The aim of the study was to examine the acute response of biochemical bone turnover markers (BTM) to high-impact jumping exercise, and to quantify the ground reaction forces (GRF) achieved during each jumping exercise, in postmenopausal women. In a randomized controlled cross-over study over three days, 29 postmenopausal women (age (mean±SD): 60.0±5.6 years) were randomly assigned to 6 x 10 repetitions of three different jumps: countermovement jump (CMJ), drop jump (DJ), diagonal drop jump (DDJ). A fourth day without jumping served as a control (CON). Blood samples were collected before (PRE), after (POST), and 2 hours after (2Hr) exercise. Bone turnover was evaluated by bone formation markers (procollagen type-1 amino-terminal propeptide (P1NP) and osteocalcin (OC)) and the bone resorption marker C-terminal telopeptide of type-1 collagen (CTX). Peak anteroposterior (Fx), mediolateral (Fy), and vertical (Fz) GRF were measured using a force platform. From PRE to POST, P1NP increased (p<0.01) by 7.7±1.8%, 9.4±1.3%, and 10.6±1.6% for CMJ, DJ, and DDJ, which were higher (p<0.01) than CON. OC increased (p<0.05) by 5.5±1.8% for DJ, which was higher (p<0.05) than CON. CTX was not significantly changed at POST. There were no significant differences in BTM Δ-values between the jumps at any time point. For the CMJ, the combined three-axis peak GRF was positively associated with the PRE to POST Δ-change in P1NP (r=0.71, p<0.05). The acute, jumping-induced increase in P1NP and OC without any rise in CTX may indicate increased bone formation. Moreover, the study shows a dose-response relationship between GRF and the acute P1NP response after countermovement jumps.

Studies from global loss-of-function mutants suggest that alternative NF-κB downstream of NF-κB inducing kinase (NIK) is a cell-intrinsic negative regulator of osteogenesis. However, the interpretation of the osteoblast and/or osteocyte contribution to the bone phenotype is complicated by simultaneous osteoclast defects in these models. Therefore, we turned to a transgenic mouse model to investigate the direct role of NIK in the osteolineage. Osx-Cre;NT3 animals (NT3-Cre +), which bear a constitutively active NIK allele (NT3) driven by Osx-Cre, were compared with their Cre-negative, Control (Ctrl) littermates. NT3-Cre + mice had elevated serum P1NP and CTX levels. Despite this high turnover state, µCT showed that constitutive activation of NIK resulted in a net increase in basal bone mass in both cortical and cancellous compartments. Furthermore, NT3-Cre + mice exhibited a greater anabolic response following mechanical loading compared with controls. We next performed RNA-Seq on nonloaded and loaded tibias to elucidate possible mechanisms underlying the increased bone anabolism seen in NT3-Cre + mice. Hierarchical clustering revealed two main transcriptional programs: one loading-responsive and the other NT3 transgene-driven. Gene ontology (GO) analysis indicated a distinct upregulation of receptor, kinase, and growth factor activities including Wnts, as well as a calcium-response signature in NT3-Cre + limbs. The promoters of these GO-term associated genes, including many known to be bone-anabolic, were highly enriched for multiple κB recognition elements (κB-RE) relative to the background frequency in the genome. The loading response in NT3-Cre + mice substantially overlapped (>90%) with Ctrl. Surprisingly, control animals had 10-fold more DEGs in response to loading. However, most top DEGs shared between genotypes had a high incidence of multiple κB-RE in their promoters. Therefore, both transcriptional programs (loading-responsive and NT3 transgene-driven) are modulated by NF-κB. Our studies uncover a previously unrecognized role for NF-κB in the promotion of both basal and mechanically stimulated bone formation. © 2019 American Society for Bone and Mineral Research.

A 22-year-old woman presented with complaints of severe pain in a wide region of the thoracolumbar spine. She developed severe pain in the thoracolumbar spine region 2 months after her first delivery and was referred 1 month later. A lateral thoracic X-ray showed depressed degenerative vertebrae (T7, T9). One month after the initial examination, thoracic sagittal magnetic resonance imaging showed low intensity areas on T1-weighted imaging and iso-high intensity areas on T2-weighted imaging at T5, 7, 8, 9 and 11. Bone mineral density measured by ultrasound was low (%YAM 76%). The bone metabolic markers were high, suggesting accelerated osteoclast activity. These findings prompted a diagnosis of pregnancy-associated osteoporosis. She was asked to stop breastfeeding and to wear a lumbar brace, and treatment with nutritional calcium, activated vitamin D3, and risedronate sodium was started. Her low back pain almost disappeared after treatment. Bone metabolic markers showed normalization 8 months after the initial examination. Risedronate sodium was stopped 2 years and 2 months after the initial examination. Teriparatide treatment was started because her bone mineral density remained low; however, the osteoblast marker P1NP was not increased 5 months after the start of teriparatide treatment.

