Evolving role of bone biomarkers in castration-resistant prostate cancer

The preferential metastasis of prostate cancer cells to bone disrupts the process of bone remodeling and results in lesions that cause significant pain and patient morbidity. Although prostate-specific antigen (PSA) is an established biomarker in prostate cancer, it provides only limited information relating to bone metastases and the treatment of metastatic bone disease with bisphosphonates or novel noncytotoxic targeted or biological agents that may provide clinical benefits without affecting PSA levels. As bone metastases develop, factors derived from bone metabolism are released into blood and urine, including N- and C-terminal peptide fragments of type 1 collagen and bone-specific alkaline phosphatase, which represent potentially useful biomarkers for monitoring metastatic bone disease. A number of clinical trials have investigated these bone biomarkers with respect to their diagnostic, prognostic, and predictive values. Results suggest that higher levels of bone biomarkers are associated with an increased risk of skeletal-related events and/or death. As a result of these findings, bone biomarkers are now being increasingly used as study end points, particularly in studies investigating novel agents with putative bone effects. Data from prospective clinical trials are needed to validate the use of bone biomarkers and to confirm that marker levels provide additional information beyond traditional methods of response evaluation for patients with metastatic prostate cancer.

Monitoring pharmacological therapy for osteoporosis

Osteoporosis is a common disease characterized by low bone strength that increases the risk of fractures. The consequences of fractures include increases in morbidity, mortality, and healthcare costs. Randomized clinical trials have shown that pharmacological therapy can reduce the risk of fractures. In clinical practice, however, failure to achieve optimal therapeutic benefit is common for reasons that include taking medication incorrectly, stopping it prematurely, malabsorption, and the presence of unrecognized diseases or conditions with adverse skeletal effects. Monitoring for anti-fracture effectiveness in individual patients is limited by the absence of clinical tools to directly measure bone strength. It is therefore necessary to monitor therapy with biomarkers such as bone mineral density and bone turnover markers. This is a review of the utility of these tools in the care of individual patients.

Osteocalcin and specific markers of bone resorption in sickle cell disease

Sickle cell disease commonly causes avascular necrosis of bone. Plain radiographs are not useful if obtained early in the disease. Radionuclide scans do not appear to increase the sensitivity of the diagnosis. Magnetic resonance imaging can detect disease but this is expensive and hard to employ on a routine or regular basis. The determination of the following new biochemical markers of bone metabolism has not been previously performed in sickle cell disease: serum osteocalcin (S-BGP), urinary cross-linked aminoterminal telopeptide of type I collagen (INTP or NTx) and urinary deoxypyridinoline (U∼DPD). As a first step or preliminary study we evaluate the usefulness of these biochemical markers of bone metabolism, by measuring the plasma or serum and urine levels of these markers in 20 adult patients with sickle cell disease. There was no change in S-BGP (p<0.9) a biochemical marker of bone formation. The two markers of bone resorption, urinary NTx (p<0.002) and U-DPD (p<0.001) increased highly significantly. Although the mean values of urinary NTx and U-DPD were significantly elevated in five patients with clinical evidence of bone complications, only two of these subjects had values above mean +2 SD of normal (control) mean values. Hence the sensitivity and specificity of these measures need to be further investigated with a larger sample size. There was significant correlation (P < 0.001) between NTx and U-DPD. These preliminary findings indicate that urinary NTx and U-DPD should be further investigated as possible biochemical markers of skeletal changes in SCD.

Changes in osteopontin and in biomarkers of bone turnover during human endotoxemia

Systemic infection and inflammation in men are associated with bone loss. Rodent studies have elucidated the pathways mediating the effects of bacterial lipopolysaccharide (LPS), activated immune cells and hormones on bone. Here we investigate the changes in biochemical parameters of bone turnover following human endotoxemia, an experimental model of self-limiting systemic infection and inflammation. Ten healthy men received in a randomised, placebo-controlled, cross-over trial once placebo and once 2 ng/kg Escherichia coli endotoxin (LPS). During the following 6 h we monitored parathyoid hormone (PTH) and osteopontin (OPN), a multifunctional protein related to bone pathophysiology, as well as biochemical markers of bone turnover: C-terminal telopeptide of type I collagen (CTX), N-terminal propeptide of type I collagen (P1NP) and osteocalcin (OC). In LPS sessions there was a transient fall in PTH at 3 h (p=0.009) and a nearly two-fold increase in OPN levels after 6 h (LPS: 155+/-19 pg/ml; placebo: 85+/-13 pg/ml, p<0.001). LPS gradually reduced CTX levels (LPS: 0.44+/-0.4 pg/ml; placebo: 0.59+/-0.06 pg/ml, p=0.003), P1NP showed a peak at 4 h (LPS: 89.9+/-14.7 pg/ml; placebo: 75+/-9.7 pg/ml, p=0.028) and circulating OC did not change. The early human response to systemic endotoxemia boosts osteopontin levels and modifies bone biomarkers, indicating a decrease in the lytic activity of osteoclasts, accompanied by an increase in the activity of immature osteoblasts. These changes might present the acute phase response of immune and bone cells to bacterial stimuli in men.

Effects of a structured weight-bearing exercise program on bone metabolism among breast cancer survivors: a feasibility trial

PURPOSE

Treatments for breast cancer, specifically hormonal therapy, accelerate bone loss (BL) among breast cancer survivors, leading to osteoporosis and an increase in fracture risk. Tai Chi Chuan (TCC) is a moderate form of weight-bearing exercise, equivalent to walking, and it has been shown to improve aerobic capacity and strength among breast cancer survivors and might also be effective in slowing bone loss in breast cancer survivors. This pilot study compared the influence of TCC with that of standard support therapy (ST; exercise control) on BL biomarkers among breast cancer survivors.

PATIENTS AND METHODS

Randomly assigned breast cancer survivors (N = 16; median age, 53 years; < 30 months after treatment) completed 12 weeks (3 times per week, 60 minutes per session) of TCC or ST. Serum levels of N-telopeptides of type I collagen (NTx), a marker of bone resorption, and bone-specific alkaline phosphatase (BSAP), a marker of bone formation, were determined according to enzyme-linked immunosorbent assay at baseline and after the intervention.

RESULTS

Using analysis of covariance, survivors in the TCC group experienced a greater increase in levels of bone formation (BSAP [microg/L]: before, 8.3; after, 10.2; change, 1.9 microg/L and 22.4%), compared with survivors in ST (BSAP [microg/L]: before, 7.6; after, 8.1; change, 0.5 microg/L [6.3%]). Survivors in the TCC group also experienced a significant decrease in bone resorption (NTx [nanomoles bone collagen equivalent; nmBCE]: before, 17.6; after, 11.1; change, -6.5 nmBCE; -36.9%), whereas women in the ST group did not (NTx [nmBCE]: before, 20.8; after, 18.8; change, -2.0 nmBCE; -9.6%).

CONCLUSION

This pilot study suggests that weight-bearing exercise exerts positive effects on BL, through increased bone formation and decreased bone resorption. Further examinations of the influence of TCC on bone health are warranted.

Diagnosis of bone metastases in urological malignancies--an update

The spread of urological malignancies to bone is a poor prognostic factor. Early detection of metastatic bony lesions assists with tailoring patient management and potentially improving quality of life. Newer therapies such as zolderonic acid for prostate cancer have reinvigorated the importance of clinicians treating bony disease. An array of biochemical and imaging options are available and the order, sensitivity and cost of such investigations need to be understood to maximise clinical benefit. Furthermore, the ideal time to investigate for bony metastases has often been controversial. Although simple history and examination, serum calcium and alkaline phosphatase and plain radiography with bone scintigraphy remain at the forefront of diagnosing bony disease, evolving diagnostic modalities, such as positron emission tomography and newer bone markers need to be considered. The aim of this review is to clarify the role of various investigations and to give clinicians a current analysis of the timing of such investigations in the context of evolving diagnostic modalities and accepted guidelines for urological malignancy.

