Epidemiologic studies have demonstrated an association of elevated plasma homocysteine levels with greater bone resorption and fracture risk. Vitamins B12 , B6 , and folic acid are cofactors in homocysteine metabolism, and supplementation with B vitamins is effective in lowering homocysteine levels in humans. However, randomized trials of supplemental B vitamins for reduction of fracture risk have been limited. Therefore, we performed an ancillary study to the Women's Antioxidant and Folic Acid Cardiovascular Study (WAFACS), a large randomized trial of women with preexisting cardiovascular disease or three or more coronary risk factors, to test whether a daily B vitamin intervention including folic acid (2.5 mg/day), vitamin B6 (50 mg/day), and vitamin B12 (1 mg/day) reduces nonspine fracture risk over 7.3 years of treatment and follow-up. Among 4810 women, we confirmed 349 nonspine fracture cases by centralized review of medical records. In a substudy of 300 women (150 in treatment group and 150 controls) with paired plasma samples at randomization and follow-up (7.3 years later), we measured two bone turnover markers, including C-terminal cross-linking telopeptide of type I collagen (CTX) and intact type I procollagen N-propeptide (P1NP). In Cox proportional hazards models based on intention-to-treat, we found no significant effects of B vitamin supplementation on nonspine fracture risk (relative hazard = 1.08; 95% confidence interval, 0.88 to 1.34). In a nested case-cohort analysis, there were no significant effects of B vitamins on fracture risk among women with elevated plasma homocysteine levels, or low levels of vitamins B12 or B6 , or folate at baseline. Furthermore, treatment with B vitamins had no effect on change in markers of bone turnover. We found no evidence that daily supplementation with B vitamins reduces fracture risk or rates of bone metabolism in middle-aged and older women at high risk of cardiovascular disease. © 2017 American Society for Bone and Mineral Research.

BACKGROUND

Vitamin D-binding protein (DBP) may alter the biological activity of total 25-hydroxyvitamin D [25(OH)D]; this could influence on the effects of vitamin D in relation to bone mineral density (BMD) and fractures. Emerging data suggest that fetuin-A may be involved in bone metabolism. We aimed to investigate the influence of DBP gene polymorphism on the relationship of vitamin D status and fetuin-A levels to BMD and bone markers.

METHODS

This cross-sectional study was part of a health survey of employees of the Electricity Generating Authority of Thailand (1,734 healthy subjects, 72% male). Fasting blood samples were assayed for 25(OH)D, fetuin-A, N-terminal propeptides of type 1 procollagen (P1NP), C-terminal cross-linking telopeptides of type I collagen (CTx-I), and DBP rs2282679 genotypes. L1-L4 lumbar spine and femoral BMD were measured using dual-energy X-ray absorptiometry.

RESULTS

The DBP rs2282679 genotype distribution conformed to the Hardy-Weinberg equilibrium. There were no correlations between 25(OH)D levels and BMD and bone markers. But a trend of positive correlation was observed for the DBP genotypes with total hip BMD, and for the interaction between 25(OH)D and DBP genotypes with BMD at all femoral sites. We further analyzed data according to DBP genotypes. Only in subjects with the AA (common) genotype, 25(OH)D levels were positively related to BMD and bone markers, while fetuin-A was negatively related to total hip BMD, independently of age, gender and BMI.

CONCLUSIONS

The interaction between vitamin D status, as measured by circulating 25(OH)D and DBP rs2282679 genotypes, modified the association between 25(OH)D and BMD and bone markers. Differences in DBP genotypes additionally influenced the correlation of fetuin-A levels with femoral BMD.

Spinal cord injury (SCI) has been associated with a marked bone loss after injury and a consequent increased risk of osteoporosis. The evaluation of bone mineral density shortly after SCI is a simple and effective method for predicting the development of osteoporosis during the first year after SCI.

BACKGROUND

Spinal cord injury (SCI) has been associated with a marked bone loss after injury and a consequent increased risk of osteoporosis and fractures. The aim of this study was to analyze the factors associated with osteoporosis development short-term after SCI.

METHODS

We included patients with complete recent SCI (<6 months) evaluating bone turnover markers (P1NP, bone ALP, and sCTx), 25-OH-vitamin D (25OHD) levels, and lumbar and femoral BMD (Lunar, Prodigy) at baseline, 6 and 12 months after SCI. The risk factors for osteoporosis analyzed included the following: age, gender, BMI, toxic habits, bone turnover markers, 25OHD levels, lumbar and femoral BMD, level, severity and type of SCI, and days-since-injury. Osteoporosis was defined according to WHO criteria.

RESULTS

Thirty-five patients aged 35 ± 16 years were included, and 52 % developed osteoporosis during the 12-month follow-up. These latter patients had lower BMD values at femur and lumbar spine and higher bone turnover markers at baseline. On multivariate analysis, the principal factors related to osteoporosis development were as follows: total femur BMD <1 g/cm(2) (RR, 3.61; 95 % CI 1.30-10.06, p = 0.002) and lumbar BMD <1.2 g/cm(2) at baseline (0.97 probability of osteoporosis with both parameters under these values). Increased risk for osteoporosis was also associated with increased baseline values of bone ALP (>14 ng/mL) (RR 2.40; 95 % CI 1.10-5.23, p = 0.041) and P1NP (>140 ng/mL) (RR 3.08; 95 % CI 1.10-8.57, p = 0.017).