Glucocorticoid use is the most common cause of osteoporosis in young individuals. In the current study, we investigated the effects of glucocorticoid treatment on circulating sclerostin concentrations and serum bone turnover markers in healthy young men. We performed additional measurements in two combined randomized, placebo-controlled, double-blind, dose-response intervention studies: 64 healthy men (age: 22 ± 2 years; BMI: 22.1 ± 1.7 kg/m²) were allocated to receive placebo (n = 16), prednisolone 7.5 mg once daily (n = 24), or prednisolone 30 mg once daily (n = 24) for 2 weeks using block randomization. Primary outcome variables were serum sclerostin and serum bone turnover markers (CTx and P1NP), before and after the intervention. Baseline characteristics and variables did not differ between intervention groups. Compared with placebo, prednisolone high-dose decreased serum sclerostin concentrations (-8.5 [-28.0 to 7.3] versus 1.5 [-6.5 to 20.0] pg/mL, p = 0.048), decreased P1NP concentrations (-28.0 [-39.3 to -18.3] versus -1.5 [-15.3 to 11.3] μg/L, p < 0.001) and increased CTx concentrations (108.0 [55.0 to 177.0] versus 64.0 [-24.3 to 120.0] ng/L, p = 0.038). Compared with placebo, prednisolone low-dose did not alter sclerostin concentrations (p = 0.5) or CTx concentrations (p = 0.7), but tended to decrease P1NP concentrations (-9.0 [-24.0 to -1.3] versus -1.5 [-15.3 to 11.3] μg/L, p = 0.095). At baseline concentrations of sclerostin were positively correlated with concentrations of CTx (Spearman's rank correlation coefficient ρ = +0.409, p = 0.001), but not with P1NP. No significant correlations were observed between changes in outcome variables during the interventions. Short-term high-dose, but not low-dose, prednisolone treatment reduces serum sclerostin concentrations in healthy young men. Whether this reflects a counter regulatory mechanism to compensate glucocorticoid-induced negative effects through other mechanisms remains to be elucidated. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Keywords: BIOCHEMICAL MARKERS OF BONE TURNOVER; CLINICAL TRIALS; CORTICOSTEROIDS; SCLEROSTIN; Wnt.

Chemokine CX3CL1 (fractalkine) may be an important factor linking thyroid status and bone remodeling, through tetrac, a derivative of thyroxine. This study explores the relationship between serum fractalkine levels and parameters of thyroid status and bone in premenopausal women with Graves' disease (GD) in comparison to healthy controls. This cross-sectional study included three premenopausal female groups: active GD; cured GD, and healthy age-, gender-, and BMI-matched controls. Measurement of serum fractalkine levels (Quantikine® ELISA), total amino-terminal peptide of procollagen type 1 (P1NP), CTx, thyroid hormones, BMD and trabecular bone score (TBS) were performed in all study subjects. Sixty women (21, 16, and 23 in active GD, cured GD, and healthy control groups, respectively) were included. Serum fractalkine levels were higher (p<0.05) in active and cured GD subjects compared to healthy controls (mean 0.7±0.14; 0.93±0.15, and 0.48±0.13 ng/ml, respectively). Lumbar spine BMD was lowest in the cured GD group in comparison to active GD and control group subjects (0.926±0.03; 1.016±0.03; 1.051±0.03 g/cm2; p<0.05, respectively). TBS was lower (p<0.05) in both GD groups than controls being lowest in those with active GD (1.395±0.02; 1.402±0.02, 1.469±0.02, respectively). Serum fractalkine concentration was positively correlated with fT4, and negatively correlated with TBS values. GD in pre-menopausal females is associated with increased serum fractalkine concentration and decreased TBS. Fractalkine may be a currently unappreciated link between hyperthyroidism and bone; further research into this possibility is needed.

Purpose: Denosumab reduces bone resorption and improves bone mineral density (BMD). Studies have analyzed subsequent treatment transitioning from bisphosphonates to denosumab based on dual-energy X-ray absorptiometry scanning (DXA). Quantitative computed tomography (QCT) can help assess cortical and trabecular bones separately in three dimensions without the interference of the surrounding osteophytes. In the present study, we analyzed the subsequent treatment transition from bisphosphonates to denosumab using QCT.