Bone-turnover markers in fracture healing

Biochemical markers of bone-turnover have long been used to complement the radiological assessment of patients with metabolic bone disease. Their implementation in daily clinical practice has been helpful in the understanding of the pathogenesis of osteoporosis, the selection of the optimal dose and the understanding of the progression of the onset and resolution of treatment. Since they are derived from both cortical and trabecular bone, they reflect the metabolic activity of the entire skeleton rather than that of individual cells or the process of mineralisation.

Quantitative changes in skeletal-turnover can be assessed easily and non-invasively by the measurement of bone-turnover markers. They are commonly subdivided into three categories; 1) bone-resorption markers, 2) osteoclast regulatory proteins and 3) bone-formation markers. Because of the rapidly accumulating new knowledge of bone matrix biochemistry, attempts have been made to use them in the interpretation and characterisation of various stages of the healing of fractures. Early knowledge of the individual progress of a fracture could help to avoid delayed or nonunion by enabling modification of the host’s biological response.

The levels of bone-turnover markers vary throughout the course of fracture repair with their rates of change being dependent on the size of the fracture and the time that it will take to heal. However, their short-term biological variability, the relatively low bone specificity exerted, given that the production and destruction of collagen is not limited to bone, as well as the influence of the host’s metabolism on their concentration, produce considerable intra- and inter-individual variability in their interpretation. Despite this, the possible role of bone-turnover markers in the assessment of progression to union, the risks of delayed or nonunion and the impact of innovations to accelerate fracture healing must not be ignored.

Effects of a prolonged submersion on bone strength and metabolism in young healthy submariners

Submariners taking part in prolonged missions are exposed to environmental factors that may adversely affect bone health. Among these, relatively high levels of CO(2), lack of sunlight exposure affecting vitamin D metabolism, limited physical activity, and altered dietary habits. The aims of this study were to examine the effect of a prolonged submersion (30 days) on changes in bone strength using quantitative bone speed of sound and in markers of bone metabolism that include bone turnover (BAP, PINP, TRAP5b, and CTx) and endocrine regulators (serum calcium, PTH, and 25[OH]D) in a group of 32 young healthy male submariners. The prolonged submersion led to increases in body weight and BMI and to a decrease in fitness level. There was a significant decrease in bone strength following the submersion. Speed of sound exhibited continued decline at 4 weeks after return to shore and returned to baseline levels at the 6-month follow-up. There was a significant increase in circulating calcium level. PTH and 25(OH)D levels decreased significantly. Significant decreases were observed in both TRAP5b and CTx levels, markers of bone resorption, as well as in N-terminal propeptide of type I collagen (PINP), a bone formation marker. Prolonged submersion led to a significant decrease in bone strength, accompanied by an overall decrease in bone metabolism. Bone strength was regained only 6 months after return to shore. Prevention and/or rehabilitation programs should be developed following periods of relative disuse even for young submariners. The effects of repeated prolonged submersions on bone health are yet to be determined.

A label-free electronic biosensor for detection of bone turnover markers

This paper describes the development of a biosensor based on label-free immunosensing for the detection of the C-terminal telopeptide bone turnover marker from type-1 collagen. A self-assembled monolayer (SAM) of dithiodipropionic acid was deposited on a gold electrode. Then streptavidin and biotinylated anti-human C-terminal telopeptide antibody were successively conjugated on the self-assembled monolayer. Electrochemical impedance measurements were made to characterize each step of the SAM/streptavidin/biotinylated antibody binding. Subsequently, electrochemical impedance was measured with different concentrations of C-teminal telopeptide. A detection limit of 50 ng/mL and a dynamic range up to 3 μg/mL were achieved. To our knowledge, this is the first attempt to develop a label-free immunosensor based on electrochemical impedance with DC bias for detection of bone-related degradation and rebuilding products. The electronic biosensor might eventually be used for quantitative point-of-care screening of bone health. It is hoped that analysis of bone turnover markers can indicate the beginning of bone diseases such as osteoarthritis and osteoporosis so that treatment might start early when it is most effective.

Osteoprotective effect of Phaseolus vulgaris L in ovariectomy-induced osteopenia in rats

OBJECTIVE

Phytoestrogens and phytoestrogen-containing plants are currently being explored as potential candidates for the treatment of estrogen-related disorders. The aim of this study was to evaluate the anti-osteoporotic effect of the phytoestrogen-rich plant Phaseolus vulgaris L, commonly known as French beans.

METHODS

Adult Sprague-Dawley rats were either bilaterally ovariectomized (OVX) or sham operated. OVX and sham control groups were administered vehicle, whereas the other two OVX groups were given 0.15 mg/kg estradiol and 1 g/kg methanolic extract of P vulgaris L seeds (MPV) orally for 10 weeks (10 rats per group). At autopsy, blood, urine, bones, and uteri of the animals were collected. Serum was evaluated for estradiol, calcium (Ca), phosphorus, alkaline phosphatase, tartarate resistant acid phosphatase, and urine for Ca. The bone density, ash density, mineral content, and mechanical strength of bones was evaluated. Scanning electron microscopic analysis of bones (tibia) was performed. Results were analyzed using analysis of variance and Tukey's multiple comparison test.

RESULTS

Compared with the OVX control, MPV (1 g/kg PO) significantly decreased serum alkaline phosphatase and reduced serum tartarate resistant acid phosphatase and urinary Ca levels. It caused an increase in bone density, ash density, and bone mechanical strength and significantly increased bone Ca. Improvement in bone microarchitecture was indicated by image analysis of scanning electron microscopic photomicrographs. No increase in weight of atrophic uterus in OVX animals was observed with MPV treatment.

CONCLUSIONS

Treatment with MPV prevented estrogen deficiency-induced osteopenia without affecting the uterine mass. The promising results of the study warrant further investigation of French beans as a potential candidate for the treatment of postmenopausal osteoporosis.

Crosstalk between osteoblasts and endothelial cells co-cultured on a polycaprolactone-starch scaffold and the in vitro development of vascularization

The reconstruction of bone defects based on cell-seeded constructs requires a functional microvasculature that meets the metabolic demands of the engineered tissue. Therefore, strategies that augment neovascularization need to be identified. We propose an in vitro strategy consisting of the simultaneous culture of osteoblasts and endothelial cells on a starch-based scaffold for the formation of pre-vascular structures, with the final aim of accelerating the establishment of a vascular bed in the implanted construct. Human dermal microvascular endothelial cells (HDMECs) were co-cultured with human osteoblasts (hOBs) on a 3D starch-based scaffold and after 21 days of culture HDMEC aligned and organized into microcapillary-like structures. These vascular-like structures evolved from a cord-like configuration to a more complex branched morphology, had a lumen and stained in the perivascular region for type IV collagen. Genetic profiling of 84 osteogenesis-related genes was performed on co-culture vs. monoculture. Osteoblasts in co-culture showed a significant up-regulation of type I collagen and immunohistochemistry revealed that the scaffold was filled with a dense matrix stained for type I collagen. In direct contact with HDMEC hOBs secreted higher amounts of VEGF in relation to monoculture and the highest peak in the release profile correlated with the formation of microcapillary-like structures. The heterotypic communication between the two cell types was also assured by direct cell-cell contact as shown by the expression of the gap junction connexin 43. In summary, by making use of heterotypic cellular crosstalk this co-culture system is a strategy to form vascular-like structures in vitro on a 3D scaffold.

The effects of a low-sodium base-producing diet including red meat compared with a high-carbohydrate, low-fat diet on bone turnover markers in women aged 45–75 years

A randomised, parallel-design dietary intervention study was conducted in women (aged 45–75 years) with prehypertension or stage 1 hypertension. The aim was to compare the effects on bone turnover of a low-Na base-producing (LNAB) Dietary Approaches to Stop Hypertension (DASH)-type diet (including six serves lean red meat/week) with a high-carbohydrate low-fat (HCLF) diet with a higher acid load (both >800 mg dietary Ca/d). Fasting serum bone markers (baseline and week 14) and 24 h urinary electrolyte excretion (baseline, weeks 4, 8, 12 and 14) were measured. After the intervention period, the LNAB group (n 46) had a fall of 26 (sem 6) % (P < 0·0001) in urinary Na, an increase in K excretion (6·8 (sem 3·6) mmol/d; P = 0·07) and, compared with the HCLF group (n 49), a greater reduction in urinary Ca excretion by 0·7 (sem 0·3) mmol/d. Serum 25-hydroxyvitamin D, intact parathyroid hormone and osteocalcin did not change, and both groups had a similar increase of 23 (sem 5) % (P < 0·0001) in C-terminal telopeptide of type I collagen. The HCLF group had an 11 (sem 4) % increase (P = 0·003) in N-terminal propeptide, type I procollagen, which could indicate an increased rate of bone turnover. The fall in urinary Ca with the lower-Na lower-acid load diet is likely to have long-term beneficial effects on bone. As bone resorption was not different between the two dietary patterns with relatively high Ca intake, the effect on bone health of a dietary pattern with a lower acid load warrants further study on a lower Ca intake.

