CRP), white blood cells (WBC), and platelets were analyzed on patients with DFO and controls.Results:The mean serum P1NP levels were significantly higher in the DFO group (n: 16), 10.5 ± 5.2 (ng/ml), than the control group (n: 11) 3.1 ± 2.8 (ng/ml), P = 0.001. P1NP showed the highest sensitivity/specificity 86.7%/80% compared to 70.6%/80%, 56.2%/45.4%, and 50%/37% for CRP, WBC and platelets, respectively. Receiver operator characteristic curves showed the best value of area under the curve of 0.9 for P1NP compared to 0.85, 0.54, and 0.46 for CRP, WBC, and platelets.Conclusion:We found marked elevation of serum P1NP in diabetic foot ulcer with bone infection with potential value in using it to diagnose DFO.

Bone turnover marker determinants in young women: results from the Safe-D study.

Background Bone turnover markers (BTMs) may provide insight into bone health in young women, but have been little studied in this demographic. We aimed to explore the association between body composition, hormonal contraception, bone mineral density and biochemical parameters and BTMs in young women. Methods Participants were community-dwelling females aged 16-25 years, living in Victoria, Australia. Carboxy-terminal cross-linking telopeptide of type 1 collagen (CTX) and total procollagen type 1 N-propeptide (P1NP) were analysed on the Roche Elecsys automated analyzer. A total of 305 were evaluated, after excluding participants with medical conditions or medications (except hormonal contraceptives), which may affect bone metabolism. Results Median (Q1, Q3) BTM values were 540 (410, 690) ng/L for CTX and 61.7 (46.2, 83.7) µg/L for P1NP. Serum CTX and P1NP were inversely associated with chronological age ( P < 0.001), transferrin ( P < 0.020) and serum dehydroepiandrosterone sulphate concentration ( P < 0.001). BTM values were up to 22% lower in combined oral contraceptive (COC) pill users ( P < 0.001). Serum CTX was inversely associated with per cent body fat ( P = 0.009) and tibial cortical volumetric bone mineral density (vBMD; P = 0.003). Serum P1NP concentrations were 23 µg/L higher in participants who reported using an osteopath in the previous year ( P = 0.007). Conclusions These data suggest that BTMs are influenced by age, COC use, body composition, iron status and hormonal profiles. Higher CTX values were associated with lower tibial cortical vBMD. Examining BTMs in relation to interventions aimed at improving bone health in young women is warranted.

Variations of parathyroid hormone and bone biomarkers are concordant only after a long term follow-up in hemodialyzed patients

End-stage renal disease is associated with mineral and bone disorders. Guidelines recommending therapies should be based on serial assessments of biomarkers, and thus on variations (Δ), rather than scattered values. We analyzed the correlations between ΔPTH and Δbone biomarkers such as bone-specific alkaline phosphatase (b-ALP), Beta-CrossLaps (CTX), osteocalcin, intact serum procollagen type-1 N-propeptide (P1NP), and tartrate-resistant acid phosphatase 5B (TRAP-5B) at different time-points. In this prospective observational analysis, variations of biomarkers were followed after 6-week (n = 129), 6-month (n = 108) and one-year (n = 93) period. Associations between variations were studied by univariate linear regression. Patients followed for one-year period were classified (increaser or decliner) according to variations reaching the critical difference. Over the 6-week period, only ΔCTX was correlated with ΔPTH (r = 0.38, p < 0.0001). Over the one-year period, correlations between ΔPTH and Δbone biomarkers became significant (r from 0.23 to 0.47, p < 0.01), except with ΔTRAP-5b. Correlations between Δbone biomarkers were all significant after one-year period (r from 0.31 to 0.68, p < 0.01), except between Δb-ALP and ΔTRAP-5b. In the head-to-head classifications (decliners/increasers), the percentage of concordant patients was significantly higher over the one-year than the 6-week period. A concordance between ΔPTH and Δbone biomarkers is observed in dialysis patients, but only after a long follow-up.

Safety and pharmacodynamic dose response of short-term prednisone in healthy adult subjects: a dose ranging, randomized, placebo-controlled, crossover study.