Methods: Thirty-two patients with postmenopausal osteoporosis to be treated with denosumab were recruited. The patients were divided into two groups (15 prior bisphosphonate and 17 naïve) based on their previous treatment. BMD of the lumbar spine and hip were evaluated by DXA and QCT at baseline and 12 months following denosumab treatment.

Results: The percentage change in volumetric BMD assessed by QCT at 12 months significantly improved in the naïve group compared with that in the prior bisphosphonate group. The region-specific assessment of femur at 12 months revealed that denosumab treatment was effective in both cortical and trabecular bones except the trabecular region of the prior bisphosphonate group.

Conclusion: Our study suggests that although denosumab treatment was useful in both treatment groups, BMD increase was significantly higher in the naïve group than in the prior-bisphosphonate group. Interestingly, in the prior-bisphosphonate group, denosumab treatment was more effective in the cortical region than the trabecular region. Our study offers insights into the subsequent treatment and permits greater confidence when switching to denosumab from bisphosphonates.

Keywords: BMD, bone mineral density; BMI, body mass index; BTM, bone turnover marker; Bisphosphonates; DXA, dual-energy X-ray absorptiometry scanning; Denosumab; Osteoporosis; QCT, quantitative computed tomography; Quantitative computed tomography; RANKL, receptor activator of nuclear factor κB ligand; Subsequent treatment; TRACP-5b, tartrate-resistant acid phosphatase 5b; eGFR, estimated glomerular filtration rate; total-P1NP, total N-terminal propeptide of type I procollagen.

Background: Recruitment and retention in longitudinal nutrition intervention studies among children is challenging and scarcely reported. This paper describes the strategies and lessons learned from a 1-year randomized double-blind placebo-controlled trial among pre-adolescent children on the effects of soluble corn fiber (SCF) on bone indices (PREBONE-Kids).

Methods: Participants (9-11 years old) were recruited and randomized into 4 treatment groups (600 mg calcium, 12 g SCF, 12 g SCF plus 600 mg calcium and placebo). Interventions were consumed as a fruit-flavored powdered drink for 1-year. School-based recruitment was effective due to support on study benefits from parents and teachers, peer influence and a 2-weeks study run-in for participants to assess their readiness to commit to the study protocol. Retention strategies focused on building rapport through school-based fun activities, WhatsApp messaging, providing health screening and travel reimbursements for study measurements. Compliance was enhanced by providing direct on-site school feeding and monthly non-cash rewards. Choice of 2 flavors for the intervention drinks were provided to overcome taste fatigue. Satisfaction level on the manner in which the study was conducted was obtained from a voluntary sub-set of participants.

Results: The study successfully enrolled 243 participants within 6 months and retained 82.7% of the participants at the end of 1 year, yielding a drop-out rate of 17.3%. Compliance to the intervention drink was 85% at the start and remained at 78.7% at the end of 1 year. More than 95% of the participants provided good feedback on intervention drinks, rapport building activities, communication and overall study conduct.

Conclusion: Successful strategies focused on study benefits, rapport building, frequent communication using social media and non-cash incentives helped improved compliance and retention rate. The lessons learned to maintain a high retention and compliance rate in this study provide valuable insights for future studies in a similar population.

Keywords: 25-OHD, serum 25-hydroxyvitamin D; BAP, bone-specific alkaline phosphatase; BMC, bone mineral content; BMD, bone mineral density; CTX, carboxy-terminal collagen crosslinks; Calcium; Compliance; DXA, dual-energy X-ray absorptiometry; MET, total metabolic equivalent; OC, osteocalcin; P1NP, procollagen type 1 amino-terminal propeptide; PBM, peak bone mass; Pre-adolescent children; SCF, soluble corn fibre; Soluble corn fiber; Study retention; iPTH, intact parathyroid hormone.

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 1 N 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.

Keywords: Bone; Marker; Menstrual cycle; Metabolism; Oestrogen; Oral contraceptive.

BACKGROUND

The study was planned to assess effect of physical exercise on bone remodeling in type I diabetics with osteopenia.

