Serum Markers Of Bone Metabolism Research Articles

Role of R-spondin 2 on osteogenic differentiation of bone marrow mesenchymal stem cells and bone metabolism in ovariectomized mice

To investigate the effects of R-spondin 2 (Rspo2) on the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and bone mineral content in ovariectomized mice. BMSCs were extracted from the bone marrow of the long bones of 7 4-week-old female C57BL/6 mice using whole bone marrow culture and passaged. After the cell phenotype was identified by flow cytometry, the 3rd generation cells were co-cultured with 10, 20, 40, 80, and 100 nmol/L Rspo2. Then, the cell activity and proliferative capacity were determined by cell counting kit 8 (CCK-8), and the intervention concentration of Rspo2 was screened for the subsequent experiments. The osteogenic differentiation ability of BMSCs was detected by alkaline phosphatase (ALP) staining, and the mRNA levels of osteogenesis-related genes [RUNX family transcription factor 2 (Runx2), collagen type Ⅰ alpha 1 (Col1), osteocalcin (OCN)] were detected by real-time fluorescence quantitative PCR (RT-qPCR). In addition, 18 10-week-old female C57BL/6 mice were randomly divided into sham operation group (sham group), ovariectomy group (OVX group), and OVX+Rspo2-intervention group (OVX+Rspo2 group), with 6 mice in each group. The sham group only underwent bilateral back incision and suturing, while the other two groups established osteoporosis mouse models by bilateral ovarian castration. Then, the mice were given a weekly intraperitoneal Rspo2 (1 mg/kg) treatment in OVX+Rspo2 group and saline at the same dosage in sham group and OVX group. After 12 weeks of treatment, the body mass and uterus mass of the mice were weighed in the 3 groups to assess whether the OVX model was successfully prepared; the tibia bones were stained with HE and immunohistochemistry staining to observe the changes in tibial bone mass and the expression level of Runx2 protein in the bone tissues. Blood was collected to detect the expressions of bone metabolism markers [ALP, OCN, type Ⅰ procollagen amino-terminal peptide (PINP)] and bone resorption marker [β-collagen degradation product (β-CTX)] by ELISA assay. Micro-CT was used to detect the bone microstructure changes in the tibia, and three-dimensional histomorphometric analyses were performed to analyze the trabeculae thickness (Tb.Th), trabeculae number (Tb.N), trabeculae separation (Tb.Sp), and bone volume fraction (BV/TV). CCK-8 assay showed that Rspo2 concentrations below 80 nmol/L were not cytotoxic ( P>0.05), and the cell viability of 20 nmol/L Rspo2 group was significantly higher than that of the control group ( P<0.05). Based on the above results, 10, 20, and 40 nmol/L Rspo2 were selected for subsequent experiments. ALP staining showed that the positive cell area of each concentration of Rspo2 group was significantly larger than that of the control group ( P<0.05), with the highest showed in the 20 nmol/L Rspo2 group. The expression levels of the osteogenesis-related genes (Runx2, Col1, OCN) significantly increased, and the differences were significant between Rspo2 groups and control group ( P<0.05) except for Runx2 in the 40 nmol/L Rspo2 group. In animal experiments, all groups of mice survived until the completion of the experiment, and the results of the body mass and uterus mass after 12 weeks of treatment showed that the OVX model was successfully prepared. Histological and immunohistochemical staining showed that the sparseness and connectivity of bone trabecula and the expression of Runx2 in the OVX group were lower than those in the sham group, whereas they were reversed in the OVX+Rspo2 group after treatment with Rspo2, and the differences were significant ( P<0.05). ELISA assay showed that compared with the sham group, the serum bone metabolism markers in OVX group had an increase in ALP and a decrease in PINP ( P<0.05). After Rspo2 intervention, PINP expression significantly reversed and increased, with significant differences compared to the sham group and OVX group ( P<0.05). The bone resorption marker (β-CTX) was significantly higher in the OVX group than in the sham group ( P<0.05), and it was significantly decreased in the OVX+Rspo2 group when compared with the OVX group ( P<0.05). Compared with the sham group, Tb.Th, Tb.N, and BV/TV significantly decreased in the OVX group, while Tb.Sp significantly increased ( P<0.05); after Rspo2 intervention, all of the above indexes significantly improved in the OVX+Rspo2 group ( P<0.05) except Tb.Th. Rspo2 promotes differentiation of BMSCs to osteoblasts, ameliorates osteoporosis due to estrogen deficiency, and promotes bone formation in mice.

Herbal formula xuling-jiangu improves bone metabolic balance in rats with ovariectomy-induced osteoporosis via the gut-bone axis.

