Changes of biochemical bone markers during the menopausal transition

Perimenopausal Bone Loss Is Associated with Ovulatory Activity-Results of the PeKnO Study (Perimenopausal Bone Density and Ovulation)

Background: During the menopausal transition, around 25% of women experience a particularly accelerated loss of bone mineral density. These so-called “fast bone losers” represent a group of patients with an increased risk of osteoporosis. The precise mechanisms underlying this extraordinary level of bone mass reduction have not yet been conclusively elucidated. The PeKnO study (Perimenopausale Knochendichte und Ovulation; Perimenopausal Bone Density and Ovulation) was a 2-year prospective study investigating menstrual cycle changes, hormonal levels, markers of bone metabolism, and changes in bone mineral density (BMD) in perimenopausal women. The PeKnO study specifically focused on the questions of when the maximum of bone loss occurs, whether the decreasing number of ovulatory cycles correlates with increased bone density loss, and which hormones play a role during these processes. Methods: Healthy women aged ≥45 years with menstrual cycles of ≤42 days and without any exogenous hormonal intake continually self-assessed the lengths of their menstrual cycles and the occurrence of LH peaks with the help of a commercially available electronic fertility monitoring device. At baseline and at 6, 12, 18, and 24 months, hormones (LH, FSH, 17β-estradiol, progesterone, cortisol) and markers of bone metabolism (bone-specific alkaline phosphatase (BAP), osteocalcin (OC), and CTX (C-terminal telopeptide) were assessed during the luteal phase. Trabecular bone density was measured in the lumbar spine (vertebrae L1 through L3) by means of quantitative computed tomography (QCT) at the beginning and at the end of the 2-year study period. Patients were divided into 3 groups according to the changes in bone mineral density (BMD) that occurred within the period of 2 years: group I with an increase in BMD, group II with a decrease in BMD of ≤7%, and group III with a decline in BMD of >7%. Women in the latter group were defined as fast bone losers. Results: From a total of 72 recruited patients with an average age of 48.1 (±2.4) at baseline, complete 2-year data were available from 49 participants. Over the course of 24 months, mean bone mineral density decreased by −4.26 (±4.65). In the same time period, the proportion of ovulatory cycles declined from 67% to 33%. The decrease in the ovulatory rate significantly correlated with an enhanced BMD loss (r = 0.68; p < 0.05). Twelve of the forty-nine participants (24.3%) showed a BMD loss of >7% and were identified as fast bone losers. Levels of the luteal phase hormones LH, FSH, 17β-estradiol, and progesterone were significantly different between the three groups. Conclusion: The PeKnO study confirms a marked decline of the ovulatory rate during perimenopause, which is associated with an increased bone density loss while estrogen levels are still adequate.

Sex-related differences in bone metabolism in osteoporosis observational study

Although the incidence is lower in men than women, osteoporosis remains a significant health issue in men as it may give rise to severe complications if not managed appropriately. As men and women show different biological and social backgrounds, we retrospectively evaluated the differences in the bone metabolism between men and women using bone biomarkers.Bone mineral density (BMD) was determined in all patients using dual-energy X-ray absorptiometry (DXA) and analyzing various bone biomarkers such as carboxyl-terminal collagen crosslinks (CTX), osteocalcin (OCT), and alkaline phosphatase (ALP). The CTX/OCT ratio was used to estimate the association between bone absorption and formation.OCT, CTX, and ALP levels were elevated in patients with osteoporosis. Women displayed a higher incidence of osteoporosis and greater reduction in BMD than men. The mean OCT level in men was lower than that in women. Moreover, men showed significantly lower OCT levels than women of aged 65 and under 80 years old. Among patients with osteoporosis, men had a higher ratio of bone markers than women.Levels of biomarkers of bone formation and absorption were increased in the osteoporosis group. However, men showed lower increases in bone formation biomarkers than did women, indicating that the rate of bone formation relative to bone absorption did not increase in men compared with that in women. Therefore, we suggest that men and women have different bone metabolism in old age.