METHODS

Twenty-four type I diabetes mellitus (DM1) with osteopenia (10 females and 14 males) were compared to thirty-eight age- and sex-matched healthy control individuals (20 females and 18 males) for biochemical and radiologic parameters of bone mass. Laboratory investigations included serum and urinary calcium, inorganic phosphorus, alkaline phosphatase, and serum "procollagen type 1 N-terminal propeptide (P1NP). Bone densitometry was assessed at neck femur using Dual Energy X-ray Absorptiometry (DEXA). Serum P1NP and DEXA were reevaluated after a planned exercise program.

RESULTS

Patients and controls were comparable with respect to serum as well as urinary biochemical parameters of bone mass namely; calcium, phosphorus and total serum alkaline phosphatase. Osteopenic DM1 patients displayed lower mean serum P1NP than control group (20.11 ± 6.72 ug\dL versus 64.96 ± 34.89 ug\dL; p < 0.05). A significant correlation was observed between BMD and degree of glycemic control reflected by serum glycated hemoglobin (r = -0.44, p, 0.030). Bone densitometry correlated with serum P1NP (r = -0.508, p, 0.011). After a planned regular exercise for 3 months, serum P1NP and BMD levels increased with percentage change of 40.88 ± 31.73 and 3.36 ± 2.94, respectively. Five patients resumed normal densitometry and they were all males.

CONCLUSIONS

Diabetic osteopenic patients displayed lower serum levels of procollagen type 1 N-terminal propeptide which reflects poor bone formation. A 3-months planned exercise program was associated with improvement of bone densitometry and significant increment of serum P1NP.

Background/objective: The deleterious effects of chronic spinal cord injury (SCI) on the skeleton in rats, especially the lower extremities, has been proved previously. However, the long-term skeletal changes after SCI in non-human primates (NHP) have been scarcely studied. This study aimed to evaluate the bone loss in limbs and vertebrae and the bone metabolic changes in NHP after unilateral cervical spinal cord contusion injury.

Methods: Twelve Macaca fascicularis were randomly divided into the SCI (n=8) and the Sham (n=4) groups. The SCI models were established using hemi-contusion cervical spinal cord injury on fifth cervical vertebra (C5), and were further evaluated by histological staining and neurophysiological monitoring. Changes of bone microstructures, bone biomechanics, and bone metabolism markers were assessed by micro-CT, micro-FEA and serological kit.

Results: The NHP hemi-contusion cervical SCI model led to consistent unilateral limb dysfunction and potential plasticity in the face of loss of spinal cord. Furthermore, the cancellous bone mass of ipsilateral humerus and radius decreased significantly compared to the contralateral side. The bone volume fraction of humerus and radius were 17.2% and 20.1% on the ipsilateral while 29.0% and 30.1% on the contralateral respectively. Similarly, the thickness of the cortical bone in the ipsilateral forelimbs was significantly decreased, as well as the bone strength of the ipsilateral forelimbs. These changes were accompanied by diminished concentration of osteocalcin and total procollagen type 1 N-terminal propeptide (t-P1NP) as well as increased level of β-C-terminal cross-linking telopeptide of type 1collagen (β-CTX) in serological testing.

Conclusions: The present study demonstrated that hemi-SCI induced loss of bone mass and compromised biomechanical performance in ipsilateral forelimbs, which could be indicated by both muscle atrophy and serological changes of bone metabolism, and associated with a consistent loss of large-diameter cells of sensory neurons in the dorsal root ganglia.

The translational potential of this article: Our study, for the first time, demonstrated the bone loss in limbs and vertebrae as well as the bone metabolic changes in non-human primates after unilateral spinal cord injury (SCI). This may help to elucidate the role of muscle atrophy, serological changes and loss of sensory neurons in the mechanisms of SCI-induced osteoporosis, which would be definitely better compared with rodent models.

Keywords: Bone microarchitecture; Non-human primates (NHP); Osteoporosis; Spinal cord injury.