Bone metabolism alteration on antiepileptic drug therapy

OBJECTIVE

To investigate whether serum total alkaline phosphatase (ALP), bone-specific ALP (bone ALP), calcium, phosphorus, 25-hydroxyvitamin D (25-OHvit D) concentrations are altered early in the course of treatment with carbamazepine or valproic acid monotherapy in ambulatory children with adequate sun exposure; and to determine the effectiveness of simultaneous supplementation with calcium and 25-OHvit D at recommended dietary allowance doses on these biochemical parameters.

METHODS

For each drug, children were divided into two groups (Group A: without supplementation; and Group B: with supplementation) and serum biochemical parameters estimated at 0, 30, 60, and 90 days of starting treatment.

STATISTICAL ANALYSIS

Serial changes in serum biochemical parameters (mean +/- SD) were compared within each of the four groups using student's paired t test. Also for each drug, serum biochemical parameters were compared between Groups A and B at 0, 30, 60, and 90 days of starting treatment using student's unpaired t test.

RESULTS

For both drugs, in Group A, serum total ALP levels were significantly increased above the normal range (P<0.0001) by 90 days of starting treatment; however, serum bone ALP level was significantly increased (P=0.002) only in children on valproic acid. For both drugs when serum biochemical parameters were compared between Groups A and B, supplementation resulted in a significant decrease in serum total ALP (P<0.0001) and bone ALP levels (P<0.001), and a significant increase in serum calcium (P<0.0001) and 25-OHvit D levels (P<0.0001) by 90 days of starting treatment.

CONCLUSION

Serum biochemical changes which indicate predisposition to development of rickets or osteomalacia appear within 90 days of starting carbamazepine or valproic acid monotherapy. However simultaneous supplementation with oral calcium and 25-OHvit D is effective in preventing the development of these adverse biochemical changes.

Bone turnover markers are correlated with total skeletal uptake of 99mTc-methylene diphosphonate (99mTc-MDP)

Background

Skeletal uptake of ^99mTc labelled methylene diphosphonate (^99mTc-MDP) is used for producing images of pathological bone uptake due to its incorporation to the sites of active bone turnover. This study was done to validate bone turnover markers using total skeletal uptake (TSU) of ^99mTc-MDP.

Methods

22 postmenopausal women (52–80 years) volunteered to participate. Scintigraphy was performed by injecting 520 MBq of ^99mTc-MDP and taking whole body images after 3 minutes, and 5 hours. TSU was calculated from these two images by taking into account the urinary loss and soft tissue uptake. Bone turnover markers used were bone specific alkaline phosphatase (S-Bone ALP), three different assays for serum osteocalcin (OC), tartrate resistant acid phosphatase 5b (S-TRACP5b), serum C-terminal cross-linked telopeptides of type I collagen (S-CTX-I) and three assays for urinary osteocalcin (U-OC).

Results

The median TSU of ^99mTc-MDP was 23% of the administered activity. All bone turnover markers were significantly correlated with TSU with r-values from 0.52 (p = 0.013) to 0.90 (p < 0.001). The two resorption markers had numerically higher correlations (S-TRACP5b r = 0.90, S-CTX-I r = 0.80) than the formation markers (S-Total OC r = 0.72, S-Bone ALP r = 0.66), but the difference was not statistically significant. TSU did not correlate with age, weight, body mass index or bone mineral density.

Conclusion

In conclusion, bone turnover markers are strongly correlated with total skeletal uptake of ^99mTc-MDP. There were no significant differences in correlations for bone formation and resorption markers. This should be due to the coupling between formation and resorption.

Detection of Unsaturated Disaccharides, Pyridinoline, and Hydroxyproline in Urine of Patients with Kashin-Beck Disease: Comparison with Controls in an Endemic Area

Objective.

To investigate the pathologic status of adult patients with Kashin-Beck disease (KBD) in an endemic area of China through detection of 5 biochemical markers in their urine, and to study the correlations between these markers and KBD.

Methods.

A total of 55 patients with KBD over age 40 years were recruited and divided into groups, Grade 1 and Grade 2, according to clinical diagnosis criteria for KBD and our inclusion criteria; 25 healthy persons were enrolled into a control group. The first-time urine of the 80 participants was collected in the morning. Three unsaturated disaccharides, pyridinoline (PYD), and hydroxyproline (HYP) were detected in urine samples with high performance liquid chromatography, ELISA, and a chemical kit. Mean levels of these markers were compared in the 3 groups.

Results.

The mean concentrations of 3 unsaturated disaccharides and PYD in the Grade 2 group were significantly higher than levels in the Grade 1 group and controls (p < 0.05). There was no significant difference between findings in the Grade 1 group and controls. Levels of 3 unsaturated disaccharides correlated with each other (p < 0.01). The correlation coefficient between PYD and HYP was 0.470 (p < 0.01). Except for HYP, the other markers all correlated with grade of KBD, rather than age or sex of subjects.

Conclusion.

The cartilage degradation of patients with Grade 2 KBD was more severe than that of Grade 1 patients and controls. The pathologic condition of Grade 1 patients was mild. Except for HYP, the markers we investigated specifically reflected the pathologic bone metabolism of adult patients with KBD. Trial registration number ChiCTR-TRC-00000140.

Clinical trial: comparison of alendronate and alfacalcidol in glucocorticoid-associated osteoporosis in patients with ulcerative colitis

BACKGROUND

Bone loss is often observed in patients with ulcerative colitis, particularly if they require glucocorticoids.

AIM

To determine whether the bisphosphonate, alendronate, is safe and effective in preserving bone mass compared to the active vitamin D3, alfacalcidol, in ulcerative colitis patients receiving glucocorticoids.

METHODS

Thirty-nine patients with ulcerative colitis and treated with glucocorticoids were randomized to receive alendronate (5 mg/day) or alfacalcidol (1 microg/day) daily for 12 months. Loss of bone mass was evaluated by bone mineral density, bone resorption by urinary N-telopeptide for type I collagen, and bone formation by serum bone alkaline phosphatase.

RESULTS

Alendronate, but not alfacalcidol, significantly increased bone mineral density in the lumbar spine. Alendronate decreased serum bone alkaline phosphatase levels, but alfacalcidol did not. Urinary N-telopeptide for type I collagen levels decreased in both groups, but were significantly lower in the alendronate group. There were no significant differences in the adverse events in the two groups.

CONCLUSION

Our study indicates that alendronate is a safe, well-tolerated and more effective therapy than alfacalcidol for preventing glucocorticoid-associated bone loss in patients with ulcerative colitis.

Prolyl-hydroxyproline dipeptide in non-hydrolyzed morning urine and its value in postmenopausal osteoporosis

BACKGROUND

Owing to the high correlation between the level of prolyl-4-hydroxyproline dipeptide in non-hydrolyzed urine and that of 4-hydroxyproline in hydrolyzed urine, we examined whether the dipeptide might function as a valuable marker of bone turnover.

METHODS

Based on densitometric measurements, 68 postmenopausal women were divided into groups of non-osteopathic, osteopenic and osteoporotic subjects. The dipeptide and current urinary resorption markers were assayed in morning urine, the former using liquid chromatography, the others plus serum formation markers by means of immunoassay procedures. Together with the assay of basal levels, diet-related changes and healing effect of yearly alendronate therapy were assessed.