The Neuropeptide Vasoactive Intestinal Peptide Levels in Serum are Inversely Related to Disease Severity of Postmenopausal Osteoporosis: A Cross-Sectional Study

Background: The neuropeptide vasoactive intestinal peptide (VIP) has been identified as inhibiting osteoclastogenesis and suppressing inflammation. Objective: This study was conducted to examine serum VIP levels in postmenopausal osteoporosis (PMOP) patients and explore the correlation of serum VIP levels with disease severity of PMOP. Methods: A total of 106 postmenopausal women diagnosed as osteoporotic were enrolled in the study and 102 postmenopausal women with normal bone mineral density (BMD) were enrolled as controls. BMD at the femoral neck (FN), lumbar spine 1-4, and total hip were examined using dual-energy X-ray absorptiometry. Genant semiquantitative grading was used for vertebral morphometry and fracture. Serum VIP levels were tested using enzyme-linked immunosorbent assay. Serum inflammatory factor interleukin-1β (IL-1β), osteoclastic activity marker tartrate-resistant acid phosphatase 5b (TRACP-5b), and estrogen-2 (E2) were also examined. Receiver operating characteristic (ROC) analyses was performed to determine the diagnostic values of serum VIP, IL-1β, TRCAP-5, and E2 with regard to Genant grade. Results: Our findings demonstrated a reduction in the serum level of VIP expressed in PMOP patients compared with controls. In the PMOP group, patients with lumbar fracture had significantly lower serum VIP concentrations in comparison with healthy controls. Serum VIP concentrations were positively associated with BMD at the FN, lumbar spine 1-4, and total hip. We also observed that serum VIP levels were positively correlated with E2 levels but negatively correlated with IL-1β and TRCAP-5 levels. In addition, ROC analysis found that reduction of serum VIP in combination with elevation of TRACP-5b may serve as an indicator of a severe Genant grade. Conclusions: Attenuated serum VIP levels were linked to disease severity of PMOP and may act as a protective marker for PMOP.

A Double-Blind Placebo-Controlled Randomized Trial Evaluating the Effect of Polyphenol-Rich Herbal Congee on Bone Turnover Markers of the Perimenopausal and Menopausal Women

Based on the benefit of polyphenolic compounds on osteoporosis, we hypothesized that the polyphenol-rich herbal congee containing the combined extract of Morus alba and Polygonum odoratum leaves should improve bone turnover markers in menopausal women. To test this hypothesis, a randomized double-blind placebo-controlled study was performed. A total of 45 menopausal participants were recruited in this study. They were randomly divided into placebo, D1, and D2 groups, respectively. The subjects in D1 and D2 groups must consume the congee containing the combined extract of M. alba and P. odoratum leaves at doses of 50 and 1500 mg/day, respectively. At the end of an 8-week consumption period, all subjects were determined serum bone markers including calcium, alkaline phosphatase, osteocalcin, and beta CTX. In addition, the hematological and blood clinical chemistry changes, and total phenolic content in the serum were also determined. The results showed that the menopausal women in D2 group increased serum alkaline phosphatase, osteocalcin, and total phenolic compounds content but decreased CTX level. Clinical safety assessment failed to show toxicity and adverse effects. Therefore, herbal congee containing the combined extract of M. alba and P. odoratum leaves is the potential functional food that can decrease the risk of osteoporosis.

Novel bone metabolism-associated hormones: the importance of the pre-analytical phase for understanding their physiological roles

The endocrine function of bone is now a recognized feature of this tissue. Bone-derived hormones that modulate whole-body homeostasis, are being discovered as for the effects on bone of novel and classic hormones produced by other tissues become known. Often, however, the data regarding these last generation bone-derived or bone-targeting hormones do not give about a clear picture of their physiological roles or concentration ranges. A certain degree of uncertainty could stem from differences in the pre-analytical management of biological samples. The pre-analytical phase comprises a series of decisions and actions (i.e., choice of sample matrix, methods of collection, transportation, treatment and storage) preceding analysis. Errors arising in this phase will inevitably be carried over to the analytical phase where they can reduce the measurement accuracy, ultimately, leading discrepant results. While the pre-analytical phase is all important, in routine laboratory medicine, it is often not given due consideration in research and clinical trials. This is particularly true for novel molecules, such as the hormones regulating the endocrine function of bone. In this review we discuss the importance of the pre-analytical variables affecting the measurement of last generation bone-associated hormones and describe their, often debated and rarely clear physiological roles.

Premenopausal Trabecular Bone Loss is Associated with a Family History of Fragility Fracture

INTRODUCTION

Although a fragility fracture family history (FFFH+) has repeatedly been shown to be associated with lower bone mineral density (BMD), its relationship to human BMD change is unclear. Animal research, however, documented that different purebred strains within rodent species have wide ranges in rates of bone acquisition during growth as well as in change post-ovariectomy. Our objective was to compare the rate of premenopausal spinal trabecular BMD change between women with and without a general family history of fragility fracture.

PARTICIPANTS AND METHODS

Healthy premenopausal community women participated in prospective observational studies at two academic medical research centres: Vancouver, Canada (n = 66) and Munich, Germany (n = 20). The primary outcome was annual spinal BMD change, measured by quantitative computed tomography (QCT). The two studies employed similar methodologies for assessing QCT and FFFH.