Introduction Involvement of the bone is common in primary hyperparathyroidism. The aim of the study was to assess bone turnover markers in response to surgery for primary hyperparathyroidism. Methods This was a retrospective study of patients diagnosed and treated for parathyroid disease between 2005 and 2012. Interventions studied were surgery and medical treatment. The main outcome measures studied were serum levels of calcium, intact parathyroid hormone (iPTH), bone-specific alkaline phosphatase, N-terminal cross-linking propeptide of type 1 procollagen (P1NP) and C-terminal cross-linking telopeptides of type I collagen (CTX), both pre- and postoperatively at 6 months and 1 year; bone mineral density (at the spine and hip assessed by dual-energy x-ray absorptiometry after 1 year of treatment. Results A total of 122 (110 female, 12 male) patients (age range 25-91 years) underwent treatment for parathyroid disease during the study period; 30 patients were treated conservatively and 92 proceeded to surgery following localisation studies. Following surgical intervention, P1NP dropped significantly from a mean of 64.68 ng/ml (standard deviation, SD ± 68.07 ng/ml) preoperatively to 26.37 ng/ml (SD ± 20.94 ng/ml) and CTX from 0.69 pg/ml (SD ± 0.44 pg/ml) to 0.15 pg/ml (SD ± 0.16 pg/ml) at 6-12 months (P < 0.0001). This change was reflected in improvement in bone mineral density (T scores) of the hip and spine by 43% (P < 0.03) and 38% (P < 0.01), respectively, following surgery. In patients treated conservatively (n = 30), there was no improvement either in the bone turnover markers or bone densitometry scans. Conclusions Surgery improves bone density in patients with parathyroid disease. Improvement in serum bone turnover markers is seen following parathyroidectomy. The association with bone density needs further evaluation in larger studies.

Schizophrenia is associated with a lowered bone mineral density. The antidiabetic and body weight lowering glucagon-like peptide-1 receptor agonist liraglutide has shown to mitigate overweight and impaired glucose tolerance associated with olanzapine and clozapine. As liraglutide has been proposed to affect bone metabolism, we evaluated the effect of liraglutide on bone turnover markers (BTM) in patients with prediabetes and schizophrenia treated with olanzapine or clozapine. Patients diagnosed with a schizophrenia spectrum disorder treated with the antipsychotic compounds clozapine and/or olanzapine, having prediabetes and a BMI above 27 kg/m² were randomized to 16 weeks of treatment with liraglutide or placebo. Fasting state serum sampled in the morning from patients (n=78) were analysed for the BTM collagen type 1 C-telopeptide (CTX) and procollagen type 1 N-terminal propeptide (P1NP). After 16 weeks of treatment, no significant changes of neither P1NP nor CTX were observed when comparing liraglutide to placebo. No association between changes of bone turnover markers and change of body weight were found in the group treated with liraglutide. In conclusion, no treatment effect on CTX nor P1NP was observed, and thus, this study does not raise any concerns in patients with schizophrenia and prediabetes treated with liraglutide regarding bone-related adverse effects.

Keywords: Antipsychotics; Bone metabolism; Collagen type 1 C-telopeptide (CTX); procollagen type 1 N-terminal propeptide (P1NP).

OBJECTIVE

This study assessed the correlation of plasma microRNA-21 expression and bone turnover markers (BTMs: CTx, P1NP) in healthy Thai postmenopausal women. We secondarily compared microRNA-21 expression between participants with normal and low bone mineral density (BMD: osteopenia and osteoporosis).

METHODS

Postmenopausal women who had never been diagnosed with fracture or never used anti-osteoporosis drugs were included in this study. Baseline characteristics were collected from all 195 participants. BTMs and plasma miR-21-5p were analyzed from blood collection at 8:00 and 9:00 am after overnight fasting for at least 8 h.

RESULTS

There was no significant correlation between miR-21-5p and any of the BTMs (CTx, r = 0.094, p = 0.19; P1NP, r = 0.05, p = 0.485). Significant correlation between miR-21-5p and P1NP was found when participants were further categorized into those aged ≥70 years (r = 0.46, p = 0.05) and those having osteoporosis (r = 0.51, p = 0.06). Slight negative correlations were found between miR-21-5p and BMD. There was statistically significant higher expression of miR-21-5p in those with low BMD when compared to the normal BMD group (p < 0.01).

CONCLUSIONS

In this study, we did not find significant correlation between plasma microRNA-21-5p expression and the BTMs. Nevertheless, there seemed to be higher expression of miR-21-5p in the low BMD participants.

Osteoporosis is a major concern in patients with Duchenne muscular dystrophy. In this novel study of teriparatide treatment in 6 patients with severe osteoporosis, bone health (fractures, vertebral morphometry, and DXA) remained stable, with no adverse events. These findings will help inform future osteoporosis research in this challenging population.

Introduction: Despite standard therapy with vitamin D and bisphosphonates (BP), many patients with Duchenne muscular dystrophy (DMD) continue to sustain fragility fractures due to long-term glucocorticoid treatment and limited mobility. We aimed to evaluate the safety and efficacy of teriparatide for the treatment of severe osteoporosis in adolescent and young adult patients with DMD.

