Increased Bone Resorption Markers Research Articles

High Salt Diet Impairs Male Fertility in Mice via Modulating the Skeletal Homeostasis.

Male reproductive functions and bone health are both adversely affected by the high salt diet (HSD). Nevertheless, the underlying mechanism via which it alters the sperm function remains largely unknown. This study examines the mechanism by which HSD affects male fertility by impairing bone health. For investigating the same, male BALB/c mice were categorized into three groups-HSD group (fed with 4% NaCl), a low salt diet (LSD) group (fed with 0.4% NaCl), and a control group (fed with a normal diet) for 6 weeks and thereafter assessed for various sperm parameters, bone turnover markers, and testosterone levels. Furthermore, the quantitative assessment of testosterone biosynthesis enzymes was performed. Interestingly, we observed that mice fed with HSD showed significant alterations in sperm parameters-motility, count, and vitality, including morphological changes compared to both the LSD and the control groups. In addition, serum analysis showed an increase in bone resorption markers and a decrease in bone formation markers in the HSD group (p < 0.05). Further, HSD caused a decrease in the testosterone level and mRNA expression of testosterone biosynthesis enzymes. Importantly, a significant decrease in bone formation marker osteocalcin (OC) was observed to coincide with the dip in testosterone level in the HSD group. Given that OC plays a key role in maintaining male fertility, the above findings suggest that a decrease in OC levels may affect the testosterone biosynthesis pathway, reducing testosterone hormone secretion and thereby resulting in decreased spermatogenesis. The study for the first time delineates and bridges the mechanism of HSD-mediated bone loss (results in a deficiency of OC) with decreased testosterone biosynthesis and thus impaired male fertility.

Disuse (post-mobilization) osteoporosis: literature review and clinical case series

Background. Disuse (рost-immobilization) osteoporosis is defined as secondary loss of bone mass in case of the absence or insufficient mechanical load on the skeleton. This disease can be associated with various risk factors, including long-time bed rest. The purpose of the research was to analyze modern literary data on the mechanisms of development, principles of diagnosis and treatment of disuse osteoporosis and to present own clinical data of disuse osteoporosis in the patients with multiple injuries of the skeleton in the conditions of war in Ukraine. Materials and methods. The review was based on the analysis of literature sources from the PubMed, WOS, Scopus, Google, Google Scholar, Cochrane Library databases for the years 2007–2022. The search was conducted using keywords: disuse osteoporosis, immobilization, bed rest, bone mineral density (BMD), bone remodeling, regeneration. Results. The data on the theory of the mechanostat are considered as links in the appearance of disuse osteoporosis. In conditions of immobilization, bone remodeling processes are slowing down. Histomorphometric studies confirm a decrease in trabecular bone density, thickness of the cortical layer, and an increase in its porosity. A change in bone architecture with a biphasic course is observed. Disruption of the synchronicity of remodeling processes with a decrease in the rate of osteoblastogenesis and an increase in osteoclastogenesis was noted, and the role of osteocytes as mechanosensors was emphasized. Disuse osteoporosis leads to a violation of biochemical marker of bone metabolism. Early laboratory manifestations of bed rest were recorded in the form of a violation of calcium level, an increase in bone resorption markers, while bone formation markers did not change significantly. Bone loss in disuse osteoporosis is manifested by a decrease in BMD indices. The greatest decrease was recorded in the lower extremities’ bones and the vertebrae of the lumbar spine. Modern methods of treatment of disuse osteoporosis involve the use of antiresorptive and osteoanabolic agents but clinical data are limited, which requires multicenter randomized studies. The article presents 3 clinical examples of disuse osteoporosis after gunshot fractures of the lower extremities’ bones.