CONCLUSIONS

The evaluation of BMD at the lumbar spine and femur short-term after SCI is a simple, effective method for predicting the development of osteoporosis during the first year after SCI. Our results also indicate the need to evaluate and treat these patients shortly after injury.

OBJECTIVE

To compare denosumab-induced changes in lumbar spine (LS) and femoral neck (FN) bone mineral density (BMD), bone markers and free soluble receptor activator of nuclear factor kappaB ligand (sRANKL) between treatment naïve postmenopausal women with low bone mass (naïve group) and those who were previously treated with a single zoledronic acid infusion (post-Zol group).

METHODS

Procollagen type 1N-terminal propeptide (P1NP), C-terminal cross-linking telopeptide of type 1 collagen (CTx) and sRANKL levels were measured in serum samples obtained at baseline and 3, 6 and 12months after denosumab initiation. LS and FN BMD were measured at baseline and 12months.

RESULTS

LS and FN BMD increased significantly in both naïve and post-Zol group (p<0.001 and p=0.025 vs. p<0.001 and p=0.017, respectively). Despite the higher P1NP and CTx levels in naïve patients at baseline (both p<0.001), denosumab caused comparable decreases in both groups at month 3, which returned to post-Zol group baseline levels at month 6 and 12 in all patients. Similarly, sRANKL levels decreased significantly at month 3 in both groups and returned to baseline levels at months 6 and 12.

CONCLUSIONS

In patients previously treated with zoledronic acid, sequential denosumab treatment is effective in terms of BMD increases and bone turnover suppression. Despite the lower baseline levels in patients pre-treated with zoledronic acid, bone markers are similarly decreased in both groups following denosumab administration and maintain their reversibility. Denosumab reversibly suppresses endogenous free sRANKL levels in both naïve and zoledronic acid pre-treated patients.

BACKGROUND

Spinal cord injury (SCI) leads to a profound muscular atrophy, bone loss and bone fragility. While there is evidence that exercising paralysed muscles may lead to reversal of muscle atrophy in the chronic period after SCI, there is little evidence that exercise can prevent muscle changes early after injury. Moreover, whether exercise can prevent bone loss and microarchitectural decay is not clear.

METHODS

A multi-centre, parallel group, assessor-blinded randomised controlled trial will be conducted. Fifty participants with acute spinal cord injury will be recruited from four SCI units in Australia and New Zealand. Participants will be stratified by site and AIS status and randomised to an experimental or control group. Experimental participants will receive a 12-week programme of functional electrical stimulation (FES)-assisted cycling. Control participants will receive a 12-week programme of passive cycling. The primary outcome is muscle cross-sectional area of the thigh and calf measured using magnetic resonance images (MRI) of the leg. Secondary outcomes include serum biomarkers of SCI osteoporosis (sclerostin, P1NP and β-CTX), markers of immune function (IL-6, IL-10, FGF2, INF-γ, TNF-α), neurological function, body composition, depression and quality of life. Leg MRIs will be measured by a single blinded assessor based in Melbourne. Serum samples will be analysed in a central laboratory. All other characteristics will be measured at baseline and 12 weeks by blinded and trained assessors at each site. The first participant was randomised on 27 November 2012.

CONCLUSIONS

The results of this trial will determine the relative effectiveness of a 12-week programme of FES-assisted cycling versus passive cycling in preventing muscle atrophy and maintaining skeletal integrity after spinal cord injury.

BACKGROUND

ACTRN12611001079932 (18 October 2011).

Patients with type-1 (T1D) and type-2 diabetes mellitus (T2D) have an increased risk of hip fracture. The underlying mechanisms may involve disturbances in the incretin hormones. Our aim was to clarify if glucose administration i.e. orally or intravenously differentially affects bone turnover markers in healthy males.

12 healthy males were included in a cross-over study consisting of three tests following an 8hour fast. First, an oral glucose tolerance test (OGTT) was performed. Subsequently, we carried out an isoglycemic intravenous glucose infusion (IIGI) that closely mimicked the glucose response curve to the oral glucose load. We analyzed blood samples for the bone turnover markers serum C-terminal telopeptide of type I collagen (s-CTX) and serum procollagen type I N propeptide (s-P1NP), as well as insulin, glucose, gastric inhibitory peptide (GIP), glucagon-like peptide-1 (GLP-1) and glucagon-like peptide-2 (GLP-2). Finally, eight of the twelve participants underwent a control experiment where they fasted for 3h (Control).

While OGTT induced a 50% reduction in s-CTX, only a ~30% reduction was seen during the IIGI and the Control. Neither intervention influenced s-P1NP. The concentration of insulin was highest during the OGTT. However, insulin was also increased significantly during the IIGI compared to the Control. Plasma concentrations of GIP, GLP-1 and GLP-2 were higher under the OGTT than during the IIGI and Control. A linear regression indicated that peak p-GIP significantly predicts nadir s-CTX (p=0.03), and that peak p-GIP could explain 34% of the variability in nadir s-CTX (adjusted R2=0.34).

This study indicates that glucose per se does not acutely affect bone turnover markers. However, gastrointestinal hormones, especially GIP, possibly in combination with hyperglycemia, may have an acute, uncoupling effect on bone turnover leading to a decrease in bone resorption but no change in bone formation.