Methods: We prospectively treated 6 patients with DMD who had severe osteoporosis with teriparatide 20 mcg subcutaneously daily for 1-2 years. Inclusion criteria were long-term glucocorticoid therapy, and severe osteoporosis despite treatment with BP, or intolerance to BP. We examined long bone and vertebral fracture outcomes, including vertebral morphometry measures, bone mineral density and content, bone formation markers, safety indices, and adverse events.

Results: The mean age at teriparatide start was 17.9 years (range 13.9-22.1 years). All 6 patients were on daily glucocorticoids (mean ± SD; duration 10.9 ± 2.5 years) and 5 were non-ambulatory. Five patients had been treated with BP for 7.9 ± 4.2 years. All had vertebral and a history of long bone fragility fractures at baseline. Vertebral heights and Genant fracture grading remained stable. Long bone fracture rate appeared to decrease (from 0.84/year to 0.09/year); one patient sustained a long bone fracture at 6 months of treatment. Trajectories for change in bone mineral density and content were not different post- vs. pre-teriparatide. Procollagen type 1 amino-terminal propeptide (P1NP) increased, while laboratory safety indices remained stable and non-concerning. No adverse events were observed.

Conclusion: In six patients with DMD treated with teriparatide for severe osteoporosis, we observed stable bone health and modest increases in P1NP, without safety concerns. Further studies are needed to better understand teriparatide efficacy for treatment of osteoporosis in patients with DMD.

Keywords: Children; Duchenne muscular dystrophy; Fracture; Osteoporosis; Parathyroid hormone; Teriparatide.

Modafinil is primarily prescribed for treatment of narcolepsy and other sleep-associated disorders. However, its off-prescription use as a cognition enhancer increased considerably, specially among youths. Given its increasing use in young adults the effect of modafinil on peak bone accrual is an important issue but has never been investigated. Modafinil treatment to young male rats caused trabecular and cortical bone loss in tibia and femur, and reduction in biomechanical strength. Co-treatment of modafinil with alendronate (a drug that suppresses bone resorption) reversed the trabecular bone loss but failed to prevent cortical loss. Modafinil increased serum type 1 pro-collagen N-terminal protein (P1NP) and collagen type 1 cross-linked C-telopeptide (CTX-1) indicating a high turnover bone loss. The drug also increased receptor activator of nuclear factor κB ligand (RANKL) to osteoprotegerin (OPG) ratio in serum which likely resulted in increased osteoclast number per bone surface. Furthermore, conditioned medium from modafinil treated osteoblasts increased the expression of osteoclastogenic genes in bone marrow-derived macrophages and the effect was blocked by RANKL neutralizing antibody. In primary osteoblasts, modafinil stimulated cAMP production and using pharmacological approach, we showed that modafinil signalled via adenosine receptors (A2AR and A2BR) which resulted in increased RANKL expression. ZM-241,385 (an A2AR inhibitor) and MRS 1754 (an A2BR inhibitor) suppressed modafinil-induced upregulation of RANKL/OPG ratio in the calvarium of new born rat pups. Our data suggests that by activating osteoblast adenosine receptors modafinil increases the production of osteoclastogenic cytokine, RANKL that in turn results in high turnover bone loss in young rats.

Spinal cord injury (SCI) leads to extensive bone loss and high incidence of low-energy fractures. Pulsed electromagnetic fields (PEMF) treatment, as a non-invasive biophysical technique, has proven to be efficient in promoting osteogenesis. However, the potential osteo-protective effect and mechanism of PEMF on SCI-related bone deterioration remain unknown. The spinal cord of rats was transected at vertebral level T12 to induce SCI. Thirty rats were assigned to the control, SCI and SCI+PEMF groups (n=10). One week after surgery, the SCI+PEMF rats were subjected to PEMF (2.0 mT, 15 Hz, 2 h/day) for 8 weeks. Micro-CT results showed that PEMF significantly ameliorated trabecular and cortical bone microarchitecture deterioration induced by SCI. Three-point bending and nanoindentation assays revealed that PEMF significantly improved bone's mechanical properties in SCI rats. Serum biomarker and bone histomorphometric analyses demonstrated that PEMF enhanced bone formation, as evidenced by significant increase in serum osteocalcin and P1NP, mineral apposition rate, and osteoblast number on bone surface. However, PEMF had no impact upon serum bone-resorbing cytokines (TRACP 5b and CTX-1) or osteoclast number on bone surface. PEMF also attenuated SCI-induced negative changes in osteocyte morphology and osteocyte survival. Moreover, PEMF significantly increased skeletal expression of canonical Wnt ligands (Wnt1 and Wnt10b) and stimulated their downstream p-GSK3β and β-catenin expression in SCI rats. This study demonstrates that PEMF can mitigate the detrimental consequence of SCI on bone quantity/quality, which might be associated with canonical Wnt signaling-mediated bone formation, and reveals that PEMF may be a promising biophysical approach for resisting osteopenia/osteoporosis following SCI in clinics.