Bone Response to Weight Loss Following Bariatric Surgery

Obesity is a global health challenge that warrants effective treatments to avoid its multiple comorbidities. Bariatric surgery, a cornerstone treatment to control bodyweight excess and relieve the health-related burdens of obesity, can promote accelerated bone loss and affect skeletal strength, particularly after malabsorptive and mixed surgical procedures, and probably after restrictive surgeries. The increase in bone resorption markers occurs early and persist for up to 12 months or longer after bariatric surgery, while bone formation markers increase but to a lesser extent, suggesting a potential uncoupling process between resorption and formation. The skeletal response to bariatric surgery, as investigated by dual-energy X-ray absorptiometry (DXA), has shown significant loss in bone mineral density (BMD) at the hip with less consistent results for the lumbar spine. Supporting DXA studies, analyses by high-resolution peripheral quantitative computed tomography (HR-pQCT) showed lower cortical density and thickness, higher cortical porosity, and lower trabecular density and number for up to 5 years after bariatric surgery. These alterations translate into an increased risk of fall injury, which contributes to increase the fracture risk in patients who have been subjected to bariatric surgery procedures. As bone deterioration continues for years following bariatric surgery, the fracture risk does not seem to be dependent on acute weight loss but, rather, is a chronic condition with an increasing impact over time. Among the post-bariatric surgery mechanisms that have been claimed to act globally on bone health, there is evidence that micro- and macro-nutrient malabsorptive factors, mechanical unloading and changes in molecules partaking in the crosstalk between adipose tissue, bone and muscle may play a determining role. Given these circumstances, it is conceivable that bone health should be adequately investigated in candidates to bariatric surgery through bone-specific work-up and dedicated postsurgical follow-up. Specific protocols of nutrients supplementation, motor activity, structured rehabilitative programs and, when needed, targeted therapeutic strategies should be deemed as an integral part of post-bariatric surgery clinical support.

Potential impact of pediatric obstructive sleep apnea on mandibular cortical width dimensions.

To analyze differences in mandibular cortical width (MCW) among children diagnosed with obstructive sleep apnea (OSA) or at high- or low-risk for OSA. A total of 161 children were assessed: 60 children with polysomnographically diagnosed OSA, 56 children presenting symptoms suggestive of high-risk for OSA, and 45 children at low risk for OSA. Children at high- and low-risk for OSA were evaluated through the Pediatric Sleep Questionnaire. MCW was calculated using ImageJ software from panoramic radiograph images available from all participants. Differences between MCW measurements in the 3 groups were evaluated using analysis of covariance and Bonferroni post-hoc tests, with age as a covariate. The association between MCW and specific cephalometric variables was assessed through regression analysis. The participants' mean age was 9.6 ± 3.1 years (59% male and 41% female). The mean body mass index z-score was 0.62 ± 1.3. The polysomnographically diagnosed OSA group presented smaller MCW than the group at low-risk for OSA (mean difference = -0.385 mm, P = .001), but no difference with the group at high-risk for OSA (polysomnographically diagnosed OSA vs high-risk OSA: P = .085). In addition, the MCW in the group at high-risk for the OSA was significantly smaller than the group at low-risk for the OSA (mean difference = -0.301 mm, P = .014). The cephalometric variables (Sella-Nasion-A point angle (SNA) and Frankfort - Mandibular Plane angle (FMA)) explained only 8% of the variance in MCW. Reductions in MCW appear to be present among children with OSA or those at high-risk for OSA, suggesting potential interactions between mandibular bone development and/or homeostasis and pediatric OSA. Fernandes Fagundes NC, d'Apuzzo F, Perillo L, et al. Potential impact of pediatric obstructive sleep apnea on mandibular cortical width dimensions. J Clin Sleep Med. 2021;17(8):1627-1634.

Fractures After Denosumab Discontinuation: A Retrospective Study of 797 Cases.

ABSTRACTA rebound of osteoclast activity during the 2 years after a treatment or prevention of osteoporosis with denosumab (Dmab) leads to an increased risk of vertebral fractures (VFs). We attempted to identify the risk factors for these VF and to examine the protective role of bisphosphonates. For that, 22 specialists in Switzerland provided data of unselected patients, treated with denosumab for osteoporosis or breast cancer without metastases under aromatase inhibitors, who have received at least two injections of Dmab, with at least 1 year of follow‐up after discontinuation. The questionnaire covered separately the periods before, during, and after Dmab treatment, and registered clinical, radiological, and lab data. For the analysis of the risk factors, the main outcomes were the time to the first VF after the treatment, the presence of multiple VFs (MVFs), and the number of VFs. The incidence of VF was 16.4% before, 2.2% during, and 10.3% after the treatment with Dmab. The risk of VF after Dmab discontinuation was associated with an increased risk of non‐vertebral fractures. The pretreatment predictors of the post‐treatment fracture risk were a parental hip fracture and previous VFs. Further risk factors appeared later, such as low total hip bone mineral density (BMD) during and after denosumab, increased bone resorption markers, and the loss of total hip BMD after the denosumab. Treatment with bisphosphonates, especially after Dmab, had a protective effect. Bisphosphonates given before Dmab did not further decrease the risk of VF in cases who got bisphosphonates after Dmab. This study shows that the risk of VF is poorly predictable before the prescription of denosumab. But during and after the treatment, bone resorption markers and BMD have a significant predictive value. Bisphosphonates after the treatment with denosumab are protective against VFs. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Functional capacity, bone mineral density and neoformation-resorption bone markers in patients under 18 years of age with reduced mobility.