RESULTS

Volunteer community participants had a mean age of 36.0 (SD, 6.9) years, body mass index 22.5 (2.4) and baseline QCT of 150.2 (22.5) mg/cm³ trabecular bone. The rates of BMD change were similar in both cities: - 3.5 (5.1)/year Vancouver, - 2.0 (3.4)/year Munich (95 % CI of difference: - 3.9, 0.9). Over a third of the women (31 of the 86, 36 %) reported FFFH+. Those with and without a FFFH were similar in demographics, nutrition, exercise, menstrual cycle and luteal phase lengths and physiological measures (serum calcium, osteocalcin and estradiol). However, women with FFFH+ lost trabecular BMD more rapidly: FFFH+, - 4.9 (5.0), FFFH-, - 2.2 (4.4) mg/cm³/year (95 % CI diff - 0.7 to - 4.8, F_1.83 = 7.88, p = 0.006). FFFH+ explained 7.7 % of the variance in QCT volumetric trabecular spinal bone change/year in these healthy premenopausal women.

CONCLUSION

This study shows for the first time that having a history of a fragility fracture in a family member is associated with a greater rate of premenopausal spinal trabecular bone loss.

Bone matrix mineralization is preserved during early perimenopausal stage in healthy women: a paired biopsy study

Bone matrix mineralization based on quantitative backscatter electron imaging remained unchanged during the first year of menopause in paired transiliac biopsy samples from healthy women. This suggests that the reported early perimenopausal reductions in bone mineral density are caused by factors other than decreases in the degree of mineralization.

INTRODUCTION

It is unknown whether perimenopausal loss of bone mass is associated with a drop in bone matrix mineralization.

METHODS

For this purpose, we measured the bone mineralization density distribution (BMDD) by quantitative backscatter electron imaging (qBEI) in n = 17 paired transiliac bone biopsy samples at premenopausal baseline and 12 months after last menses (obtained at average ages of 49 ± 2 and 55 ± 2 years, respectively) in healthy women. For interpretation of BMDD outcomes, previously measured bone mineral density (BMD) and biochemical and histomorphometric markers of bone turnover were revisited for the present biopsy cohort.

RESULTS

Menopause significantly decreased BMD at the lumbar spine (-4.5 %) and femoral neck (-3.8 %), increased the fasting urinary hydroxyproline/creatinine ratio (+60 %, all p < 0.01) and histomorphometric bone formation rate (+25 %, p < 0.05), but affected neither cancellous nor cortical BMDD variables (paired comparison p > 0.05). Mean calcium concentrations of cancellous (Cn.CaMean) and cortical bone (Ct.CaMean) were within normal range (p > 0.05 compared to established reference data). Ct.CaMean was significantly correlated with Cn.CaMean before (R = 0.81, p < 0.001) and after menopause (R = 0.80, p < 0.001) and to cortical porosity of mineralized tissue (Ct.Po.) after menopause (R = -0.57, p = 0.02).

CONCLUSIONS

Surprisingly, the BMDD was found not affected by the changes in bone turnover rates in this cohort. This suggests that the substantial increase in bone formation rates took place shortly before the second biopsy, and the bone mineralization changes lag behind. We conclude that during the first year after the last menses, the degree of bone matrix mineralization is preserved and does not contribute to the observed reductions in BMD.

Detection of Bone Metastases in Breast Cancer (BC) Patients by Serum Tartrate-Resistant Acid Phosphatase 5b (TRACP 5b), a Bone Resorption Marker and Serum Alkaline Phosphatase (ALP), a Bone Formation Marker, in Lieu of Whole Body Skeletal Scintigraphy with Technetium99m MDP

Bone metastases are a serious problem in patients with advanced cancer disease and their presence usually signifies serious morbidity prior to the patient's death. In breast cancer patients the incidence of bone metastasis is observed to be very high at 70 %, as seen during post-mortem examination. Bone metastasis is difficult to diagnose, treat or follow clinically without radiological tools. This study was designed to evaluate the utility of a novel bone resorption marker-serum tartrate-resistant acid phosphatase 5b (TRACP5b) and the bone formation marker such as serum total alkaline phosphatase (ALP), in comparison with whole body skeletal scintigraphy with Technetium99m MDP for the diagnosis of bone metastases (BM) in breast cancer (BC) patients. This study is intended to help the clinician to diagnose bone metastasis without resorting to radiological tools, as they are not cost effective and carry the risk of radiation.