Keywords: ANIMAL STUDIES; CT SCANNING; Rat; spinal cord injury.

Objective: In this study, we collected samples from postmenopausal women aged >60 y and evaluated bone mineral density (BMD) in addition to other biochemical variables to evaluate risk factors for osteoporosis. Furthermore, we investigated whether an association exists between the CpG island methylation levels in the promoter region of the TBC1D8 gene and osteoporosis incidence. Our goal was to identify contributing factors to the pathogenesis of osteoporosis and provide a theoretical basis for osteoporosis testing and therapy.

Materials and methods: We used questionnaires to collect data from Chinese Han women in their communities. The following parameters were measured: uric acid, high density lipoprotein, low density lipoprotein, fasting blood glucose, serum creatinine, serum calcium, serum phosphorus, alkaline phosphatase, P1NP, β-CTX, PTH, 25(OH)D and bone mineral density from lumbar spine 1 to 4, femoral neck, and total hip. DNA was also extracted to assess the methylation level of the TBC1D8 gene.

Conclusions: Our findings suggest that a lower body mass index (BMI) infrequent exercise and certain sleep durations may be associated with osteoporosis. In addition, higher serum creatinine, β-CTX and PTH and lower 25(OH)D levels may be associated with osteoporosis. In Chinese Han postmenopausal women, decreased methylation of the TBCF1D8 gene promoter CpG islands is associated with osteoporosis. Finally, we also observed that TBC1D8 is negatively correlated with high density lipoprotein in postmenopausal women with osteoporosis.

Keywords: methylation; osteoporosis; postmenopausal women.

Background: High vegetable intake is associated with beneficial effects on bone. However, the mechanisms remain uncertain. Green leafy vegetables are a rich source of vitamin K1, which is known to have large effects on osteoblasts and osteocalcin (OC) metabolism.

Objective: To examine the effects of consumption of two to three extra serves of green leafy vegetables daily on bone metabolism.

Methods: Thirty individuals (mean age 61.8 ± 9.9 years, 67% male) completed three experimental phases in a randomised controlled crossover design, each lasting four weeks, with a washout period of four weeks between phases (clinical trial registration: ACTRN12615000194561). The three experimental phases were: (i) increased dietary vitamin K1 by consuming green leafy vegetables (H-K; ~200 g/d containing 164.3 [99.5-384.7] μg/d of vitamin K1); (ii) low vitamin K1 by consuming vitamin K1-poor vegetables (L-K; ~200 g/d containing 9.4 [7.7-11.6] μg/d of vitamin K1); and (iii) control (CON) where participants consumed an energy-matched non-vegetable control. OC forms, total OC (tOC), carboxylated OC (cOC) and undercarboxylated OC (ucOC), were measured in serum pre- and post-intervention for each experimental phase using a sandwich-electrochemiluminescence immunoassay.

Results: Pre-intervention tOC, ucOC and ucOC:tOC levels were similar between phases (P > .05). Following H-K, but not L-K, tOC, ucOC and ucOC:tOC levels were significantly lower compared to pre-intervention levels (P ≤ .001) and compared to CON (~14%, 31% and 19%, respectively, all P < .05), while cOC remained unchanged.

Conclusions: In middle-aged healthy men and women, an easily achieved increase in dietary intake of vitamin K1-rich green leafy vegetables substantially reduces serum tOC and ucOC suggesting increased entry of OC into bone matrix, where it may improve the material property of bone. In conjunction with previous epidemiological and randomised controlled trial data, these findings suggest that interventions to increase vegetable intake over extended periods should include bone end points including fracture risk.