BackgroundGlucocorticoids (GCs), such as prednisone, are the standard of care for several inflammatory and immunologically mediated diseases, but their chronic systemic administration is severely limited by serious adverse effects that are both dose and time dependent. Short-term treatment (7–14 days) with oral prednisone is used for many acute inflammatory and allergic conditions. This study was conducted to characterize the safety and pharmacodynamic (PD) dose–response of a 7-day course of oral prednisone on biomarkers of GC receptor agonism.MethodsIn this randomized, single-blind, placebo-controlled, crossover study (A9001309), 37 healthy subjects received placebo or a prednisone dose from 2.5–60 mg daily over 7 days in each of three treatment periods. White blood cell counts and plasma samples for measuring cortisol, osteocalcin and procollagen type 1 N-propeptide (P1NP) were obtained at 2, 4, 8, and 12 h post-dose on Day 1, immediately prior to dosing on Days 1, 2, and 4, and at nominal dosing time on Days 0 and 8. Urine samples for urinary N-terminal cross-linked telopeptide of type 1 collagen (uNTX) were collected on Days 0, 1, 2, 4, and 8. Serum samples for adiponectin were obtained prior to dosing on days 0, 1, 4 and 8.ResultsDaily doses of prednisone up to 60 mg resulted in dose- and time-dependent decreases in plasma osteocalcin, plasma P1NP, serum cortisol, and absolute blood eosinophil counts. Absolute blood neutrophil counts increased, while blood lymphocyte counts rebounded to an increased level following an initial rapid decrease after dosing. An increase was observed for uNTX and adiponectin. The incidence of adverse effects with prednisone was not dose related, and nervous system disorders, mainly headache, were the most frequently reported adverse effects.ConclusionsThis characterization provides important and relevant information on safety and PD responses of short-term prednisone dosing over the commonly-used clinical dose range, and also provides a reference for early clinical development of dissociated agents targeting a differentiated PD profile.Trial registration numberNCT02767089 (retrospectively registered: 21 April 2016).

Diurnal Rhythms of Bone Turnover Markers in Three Ethnic Groups.

Context:Ethnic groups differ in fragility fracture risk and bone metabolism. Differences in diurnal rhythms (DRs) of bone turnover and PTH may play a role.Objective:We investigated the DRs of plasma bone turnover markers (BTMs), PTH, and 1,25(OH)2D in three groups with pronounced differences in bone metabolism and plasma PTH.Participants:Healthy Gambian, Chinese, and white British adults (ages 60–75 years; 30 per country).Interventions:Observational study with sample collection every 4 hours for 24 hours.Main Outcomes:Levels of plasma C-terminal telopeptide of type I collagen, procollagen type-1 N-propeptide, N-mid osteocalcin, bone alkaline phosphatase, PTH, and 1,25-dihydroxyvitamin D were measured. DRs were analyzed with random-effects Fourier regression and cross-correlation and regression analyses to assess associations between DRs and fasting and 24-hour means of BTMs and PTH.Results:Concentrations of BTMs, PTH, and 1,25-dihydroxyvitamin D were higher in Gambians compared to other groups (P < .05). The DRs were significant for all variables and groups (P < .03) and were unimodal, with a nocturnal peak and a daytime nadir for BTMs, whereas PTH had two peaks. The DRs of BTMs and PTH were significantly cross-correlated for all groups (P < .05). There was a significant positive association between C-terminal telopeptide of type I collagen and PTH in the British and Gambian groups (P = .03), but not the Chinese group.Conclusions:Despite ethnic differences in plasma BTMs and PTH, DRs were similar. This indicates that alteration of rhythmicity and loss of coupling of bone resorption and formation associated with an elevated PTH in other studies may not uniformly occur across different populations and needs to be considered in the interpretation of PTH as a risk factor of increased bone loss.

Clinical utility of C-terminal telopeptide of type 1 collagen in multiple myeloma.

Myeloma bone disease (MBD) is a major cause of morbidity in multiple myeloma (MM). We investigated bone turnover markers (BTM) as relapse predictors and biomarkers for monitoring MBD. We measured C-terminal telopeptide of type I collagen (CTX-1), and Procollagen type 1 N Propeptide (P1NP) in 86 MM patients and 26 controls. CTX-1 was higher in newly diagnosed patients compared to control, remission and relapse (P < 0·05), and decreased following treatment. In the setting of relapse, a CTX-1 rise greater than the calculated least significant change (LSC) was observed in 26% of patients 3-6 months prior to relapse (P = 0·007), and in 60·8% up to 3 months before relapse (P = 0·015). Statistically significant changes in CTX-1 levels were also observed in patients who were with and without bisphosphonate therapy at the time of relapse. In patients with normal renal function, mean CTX-1 level was highest in the newly diagnosed group (0·771 ± 0·400 μg/l), and lowest in the remission group (0·099 ± 0·070 μg/l) (P < 0·0001). P1NP levels were not statistically different across the patient groups. We conclude that CTX-1, measured on an automated hospital laboratory platform, has a role in routine treatment monitoring and predicting relapse of MBD, even in patients on bisphosphonates.