BACKGROUND

We investigated various serum inflammatory markers to predict ablation responders who have no atrial fibrillation (AF) relapse after the initial ablation.

METHODS

Forty-four consecutive AF patients (age: 59 ± 8 years, paroxysmal: 31, CHADS₂: 1.1 ± 1.1) who underwent an initial pulmonary vein isolation were investigated. Various serum inflammatory markers, such as adiponectin, ANP, BNP, 1CTP, F1+2, hs-CRP, IL-6, intact P1NP, MDA-LDL, MMP-2, TGF-β, TIMP-2, and TNF-α, were evaluated prior to ablation. AF relapse was defined as AF documented in telemonitoring electrocardiograms twice a day during 9.7 ± 2.4 months of follow-up with three months of a blanking-period.

RESULTS

A total of 29 patients (paroxysmal: 21) maintained sinus rhythm after the initial catheter ablation. These ablation responders had significantly lower MMP-2 (Sinus vs. Relapsed: 748 ± 132.7 vs. 841.2 ± 152.4 ng/mL, P=0.042) and TNF-α (1.1 ± 0.4 vs. 1.8 ± 1.7 pg/mL, P=0.046) levels prior to ablation. A BNP-adjusted Cox multivariate regression analysis revealed that the independent predictive factor for AF recurrence was high MMP-2 levels (>766 ng/mL) accompanied by high TNF-α levels (>1.2 pg/mL).

CONCLUSIONS

The levels of MMP-2 and TNF-α might be useful for predicting initial AF catheter ablation responders.

BACKGROUND

The aim of this study was the investigation of the diagnostic value of the amino-terminal propeptide of type I collagen (P1NP) and the tumour markers, CA 15-3 and CA 125, in patients with breast and ovarian cancer.

METHODS

Serum levels of P1NP, CA 15-3 and CA 125 were analyzed using specific immunoassays. Baseline serum samples of 66 patients with metastatic breast cancer and 34 patients with metastatic ovarian cancer under chemotherapy were investigated.

RESULTS

P1NP concentrations were elevated in up to 70% of patients with confirmed bone metastases. The P1NP levels were significantly higher in patients with bone metastases (median: 134 ng/ml) than in those without bone spread (median: 58.5 ng/ml).

CONCLUSIONS

Markers of biochemical bone remodeling can be used in assessing and managing patients with malignancies that metastasize to bone. These markers are abnormally raised in the blood of patients with metastatic bone disease.

We still lack understanding of why some implants fail while most remain stable after decades of use. Proinflammatory cytokines, matrix proteins and bone regulating cytokines of the RANKL/OPG (receptor activator of nuclear factor kappa B ligand/osteoprotegerin) and Wnt/β-catenin pathways are mandatory for normal bone repair but their spatial and temporal role in the healing of primary total hip arthroplasties (THA) has not been previously shown.

Twenty-four osteoarthritis patients with one-sided well-fixed primary THA were prospectively monitored during 18years (18Y) with repeated blood samples, clinical variables and radiographs. Eighty-one healthy donors divided in three age- and gender-matched groups and twenty osteoarthritis patients awaiting THA and serving as control of the validity of stored plasma in THA patients, were included. Plasma was analyzed for C-reactive protein (CRP), interleukin (IL)-6, IL-8, IL-1β, tumor necrosis factor (TNF)-α, osteopontin (OPN), secreted protein acidic and rich in cysteine (SPARC/osteonectin), osteocalcin (OC), bone specific alkaline phosphatase (BALP), N-terminal propeptide of collagen type I (P1NP), RANKL, OPG, the Wnt agonistic ligands (Wnt)-1 and Wnt-3a, and the Wnt antagonists sclerostin, Dickkopf (Dkk)-1, Dkk-3, Dkk-4, secreted frizzled related protein (sFRP)-1, sFRP-3 and Wnt inhibitory factor-1 (Wif-1).

Inflammatory mediators in arthroplasty patients (CRP, IL-6, OPN) increased significantly on day one after surgery vs preoperative value (PR) and healthy subjects and returned to baseline at 6W. TNF-α did not change relative preoperative level or healthy subjects. SPARC and OC increased in a biphasic fashion with the primary phase beginning shortly after surgery and lasting 3M (SPARC) and 2Y (OC) while the secondary phase peaked at 1Y (SPARC) and 13Y (OC), with both returning to basal level at 15Y. BALP peaked at 3M after surgery with a return to basal level at 2Y followed by a continuous increase from 5Y until 18Y. P1NP increased immediately after surgery and returned to basal level at 6W followed by a new peak at 10Y returning to basal at 13Y. IL-8 and IL-1β peaked at 5Y post-THA and returned to basal level at 10Y. RANKL/OPG and Wnt/β-catenin remained at preoperative levels until 5Y post-THA when a sustained increase in OPG level, paralleled by a sustained decrease in sclerostin, started and lasted until 18Y. Despite a strong increase by RANKL at 13Y, the OPG/RANKL-ratio remained high between 5Y and 18Y. Dkk-1 and sFRP-1 remained at basal level until 5Y followed by a peak at 7Y and a return to basal level at 15Y. Similarly, RANKL increased after 5Y, peaked at 13Y and returned to basal levels at 18Y, thus coinciding with Wnt-1. In contrast, Wnt3a, Dkk-3, Dkk-4, sFRP-3 and Wif-1 did not differ from preoperative levels or healthy subjects during the course of the follow-up.