EXPERIMENTAL DESIGN

Four groups of samples were analysed. 1st group consists 52 normal female (cancer free women), 2nd group consists 38 BC patients without bone metastasis, 3rd group consists 27 breast cancer patients with limited bone metastasis (3 or less than 3 skeletal lesions) and 4th group consists 35 breast cancer patients with extensive bone metastasis (4 or more than 4 skeletal lesions), conformed by whole body skeletal scintigraphy with Technetium99m MDP. One way ANOVA was used to compare serum TRACP5b and serum ALP among these groups. Both serum TRACP5b and serum ALP are not markedly elevated in limited bone metastasis but are strongly elevated in extensive bone metastasis (p < 0.0001). As seen in this study the biochemical bone resorption marker, serum TRACP5b, abnormally increased in extensive bone metastasis of breast cancer patients and can be used as a specific marker for bone metastasis in lieu of radiological tools.

Melatonin osteoporosis prevention study (MOPS): a randomized, double-blind, placebo-controlled study examining the effects of melatonin on bone health and quality of life in perimenopausal women

The purpose of this double-blind study was to assess the effects of nightly melatonin supplementation on bone health and quality of life in perimenopausal women. A total of 18 women (ages 45-54) were randomized to receive melatonin (3mg, p.o., n=13) or placebo (n=5) nightly for 6months. Bone density was measured by calcaneal ultrasound. Bone turnover marker (osteocalcin, OC for bone formation and NTX for bone resorption) levels were measured bimonthly in serum. Participants completed Menopause-Specific Quality of Life-Intervention (MENQOL) and Pittsburgh Sleep Quality Index (PSQI) questionnaires before and after treatment. Subjects also kept daily diaries recording menstrual cycling, well-being, and sleep patterns. The results from this study showed no significant change (6-month-baseline) in bone density, NTX, or OC between groups; however, the ratio of NTX:OC trended downward over time toward a ratio of 1:1 in the melatonin group. Melatonin had no effect on vasomotor, psychosocial, or sexual MENQOL domain scores; however, it did improve physical domain scores compared to placebo (mean change melatonin: -0.6 versus placebo: 0.1, P<0.05). Menstrual cycling was reduced in women taking melatonin (mean cycles melatonin: 4.3 versus placebo: 6.5, P<0.05), and days between cycles were longer (mean days melatonin: 51.2 versus placebo: 24.1, P<0.05). No differences in duration of menses occurred between groups. The overall PSQI score and average number of hours slept were similar between groups. These findings show that melatonin supplementation was well tolerated, improved physical symptoms associated with perimenopause, and may restore imbalances in bone remodeling to prevent bone loss. Further investigation is warranted.

Mechanism of action and morphologic changes in the alveolar bone in response to selective alveolar decortication-facilitated tooth movement

BACKGROUND AND PURPOSE

The aim of this study was to test if corticotomy-induced osteoclastogenesis and bone remodeling underlie orthodontic tooth movement and how selective alveolar decortication enhances the rate of tooth movement.

MATERIALS AND METHODS

A total of 114 Sprague-Dawley rats were included in 3 treatment groups: selective alveolar decortication alone (SADc); tooth movement alone (TM); and "combined" therapy (SADc + TM). Surgery was performed around the buccal and palatal aspects of the left maxillary first molar tooth and included 5 decortication dots on each side. Tooth movement was performed on the first molar using a 25-g Sentalloy spring. Measurements were done at baseline (day 0: no treatment rendered) and on days 3, 7, 14, 21, 28 and 42. Microcomputed tomography, Faxitron analyses, and quantitative real-time polymerase chain reaction (q-PCR) of expressed mRNAs were used to assess changes.

RESULTS

The combined group showed increased tooth movement (P = 0.04) at 7 days compared with the tooth movement group with significantly decreased bone volume (62%; P = 0.016) and bone mineral content (63%; P = 0.015). RNA markers of osteoclastic cells and key osteoclastic regulators (M-CSF [macrophage colony-stimulating factor], RANKL [receptor activator of nuclear factor kappa-B ligand], OPG [osteoprotegerin], calcitonin receptor [CTR], TRACP-5b [tartrate-resistant acid phosphatase 5b], cathepsin K [Ctsk]) all showed expression indicating increased osteoclastogenesis in the combined group. RNA markers of osteoblastic cells (OPN [osteopontin], BSP [bone sialoprotein], OCN [osteocalcin]) also showed increased anabolic activity in response to the combination of alveolar decortication and tooth movement.

CONCLUSIONS

The data suggest that the alveolar decortication enhances the rate of tooth movement during the initial tooth displacement phase; this results in a coupled mechanism of bone resorption and bone formation during the earlier stages of treatment, and this mechanism underlies the rapid orthodontic tooth movement.