RESULTS

Concentration levels in controls and osteoporotic subjects differed significantly; receiver operating characteristics yielded sensitivity of 0.743, specificity of 0.908, area under curve of 0.903, and cut-off of 10.2 micromol/mmol of creatinine. Spearman rank correlation showed the highest pair coefficient between the dipeptide and osteocalcin. Diet-related changes were not found. Following therapy, a significant decline occurred already within a trimester, whilst with the other resorption markers not until 6 months.

CONCLUSIONS

The ease of the dipeptide assay in non-hydrolyzed urine surpasses that of hydroxyproline, and the results present the compound as a real competition to other commonly assessed markers in osteopathies.

Vitamin K in combination with other biochemical markers to diagnose osteoporosis

The significance of a multiparametric classification approach of vitamin K is analysed to differentiate premenopausal (CTRL), postmenopausal non-osteoporotic (nOSP) and osteoporotic (OSP) women. Data records of women between 28 and 74 years of age were used for evaluation. Bone mineral density was determined by quantitative computed tomography of the lumbar spine using the T-score to diagnose osteoporosis. Vitamin K and biochemical markers of bone formation and resorption--alkaline phosphatase (AP), bone alkaline phosphatase (bAP), osteocalcin (OC), undercarboxylated osteocalcin (ucOC), procollagen type I carboxyterminal propeptide (PICP), pyridinoline (PYD), deoxypyridinoline (DPD), N-terminal cross-linked telopeptide of type I collagen (NTx) and bone sialo protein (BSP)--were analysed in all women on days 1 and 42. Vitamin K was significantly lower in the OSP group versus nOSP and CTRL. The odds ratio results revealed the following: vitamin K, 16.7; PYD, 7.5; NTx, 6.0; DPD, 2.7; and ucOC, 2.7. Vitamin K represented a sensitivity rate of 64% and a specificity rate of 82%. In the receiver operating curve analysis, vitamin K reached the highest area under curve (AUC) score. The combination of vitamin K and AP, bAP and PYD resulted in increased AUC scores (>0.9). The parameter combination of vitamin K/PYD and vitamin K/bAP demonstrated a sensitivity rate of 75-88%, with a specificity rate of more than 82%. The data suggests that a combination of vitamin K with other biochemical bone indices might be a useful tool for assessing bone metabolism, especially in metabolic bone diseases such as osteoporosis.

Zoledronic acid decreased osteolysis but not bone metastasis in a nude mouse model of canine prostate cancer with mixed bone lesions

BACKGROUND

Bone metastasis is the most common cause of morbidity and mortality in patients with advanced prostate cancer and is manifested primarily as mixed osteoblastic and osteolytic lesions. However, the mechanisms responsible for bone metastases in prostate cancer are not clearly understood, in part due to the lack of relevant in vivo models that mimic the clinical presentation of the disease in humans. We previously established a nude mouse model with mixed bone metastases using intracardiac injection of canine prostate cancer cells (Ace-1). In this study, we hypothesized that tumor-induced osteolysis promoted the incidence of bone metastases and osteoblastic activity.

METHODS

We studied the effect of inhibition of osteolysis with zoledronic acid (ZA) on the prevention and progression of Ace-1 bone metastases in nude mice using prophylactic and delayed treatment protocols. Bioluminescent imaging, radiography, and histopathological evaluation were performed to monitor the effect of ZA on the incidence, progression and nature of bone metastases.

RESULTS

Unexpectedly, there was no significant difference in tumor burden and the incidence of metastasis between control and treatment groups as detected by bioluminescent imaging and bone histomorphometry. However, radiographic and histopathological analysis showed a significant treatment-related decrease in osteolysis, but no effect on tumor-induced trabecular bone thickness in both treatment groups compared to controls.

CONCLUSION

Our results demonstrated that the incidence of prostate cancer bone metastases in vivo was not reduced by zoledronic acid even though zoledronic acid inhibited bone resorption and bone loss associated with the mixed osteoblastic/osteolytic bone metastases in the Ace-1 model.

Bone markers and their prognostic value in metastatic bone disease: clinical evidence and future directions

BACKGROUND

Bone metastases are prevalent among patients with advanced solid tumors. Metastatic bone disease alters bone homeostasis, resulting in reduced bone integrity and, consequently, increased skeletal complications. Biochemical markers of bone metabolism may meet an unmet need for useful, noninvasive, and sensitive surrogate information for following patients' skeletal health.

MATERIALS AND METHODS

Data for this review were identified by searches of PubMed, and references from relevant articles using the search terms "bone markers" or individual bone marker nomenclature, "cancer," and "metastases." Abstracts and reports from meetings were included only when they related directly to previously published work. Only papers published in English between 1990 and 2007 were included.

RESULTS

Recent retrospective analyses with bisphosphonates, and particularly with zoledronic acid, have shown significant correlations between biochemical markers of bone metabolism levels and clinical outcomes, especially for bone resorption markers. Clinical results for biochemical markers of bone formation and resorption and other emerging markers of bone metabolism including bone sialoprotein, receptor-activator of nuclear factor-kappaB ligand, osteoprotegerin, and other markers are presented. However, biochemical markers of bone metabolism are not yet an established surrogate endpoint for treatment efficacy.

CONCLUSIONS

Biochemical markers of bone metabolism may allow physicians to identify which patients with metastatic bone disease are at high risk for skeletal-related events or death and who may be responding to therapy. Prospective randomized clinical trials are underway to further assess the utility of markers of bone metabolism in patients with bone metastases.

Altered bone metabolism in inflammatory disease: role for nutrition

Osteoporosis is a major public health problem, and as life expectancy and the world's population continue to increase will become even more important. Thus, there is an urgent need to develop and implement nutritional approaches and policies for the prevention and treatment of osteoporosis. Patients with some chronic inflammatory diseases appear to be more likely to develop osteopenia, and in some cases earlier in life, which is of particular concern as the incidence of inflammatory diseases in the Western world is increasing. While the cause of bone loss in patients with inflammatory disease is multifactorial, nutrition may have a role. Many of these patients may have one or more nutritional deficiencies, which can lead to altered rates of bone metabolism. On the other hand, some nutritional factors may attenuate the inflammatory process itself, and thus may indirectly benefit bone metabolism and bone health in patients with inflammatory disease. The present review will consider these issues, particularly in the context of inflammatory bowel disease, coeliac diease and atherosclerosis.

Osterix overexpression enhances osteoblast differentiation of muscle satellite cells in vitro

Muscle satellite cells have long been considered a distinct myogenic lineage responsible for postnatal growth, repair and maintenance of skeletal muscle. Recent studies have demonstrated that they are multi-potential. Osterix (Osx), a novel zinc-finger-containing transcription factor of the sp family, is required for osteoblast differentiation and bone formation. It was hypothesized that Osx overexpression would enhance osteoblast differentiation of muscle satellite cells in vitro. Recombinant adenovirus-mediated Osx gene (Ad-Osx) was constructed and used to transfect muscle satellite cells. Osx overexpression inhibited myogenesis, as demonstrated by suppression of MyoD and myogenin mRNA levels and reduced myotube formation. Muscle satellite cells transduced with Ad-Osx exhibited apparent osteoblast differentiation as determined by the expression of related osteoblastic genes, increased activity of alkaline phosphatase and the formation of mineralized nodules. These results confirmed the ability of Osx to enhance osteoblast differentiation of muscle satellite cells in vitro, and the competence of muscle satellite cells as promising seed cells for bone tissue engineering.