The primary peak of proinflammatory cytokines involved in the initiation of bone healing after trauma is in line with previous results. The primary phase of increased matrix proteins, P1NP and BALP paralleled by RANKL, OPG and Wnt/β-catenin remaining at preoperative level until 5Y, support a strong formation of mineralized matrix and to a lesser degree bone during this phase. The secondary proinflammatory peak at 5Y is likely a trigger of coupled bone remodeling and neosynthesis as it is followed by increased levels of the bone anabolic turnover marker, BALP, and mediators of the RANKL/OPG and Wnt/β-catenin pathways. A continuous increase by OPG level and the bone turnover marker, BALP, lasting from 5Y until 18Y and paralleled by a similar decrease in sclerostin level support their being key regulators of bone anabolism, whereas the transient and opposed activities of RANKL, Wnt-1, Dkk-1 and sFRP-1 serve as fine tuning tools during the coupled remodeling phase.

BACKGROUND

Vitamin B12 deficiency and bone fractures are common in vegetarians. However, a direct relationship between vitamin B12 status and bone metabolism in vegetarians has not been tested sufficiently.

METHODS

Our study included 96 vegetarians (23 German vegans, and 54 German and 19 Indian lacto-, lacto-ovo-vegetarians) and 89 omnivores (Germans and Asian-Indian immigrants in Oman). Blood concentrations of total vitamin B12, holotranscobalamin (holoTC), 25OH-vitamin D (25(OH)D), total homocysteine (tHcy), methylmalonic acid (MMA), and the bone turnover markers (BTMs) bone alkaline phosphatase (BAP), osteocalcin (OC), pro-collagen type I N-terminal peptide (PINP) and C-terminal telopeptides of collagen I (CTx) were measured.

RESULTS

Vegetarians from both population groups exhibited significantly higher concentrations of tHcy, MMA, folate, and BAP, but lower concentrations of holoTC and cobalamin compared with omnivores from the same population. Additionally, German vegetarians had higher circulating activities of BAP as well as higher CTx, OC, and PINP compared with their omnivorous controls. HoloTC and MMA were correlated with OC, CTx and BAP. Subjects with low vitamin B12 status (holoTC < or =35 pmol/L and MMA >271 nmol/L) had significantly lower serum concentrations of 25(OH)D, but higher tHcy and the BTMs P1NP, BAP, OC, and CTx, compared with subjects with normal vitamin B12 status. Multiple regression analysis showed that the association between BTMs and markers of vitamin B12 status was independent from the association with 25(OH)D. Approximately 12%-14% of the variation in the concentration of BTMs was explained by a regression model including holoTC, MMA and 25(OH)D. The strictness of the diet was not related to the magnitude of change in BTMs.

CONCLUSIONS

Low vitamin B12 status is related to increased bone turnover in vegetarians which is independent from vitamin D status.

BACKGROUND

Recent observational studies have suggested that the use of selective serotonin reuptake inhibitors is associated with an increased fracture risk and an accelerated bone loss, although conflicting results have been reported. Furthermore, because many of these studies have been performed in depressed women, confounding by indication may influence these findings.

OBJECTIVE

The objective of the study was to determine whether selective serotonin reuptake inhibitors affect bone metabolism Design: This was a randomized controlled trial.

METHODS

The study was conducted in four US clinical sites.

METHODS

Healthy peri- and postmenopausal women participated in the study.

METHODS

The intervention was escitalopram (10-20 mg/d) for the treatment of vasomotor symptoms.

METHODS

Serum carboxyterminal collagen crosslinks (CTX) and serum amino-terminal propeptide of type I collagen (P1NP) were measured.

RESULTS

One hundred forty-one peri- or postmenopausal nondepressed women (mean age 53.7 y, SD 4.1) had baseline and 8-week follow-up samples available for analysis and were included in the study (69 escitalopram, 72 placebo). The groups were balanced across a broad range of baseline characteristics, including age, race, body mass index, smoking status, and mood symptoms. The between-group differences in the change in CTX and P1NP from baseline to week 8 were compared by a repeated-measures linear regression model adjusted for race, clinical center, and baseline measurement. Treatment with escitalopram reduced serum P1NP by 1.02 ng/mL on average [95% confidence interval (CI) -5.17, 3.12] compared with a reduction of 1.88 ng/mL (95% CI -4.82, 1.06) in the placebo group (P = .65). Similarly, serum CTX decreased 0.02 ng/mL on average (95% CI -0.05, 0.01) in the escitalopram group compared with 0.00 ng/mL (95% CI -0.02, 0.02) in the placebo group (P = .24). The results were similar when the analysis was restricted to those women whose adherence to study medication was 70% or greater.

CONCLUSIONS

Although the study was limited to 8 weeks, these results suggest that escitalopram does not significantly alter bone metabolism in the short term.