The XuLing JianGu recipe (XLJGR) is an empirical traditional Chinese medicine formula used for the treatment of osteoporosis. This study aims to explore the effects of XLJGR on the intestinal microbiota composition and endogenous metabolites in ovariectomized (OVX) rats. An OVX rat model was established to evaluate the intervention effects of XLJGR. The measured indicators included bone density, serum bone metabolism markers, and an analysis of the types and abundances of intestinal microbiota, along with changes in endogenous metabolites. Additionally, MC3T3-E1 cells were used to validate the differential metabolites. XLJGR significantly reduced the abundance of Bacteroides, Butyricicoccus, and other bacterial strains in the gut. KEGG metabolic pathway enrichment analysis showed that XLJGR intervention led to notable changes in pathways such as peptidoglycan biosynthesis, carbapenem biosynthesis, and vancomycin resistance. Moreover, XLJGR significantly upregulated key intestinal microbiota metabolites, including gabapentin(GAB), camphoric acid(CAA), and nonanedioic acid(AZA), thereby promoting the proliferation and osteogenic differentiation of MC3T3-E1 cells. This study highlights the potential biomedical applications of XLJGR in promoting bone health by positively affecting intestinal microbiota and metabolic characteristics. These findings suggest that XLJGR may serve as a viable alternative in the treatment of osteoporosis, warranting further exploration of its therapeutic mechanisms and clinical applications.

Low bone mineral density and its influencing factors in spinal muscular atrophy without disease-modifying treatment: a single-centre cross-sectional study

BackgroundChildren with spinal muscular atrophy (SMA) are at risk of low bone mineral density (BMD) and bone fragility. This study aims to assess lumbar spine BMD measured by quantitative computed tomography (QCT) and investigate influencing factors of low BMD in children with SMA without disease-modifying treatment.MethodsDemographic data, laboratory parameters, QCT data, and data on spinal radiographs were collected. A linear regression model was carried out to explore the correlations between BMD and its related factors.ResultsSixty-six patients with SMA who had complete records between July 2017 and July 2023 were analyzed, with SMA with a mean age of 5.4 years (range, 2.4–9.7 years), including type 1 in 14, type 2 in 37, and type 3 in 15. 28.8% of patients (19/66) were diagnosed with low BMD (Z-scores ≤ − 2), and the mean BMD Z-scores on QCT was − 1.5 ± 1.0. In our model, BMD Z-scores was associated with age (β=-0.153, p = 0.001). SMA phenotype and serum bone metabolism markers, such as serum phosphorus (P), alkaline phosphatase (ALP) and 25-Hydroxyvitamin D (25-OH-D) levels did not independently predict low BMD. ROC analysis showed that the age ≥ 6.3 years predicts a Z-scores ≤ -2.0 with a sensitivity of 68.4% and a specificity of 68.1%.ConclusionsLow BMD were highly prevalent in children with SMA without disease-modifying treatment in our centre. Regular monitoring of BMD is necessary for all types of SMA children, especially those aged ≥ 6.3 years.

Comparison of Denosumab with Romosozumab in the treatment of male osteoporosis: a retrospective cohort study

We aimed to investigate the efficacy of romosozumab treatment compared with that of denosumab in especially male osteoporosis patients. This retrospective cohort study included 174 Japanese male patients receiving either denosumab or romosozumab for 12 months. Propensity score matching extracted 50 patients per treatment group for standardization of group characteristics. The endpoints include the rate of change in the bone mineral density (BMD) of the lumbar spine, total hip, and femoral neck after 12 months of treatment as well as the changes in serum bone metabolism markers. The mean 12-month percentage increase in the lumbar spine BMD from baseline was significantly greater with romosozumab (13.0% ±1.7%) than with denosumab (4.5%±0.6%) (P < 0.01). The total hip and femoral neck BMD exhibited a similar trend at 12 months; however, no significant between-group differences were observed. With denosumab, bone formation, and resorption marker levels significantly decreased at 6 and 12 months. Conversely, with romosozumab, the levels of bone formation markers increased transiently at 6 months before returning to baseline, whereas bone resorption markers significantly decreased at both time points. Romosozumab demonstrated significantly superior effects over denosumab in improving BMD, especially of the lumbar spine, suggesting that romosozumab can be used for treating male osteoporosis.

Association between changes in serum bone metabolism markers and bone microarchitecture changes during basic combat training – The ARMI study