Prolonged immobilization associated with several neurological disorders causes se condary osteoporosis with pathological fractures and persistent bone pain. To establish the association between bone mineral density (BMD), neoformation and bone resorption markers and the degree of functional capacity in children under 18 years of age with reduced mobility. Pa tients and Method: Cross-sectional study conducted in Ciudad Real, Spain between January 1, 2016, and December 31, 2017 with patients aged between 6 and 18 years diagnosed with different neuro logical disorders. The following variables were analyzed: age, sex, pubertal stage, functional capacity according to the Functional Mobility Scale (FMS), which assesses the ability to walk from 5, 50 to 500 meters, BMD, 25-hydroxy-vitamin D, alkaline phosphatase and osteocalcin in blood, and N-terminal telopeptide crosslinks in collagen type I (NTX-I) in urine. BMD, alkaline phosphatase, osteocalcin, and NTX-I values are expressed in Z score according to reference values for age and sex. The Pear son and Spearman correlations were used for data analysis. 36 patients (52.7% girls) with an average age of 8.6±4.7 years. Mean FMS value: 5.3 out of 18. Mean BMD: -1.99 ± 1.7 standard deviations (SD), mean alkaline phosphatase: -2.64 ± 1.08, mean osteocalcin: -2.15 ± 1.39, and mean NTX-I: +3 ± 1.72. There was a significant association between BMD and FMS for 5 meters (r = 0.395; p = 0.017) and for total score (r = 0.365; p = 0.029). There were no significant differences according to the stages of pubertal development. In this population, there was a decrease in BMD and bone neoformation markers, and an increase of bone resorption markers with no association with pubertal development. Patients with a lower degree of mobility present a lower BMD.

Evaluation of hematology, general serum biochemistry, bone turnover markers and bone marrow cytology in a glucocorticoid treated ovariectomized sheep model for osteoporosis research.

Osteoporosis is a metabolic disorder characterized by a loss of bone mass and structure and increasing the risk of fragility fractures, mostly among postmenopausal women. Sheep is a recognized large animal model for osteoporosis research. An experimental group of ewes (3-4 years old) was subjected to ovariectomy (OVX) and weekly glucocorticoid (GC) application for 24 weeks and compared with a sham control group. Blood and bone marrow parameters were analyzed before and 24 weeks after OVX and GC administration. Osteopenia was confirmed through micro-computed tomography and histomorphometric analysis of L4 vertebra in the study end. A statistically significant increase was observed in mean corpuscular volume, mean cell hemoglobin and monocytes and a decrease in red blood count and eosinophils (p<0.05). Alkaline phosphatase (ALP), gamma-glutamyl transpeptidase, magnesium and α1-globulin increased, and creatinine, albumin, sodium and estradiol decreased (p<0.05). A slight decrease of bone formation markers (bone ALP and osteocalcin) and an increase of bone resorption markers (C-terminal telopeptides of collagen type 1 and tartrate-resistant acid phosphatase) were observed, but without statistical significance. This study aims to contribute to better knowledge of sheep as a model for osteoporosis research and the consequences that a performed induction protocol may impose on organic metabolism.