Initial military training (IMT) is associated with increased stress fracture risk. In prior studies, supplemental calcium (Ca) and vitamin D provided daily throughout IMT reduced stress fracture incidence, suppressed parathyroid hormone (PTH), and improved measures of bone health compared with placebo. Data were analyzed from a randomized, double-blind, placebo-controlled trial to determine whether single-nucleotide polymorphisms (SNPs) in Ca and vitamin D-related genes were associated with circulating biomarkers of bone metabolism in young adults entering IMT, and whether responses to Ca and vitamin D supplementation were modulated by genotype. Associations between SNPs, including vitamin D receptor (VDR), vitamin D binding protein (DBP), and 1-alpha-hydroxylase (CYP27B1), and circulating biomarkers were measured in fasting blood samples from volunteers (n = 748) starting IMT. Volunteers were block randomized by race and sex to receive Ca (2000 mg) and vitamin D (1000 IU) or placebo daily throughout Army or Air Force IMT (7 to 9 weeks). Total Ca and vitamin D intakes were calculated as the sum of supplemental intake based on intervention compliance and dietary intake. Relationships between SNPs, Ca, and vitamin D intake tertile and change in biomarkers were evaluated in trial completers (n = 391). At baseline, the minor allele of a DBP SNP (rs7041) was positively associated with both 25OHD (B = 4.46, p = 1.97E-10) and 1,25(OH)2 D3 (B = 9.63, p < 0.001). Combined genetic risk score (GRS) for this SNP and a second SNP in the VDR gene (rs1544410) was inversely associated with baseline 25OHD (r = -0.28, p < 0.001) and response to Ca and vitamin D intake differed by GRS (p < 0.05). In addition, presence of the minor allele of a second VDR SNP (rs2228570) was associated with lower P1NP (B = -4.83, p = 0.04) and osteocalcin (B = -0.59, p = 0.03). These data suggest that VDR and DBP SNPs are associated with 25OHD status and bone turnover and those with the highest GRS require the greatest vitamin D intake to improve 25OHD during IMT. © 2016 American Society for Bone and Mineral Research.

OBJECTIVE

To compare bone parameters measured by calcaneous quantitative ultrasonography (BUS) in subjects with and without metabolic syndrome (MetS). In addition, we wanted to examine the association of each of the individual components of the syndrome with BUS measurements, to study the relationship between calciotropic hormones or bone turnover markers with BUS parameters in subjects with or without MetS, and to explore the possibility that the relationship between prevalent vertebral and non-vertebral fractures and BUS is influenced by MetS status.

METHODS

Cross-sectional study.

RESULTS

We investigated 1209 (421 men and 788 women) participants from the Camargo Cohort Study. Prevalence of MetS was 27% in men and 31% in women. Women, but not men, with MetS had higher age-adjusted BUS parameters compared with those without (p<0.05), the difference disappearing after adjustment for BMI. Out of the five single components of MetS, only waist perimeter was significantly associated with BUS (p<0.01), the association being restricted to women. In men and women with MetS (but not without) a positive significant association was observed between BUS and 25OHD levels. BUS parameters were associated with serum P1NP or CTX in normal women, but not in those with MetS. Prevalent vertebral and non-vertebral fractures and BUS parameters (BUA and SOS, respectively) are inversely associated, but this relationship, however, is not influenced by MetS status.

CONCLUSIONS

BUS parameters are higher in women with MetS, and this difference disappears after adjusting for BMI. MetS status did not influence the relationship between BUS parameters and vertebral or non-vertebral fractures.

Bone turnover markers (BTMs) are used to evaluate bone health together with bone mineral density and fracture assessment. Vitamin D supplementation is widely used to prevent and treat musculoskeletal diseases but existing data on vitamin D effects on markers of bone resorption and formation are inconsistent. We therefore examined the effects of vitamin D supplementation on bone-specific alkaline phosphatase (bALP), osteocalcin (OC), C-terminal telopeptide (CTX), and procollagen type 1 N-terminal propeptide (P1NP). This is a post-hoc analysis of the Styrian Vitamin D Hypertension Trial, a single-center, double-blind, randomized, placebo-controlled trial (RCT) performed at the Medical University of Graz, Austria (2011-2014). Two hundred individuals with arterial hypertension and 25-hydroxyvitamin D (25[OH]D) levels <75 nmol/L were randomized to 2800 IU of vitamin D daily or placebo for eight weeks. One hundred ninety-seven participants (60.2 ± 11.1 years; 47% women) were included in this analysis. Vitamin D had no significant effect on bALP (mean treatment effect (MTE) 0.013, 95% CI -0.029 to 0.056 µg/L; p = 0.533), CTX (MTE 0.024, 95% CI -0.163 to 0.210 ng/mL, p = 0.802), OC (MTE 0.020, 95% CI -0.062 to 0.103 ng/mL, p = 0.626), or P1NP (MTE -0.021, 95% CI -0.099 to 0.057 ng/mL, p = 0.597). Analyzing patients with 25(OH)D levels <50 nmol/L separately (n = 74) left results largely unchanged. In hypertensive patients with low 25(OH)D levels, we observed no significant effect of vitamin D supplementation for eight weeks on BTMs.

BACKGROUND

The objective of this study was to assess the utility of the bone formation marker procollagen type 1 amino-terminal propeptide (P1NP) in indicating bone metastases in patients with prostate carcinoma. Alkaline phosphatase (AP) and prostate-specific antigen (PSA) were measured as a comparison.