ImportanceU.S. Army Basic Combat Training (BCT) improves tibial volumetric bone mineral density (BMD) and structure in most, but not all soldiers. Few studies have investigated whether changes in serum bone biomarkers during BCT are associated with changes in tibial BMD and bone structure following BCT. ObjectiveTo characterize bone biomarker changes during BCT and to investigate the relationship between changes in bone biomarkers and changes in tibial BMD and bone structure. MethodsWe enrolled 235 trainees entering BCT in this ten-week prospective observational study. Trainees provided fasted blood samples and questionnaires weekly throughout BCT. Procollagen type 1 N-terminal propeptide (PINP) and C-terminal telopeptide of type 1 collagen (CTX) were measured by enzyme-linked immunoabsorbent assays every two weeks during BCT. We evaluated body composition and mass via dual-energy X-ray absorptiometry and bone structure, microarchitecture, and mineral density at the distal tibia via high-resolution peripheral quantitative computed tomography at baseline and post-BCT. ResultsBoth male (n = 110) and female trainees (n = 125) were young (20.9 ± 3.7 and 20.7 ± 4.3 years, respectively), with normal to overweight BMIs (25.2 ± 4.1 and 24.2 ± 3.6 kg/m2, respectively). In female trainees, PINP increased during and post-BCT compared to baseline, with the greatest increase in PINP at week four (45.4 % ± 49.6, p < 0.0001), whereas there were no changes in CTX. PINP also increased in male trainees, but only at weeks two and four (21.9 % ± 24.5, p = 0.0027 and 35.9 % ± 35.8, p < 0.0001, respectively). Unlike female trainees, in males, CTX was lower than baseline at weeks four, eight, and post-BCT. The change in PINP from baseline to week four of BCT was positively associated with changes in tibial BMD, Tb.BMD, Tb.Th, Tb.BV/TV, Ct.Th, Ct.Ar, and Ct.Po from the baseline to post-BCT. ConclusionThe bone formation marker PINP increases during U.S. Army BCT, especially during the first four weeks. Increases in PINP, but not CTX, were correlated with improved BMD and bone structure in the distal tibia.

Impact of Lactobacillus acidophilus and Its Combination with Isoflavone Products on Calcium Status, Calcium Transporters, and Bone Metabolism Biomarkers in a Post-Menopausal Osteoporotic Rat Model.

Osteoporosis in menopausal women requires alternatives to current medications, considering their adverse effects. In this context, probiotics and isoflavone products are promising dietary interventions. The objective of our study was to examine the impacts of Lactobacillus acidophilus and its combination with daidzein and tempeh on calcium status, calcium transporters, and bone metabolism biomarkers in a post-menopausal osteoporotic rat model. A total of 48 female Wistar rats were exposed to a two-stage experiment involving calcium deficit induction and subsequent dietary interventions across six groups. Calcium levels, the gene expression of TRPV5 and TRPV6 calcium transporters, bone histopathology, serum bone metabolism markers, and blood biochemistry were evaluated. The results revealed that, while decreasing serum calcium levels, the groups that received the probiotic L. acidophilus and isoflavone combination exhibited increased bone metabolism biomarkers and decreased calcium transporter expressions, akin to the effects of bisphosphonate. Additionally, significant improvements in bone histopathology were observed in these groups. However, the group receiving probiotic L. acidophilus alone did not exhibit significant changes in bone resorption biomarkers, calcium transporter expression, or various blood parameters. Meanwhile, the combination of probiotic L. acidophilus with tempeh positively influenced hematological parameters and reduced cholesterol and triglyceride levels, but it led to elevated blood glucose levels. Correlation analyses highlighted associations between serum calcium levels, calcium transporter expression, and bone metabolism biomarkers. In conclusion, our findings suggest that the daily consumption of probiotic L. acidophilus in combination with isoflavone products may improve bone health in ovariectomized rats, warranting further research to elucidate potential interactions with other nutrients.

An HFD negatively influences both joint and liver health in rabbits with and without an enzymatically-induced model of arthritis

Osteoarthritis (OA) is a common arthritis types in animals that causes persistent pain and reduces quality of life. Although a high-fat diet (HFD) is widely believed to induce obesity and have adverse effects on the body, the connection between HFD and joint health is not well understood. Therefore, in this study, 32 healthy male New Zealand rabbits were randomly divided into four groups: healthy rabbits fed a standard diet (NDG, n=8) or an HFD (HDG, n=8), rabbits fed a standard diet (OAG, n=8) and an HFD (HOG, n=8), and arthritis was induced by intra-articular enzyme injection. After 12 weeks of HFD feeding, articular cartilage, synovium, and subchondral bone were isolated and collected. Joint tissue damage was evaluated using histopathological and imaging tests. The results showed that there was no significant difference in body weight between rabbits fed a normal diet and those fed an HFD. However, the HFD led to an increase in joint injuries in both induced and non-induced arthritis rabbits. Specifically, the HFD induced lipid metabolism disorders and liver damage in vivo, significantly elevating the levels of serum inflammatory cytokines and bone metabolism markers. Moreover, HFD exacerbated articular cartilage damage in the joints and increased the accumulation of inflammatory cells in synovial tissue, resulting in a notable increase in synovial macrophages and inflammatory cytokines. Additionally, HFD accelerated the bone resorption process in subchondral bone, leading to the destruction of bone mass and subchondral bone microstructure. In summary, the results of this study indicate that an HFD can cause histological damage to the articular cartilage, synovium, and subchondral bone in rabbits, exacerbating arthritis in pre-existing joint damage. Notably, weight is not the primary factor in this effect.