Baseline bone morphometry and cellular activity modulate the degree of bone loss in the appendicular skeleton during disuse

Bone is sensitive to the removal of mechanical loading and the severity of unloading-induced bone loss may be influenced by an individual's genotype, gender, and the specific anatomical region. Whether these factors influence bone's mechanosensitivity directly or indirectly through differences in phenotypic baseline bone morphology and cellular activity is unknown. Here, we examined whether indices of baseline bone morphology and cellular activity are associated with the gender- and site-specific susceptibility of bone to unloading. Adult mice (4 months old, BALB/cByJ x C3H/HeJ) were assigned to one of six groups: male and female baseline controls (n=20 each), age-matched controls (n=10 each), or disuse (n=11 males, n=12 females). All baseline controls were sacrificed (0 day) to establish baseline bone morphology with micro-computed tomography (n=10 each gender) or baseline cellular activities using histomorphometry and tartrate-resistant acid phosphatase staining (n=10 each gender). Age-matched control and disuse mice were sacrificed (21 days) to determine disuse-induced bone loss by micro-computed tomography. Following 21 days of unloading, trabecular bone loss in the distal femur and proximal tibia was, on average, 3-fold greater in the metaphyses than in the epiphyses and 2-fold greater in females than in males. Disuse-induced changes in cortical bone were 2-fold smaller than trabecular bone losses and were more apparent in females (5 of 6 regions) than in males (1 of 6 regions). Bone loss was inversely related to baseline bone volume fraction (R(2)=0.51 for females and 0.43 for males) and directly related to baseline bone surface to volume ratio (R(2)=0.69 for females and 0.60 for males). Additionally, trabecular bone loss was correlated with baseline mineral apposition rates and osteoclast surface to bone surface ratios (R(2)=0.86 and 0.46, respectively, genders combined). These data demonstrate that baseline bone morphology and cellular activity modulate bone loss and that, independent of gender, anatomical regions with low bone quantity, high surface-to-volume ratios, and high levels of osteoblastic and osteoclastic activity are particularly susceptible to disuse.

Does low-dose and short-term glucocorticoids treatment increase the risk of osteoporosis in rheumatoid arthritis female patients?

Rheumatoid arthritis (RA) is frequently complicated by peri-articular and generalized osteoporosis due to increased bone resorption by activated osteoclasts. Pro-inflammatory cytokines, such as TNF-alpha, interleukin 1 (IL1), and interleukin 6 (IL6) are thought, among other factors, to be directly responsible for this extra-articular complication of RA. Glucocorticoids (GCS) commonly prescribed in RA due to their strong anti-inflammatory effect are also well known for causing secondary osteoporosis during a prolonged use. An influence of low-dose GCS therapy (8.7 mg per day) on a bone turnover in female RA patients with or without previous history of GCS treatment was investigated by measuring bone mineral content (BMC), bone mineral density (BMD), and various biochemical markers of inflammation and bone metabolism in comparison to results obtained from: (1) RA patients who have not been treated with GCS and (2) the control group of healthy individuals. Sixty-two female patients with established active RA and 178 healthy individuals from the control group have been investigated. The RA patients were divided into three groups: 21 treated with GCS before the trial--these patients have continued GCS therapy using low doses during the observation; 21 with low-dose GCS therapy launched at the beginning of the trial; and 20 left without GCS treatment. All patients have been assessed twice: at the beginning and after 12 months of observation. BMC and BMD have been measured in all patients in a distal part of forearm. Additionally, several different biochemical markers of osteoporosis and inflammation have been determined. We did not notice any increase in bone metabolism between RA patients receiving GCS therapy for the first time and those treated without GCS after 12 months of observation. Results of BMC, BMD osteocalcin level, total and bone alkaline phosphatase, carboxy-terminal collagen cross links, carboxy-terminal propeptides of type 1 collagen, deoxypyridynoline, and calcium/creatinine ratio were comparable in both groups at the end of the study. There was a significant decrease of the level of IL-6 in patients who had GCS therapy launched at the beginning of observation (p<0.01). However, levels of C-reactive protein (CRP) and alpha1-acid-glycoprotein (AGP) have not changed; the level of ESR dropped significantly (p<0.05) in this group. In contrast, in the group of patients with the previous history of prolonged GCS treatment receiving low doses of GCS during the trial, statistically significant increase of CRP and AGP could be observed (p<0.05) along with further significant worsening of the primary low BMD (p<0.05). Based on the obtained data, we came to the conclusion that anti-inflammatory effect of the low-dose GCS therapy in RA patients without previous history of their use may balance their direct negative effect on BMC and BMD. In this group of RA patients, benefits resulting from the 12-month GCS therapy prevail over adverse effects, even if calcium with vitamin D3 supplementation, biphosphonians, or estrogens have not been introduced. On the other hand, low-dose GCS therapy could have no benefit for RA patients with the previous history of their prolonged use, as a rise of markers of inflammation and bone turnover, resulting in the further bone loss, has been observed.

Effects of exercise training with weighted vests on bone turnover and isokinetic strength in postmenopausal women

The effects of 12 wk of exercise training using weighted vests on bone turnover and isokinetic strength were evaluated in postmenopausal women randomly assigned as exercisers (EX; n = 9) or controls (CON; n = 7). Training included 3 multimodal exercise sessions per wk wearing weighted vests. The vest load was progressively increased each wk to a maximum of 15% of body weight. Bone turnover was determined from resting levels of serum osteocalcin and NTx. Knee and ankle strength were measured at 60 degrees/s and 180 degrees/s using an isokinetic dynamometer. After 12 wk, NTx decreased by 14.5% (P <or= .05) in EX, with no significant changes in osteocalcin. EX also showed a 40% (P <or= .05) improvement in ankle plantar-flexion strength at 60 degrees/s. Relative body fat significantly decreased and fat-free mass increased in EX. Exercise compliance was 80%. These findings support the use of progressive exercise training using weighted vests in postmenopausal women.

A cross-sectional study of bone turnover markers in healthy premenopausal women

BACKGROUND

Biochemical markers of bone turnover (BTMs) provide useful information in the diagnosis and management of metabolic bone diseases. Currently, there exist few published reference ranges for bone markers in healthy premenopausal women using the newer, automated assays of bone turnover. This cross-sectional study of healthy premenopausal women was performed to determine reference ranges for four different markers of bone turnover and to compare reference ranges in users and non-users of oral contraceptives (OCs).

METHODS

Urinary N-telopeptide of type 1 collagen (NTX) was determined from fasting second morning-void urine of healthy premenopausal women. In addition, fasting serum was collected for determination of C-telopeptide of type I collagen (CTX), bone-specific alkaline phosphatase (bone ALP), and N-terminal propeptide of type 1 procollagen (PINP). Subjects underwent central dual energy X-ray absorptiometry and completed a questionnaire regarding medical history and activities known to affect bone health.

RESULTS

Serum and urine samples were collected from 237 healthy premenopausal women (119 OC users and 118 non-users) between the ages of 28 and 45 years. The mean age of subjects was 37 years, with a mean bone mineral density T-score of -0.1 at the lumbar spine and 0.0 at the total hip. Logarithmic transformation produced normal distributions for all markers but NTX. Mid-95% ranges for each marker were generally consistent with those reported by manufacturers. For each BTM examined, values were skewed toward the lower end of the range. Median NTX levels for OC users and non-users were 16.0 and 29.0 nmol/mmol creatinine, respectively. The mid-95% ranges for NTX in OC users and non-users were 3-60 and 4-64 nmol/mmol creatinine, respectively. Median levels of CTX, bone ALP, and PINP were also lower in OC users than non-users. The mean level of each BTM was significantly lower in OC users than non-users (P<0.01), whereas reference ranges (geometric mean+/-2 SD) were somewhat similar for the two groups.

CONCLUSION

Values obtained from this well-characterized population provide reference ranges for BTMs in healthy premenopausal women. Median and mean BTM levels for OC users were consistently lower compared with non-users; thus, separate reference ranges are required for these two groups of premenopausal women. The relevance of premenopausal reference ranges for postmenopausal women remains uncertain.