METHODS

The serum samples of 100 patients were analysed using a specific immunoassay. The patients were divided into three groups, 32 patients with benign prostate hyperplasia (BPH), 38 patients with prostate carcinoma and 30 patients with prostate carcinoma with bone metastases.

RESULTS

PINP concentrations were elevated in about 87% of the patients with confirmed bone metastases, the P1NP levels were significantly (p < or = 0.001) higher (median: 194.7 ng/ml) than in the patients without bone involvement (median: 38.0 ng/ml) and the BPH patients (median: 42.2 ng/ml), who both presented P1NP levels within the normal range.

CONCLUSIONS

P1NP is a reliable predictor of the presence or absence of bone metastases in prostate carcinoma.

BACKGROUND

Plasma concentrations of procollagen peptides are decreased in osteogenesis imperfecta (OI), whereas other bone formation markers may be increased. We examined the utility of combining these markers in the diagnosis of OI in adults.

METHODS

We measured plasma concentrations of procollagen-1 N-peptide (P1NP), osteocalcin, and bone alkaline phosphatase in 24 patients with nondeforming OI, 25 patients with low bone mass due to other causes, and 38 age- and sex-matched controls. The discriminant ability of various test combinations was assessed by the construction of ROC curves.

RESULTS

The median (range) ratio of osteocalcin to P1NP was significantly greater in patients with type I OI [1.75 (0.80-3.86)] than in controls [0.59 (0.34-0.90)] and patients with other causes of low bone mass [0.48 (0.05-1.38); P <0.0001]. This ratio allowed nearly complete differentiation between healthy controls and patients with type I OI, but not patients with type IV OI. With a cutoff of 0.97 for osteocalcin:P1NP, the sensitivity and specificity were maximized at 95% (95% CI 76%-100%) and 88% (69%-97%), respectively, for patients with other causes of low bone mass vs those with type I OI only. For patients with other causes of low bone mass vs all OI patients, sensitivity and specificity were 83% (63%-95%) and 88% (69%-97%), respectively. The addition of bone alkaline phosphatase data did not improve the discriminant ability of the osteocalcin:P1NP ratio.

CONCLUSIONS

The osteocalcin:P1NP ratio is a sensitive and specific test for type I OI in adults, but it has less utility in the diagnosis of other types of nondeforming OI.

BACKGROUND

Routinely, nephrologists rely on different biochemical markers like intact PTH (iPTH), bone-specific alkaline phosphatase (BALP), plasmatic calcium and phosphate. The aim of the present study was to evaluate different other bone markers like N-terminal propeptide of type 1 procollagen (P1NP), active isoform 5b of the tartrate-resistant acid phosphatase (TRAP 5b) and beta-crossLaps (CTXS) as well as full-length PTH (wPTH), presumed non-(1-84) PTH, and their ratio in the diagnosis of renal osteodystrophy with high and low turnover. We also determined 25 hydroxyvitamin D (25VTD), 1-25 dihydroxyvitamin D and homocystein (HCY).

METHODS

We performed those parameters on 73 patients with end-stage renal disease according to the manufacturers' instructions.

RESULTS

There were very strong correlations between the bone markers concentrations, particularly between BALP and P1NP (r=0.953). We did not observe any correlation between the ratio whole PTH/non-(1-84) PTH and any of the usual bone markers. This ratio was significantly (p<0.05) higher in low and high bone turnover patients than in normal patients according to the K/DOQI. We found a correlation between low levels of 25VTD and high levels of HCY.

CONCLUSIONS

BALP offers the best clinical and analytical profile as the easier marker of choice in hemodialyzed patients for the diagnosis of bone disease.

The effects of vitamin E on cardiovascular and bone health are conflicting with beneficial and detrimental findings reported. To investigate this further, we carried out a cross-sectional study to determine the relationship between circulating concentrations of the 2 vitamin E isomers, α- and γ-tocopherol (TP) with bone turnover and arterial stiffness. Two hundred and seventy eight post-menopausal women with mean age [SD] 60.9 [6.0] years were studied. Fasting serum α-TP and γ-TP, bone turnover markers; procollagen type 1 amino-terminal propeptide (P1NP) and C-terminal telopeptide of type 1 collagen (CTX), parathyroid hormone (PTH), total cholesterol (TC) and triglycerides (TG) were measured. Pulse wave velocity (PWV) and central augmentation index (AI) as markers of arterial stiffness were also determined. A positive correlation was observed between α-TP and γ-TP (r=0.14, p=0.022). A significant negative association between α-TP and P1NP only was seen in multiple linear regression analysis following adjustment for serum TC and TG (p=0.016). In a full multi-linear regression model, following correction for age, years since menopause, smoking habits, alcohol intake, use of calcium supplements, BMI, PTH, serum calcium, and estimated glomerular filtration rate (eGFR), the association between α-TP and P1NP remained significant (p=0.011). We did not observe any significant association between γ-TP or α-TP/γ-TP ratio with P1NP or CTX. P1NP was significantly lower in subjects with α-TP concentrations of >30 μmol/L (α-TP >30 μmol/L; P1NP: 57.5 [20.7], α-TP<30 μmol/L; P1NP: 65.7 [24.9] μg/L, p=0.005). PWV was significantly associated with α-TP/γ-TP ratio (p=0.04) but not with serum α-TP or γ-TP in a full multi-linear regression model adjusting for serum lipids, age, and blood pressure. The data suggest that high serum concentrations of α-TP may have a negative effect on bone formation. The balance of α-TP and γ-TP may be important in maintaining arterial compliance. Longitudinal studies are needed to investigate the impact of the vitamin E isomers on bone and cardiovascular health.