Impact of high fat and low lean mass phenotype on bone mineral content: A cross-sectional study of Chinese adolescent population

Background and ObjectiveResearch on body composition phenotypes and bone health in adolescents is limited. Hence, this study aimed to analyze the relationship between different body composition phenotypes, bone mineral content, and bone metabolism markers in Chinese adolescents. MethodsIn this cross-sectional study, 1852 adolescents aged 12 to 18 years were selected from six schools in Yinchuan City between 2017 and 2020 using stratified cluster random sampling. The participant's body composition and bone mineral content (BMC) were measured using bioelectrical impedance analysis (BIA). Serum bone metabolic markers (OC, CTX, and Ca) were measured. Based on their FMI and LMI, individuals were categorized into four body composition phenotypes: low fat mass-low lean mass (LFMI-LLMI), low fat mass-high lean mass (LFMI-HLMI), high fat mass-high lean mass (HFMI-HLMI), high fat mass-low lean mass (HFMI-LLMI). ResultsThere was a statistically significant difference between the four different body composition phenotypes with BMC, CTX and Ca in boys (all P < 0.05), similar conclusions were found in girls, except the OC and CTX. After adjusting for age, gender, smoking, drinking, and others, compared with the LFMI-HLMI reference group, the two high FMI groups (HFMI-LLMI and HFMI-HLMI) had a greater negative correlation with BMC, while the low BMC risk of the HFMI-LLMI group was the highest (OR = 33.28; 95%CI: 11.12–99.63; P < 0.001). The correlation between BMC of different body composition phenotypes in boys was greater than that in girls. HFMI-HLMI is a risk phenotype negatively associated with Ca content (β = −0.12; 95%CI: −0.19 to −0.04; P < 0.05). Regardless of body composition level, BMC was always negatively correlated with fat mass (LLMI: β = −0.27; 95%CI: −0.32–0.21; HLMI: β = −0.52, 95%CI: −0.65–0.40) and positively correlated with lean mass (LFMI: β =0.24; 95%CI: 0.20–0.28; HFMI: β =0.23, 95%CI:0.13–0.33) (all P < 0.001). The fat mass showed different correlations with OC and CTX in girls and boys based on LLMI or HLMI (all P < 0.05). ConclusionHFMI-LLMI is a risk phenotype of low BMC in Chinese adolescents, and the relationship between fat mass and bone metabolism markers is affected by lean body mass and gender.

Optimal Intermittent Administration Interval of Abaloparatide for Bone Morphogenetic Protein-Induced Bone Formation in a Rat Spinal Fusion Model.

Both bone morphogenetic protein 2 (BMP-2) and abaloparatide are used to promote bone formation. However, there is no consensus about their optimal administration. We investigated the optimal administration theory for the pairing of BMP-2 and abaloparatide in a rat spinal fusion model. Group I was only implanted in carriers and saline. Carriers with 3 µg of recombinant human BMP-2 (rhBMP-2) were implanted in other groups. Abaloparatide injections were administered three times a week for group III (for a total amount of 120 µg/kg in a week) and six times a week for group IV (for a total amount of 120 µg/kg in a week) after surgery. They were euthanized 8 weeks after the surgery, and we explanted their spines at that time. We assessed them using manual palpation tests, radiography, high-resolution micro-computed tomography (micro-CT), and histological analysis. We also analyzed serum bone metabolism markers. The fusion rate in Groups III and IV was higher than in Group I, referring to the manual palpation tests. Groups III and IV recorded greater radiographic scores than those in Groups I and II, too. Micro-CT analysis showed that Tbs. Sp in Groups III and IV was significantly lower than in Group I. Tb. N in Group IV was significantly higher than in Group I. Serum marker analysis showed that bone formation markers were higher in Groups III and IV than in Group I. On the other hand, bone resorption markers were lower in Group IV than in Group I. A histological analysis showed enhanced trabecular bone osteogenesis in Group IV. Frequent administration of abaloparatide may be suitable for the thickening of trabecular bone structure and the enhancement of osteogenesis in a rat spinal fusion model using BMP-2 in insufficient doses.

Markers of bone metabolism and overall survival in men with bone-metastatic hormone sensitive prostate cancer (HSPC): A subset analysis of SWOG S1216, a phase III trial of androgen deprivation with or without orteronel.