Contribution of the putative genetic factors and ANKH gene polymorphisms to variation of circulating calciotropic molecules, PTH and BGP

It is well known that regulation of calcium homeostasis in bone remodeling is one of the most crucial factors for maintaining healthy bones. Parathyroid hormone (PTH) is probably the most important hormone that participates in the bone remodeling process. Another important biochemical factor governing bone metabolism is osteocalcin (BGP). Although the physiological functions of both of these factors are well known, there is still very little known regarding their specific genetic determination and in particular, the specific genes that may regulate the circulating concentrations of these substances. In the present study, we examined whether nine single nucleotide polymorphisms (SNPs) in the human homologue of the mouse progressive ankylosis gene (ANKH)-one of the key genetic factors involved in bone mineralization-can be associated with PTH and BGP levels in apparently healthy human populations. The study sample comprised 244 nuclear families (840 individuals). After adjustment of BGP and PTH for the significant covariates (sex, age and BMI), the contribution of the putative genetic effects was statistically significant (P < 0.001) for both biochemical factors: 45.27 +/- 10.8% for PTH and 30.19 +/- 12.6% for BGP. Application of transmission disequilibrium tests (TDTs) revealed a significant association (P < 0.05) between PTH and two SNPs: rs39968 and rs875525. However, the association became particularly significant for four TDTs (P-values ranging from 0.0025 to 0.0008) when the association with the haplotypes generated from the above SNP was tested. This association remained significant even after correction for multiple testing with a false discovery rate of 0.05.

Clinical Utility of Biochemical Markers of Bone Metabolism for Improving the Management of Patients with Advanced Multiple Myeloma

Osteolytic bone lesions from advanced multiple myeloma (MM) result in significant skeletal morbidity. Therefore, biochemical markers of bone metabolism, such as the N-terminal and C-terminal telopeptides of type I collagen, bone-specific alkaline phosphatase, and osteocalcin, have been investigated as tools for evaluating the extent of bone disease, risk of skeletal morbidity, and response to antiresorptive treatment. Several studies have shown that the majority of biochemical markers of bone metabolism are increased in patients with MM with osteolytic bone lesions, thus reflecting changes in bone metabolism associated with tumor growth. There is also a growing body of evidence that markers of bone metabolism correlate with the risk of skeletal complications, disease progression, and death. In addition, bone markers could potentially be used as a tool for early diagnosis of bone lesions. The aim of this review is to improve our understanding of bone markers as a clinical tool for the management of malignant bone disease in patients with MM.

Genetic and constitutional influences on bone turnover markers: a study of male twin pairs

Biochemical markers of bone turnover originating from type I procollagen synthesis or type I collagen breakdown were examined in men using a classic twin study design based on monozygotic (MZ) and dizygotic (DZ) twins. The aim was to estimate the influence of heredity (genes and shared family childhood elements) and constitutional factors in determining procollagen type I amino-terminal propeptide (PINP), type I collagen carboxy-terminal telopeptide (ICTP), and urinary amino-terminal type I collagen telopeptide (NTx) marker levels in a sample of in 98 MZ and 108 DZ male twin pairs. We are not aware of any prior studies conducted in men that address the influence of genetic factors on bone turnover marker variability. The findings support a dominant role for heredity in the variation of bone resorption marker levels in men, with additive genetic effects explaining two-thirds of the variance in the bone resorption markers NTx and ICTP. Genetic factors may contribute less for PINP, a marker of bone formation. The genetic loci influencing PINP or NTx and body weight/disc axial area, although related in part, appeared to be largely independent, indicating that genetic effects on bone turnover are unlikely to be to a large degree a result of genetic regulation of individual body weight.

Menstrual cycle lengths and bone mineral density: a cross-sectional, population-based study in rural Chinese women ages 30-49 years

INTRODUCTION

The menstrual cycle involves periodic fluctuations in estrogen and progesterone levels. Longer cycles have been associated with longer follicular phase, delayed estrogen peak and a lower mean oestradiol level of the entire cycle.

METHODS

We hypothesized that prolonged menstrual cycle length is associated with decreased bone mineral density (BMD) in a population of pre- and perimenopausal women. This population-based cross-sectional study was conducted in rural Anhui province, China. It includes 4,771 women, aged 30 to 49 years, who did not smoke or drink alcohol, and did not use oral contraceptives or breastfeed during the previous year. Dual-energy X-ray absorptionometry (DEXA) BMD measurements were taken at four skeletal sites: whole body, total hip, femoral neck and lumbar spine. Menstrual cycle characteristics (polymenorrhea, short normal, long normal, oligomenorrhea, 90-day amenorrhea, irregular cycle) in the prior year were assessed by questionnaire.

RESULTS

Prolonged menstrual cycle was consistently associated with decreased BMD at whole body, total hip, and femoral neck in both age 30-39, and age 40-49 stratum (p(trend)<0.05). Prolonged menstrual cycle was also associated with decreased lumbar spine BMD for women aged 40-49 (p(trend)<0.05). Among women with normal cycles aged 30-39, menstrual cycle length in the previous year was inversely associated with whole-body BMD (p<0.05). Women with 90-day amenorrhea had significantly lower mean total hip and femoral neck BMD relative to women with short normal cycles in the 30-39 age group; and had significantly lower whole body and total hip BMD relative to short normal cycles in the 40-49 age group. BMD in polymenorrheic women did not differ from BMD in women with short normal cycles at any of the skeletal sites.

CONCLUSIONS

We conclude that prolonged menstrual cycle length is associated with decreased BMD in pre- and perimenopausal women in this population.

Effect of treadmill gait on bone markers and bone mineral density of quadriplegic subjects

Quadriplegic subjects present extensive muscle mass paralysis which is responsible for the dramatic decrease in bone mass, increasing the risk of bone fractures. There has been much effort to find an efficient treatment to prevent or reverse this significant bone loss. We used 21 male subjects, mean age 31.95 +/- 8.01 years, with chronic quadriplegia, between C4 and C8, to evaluate the effect of treadmill gait training using neuromuscular electrical stimulation, with 30-50% weight relief, on bone mass, comparing individual dual-energy X-ray absorptiometry responses and biochemical markers of bone metabolism. Subjects were divided into gait (N = 11) and control (N = 10) groups. The gait group underwent gait training for 6 months, twice a week, for 20 min, while the control group did not perform gait. Bone mineral density (BMD) of lumbar spine, femoral neck, trochanteric area, and total femur, and biochemical markers (osteocalcin, bone alkaline phosphatase, pyridinoline, and deoxypyridinoline) were measured at the beginning of the study and 6 months later. In the gait group, 81.8% of the subjects presented a significant increase in bone formation and 66.7% also presented a significant decrease of bone resorption markers, whereas 30% of the controls did not present any change in markers and 20% presented an increase in bone formation. Marker results did not always agree with BMD data. Indeed, many individuals with increased bone formation presented a decrease in BMD. Most individuals in the gait group presented an increase in bone formation markers and a decrease in bone resorption markers, suggesting that gait training, even with 30-50% body weight support, was efficient in improving the bone mass of chronic quadriplegics.

Using Dihydropyridine-Release Strategies to Enhance Load Effects in Engineered Human Bone Constructs

We report on the development of a novel biodegradable scaffold capable of enhancing mechanical signals for tissue-engineering applications. It has been shown that mechanotransduction enhances bone formation in vitro and in vivo; in tissue-engineering applications, this phenomenon is exploited through the use of mechanical bioreactors to generate bone tissue. The dihydropyridine agonist Bay K8644 (Bay) acts to increase the opening time of mechanosensitive voltage-operated calcium channels (VOCCs), specifi- cally L-type VOCCs, which are known to play a fundamental role in the early mediation of mechanotransduction. We have produced porous 3-dimensional, Bay-encapsulated biodegradable poly(L-lactide) acid scaffolds using a solvent-casting and salt-leaching technique. The effects of the released Bay on osteoid production and mineralization in human bone cell-seeded constructs following incubation in a perfusion-compression bioreactor in vitro was investigated using Western blotting techniques and a calcium assay protocol developed in our lab. Our newly developed scaffolds act by slowly releasing the calcium channel agonist Bay K8644 as observed using ultraviolet spectroscopy, maintaining the open state of mechanosensitive VOCCs responding to load, which augments the load signal at sites of strain across the scaffold. Our results demonstrate that, in the presence of physiological loading regimes in vitro, release of Bay enhances collagen I protein production and osteoid calcification more than non-Bay control constructs do. Osteopontin and alpha2delta1 VOCC subunit protein levels were also higher as a result of perfusion-compression conditioning. These results indicate that Bay-encapsulated scaffolds can be used in the presence of load to enhance the production of load-bearing engineered tissue.