Bone mineral density in women with systemic lupus erythematosus, its association with bone turnover markers, levels of estradiol and interleukin-6

Introduction: Osteoporosis is frequently diagnosed in patients with systemic lupus erythematosus (SLE). Potential causes and mechanisms of the development of this disease in patients with SLE are still being studied. Aim: To study bone mineral density (BMD) of women with SLE in Ukraine, evaluate its association with the level of bone turnover markers, interleukin-6 (IL-6) and serum estradiol levels. Material and methods: In total, 91 SLE women and 29 healthy individuals were examined. Apart from clinical risk factors for osteoporosis development, the levels of IL-6, bone formation and resorption markers, serum estradiol and their association with reduced BMD were evaluated. The deterioration of BMD was detected by dual-energy X-ray absorptiometry. Results and discussion: Reduced BMD in women with SLE is found in 35.2%. In the study group, 28 women with SLE (48.3%) have decreased levels of bone formation markers, while 30 women (51.7%) have increased bone resorption markers. Imbalance of bone metabolism is highly associated with the severity of the disease, IL-6, and an exposure dose of glucocorticoids. The level of estradiol in women with SLE is 1.8 times lower than in individuals from the control group. The deterioration of the BMD is closely related to the bone turnover disorder, level of IL-6 and estradiol. Conclusions: Independent predictors of BMD disorder in SLE women are levels of osteocalcin and C-terminal telopeptide of type I collagen as well as IL-6 and decreased level of serum estradiol.

Low Bone Mineral Density and High Bone Turnover in Patients With Non-Hodgkin's Lymphoma (NHL) Who Receive Frontline Therapy: Results of a Multicenter Prospective Study.

Chemotherapy associated osteoporosis is a severe problem in patients with malignant diseases as it increases the risk for fractures and deteriorates quality of life. There are very limited data in the literature for the effect of chemotherapy on bone metabolism of adult patients with Non-Hodgkin Lymphoma (NHL). We prospectively evaluated bone remodeling pre- and post-chemotherapy in 61 patients with newly diagnosed NHL. First-line chemotherapy resulted in high bone turnover, which led to increased bone loss and reduced bone mineral density (BMD) of lumbar spine (L1-L4) and femur neck (FN). The reduction of L1-L4 and FN BMD post-chemo was more profound in males and in older patients (>55 years). Patients who received 8 cycles of chemotherapy had a greater reduction of L1-L4 and FN BMD as compared to 6 cycles. The administration of chemotherapy also resulted in a dramatic increase of bone resorption markers (CTX and TRACP-5b), bone formation markers, (bALP and Osteocalcin) and of osteoblast regulator Dickkopf-1. During study period, one patient had a pathological fracture in his right FN.

Changes in mechanical loading affect arthritis-induced bone loss in mice.

Arthritis induces bone loss by inflammation-mediated disturbance of bone homeostasis. On the other hand, pain and impaired locomotion are highly prevalent in arthritis and result in reduced general physical activity and less pronounced mechanical loading. Bone is affected by mechanical loading, directly through impact with the ground during movement and indirectly through muscular activity. Mechanical loading in its physiological range is essential for maintaining bone mass, whereas disuse leads to bone loss. The aim of this study was to investigate the impact of mechanical loading on periarticular bone as well as inflammation during arthritis. Mechanical loading was either blocked by botulinum neurotoxin A (Botox) injections before induction of arthritis, or enhanced by cyclic compressive loading, three times per week during arthritis induction. Arthritis was verified and evaluated histologically. Trabecular and cortical bone mass were investigated using micro-computed tomography (μCT), subchondral osteoclastogenesis and bone turnover was assessed by standard methods. Inhibition of mechanical loading enhanced arthritis-induced bone loss while it did not affect inflammation. In contrast, enhanced mechanical loading mitigated arthritis-induced bone loss. Furthermore, the increase in bone resorption markers by arthritis was partly blocked by mechanical loading. In conclusion, enhanced arthritic bone loss after abrogation of mechanical loading suggests that muscle forces play an essential role in preventing arthritic bone loss. In accordance, mechanical loading of the arthritic joints inhibited bone loss, emphasizing that weight bearing activities may have the potential to counteract arthritis-mediated bone loss.

Antiresorptive agents' bone-protective and adjuvant effects in postmenopausal women with early breast cancer.