Circulating biomarkers of bone metabolism are significantly associated with overall survival (OS) in men with advanced prostate cancer. In the SWOG S1216 phase III trial, we showed that elevated bone biomarkers are significantly associated with an increased risk of death in hormone-sensitive prostate cancer (HSPC) regardless of the status of bone metastases, identifying three risk groups with differential OS outcomes based on bone biomarker status. Here we report the association of bone biomarkers with OS in men with HSPC and documented skeletal metastases as part of a planned subset analysis of S1216. Bone resorption [C-telopeptide (CTx); Pyridinoline (PYD)] and bone formation markers [C-terminal collagen propeptide (CICP); bone alkaline phosphatase (BAP)] were assessed in blood from men with bone metastatic HSPC. Patients were randomly divided into training (n = 238) and validation (n = 475) sets. In the training set, recursive partitioning that maximizes discrimination of OS was used to identify the dichotomous cut-point for each biomarker and for a combination of biomarker split points to define prognostic groups. In the validation set, Cox proportional hazards models were used to assess the impact of biomarkers on OS, adjusted for patient and tumor characteristics. Of 1279 men, 713 had both baseline bone metastases and evaluable bone biomarkers. Patient characteristics were similar between the overall population and the subset with bone metastases. Elevated levels of CICP, CTX, and PYD were strongly prognostic for OS. Hazard ratios (95% CI) for OS adjusted for treatment arm and baseline clinical variables were: BAP-1.31 (0.93, 1.84), p = 0.12; CICP-1.58 (1.09, 2.29), p < 0.02; CTx - 1.55 (1.12, 2.15), p = 0.008; and PYD-1.66 (1.27, 2.217), p = 0.0002. There was no evidence of interaction between elevated biomarkers and treatment (all p > 0.2). Recursive partitioning algorithms identified four groups of patients with differential OS outcomes based on bone biomarkers, adjusted for baseline clinical variables, with median OS ranging from 2.3 years (highest risk group) to 7.5 years (lowest risk group). In this planned S1216 subset analysis of men with HSPC and bone metastases, elevated serum markers of bone metabolism were significantly associated with worse OS. Bone biomarker levels alone and in combination with patient and tumor characteristics identify unique subsets of men with differential OS outcomes. NCT01809691.

Effect of Tempeh and Daidzein on Calcium Status, Calcium Transporters, and Bone Metabolism Biomarkers in Ovariectomized Rats.

Menopause marks a critical life stage characterized by hormonal changes that significantly impact bone health, leading to a heightened susceptibility to bone fractures. This research seeks to elucidate the impact of daidzein and tempeh on calcium status, calcium transporters, and bone metabolism in an ovariectomized rat model. Forty female Wistar rats, aged 3 months, participated in a two-phase experiment. The initial phase involved inducing a calcium deficit, while the second phase comprised dietary interventions across five groups: Sham (S) and Ovariectomy (O) with a standard diet, O with bisphosphonate (OB), O with pure daidzein (OD), and O with tempeh (OT). Multiple parameters, encompassing calcium levels, calcium transporters, bone histopathology, and serum bone metabolism markers, were evaluated. The findings revealed that the OT group showcased heightened levels of bone turnover markers, such as pyridinoline, C-telopeptide of type I collagen, bone alkaline phosphatase, and procollagen type I N-terminal propeptide, in contrast to S and O groups, with statistical significance (p < 0.05). Histopathologically, both the OD and OT groups exhibited effects akin to the OB group, indicating a decrease in the surface area occupied by adipocytes in the femoral bone structure, although statistically non-equivalent, supporting the directionally similar trends. Although TRPV5 and TRPV6 mRNA expression levels in the jejunum and duodenum did not display statistically significant differences (p > 0.05), the OD and OT groups exhibited increased expression compared to the O group. We hypothesized that obtained results may be related to the effect of isoflavones on estrogen pathways because of their structurally similar to endogenous estrogen and weak estrogenic properties. In conclusion, the daily consumption of pure daidzein and tempeh could potentially improve and reinstate calcium status, calcium transport, and bone metabolism in ovariectomized rats. Additionally, isoflavone products demonstrate effects similar to bisphosphonate drugs on these parameters in ovariectomized rats.

GnRH antagonist monotherapy versus a GnRH agonist plus bicalutamide for advanced hormone-sensitive prostate cancer; KYUCOG-1401.

To compare the effectiveness and safety of gonadotropin-releasing hormone (GnRH) antagonist monotherapy to combined androgen blockade (CAB) with a GnRH agonist and bicalutamide in patients with advanced hormone-sensitive prostate cancer (HSPC). The study was conducted as KYUCOG-1401 trial (UMIN000014243) and enrolled 200 patients who were randomly assigned to either group A (GnRH antagonist monotherapy followed by the addition of bicalutamide) or group B (CAB by a GnRH agonist and bicalutamide). The primary endpoint was PSA progression-free survival. The secondary endpoints were the time to CAB treatment failure, radiographic progression-free survival, overall survival, changes in serum parameters, including PSA, hormones, and bone and lipid metabolic markers, and adverse events. PSA progression-free survival was significantly longer in group B (hazard ratio [HR], 95% confidence interval [CI]; 1.40, 1.01-1.95, p = 0.041). The time to CAB treatment failure was slightly longer in group A (HR, 95% CI; 0.80, 0.59-1.08, p = 0.146). No significant differences were observed in radiographic progression-free survival or overall survival. The percentage of patients with serum testosterone that did not reach the castration level was higher at 60 weeks (p = 0.046) in group A. No significant differences were noted in the serum levels of bone metabolic or lipid markers between the two groups. An injection site reaction was more frequent in group A. The present results support the potential of CAB using a GnRH agonist and bicalutamide as a more effective treatment for advanced HSPC than GnRH antagonist monotherapy.