An update on biomarkers of bone turnover and their utility in biomedical research and clinical practice

BACKGROUND

Maintenance of the structural and functional integrity of the skeleton is a critical function of a continuous remodeling driven by highly associated processes of bone resorption and synthetic activities driven by osteoclasts and osteoblasts, respectively. Acceleration of bone turnover, accompanied with a disruption of the coupling between these cellular activities, plays an established role in the pathogenesis of metabolic bone diseases, such as osteoporosis. During the past decades, major efforts have been dedicated to the development and clinical assessment of biochemical markers that can reflect the rate of bone turnover. Numerous studies have provided evidence that serum levels or urinary excretion of these biomarkers correlate with the rate of bone loss and fracture risk, proving them as useful tools for improving identification of high-risk patients.

OBJECTIVE

The aim of the present review is to give an update on biomarkers of bone turnover and give an overview of their applications in epidemiological and clinical research.

DISCUSSION

Special attention is given to their utility in clinical trials testing the efficacy of drugs for the treatment of osteoporosis and how they supplement bone mass measurements. Recent evidence suggests that biochemical markers may provide information on bone age that may have indirectly relates to bone quality; the latter is receiving increasing attention. A more targeted use of biomarkers could further optimize identification of high-risk patients, the process of drug discovery, and monitoring of the efficacy of osteoporosis treatment in clinical settings.

Evidence-based recommendations for monitoring bone disease and the response to enzyme replacement therapy in Gaucher patients

BACKGROUND

Bone disease is a serious complication of Gaucher disease. Untreated, it can result in pain, permanent bone damage and disability. Enzyme replacement therapy reverses many of the clinical signs of Gaucher bone disease but early assessment and treatment, and regular monitoring, are essential in optimising outcomes.

SCOPE

In September 2005, a group of European experts met to review current knowledge and identify best practice and unmet needs in the monitoring of Gaucher bone disease and the response to enzyme replacement therapy.

METHODS

Medline searches of peer-reviewed literature (no date restrictions) were conducted and supplemented by additional information considered relevant by panellists to furthering discussions.

FINDINGS AND CONCLUSIONS

The group's recommendations included: currently used biochemical bone markers are not clinically practical or reliable; plain X-rays should not be the sole method of assessing bone disease; MRI is the most sensitive method for monitoring bone marrow infiltration by Gaucher cells; semi-quantitative methods for assessing bone marrow infiltration in routine clinical practice should use readily available technology, include an assessment of Gaucher cell infiltration in the lumbar spine and femur, and be validated for inter-rater reliability and in comparison to other methods; a multidisciplinary approach is required for the treatment of Gaucher patients; all Gaucher patients should receive a comprehensive initial radiologic evaluation for bone disease and ongoing radiological monitoring at least once every 2 years.

Altered levels of biochemical indices of bone turnover and bone-related vitamins in patients with Crohn's disease and ulcerative colitis

BACKGROUND

The pathogenesis of inflammatory bowel disease-associated osteopenia may be related to pathological rates of bone turnover; however, the literature shows mixed results.

AIM

To compare bone biomarkers in inflammatory bowel disease patients (Crohn's disease: n = 68, and ulcerative colitis: n = 32, separately) with age- and sex-matched healthy controls.

SUBJECTS

Patients and controls were recruited from Cork University Hospital and Cork City area, respectively.

RESULTS

Relative to that in their respective controls, Crohn's disease (n = 47) and ulcerative colitis (n = 26) patients (i.e. excluding supplement users) had significantly (P < 0.05-0.001) higher serum undercarboxylated osteocalcin (by 27% and 63%, respectively) and bone-specific alkaline phosphatase (by 15% and 21%, respectively) and urinary Type I collagen cross-linked N-telopeptides concentrations (by 87% and 112%, respectively). Relative to that in their respective controls, Crohn's disease and ulcerative colitis patients had significantly (P < 0.01) lower serum total osteocalcin (by 20% and 42%, respectively) and 25-hydroxyvitamin D (by 37% and 42%, respectively), while serum parathyroid hormone levels were similar. In the combined patient group (n = 100), undercarboxylated osteocalcin was positively associated with bone markers.

CONCLUSIONS

Both Crohn's disease and ulcerative colitis patients have altered bone turnover relative to that in healthy controls.

Tamoxifen treatment after adjuvant chemotherapy has opposite effects on bone mineral density in premenopausal patients depending on menstrual status

PURPOSE

Adjuvant chemotherapy followed by tamoxifen is a standard treatment option for women with intermediate or high-risk hormone receptor-positive breast cancer. Premenopausal women treated with chemotherapy often develop early menopause and thus, enter a period of accelerated bone loss. We conducted a prospective study of the effect of sequential adjuvant therapy with chemotherapy followed by tamoxifen on bone mineral density (BMD) in premenopausal patients.

PATIENTS AND METHODS

One hundred eleven premenopausal women with early breast cancer were treated with adjuvant chemotherapy. Patients with hormone receptor-positive tumors went on to tamoxifen 6 months after the beginning of the chemotherapy (tamoxifen group), while those with hormone receptor-negative tumors received no further therapy (control group). The effect of tamoxifen and menstrual status on BMD was studied.

RESULTS

Tamoxifen treatment and menopausal status correlated significantly with the changes in lumbar spine BMD (P < .0001). A significant bone loss was noted in those tamoxifen-treated patients who continued to menstruate after chemotherapy. At 3 years of follow-up, menstruating patients on tamoxifen had lost -4.6% of their baseline BMD values, while a modest gain of +0.6% was noted in the control group. In contrast, bone loss was reduced among tamoxifen-treated women as compared with controls in patients who developed chemotherapy-induced early menopause. In amenorrheic patients, the lumbar spine BMD values decreased -6.8% in tamoxifen users and -9.5% in the controls, respectively.

CONCLUSION

We conclude that tamoxifen usage was associated with bone loss in patients who continued to menstruate after adjuvant chemotherapy. On the contrary, tamoxifen decreased bone loss in those women who developed chemotherapy-induced amenorrhea.

Pediatric reference intervals for bone markers

Bone markers are specific bone-derived molecules that reflect bone remodeling activity and can be classified into two categories: bone formation and bone resorption markers. Children have significantly elevated bone marker levels due to high skeletal growth velocity and rapid bone turnover during childhood growth. Many physiological and pathological processes may influence bone metabolism and bone marker concentrations during childhood growth. Measurements of bone markers may be useful in investigating skeletal diseases in children and monitoring the response to treatment. This review documents recent advances in analytical methods, preanalytical considerations related to each marker and particularly highlights the most valuable bone formation markers, bone alkaline phosphatase and osteocalcin, and bone resorption markers, pyridinium cross-links and cross-linked telopeptides. Age- and sex-specific pediatric reference intervals and their limitations in clinical application are also discussed.

Relations between interleukin-1, its receptor antagonist gene polymorphism, and bone mineral density in postmenopausal Korean women

We investigated the relation between polymorphisms in the interleukin-1(IL-1) and IL-1 receptor antagonist (IL-1ra) gene, and bone mineral density (BMD) in postmenopausal Korean women. The IL-1alpha C(-889)T polymorphism, and IL-1beta C(-511)T polymorphism were examined by restriction fragment length polymorphism, and 86-bp variable number tandem repeat polymorphism in the IL-1ra gene was analyzed by the polymerase chain reaction and electrophoresis in 202 postmenopausal Korean women. Serum osteocalcin, and C-telopeptide of type I collagen were measured using a radioimmunoassay and enzyme-linked immunosorbent assay, respectively. BMD at the lumbar spine and proximal femur was measured by dual-energy X-ray absorptiometer. No significant differences in BMD or in serum bone markers levels were noted across the IL-1alpha or IL-1beta genotype. There were no significant differences in the distribution of IL-1alpha or IL-1beta genotype according to the status of bone mass. BMD in women carrying the A2 allele of the IL-1ra gene was significantly lower than those without this allele, and the A2 allele was more frequent in osteoporotic women than in normal women. These data suggest that IL-1ra gene VNTR polymorphism is a genetic factor that may affect BMD in Korean women.