Potent antiresorptive drugs (bisphosphonate and denosumab) are often used to protect bone health in postmenopausal breast cancer patients. In addition, clinical trials have shown that these drugs increase disease-free survival, though the mechanism of adjuvant benefit is largely unknown. Here we review the bone health and adjuvant data for both classes of antiresorptive drugs and highlight differences in their pharmacology. Inhibition of bone resorption is vitally important to protect against osteoporotic fractures, and may also contribute to adjuvant survival benefits by making the bone microenvironment less amenable to breast cancer metastasis. After a course of therapy, stoppage of bisphosphonates yields a persistent antiresorptive effect, whereas discontinuation of denosumab causes a rebound increase in bone resorption markers and a loss of bone mineral density to baseline levels. Whether the potential adjuvant benefits of denosumab are also rapidly lost after drug discontinuation deserves further investigation.

Beneficial effects of Cuscuta chinensis extract on glucocorticoid-induced osteoporosis through modulation of RANKL/OPG signals.

Cuscuta chinensis Lam. (Convolvulaceae) is an important herbal medicine widely used to improve sexual function, treat osteoporosis, and prevent aging, and has been reported to exhibit anti-osteoporotic effects in vitro. However, the activity of Cuscuta chinensis Lam. on glucocorticoid-induced osteoporosis still remains unclear. The present study aimed to assess the protective effect and the underlying mechanism of action of Cuscuta chinensis extract (CCE) against glucocorticoid-induced osteoporosis in vivo. Sprague-Dawley rats were randomly divided into four groups as follows: control group, osteoporosis group, and 2 CCE-treated osteoporosis groups (100 mg·kg-1·day-1). Blood samples and femur bones were collected for immunohistochemistry, biochemical, mRNA expression, and western blot analysis. HPLC analysis revealed that chlorogenic acid, quercetin, and hyperin were the major constituents of CCE. The results indicated that CCE increased bone length, bone weight, and bone mineral density and suppressed dexamethasone (DEX)-induced reduction in body weight. In addition, TRAP staining indicated that CCE reduced osteoclasts in DEX-induced osteoporosis rats. Mechanistically, CCE treatment alleviated the increase of bone resorption markers and the decline of osteogenic markers, which might be partially mediated by regulation of RANKL/OPG and RunX2 pathways. These results suggest that CCE showed promising effects in the protection against glucocorticoid-induced osteoporosis through protecting osteoblasts and suppressing osteoclastogenesis.

Morin protects glucocorticoid-induced osteoporosis through regulating the mitogen-activated protein kinase signaling pathway.

Our aim is to investigate the potential therapeutic value of morin against osteoporosis and elucidate the mechanism of action. Osteoporosis was induced in rats by a subcutaneous injection of dexamethasone (DEX) for 5weeks. Body weight was regularly monitored. Body mineral density (BMD) was determined at proximal femurs using dual energy X-ray absorptiometry. Pathological examination was performed by hematoxylin and eosin staining. The relative expression of osteogenic and bone resorption markers was determined by real-time polymerase chain reaction and Western blotting, respectively. Activation of the MAPK signaling pathway was analyzed by Western blotting. Body weight and BMD were both significantly decreased in osteoporotic rats, although BMD was partially restored by intraperitoneal morin administration. Morin treatment also increased the number of trabecular bones in DEX-induced rats. Mechanistically, morin reversed the decrease of osteogenic markers and increase of bone resorption markers, which might eventually be mediated by modulation of MAPK signaling cascades. Here, we uncovered the therapeutic effect of morin against osteoporosis and demonstrated its suppressive action on the MAPK pathway in this disease.

Ficus deltoidea Prevented Bone Loss in Preclinical Osteoporosis/Osteoarthritis Model by Suppressing Inflammation.