The relationship between coronary artery calcification and bone metabolic markers in maintenance hemodialysis patients

BackgroundTo study the influencing factors for coronary artery calcification (CAC) in maintenance hemodialysis (MHD) patients and the relationship between CAC and bone metabolism markers and to attempt to find a reliable marker linking vascular calcification and bone metabolism in MHD patients.MethodsA total of 123 patients were enrolled. CAC was assessed by multislice spiral computed tomography (MSCT), and the CAC score (CACS) was evaluated using the Agaston method. Routine laboratory parameters, including triglycerides (TG), total cholesterol (TC), glucose (Glu), calcium (Ca), phosphorus (P), magnesium (Mg), etc., were measured. Serum markers of bone metabolism, such as alkaline phosphatase(ALP), calcitonin (CT), 25-hydroxy vitamin D [25-(OH)D], intact parathyroid hormone (iPTH), total type I procollagen amino-terminal peptide (tPINP), N-terminal mid-fragment of osteocalcin (N-MID OC), and β-type I collagen crosslinked carboxyl-terminal peptide (β-CTX), were also measured.ResultsAmong 123 MHD patients, 37 patients (30.08%) did not have CAC, and 86 patients (69.92%) had CAC, including 41 patients (47.67%) with mild calcification and 45 patients (52.33%) with moderate to severe calcification. Age, Body Mass Index(BMI), the prevalence of hypertension and diabetes mellitus, TC, Glu, P, and Ca×P in the calcification group were higher than those in the noncalcification group, whereas Mg, iPTH, tPINP, N-MID OC, and β-CTX were lower than those in the noncalcified group (P < 0.05). Compared with the mild calcification group (0<CACS<400), P and Ca×P levels were higher in the moderate to severe calcification group (CACS ≥ 400), and ALP, iPTH, N-MID OC, tPINP, and β-CTX concentrations were lower (P < 0.05). Correlation analysis showed that the CACS was positively correlated with TC, LDL-C, P, and Ca×P (P < 0.05) and negatively correlated with N-MID OC and β-CTX (P < 0.05). There was no significant correlation between the CACS and other parameters (P > 0.05). A logistic regression model was used to evaluate the influencing factors for CAC. The results showed that age, BMI, TC, Glu, P, and Ca×P were risk factors for CAC and its severity in MHD patients, whereas diabetes mellitus, Mg, and N-MID OC were protective factors for CAC in MHD patients. In addition, N-MID OC was a protective factor for the severity of CAC. After adjusting for the corresponding confounding factors, the results of the risk factors were consistent, and N-MID OC was still an independent protective factor for CAC and its severity.ConclusionsElevated serum P and Ca×P were independent risk factors for CAC in MHD patients, and serum Mg may be an independent protective factor for CAC. CAC was closely related to abnormal bone metabolism and bone metabolic markers in MHD patients. Relatively low bone turnover can promote the occurrence and development of CAC. N-MID OC may be a reliable bone metabolic marker linking vascular calcification and bone metabolism in MHD patients.

Changes in Serum Bone Metabolism Markers after Living Donor Liver Transplantation (LDLT) and Their Association with Fracture Occurrences.

Living donor liver transplantation (LDLT) is lifesaving, but can lead to osteoporosis and fractures. In our 3-year study of 25 LDLT recipients, we observed significant reductions in lumbar spine and femoral neck T scores, along with bone resorption marker reductions and liver regeneration marker increases. Serum calcium levels increased, while osteoprotegerin (OPG) decreased and Dickkopf-related protein 1 (DKK-1) increased. Patients who suffered fractures within 3 years of LDLT had higher serum OPG, lower serum nuclear factor kappa B ligand (RANKL), a higher OPG/RANKL ratio and higher serum DKK-1 levels. OPG, RANKL, OPG/RANKL ratio and DKK-1 levels before LDLT predicted hip or spine fractures within three years after LDLT. Further research is necessary to determine the optimal level of osteoclastic activity for preventing fracture onset.

Bone biomarkers and subsequent survival in men with bone-metastatic hormone sensitive prostate cancer (HSPC): Results from the phase III SWOG S1216 trial of androgen deprivation +/- orteronel.