OBJECTIVE

Long-term glucocorticoid use is accompanied by rapid bone loss; however, early treatment with bisphosphonates prevents bone loss and reduces fracture risk. The aim of this study was to examine the effects of two bisphosphonates, i.v. zoledronic acid (ZOL) versus oral risedronate (RIS), on bone turnover markers (BTMs) in subjects with glucocorticoid-induced osteoporosis (GIO).

METHODS

Patients were randomly stratified according to the duration of pre-study glucocorticoid therapy [prevention subpopulation (ZOL, n = 144; RIS, n = 144) ≤3 months, treatment subpopulation (ZOL, n = 272; RIS, n = 273) >3 months]. Changes in β-C-terminal telopeptides of type 1 collagen (β-CTx), N-terminal telopeptide of type I collagen (NTx), procollagen type 1 N-terminal propeptide (P1NP) and bone-specific alkaline phosphatase (BSAP) from baseline were measured on day 10 and months 3, 6 and 12.

RESULTS

At most time points, there were significantly greater reductions (P < 0.05) in the concentrations of serum β-CTx, P1NP and BSAP and urine NTx in subjects on ZOL compared with RIS in both males and females of the treatment and prevention subpopulations. In pre- and post-menopausal women, there were significantly greater reductions in the concentrations of BTMs with ZOL compared with RIS. At 12 months, ZOL had significantly greater reductions compared with RIS (P < 0.05) for β-CTx, P1NP, BSAP and NTx levels, independent of glucocorticoid dose.

CONCLUSIONS

Once-yearly i.v. infusion of ZOL 5 mg was well tolerated in different subgroups of GIO patients. ZOL was non-inferior to RIS and even superior to RIS in the response of BTMs in GIO patients.

BACKGROUND

ClinicalTrials.gov, http://clinicaltrials.gov, NCT00100620.

BACKGROUND

The African-American skeleton is resistant to PTH; whether it is also resistant to PTHrP and the hormonal milieu of lactation is unknown.

OBJECTIVE

The objective of the study was to assess bone turnover markers in African-Americans during lactation vs Caucasians.

METHODS

A prospective cohort study with repeated measures of markers of bone turnover in 60 African-American women (3 groups of 20: lactating, bottle feeding, and healthy controls), compared with historic Caucasian women.

METHODS

The study was conducted at a university medical center.

METHODS

Biochemical markers of bone turnover and calcium metabolism were measured.

RESULTS

25-Hydroxyvitamin D (25-OHD) and PTH were similar among all 3 African-American groups, but 25-OHD was 30%-50% lower and PTH 2-fold higher compared with Caucasians (P < .001, P < .002), with similar 1,25 dihydroxyvitamin D [1,25(OH)(2)D] values. Formation markers [amino-terminal telopeptide of procollagen-1 (P1NP) and bone-specific alkaline phosphatase (BSAP)] increased significantly (2- to 3-fold) in lactating and bottle-feeding African-American women (P1NP, P < .001; BSAP, P < .001), as did resorption [carboxy-terminal telopeptide of collagen-1 (CTX) and serum amino-terminal telopeptide of collagen 1 (NTX), both P < .001]. P1NP and BSAP were comparable in African-American and Caucasian controls, but CTX and NTX were lower in African-American vs Caucasian controls. African-American lactating mothers displayed quantitatively similar increases in markers of bone formation but slightly lower increases in markers of resorption vs Caucasians (P = .036).

CONCLUSIONS

Despite reported resistance to PTH, lactating African-American women have a significant increase in markers of bone resorption and formation in response the hormonal milieu of lactation. This response is similar to that reported in Caucasian women despite racial differences in 25-OHD and PTH. Whether this is associated with similar bone loss in African-Americans as in Caucasians during lactation is unknown and requires further study.

There has been a marked secular trend in recent decades toward patients with Paget's disease presenting at a greater age and having less extensive skeletal involvement. Over a similar time frame more potent bisphosphonates with a long duration of effect have been developed, raising the prospect of many patients needing only once in a lifetime treatment. We studied a cohort of 107 patients who had been treated with intravenous zoledronate for the first time at a mean age of 76 years. Sequential measurements of the bone turnover marker procollagen-1 NT-peptide (P1NP) were made for up to 10 years. By 9 years, 64% showed some loss of zoledronate effect (defined as a doubling of P1NP from the nadir value after treatment), but only 14% had a biochemical relapse (defined as a P1NP value >80 μg/L). The mortality rate was substantially greater than the relapse rate-by 10 years more than half the cohort had died (p < 0.0001). We conclude that for the majority of older people with Paget's disease a single intravenous infusion of zoledronate will provide disease suppression for the remainder of their lives. © 2016 American Society for Bone and Mineral Research.

UNASSIGNED

Diabetes mellitus is associated with increased fracture risk despite preservation of bone density and reduced bone turnover.

UNASSIGNED

We tested the hypothesis that circulating advanced glycation end products (AGEs) and endogenous secretory receptor for AGEs (esRAGE) differentially modulate bone turnover and predict fracture risk in older men.