Osteoporosis (OP) and osteoarthritis (OA) are debilitating musculoskeletal diseases of the elderly. Ficus deltoidea (FD) or mistletoe fig, a medicinal plant, was pre-clinically evaluated against OP- and OA-related bone alterations, in postmenopausal OA rat model. Thirty twelfth-week-old female rats were divided into groups (n = 6). Four groups were bilateral ovariectomized (OVX) and OA-induced by intra-articular monosodium iodoacetate (MIA) injection into the right knee joints. The Sham control and OVX-OA non-treated groups were given deionized water. The three other OVX-OA groups were orally administered daily with FD extract (200, 400mg/kg) or diclofenac (5mg/kg) for 4weeks. The rats' bones and blood were evaluated for protein and mRNA expressions of osteoporosis and inflammatory indicators, and micro-CT computed tomography for bone microstructure. The non-treated OVX-OA rats developed severe OP bone loss and bone microstructural damage in the subchondral and metaphyseal regions, supported by reduced serum bone formation markers (osteocalcin, osteoprotegerin) and increased bone resorption markers (RANKL and CTX-I). The FD extract significantly (p < 0.05) mitigated these bone microstructural and biomarker changes by dose-dependently down-regulating pro-inflammatory NF-κβ, TNF-α, and IL-6 mRNA expressions. The FD extract demonstrated good anti-osteoporotic properties in this OP/OA preclinical model by stimulating bone formation and suppressing bone resorption via anti-inflammatory pathways. This is among the few reports relating the subchondral bone plate and trabecular thickening with the metaphyseal trabecular osteopenic bone loss under osteoporotic-osteoarthritis conditions, providing some insights on the debated inverse relationship between osteoporosis and osteoarthritis.

Bariatric Surgery: Weighing In on Bone Loss.

Bariatric Surgery: Weighing In on Bone Loss.

Anti-climacterium effects of pomegranate concentrated solutions in ovariectomized ddY mice.

In the present study, the complex anti-climacterium potential of standardized pomegranate concentrated solution (PCS) was investigated using bilateral ovariectomy (OVX) female ddY mice. Changes in body weight and gain during experimental periods, food consumption, serum estradiol levels, total body and abdominal fat densities, abdominal fat pads, and uterus weights were observed, along with the histopathology of abdominal fat pads and uterus for anti-obesity and estrogenic effects. In addition, liver weights, serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) levels, and histopathological inspections were performed to explore the hepato-protective effects. Serum total cholesterol (TC), low density lipoprotein (LDL), high density lipoprotein, and triglyceride (TG) levels were monitored for hypolipidemic effects with total body and femur mean bone mineral density (BMD), right femur wet, dry and ash weights, strength, serum osteocalcin, bone-specific alkaline phosphatase (bALP) contents, and histological and histomorphometrical analyses for anti-osteoporosis activity. As a result of OVX, notable increases in body weight and gains, food consumption, abdominal fat mass densities, weights of abdominal fat pads deposited in the abdominal cavity, and serum AST, ALT, TC, LDL, TG, and osteocalcin levels were observed, along with decreases in the uterus, liver, and femur weights, mean total body and femur BMD, femur strength, serum bALP, and estradiol levels. In addition, marked hypertrophic alterations in adipocytes located in the deposited abdominal fat pads, liver steatosis, uterine disused atrophic changes, and decreases in bone mass and structures of the femur were also observed in OVX control mice with significant increases in bone resorption markers based on histopathological and histomorphometrical analysis. However, these estrogen-deficient climacterium symptoms were significantly (P<0.05 or P<0.01) inhibited after 84 days of continuous treatment with estradiol and PCS (1, 2 and 4 ml/kg), respectively. The present results suggested that PCS was able to effectively inhibit or refine the climacterium symptoms, including obesity, hyperlipidemia, hepatic steatosis, and osteoporosis, induced by OVX in ddY mice.

Association between sleep apnea and low bone mass in adults: a systematic review and meta-analysis.

This study aimed to synthesize existing evidence on the potential association between sleep apnea and low bone mass in adults. Electronic searches of five databases were performed. The inclusion criteria consisted of studies in humans that assessed potential associations between sleep apnea and bone metabolic diseases in an adult population. For diagnosis of sleep apnea overnight polysomnography, home polygraphy, or validated records from healthcare databases were considered. Reduced bone density, osteoporosis, serum/urinary levels for markers of bone formation and resorption, or risk of fractures caused without history of trauma were considered indicators of low bone mass. A random-effects model meta-analysis was applied when possible. Of the 963 relevant references, 12 studies met our inclusion criteria and were assessed to be of medium to low bias. Nine out of 12 studies reported an association between sleep apnea and low bone mass (increased bone resorption markers, reduced bone density, and higher risk of osteoporosis). Two studies did not report a significant association, whereas one study reported an increase of bone density in sleep apnea patients compared to non-sleep apnea patients. Meta-analysis of 2 studies (n=112,258 patients) showed that sleep apnea was a significant risk factor for osteoporosis (odds ratio (OR), 1.92; 95%CI, 1.24 to 2.97; I2=66%); females only had an OR of 2.56 (95% CI, 1.96 to 3.34; I2=0%) while the OR in males was 2.03 (95% CI, 1.24 to 3.35; I2=38%). An association between sleep apnea and low bone mass in adults is plausible, but supporting evidence has a risk of bias and is inconsistent.