Assessment of soy phytoestrogens' effects on bone turnover indicators in menopausal women with osteopenia in Iran: a before and after clinical trial

BACKGROUND

Osteoporosis is the gradual declining in bone mass with age, leading to increased bone fragility and fractures. Fractures in hip and spine are known to be the most important complication of the disease which leads in the annual mortality rate of 20% and serious morbidity rate of 50%. Menopause is one of the most common risk factors of osteoporosis. After menopause, sex hormone deficiency is associated with increased remodeling rate and negative bone balance, leading to accelerated bone loss and micro-architectural defects, resulting into increased bone fragility. Compounds with estrogen-like biological activity similar to "Isoflavones" present in plants especially soy, may reduce bone loss in postmenopausal women as they are similar in structure to estrogens. This research, therefore, was carried out to study the effects of Iranian soy protein on biochemical indicators of bone metabolism in osteopenic menopausal women.

MATERIALS AND METHODS

This clinical trial of before-after type was carried out on 15 women 45-64 years of age. Subjects were given 35 g soy protein per day for 12 weeks. Blood and urine sampling, anthropometric measurement and 48-h-dietary recalls were carried out at zero, 6 and 12 weeks. Food consumption data were analyzed using Food Proccessor Software. For the study of bone metabolism indicators and changes in anthropometric data as well as dietary intake, and repeated analyses were employed.

RESULTS

Comparison of weight, BMI, physical activity, energy intake and other intervening nutrients did not reveal any significant changes during different stages of the study. Soy protein consumption resulted in a significant reduction in the urinary deoxypyridinoline and increasing of total alkaline phosphatase (p < 0.05), although the alterations in osteocalcin, c-telopeptide, IGFBP3 and type I collagen telopeptide were not significant.

CONCLUSION

In view of beneficial effect of soy protein on bone metabolism indicators, inclusion of this relatively inexpensive food in the daily diet of menopausal women, will probably delay bone resorption, thereby preventing osteoporosis.

41Ca and accelerator mass spectrometry to monitor calcium metabolism in end stage renal disease patients

BACKGROUND

Monitoring bone resorption with measurements of bone density and biochemical markers is indirect. We hypothesized that bone resorption can be studied directly by serial measurements of the ratio (41)Ca/Ca in serum after in vivo labeling of calcium pools with (41)Ca. We report the preparation of an intravenous (41)Ca dose suitable for humans, an analytical method for determining (41)Ca/Ca isotope ratios in biological samples, and studies in human volunteers.

METHODS

(41)Ca was formulated and aliquoted into individual vials, and to the extent possible, the (41)Ca doses were tested according to US Pharmacopeia (USP) guidelines. A 10 nCi dose of (41)Ca was administered intravenously to 4 end stage renal disease (ESRD) patients on hemodialysis and 4 healthy control individuals. Distribution kinetics were determined over 168 days. Calcium was isolated with 3 precipitation steps and a cation-exchange column, and (41)Ca/Ca ratios in serum were then measured by accelerator mass spectrometry.

RESULTS

The dosing solution was chemically and radiologically pure, contained <0.1 endotoxin unit/mL, and passed USP sterility tests. Quantification of (41)Ca/Ca ratios was linear from 6 x 10(-14) to 9.1 x 10(-10). The run-to-run imprecision (as CV) of the method was 4% at 4.6 x 10(-11) and 6% at 9.1 x 10(-10). The area under the curve of (41)Ca in the central compartment vs time was significantly less for ESRD patients than for controls (P < 0.005).

CONCLUSIONS

Isotope ratios spanning 5 orders of magnitude can be measured by accelerator mass spectrometry with excellent precision in the range observed in samples collected from patients who have received 10 nCi of (41)Ca. The (41)Ca at this dose caused no adverse effects in 8 volunteers. This is the first report of the use of (41)Ca to monitor differences in bone turnover between healthy individuals and ESRD patients.

Clinical Outcome of Salmon Calcitonin Nasal Spray Treatment in Postmenopausal Women after Total Hip Arthroplasty

OBJECTIVE

The increasing rate of hip fractures is giving rise to a number of socio-economic problems for the aging community. In addition to being unable to resume their previous living habits, many patients fail to achieve full functional recovery after the fractures. Total hip arthroplasty (THA) is a successful operation for the majority of patients with all forms of hip fractures, being performed increasingly often throughout the world. Revision rates for THA range up to 20% per year. Aseptic loosening is the reason for 75% of the revisions. An additional problem post-THA is the rate of heterotopic soft tissue calcification after THA, resulting in severely impaired function, pain, and a reduced range of hip movement.

SUBJECTS

In an open study, 37 women who had undergone cementless THA after accidental hip fractures were treated twice daily with 200 IU of salmon calcitonin nasal spray for 12 months. Simultaneously the patients received one bag of 1,000 mg calcium plus 880 IU vitamin D daily throughout the treatment period of 1 year. A parallel group of 38 women with a similar clinical status in terms of hip fractures and cementless THA were treated with only one bag of 1,000 mg calcium plus 880 IU vitamin D daily through the treatment period.

RESULTS

The results of this 12-month clinical trial show that 200 IU of salmon calcitonin nasal spray per day significantly improves the clinical outcome of postmenopausal elderly women following THA. Treatment with a salmon calcitonin nasal spray significantly reduces bone turnover, loss of bone density, and pain. The functional status of the patients was improved and the risk of falling reduced by rehabilitation during the observation period of 12 months. Additionally, calcitonin promoted the repair of hip fractures and was associated with a significantly lesser rate of refractures as well as periprosthetic ossifications.

CONCLUSION

The increasing revision rate for THA during the first year and the patient's problem of resuming their previous living habits are the main foci of our study. Calcitonin nasal spray seems to cause few side effects. The additive treatment appears to improve the clinical outcome of THA in elderly postmenopausal women.

Early alteration in bone metabolism in epileptic children receiving carbamazepine monotherapy owing to the induction of hepatic drug-metabolizing enzymes

The purpose of this study was to investigate, by a prospective, self-controlled method, whether early treatment with carbamazepine monotherapy can alter bone metabolism in ambulatory epileptic children with adequate sun exposure, based on the determination of total serum alkaline phosphatase and its bone isoenzyme activities. Serum total alkaline phosphatase and its bone, liver, and intestinal isoenzyme activities were evaluated in 22 epileptic ambulatory children (13 males and 9 females, aged from 5 to 12 years) before and at 3, 6, and 12 months of carbamazepine monotherapy. Serum concentrations of other biochemical markers of bone and liver metabolism, such as calcium, phosphorus, magnesium, gamma-glutamyltransferase, alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase, were also measured in the study participants before and at 6 and 12 months of treatment. Carbamazepine was prescribed at normal dosages (16.4-20 mg/kg/day). Serum total alkaline phosphatase activities were significantly increased at 3 (P = .000), 6 (P = .024), and 12 (P = .037) months of treatment; serum bone alkaline phosphatase activities at 3 (P = .000), 6 (P = .008), and 12 (P = .017) months of treatment; and serum liver alkaline phosphatase activities at 3 (P = .000), 6 (P = .049), and 12 (P = .008) months of treatment, whereas serum intestinal alkaline phosphatase isoenzyme activity was significantly increased only at 3 months of treatment (P = .035). Serum gamma-glutamyltransferase activities were also significantly increased at 6 (P = .000) and 12 (P = .000) months of treatment. No significant changes in the concentrations of serum calcium, phosphorus, magnesium, alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase were noted at 6 and 12 months of treatment. There was a significant correlation between serum gamma-glutamyltransferase activities and serum total alkaline phosphatase activities (r = .689, P = .000 at 6 months; r = .493, P = .020 at 12 months), bone alkaline phosphatase activities (r = .700, P = .000 at 6 months; r = .466, P = .029 at 12 months), and liver alkaline phosphatase activities (r = .427, P = .047 at 6 months; r = .425, P = .048 at 12 months). These findings indicate that ambulatory children who receive carbamazepine monotherapy, even when residing in a country with adequate sunlight, can have their bone metabolism altered early in the course of treatment, as indicated by the elevated activities of serum bone alkaline phosphatase isoenzyme. This early alteration in bone metabolism is probably due to the hepatic enzyme-inducing character of carbamazepine.