5048 Background: We previously reported that circulating serum biomarkers of bone metabolism were significantly associated with overall survival (OS) in men with advanced prostate cancer, either in the hormone sensitive (Lara, et al. ASCO 2022) or castration resistant state (Lara, et al. JNCI 2016). In S1216, we showed that elevated bone biomarkers were significantly associated with an increased risk of death in HSPC regardless of bone metastases (mets). We also identified three risk groups (low, intermediate, and poor) with differential OS outcomes (median OS: 8.2, 5.1, and 2.1 years, respectively) based on combinations of bone biomarkers in these patients. Here we report the association of bone biomarkers with OS in men with HSPC and documented skeletal mets as part of a planned analysis of S1216. Methods: Bone resorption [C-telopeptide (CTx) and Pyridinoline (PYD)] and bone formation markers [C-terminal collagen propeptide (CICP) and bone alkaline phosphatase (BAP)] were assessed from patient sera. Patients were randomly divided into training (n=238) and validation (n=475) sets. In the training set, recursive partitioning that maximizes discrimination of OS was used to identify the dichotomous cut-point for each biomarker and for a combination of biomarker split points to define prognostic groups. In the validation set, Cox proportional hazards models were used to assess the impact of biomarkers on OS, adjusted for patient and tumor characteristics. Results: Of 1,279 men in S1216, 713 had both baseline bone mets and evaluable bone biomarkers. Patient characteristics were similar between the overall population and the subset with bone mets. Elevated levels of CICP, CTX, and PYD were strongly prognostic for OS, but not for BAP. Hazard ratios (95% CI) for OS adjusted for treatment arm and baseline clinical variables were: BAP – 1.31 (0.93, 1.84), p=0.12; CICP – 1.58 (1.09, 2.29), p&lt;0.02; CTx – 1.55 (1.12, 2.15), p=0.008; and PYD – 1.66 (1.27, 2.217), p=0.0002. There was no evidence of interaction between elevated biomarkers and treatment (all p&gt;0.2). Recursive partitioning algorithms identified four groups of patients with differential OS outcomes based on bone biomarkers, adjusted for baseline clinical variables, with median OS ranging from 2.3 years (highest risk group) to 7.5 years (lowest risk group). Conclusions: In this subset analysis of men with HSPC and bone mets in S1216, elevated serum markers of bone metabolism were significantly associated with worse OS. Bone biomarker levels alone and in combination with patient and tumor characteristics identify unique subsets of men with differential OS outcomes. Clinical trial information: NCT01809691 .

D-Mannose prevents bone loss under weightlessness

BackgroundAstronauts undergo significant microgravity-induced bone loss during space missions, which has become one of the three major medical problems hindering human's long-term space flight. A risk-free and antiresorptive drug is urgently needed to prevent bone loss during space missions. D-mannose is a natural C-2 epimer of D-glucose and is abundant in cranberries. This study aimed to investigate the protective effects and potential mechanisms of D-mannose against bone loss under weightlessness.MethodsThe hind legs of tail-suspended (TS) rats were used to mimic weightlessness on Earth. Rats were administered D-mannose intragastrically. The osteoclastogenic and osteogenic capacity of D-mannose in vitro and in vivo was analyzed by micro-computed tomography, biomechanical assessment, bone histology, serum markers of bone metabolism, cell proliferation assay, quantitative polymerase chain reaction, and western blotting. RNA-seq transcriptomic analysis was performed to detect the underlying mechanisms of D-mannose in bone protection.ResultsThe TS rats showed lower bone mineral density (BMD) and poorer bone morphological indices. D-mannose could improve BMD in TS rats. D-mannose inhibited osteoclast proliferation and fusion in vitro, without apparent effects on osteoblasts. RNA-seq transcriptomic analysis showed that D-mannose administration significantly inhibited the cell fusion molecule dendritic cell-specific transmembrane protein (DC-STAMP) and two indispensable transcription factors for osteoclast fusion (c-Fos and nuclear factor of activated T cells 1 [NFATc1]). Finally, TS rats tended to experience dysuria-related urinary tract infections (UTIs), which were suppressed by treatment with D-mannose.ConclusionD-mannose protected against bone loss and UTIs in rats under weightlessness. The bone protective effects of D-mannose were mediated by inhibiting osteoclast cell fusion. Our findings provide a potential strategy to protect against bone loss and UTIs during space missions.

Effect of inhaled corticosteroids on bone mineral density in patients with asthma.

Inhaled corticosteroids (ICS) are a safe treatment for asthma. However, at higher doses, ICS use has been reported to inhibit adrenocortical function. This study aimed to evaluate the effect of ICS on bone mineral density (BMD) in adult patients with asthma. Ultrasonic bone densitometry was performed in 40 patients (14 men, 26 women, mean age 61.2 years, mean duration of asthma 6.19 years) who were receiving ICS for asthma, and the whole bone density, thickness of cortical bone, and density of cancellous bone of the radius was measured. The age-matched mean was set as 100%. Lifetime cumulative dose of ICS was calculated using all past prescriptions. No significant correlations were observed between lifetime cumulative ICS dose and whole bone density (r² = 0.011), cortical bone thickness (r² = 0.022), and cancellous bone density (r² = 0.004). No significant differences were observed between lower and higher lifetime cumulative ICS dose among these BMD parameters (104% vs 97%, 103% vs 99%, and 106% vs 91%, respectively). No significant correlations or differences in lifetime cumulative ICS dose were observed by asthma severity, asthma duration, and pulmonary function. Also, serum markers of bone metabolism showed no significant correlations or differences with lifetime cumulative ICS dose. In the entire study population, long-term ICS use was safe and was not associated with an increased risk of osteoporosis.