Keywords: Ageing; BMD, bone mineral density; Bone; CON, control; CTX, collagen type I C-terminal cross-linked telopeptide; FFQ, food frequency questionnaire; GCMS, gas-chromatography mass spectrometry; H-K, experimental phase with high vitamin K1 intake; L-K, experimental phase with low vitamin K1 intake; METs, metabolic equivalents; MK, menaquinones; Nutrition; OC, osteocalcin; Osteocalcin; P1NP, N-terminal propeptide of type I collagen; PK, phylloquinone; RCT, randomised controlled trial; USDA, United States Department of Agriculture; VIABP, Vegetable intake and blood pressure study; VKDP, vitamin K dependant proteins; Vitamin K; cOC, carboxylated osteocalcin; tOC, total osteocalcin; ucOC, undercarboxylated osteocalcin; ucOC:tOC, fraction of undercarboxylated osteocalcin.

Several decades ago, a clinical condition that included severe bone overgrowth was described in a few patients in South Africa. The autosomal-recessive disease that later was named sclerosteosis was found to be caused by a mutation in the SOTS gene causing a lack of the protein sclerostin. This protein is produced by osteocytes and exerts its effect as an inhibitor of bone formation by blocking the Wnt signaling pathway. By the use of a monoclonal antibody that can block sclerostin a novel therapeutic pathway for rebuilding bone has been described. Preclinical studies have shown increased bone mass following subcutaneously administered anti-sclerostin antibody in animals with induced postmenopausal osteoporosis as well as in intact male rats and non-human primates. In a phase II study the efficacy and safety of an anti-sclerostin antibody, romosozumab, has been evaluated in 419 postmenopausal women for 12 months. 70, 140 or 210 mg was given subcutaneously monthly or every three months and compared to 70 mg of oral alendronate given once a week or 20 μg of teriparatide subcutaneously once daily. All dose levels of romosozumab were associated with significant increase in BMD with the most pronounced gain in the group receiving 210 mg where lumbar spine BMD increased with 11.3% from baseline. The BMD for the placebo group decreased by 0.1% while the alendronate group increased 4.1% and the teriparatide increased 7.1%. Biochemical markers revealed a transitory increase in the bone formation marker P1NP while no change in the bone resorption marker β-CTX. In comparison, teriparatide resulted in an increase for both P1NP and β-CTX for the complete study period. Even though the rapid gain in BMD is promising when considering a treatment option for osteoporosis and other conditions with bone loss, there are so far no published studies on whether anti-sclerostin can reduce the number of fractures. Wnt signaling might also play an important role in fracture healing with substances that causes an upregulation of the Wnt pathway producing enhancement of the fracture healing process. Healing of experimental fractures in various animal models have shown improvement following subcutaneously administered anti-sclerostin antibody. While there are no published reports on the potential effect of systemically administered anti-sclerostin antibodies on fracture healing in humans.

Osteoporosis is a multifactorial disease characterized by the loss of bone mass and deterioration of the internal structure of the bone, increasing the risk of fractures, and is becoming an economic and social problem. The main treatment is pharmacological, however, the population demands other therapies, such as foods with nutrients beneficial to bone health. Seventy-eight healthy menopausal women at risk of osteoporosis or untreated osteopenia were recruited for a randomized, parallel, double-blind clinical trial with two intervention groups: one group consumed a serving a day of the experimental enriched product (experimental group (EG)) and the other group (control group (CG)) consumed the same product without enrichment. The main objective was to compare the effect of consuming a dairy preparation to reconstitute, similar to yogurt when prepared, enriched in calcium, vitamin D, vitamin K, vitamin C, zinc, magnesium, L-leucine and probiotic (Lactobacillus plantarum 3547) on bone metabolism markers for 24 weeks. The EG showed a significantly increased bone mass compared to the CG (0.01 ± 0.03 vs. -0.01 ± 0.03 kg; p < 0.05). In addition, the EG maintained their bone mineral density (BMD) compared to the CG, whose BMD significantly decreased at the end of the study. For biochemical markers, the EG significantly increased the serum levels of the N-terminal propeptide of type I collagen (P1NP) bone formation marker (13.19 ± 25.17 vs. -4.21 ± 15.62 ng/mL; p < 0.05), and decreased the carbo-terminal telopeptide of type I collagen (CTx) bone resorption marker compared to the CG (-0.05 ± 0.19 vs. 0.04 ± 0.14 ng/mL; p < 0.05). On the other hand, the EG exhibited a significantly decreased systolic and diastolic blood pressure compared to the start of the study. Finally, the EG significantly increased their dietary calcium and vitamin D intake compared to the CG. In conclusion, the regular consumption of a dairy product to reconstitute enriched with bioactive nutrients improves bone health markers in menopausal women at risk of osteoporosis without pharmacological treatment.

Keywords: bone mineral density; functional foods; nutrition; osteoporosis; prevention.