Modeling and remodeling effects of intermittent administration of teriparatide (parathyroid hormone 1-34) on bone morphogenetic protein-induced bone in a rat spinal fusion model

BackgroundBone morphogenetic protein (BMP)-based tissue engineering has focused on inducing new bone efficiently. However, modeling and remodeling of BMP-induced bone have rarely been discussed. Teriparatide (parathyroid hormone [PTH] 1-34) administration initially increases markers of bone formation, followed by an increase in bone resorption markers. This unique activity would be expected to accelerate the modeling and remodeling of new BMP-induced bone. MethodsMale Sprague-Dawley rats underwent posterolateral spinal fusion surgery and implantation of collagen sponge containing either 50μg recombinant human (rh)BMP-2 or saline. PTH 1-34 (60μg/kg, 3 times/week) or saline injections were continued from preoperative week 2 week to postoperative week 12. The volume and quality of newly formed bone were monitored by in vivo micro-computed tomography and analyses of bone histomorphometry and serum bone metabolism markers were conducted at postoperative week 12. ResultsMicrostructural indices of the newly formed bone were significantly improved by PTH 1-34 administration, which significantly decreased the tissue volumes of the fusion mass at postoperative week 12 compared to that at postoperative week 2. Bone histomorphometry and serum analyses showed that PTH administration significantly increased both bone formation and resorption markers. Analysis of the histomorphometry of cortical bone identified predominant periosteal bone resorption and endosteal bone formation. ConclusionsLong-term intermittent administration of PTH 1-34 significantly accelerated the modeling and remodeling of new BMP-induced bone. Clinical relevanceOur results suggest that the combined administration of rhBMP-2 and PTH 1-34 facilitates qualitative and quantitative improvements in bone regeneration, by accelerating bone modeling and remodeling.

Increased bone resorption markers in young patients with inflammatory bowel disease

Increased bone resorption markers in young patients with inflammatory bowel disease

Relationship of pharmacokinetics, changes of bone turnover markers and BMD/fractures efficacy during treatment with anabolic agents;Teriparatide daily and once weekly subcutaneous injections.

Teriparatide(recombinant human PTH1-34, 20 μg daily subcutaneous injection)has been approved for osteoporosis patients at high risk of fracture in many countries including Japan. Teriparatide daily injection therapy has been reported to increase BMD, improve microarchitecture of bone, and reduce the risk of new vertebral fractures and that of non-vertebral fractures. Pharmakokinetic(PK)study after a single Teriparatide injection of the daily dose in healthy Japanese postmenopausal women(n=18)revealed very rapid achievement of peak blood level(median of tmax=0.25 hr)followed by fast disappearance from the blood(mean t1/2=0.708 hr, n=17). Consistent with these PK characteristics, a rapid increase in bone formation marker and later increase in bone resorption marker has previously been observed, which was described as a bone anabolic window. More recently, once weekly subcutaneous injection of teriparatide acetate(56.5 μg)has been reported to reduce the risk of new vertebral fractures compared with placebo and has been approved in Japan. PK study after injection of the higher weekly dose in healthy Japanese postmenopausal women(n=10)revealed a relatively slow achievement of the peak blood level(mean tmax=0.875 hr)compared to daily injections, followed by relatively slow disappearance from the blood(mean t1/2=1.295 hr). Consistent with these PK characteristics, an initial(<24 hr)transient decrease of bone formation markers(serum osteocalcin and P1NP)and transient increase of bone resorption markers(serum NTX and urinary CTX)were observed. However, afterword, the bone formation and resorption markers were increased and decreased, respectively, for longer than 1 week from the baseline levels. The relationship of pharmacokinetics, changes of bone turnover markers and BMD/fractures efficacy during daily versus weekly teriparatide treatment needs to be clarified.