UNASSIGNED

A total of 3384 community-dwelling men aged 70 to 89 years.

UNASSIGNED

Collagen type I C-terminal cross-linked telopeptide, N-terminal propeptide of type I collagen (P1NP), and total osteocalcin (TOC) were assayed using immunoassay and undercarboxylated osteocalcin (ucOC) following hydroxyapatite binding. Plasma N-carboxymethyllysine (CML) and esRAGE were assayed using immunoassay. Methylglyoxal and glyoxal were assayed using mass spectrometry. Incident hip fractures were ascertained.

UNASSIGNED

Median age was 76.3 years (interquartile range, 74.2 to 79.1 years). Plasma CML was measured in 3011 men, methylglyoxal and glyoxal in 766 men, and esRAGE in 748 men. Plasma CML, methylglyoxal, glyoxal, and esRAGE were similar in men without and with diabetes (all P>> 0.05). CML was positively associated with fasting glucose (r = 0.06, P < 0.001), and esRAGE was inversely associated (r = -0.08, P = 0.045). esRAGE was positively associated with bone formation (P1NP, r = 0.17, P < 0.001; ucOC, r = 0.11, P = 0.008; TOC, r = 0.16, P < 0.001). Incident hip fractures occurred in 106 men during follow-up. Men with CML in the third quartile of values had reduced incidence of hip fracture compared with men in the lowest quartile (hazard ratio, 0.49; 95% CI, 0.24 to 0.99; P = 0.045).

UNASSIGNED

Glycemia associates positively with CML and reciprocally with esRAGE in older men. Circulating esRAGE modulates bone turnover in older men, whereas CML predicts incidence of hip fracture.

Macrophages have established roles supporting bone formation. Despite their professional phagocytic nature, the role of macrophage phagocytosis in bone homeostasis is not well understood. Interestingly, apoptosis is a pivotal feature of cellular regulation and the primary fate of osteoblasts is apoptosis. Efferocytosis (phagocytosis of apoptotic cells) is a key physiologic process for the homeostasis of many tissues, and is associated with expression of osteoinductive factors. To test effects of macrophage depletion and compromised phagocytosis on bone, 16-week-old male C57BL/6J mice were treated with trabectedin-a chemotherapeutic with established anti-macrophage effects. Trabectedin treatment reduced F4/80+ and CD68+ macrophages in the bone marrow as assessed by flow cytometry, osteal macrophages near the bone surface, and macrophage viability in vitro. Trabectedin treatment significantly reduced marrow gene expression of key phagocytic factors (Mfge8, Mrc1), and macrophages from treated mice had a reduced ability to phagocytose apoptotic mimicry beads. Macrophages cultured in vitro and treated with trabectedin displayed reduced efferocytosis of apoptotic osteoblasts. Moreover, efferocytosis increased macrophage osteoinductive TGF-β production and this increase was inhibited by trabectedin. Long-term (6-week) treatment of 16-week-old C57BL/6J mice with trabectedin significantly reduced trabecular BV/TV and cortical BMD. Although trabectedin reduced osteoclast numbers in vitro, osteoclast surface in vivo was not altered. Trabectedin treatment reduced serum P1NP as well as MS/BS and BFR/BS, and inhibited mineralization and Runx2 gene expression of osteoblast cultures. Finally, intermittent PTH 1-34 (iPTH) treatment was administered in combination with trabectedin, and iPTH increased trabecular bone volume fraction (BV/TV) in trabectedin-treated mice. Collectively, the data support a model whereby trabectedin significantly reduces bone mass due to compromised macrophages and efferocytosis, but also due to direct effects on osteoblasts. This data has immediate clinical relevance in light of increasing use of trabectedin in oncology. © 2017 American Society for Bone and Mineral Research.

OBJECTIVE

Engagement in high volumes of physical activity coupled with energy restriction during periods of musculoskeletal development may compromise bone health. Jockeys limit caloric intakes on a weekly basis often from their mid-to-late teens. The aim of this study was to establish whether calcium and vitamin D supplementation would improve bone turnover markers (BTM) and non-weight bearing bone properties of young male jockeys.

METHODS

A six-month randomised, double-blinded, placebo-controlled trial with two groups of apprentice male jockeys was conducted.

METHODS

Participants (age 20.18±3.23years) were supplemented with 800mg of calcium and 400IU of vitamin D (n=8) or a placebo (n=9) daily. Bone properties were assessed at the ultra-distal (4%) and proximal (66%) radius using pQCT at baseline and six months. Vitamin D, P1NP and CTX were assessed.

RESULTS

ANCOVA results for blood-borne markers indicated higher vitamin D levels (18.1%, p=0.014, partial η2=0.38) and lower CTX (ng·L-1) (-24.8%, p=0.011, partial η2=0.40) in the supplemented group with no differences observed in P1NP. Analysis of bone variables indicated no between group differences in either trabecular or cortical bone properties at the 4% and 66% sites post-intervention.

CONCLUSIONS

This trial is the first to examine the efficacy of calcium and vitamin D supplementation in improving non-weight bearing bone properties in a young male athletic population. Results indicate positive alterations to bone metabolism; however, longer duration or higher dosage appears to be required to detect changes in bone material properties at the radius. Further examination of such interventions in weight-restricted athletes is warranted.