Serum cytokines and bone metabolic markers in patients with rheumatoid arthritis treated with biological disease modifying anti-rheumatic drugs.

/objectives Several biological disease-modifying anti-rheumatic drugs (bDMARDs) have been widely used for the management of rheumatoid arthritis (RA). These drugs target different molecules important for the pathophysiology of RA; however, only a few studies have compared the effects of these biological drugs on cytokines and bone metabolic markers. The main aim of this study is to clarify the effects of bDMARDs with different modes of action on the cytokine and bone metabolic marker levels in patients with RA. Patients with RA who were initiated on infliximab, tocilizumab, or abatacept as the first bDMARD were prospectively enrolled in this study. Serum cytokine and bone metabolic marker levels were measured longitudinally, and changes in their levels were compared. A total of 174 patients were enrolled in this study, with 55, 70, and 49 patients in the infliximab, tocilizumab, and abatacept groups, respectively. At six months, despite the similar clinical effectiveness of the three drugs, changes in the cytokine and bone metabolic marker levels were distinct; interferon-γ and tumor necrosis factor-α levels were significantly increased with infliximab, interleukin-6 levels were increased with tocilizumab, and interleukin-1β and interleukin-8 levels were increased with abatacept treatment. Bone-specific alkaline phosphatase and osteocalcin levels increased more significantly with tocilizumab than with infliximab, while osteopontin and osteonectin levels decreased with infliximab treatment. bDMARDs with different modes of action exert different effects on the cytokine and bone metabolic marker levels in patients with RA.

Excessive fructose intake inhibits skeletal development in adolescent rats via gut microbiota and energy metabolism.

Excessive fructose intake from desserts and beverages may influence bone development among adolescents. The gut microbiota (GM) and energy metabolism play important roles in bone development. In this study, 40 female adolescent rats were randomly assigned to the control group, the fructose group with two concentrations, and the glucose group as the positive control group. After 10 weeks, serum glucose and lipids were detected by means of an automatic analyzer, and the bone microstructure was analyzed by Micro-CT. Then, the GM was determined via 16S rRNA sequencing analysis, and energy metabolism was detected by measuring serum carbohydrate metabolites. At last, bone metabolism markers were measured via ELISA kits. The results showed that excessive fructose intake could increase body weight and influence the glucolipid metabolism of female adolescent rats. Meanwhile, the bone microstructures were impaired with excessive fructose intake. Mechanistically, excessive fructose intake shifted the GM of rats with the decrease of Lachnospiraceae, Ruminococcaceae, and increase of Allobaculum, Lachnospiraceae. Energy metabolism analysis suggested that most metabolites of fructose did not enter the tricarboxylic acid cycle to provide energy for the body’s development. Furthermore, serum bone metabolism markers showed that excessive fructose intake could decrease both bone formation and resorption. Our results suggested that excessive fructose intake could inhibit skeletal development in adolescents. One potential mechanism might be that it affected the intestinal microbiota homeostasis in the juvenile body, thus changing the energy metabolism level, and ultimately affecting the bone metabolic balance.

Current Aspects on the Pathophysiology of Bone Metabolic Defects during Progression of Scoliosis in Neurofibromatosis Type 1.

Neurofibromatosis type 1 (NF1), which is the most common phacomatoses, is an autosomal dominant disorder characterized by clinical presentations in various tissues and organs, such as the skin, eyes and nervous and skeletal systems. The musculoskeletal implications of NF1 include a variety of deformities, including scoliosis, kyphoscoliosis, spondylolistheses, congenital bony bowing, pseudarthrosis and bone dysplasia. Scoliosis is the most common skeletal problem, affecting 10–30% of NF1 patients. Although the pathophysiology of spinal deformities has not been elucidated yet, defects in bone metabolism have been implicated in the progression of scoliotic curves. Measurements of Bone Mineral Density (BMD) in the lumbar spine by using dual energy absorptiometry (DXA) and quantitative computer tomography (QCT) have demonstrated a marked reduction in Z-score and osteoporosis. Additionally, serum bone metabolic markers, such as vitamin D, calcium, phosphorus, osteocalcin and alkaline phosphatase, have been found to be abnormal. Intraoperative and histological vertebral analysis confirmed that alterations of the trabecular microarchitecture are associated with inadequate bone turnover, indicating generalized bone metabolic defects. At the molecular level, loss of function of neurofibromin dysregulates Ras and Transforming Growth factor-β1 (TGF-β1) signaling and leads to altered osteoclastic proliferation, osteoblastic activity and collagen production. Correlation between clinical characteristics and molecular pathways may provide targets for novel therapeutic approaches in NF1.