Progesterone and bone: actions promoting bone health in women

Estradiol (E(2)) and progesterone (P(4)) collaborate within bone remodelling on resorption (E(2)) and formation (P(4)). We integrate evidence that P(4) may prevent and, with antiresorptives, treat women's osteoporosis. P(4) stimulates osteoblast differentiation in vitro. Menarche (E(2)) and onset of ovulation (P(4)) both contribute to peak BMD. Meta-analysis of 5 studies confirms that regularly cycling premenopausal women lose bone mineral density (BMD) related to subclinical ovulatory disturbances (SODs). Cyclic progestin prevents bone loss in healthy premenopausal women with amenorrhea or SOD. BMD loss is more rapid in perimenopause than postmenopause-decreased bone formation due to P(4) deficiency contributes. In 4 placebo-controlled RCTs, BMD loss is not prevented by P(4) in postmenopausal women with increased bone turnover. However, 5 studies of E(2)-MPA co-therapy show greater BMD increases versus E(2) alone. P(4) fracture data are lacking. P(4) prevents bone loss in pre- and possibly perimenopausal women; progesterone co-therapy with antiresorptives may increase bone formation and BMD.

Bone mineral density loss during adjuvant chemotherapy in pre-menopausal women with early breast cancer: is it dependent on oestrogen deficiency?

Pre-menopausal women given adjuvant chemotherapy for breast cancer experience both premature ovarian failure and loss of bone mineral density (BMD), and this study was designed to see if these observations are causally linked. Chemotherapy was administered to 41 pre-menopausal women with early breast cancer enrolled prospectively in a study of ovarian function and BMD in such women given systemic therapy. After giving written informed consent, all patients underwent baseline and regular on-treatment measurements of BMD by dual-energy X-ray absorptiometry (DXA) scan, bone turnover and ovarian function by analysis of serum hormone levels and self-reported menstrual diaries. Baseline lumbar spine BMD in the 41 women given chemotherapy was higher than the normal population (Z score 0.28 ± 0.14 (mean ± SEM), P = 0.047), and fell significantly over the first 6 months from a mean of 1.05-1.01 g/m(2), P < 0.0001, and similar but smaller changes were demonstrated in hip BMD. This fall was independent of age at diagnosis, type of chemotherapy, development of amenorrhoea or either baseline or on-treatment estradiol concentration. During the 6 months after completion of adjuvant chemotherapy, BMD fell further only in those women with low estradiol or experiencing amenorrhoea during the first 6 months, although all groups showed evidence of increased bone turnover. This study demonstrates loss of both spine and hip BMD in pre-menopausal women during 6 months' adjuvant systemic chemotherapy to be independent of changes in ovarian function. Ovarian function was, however, related to BMD changes after chemotherapy ceased.

Bone Turnover Markers Relations to Postmenopausal Osteoporosis

Osteoporosis is a systemic disease characterized by low bone mass and high bone turnover markers in postmenopausal women (PM). The relationship between biochemical bone markers C-telopeptides of type 1 collagen (CTX) and osteocalcin (OC), and bone mineral density (BMD) in the postmenopausal period was examined in 104 PM women divided into three groups according to their BMD: group A - control PM with normal bone density, group B - osteopenic PM and group C - osteoporotic PM. Mean CTX values were highest in group C (0.54±0.24 ng/mL) compared to group B (0.44±0.21 ng/mL) (p<0.0001), and group A (0.33±0.13 ng/mL) (p<0.029). Mean OC levels in group C (26.83±9.91 ng/mL) were significantly higher compared to group A (20.47±7.03 ng/mL) (p<0.011) but not significantly higher compared to group B (24.11±8.38 ng/mL) (p>0.05). Postmenopause duration was longest in group C (13.1±8.31 yrs) compared to group B (9.6±6.24 yrs), and group A (8.15±6.86 yrs). Postmenopausal women developed osteoporosis with longer menopause duration. PM osteoporotic women were characterized by increased levels of bone turnover markers indicating increased rate of bone remodeling, which resulted in excessive bone resorption, and loss of bone mass. Long-term persistence of high bone resorption marker CTX, insufficiently compensated with bone formation marker OC, enabled osteoporosis development.

Short-term exposure to dioxin impairs bone tissue in male rats

Chronic and sub-chronic studies in rats have previously shown that dioxin-like compounds impair the bone tissue homeostasis. In the present study, tibiae and serum were analyzed to study possible effects of short term dioxin exposure on rats. Two month old (ca. 200g) male rats were injected with 50microg 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) kg(-1) bw and tibiae were excised 5d following the exposure. Bone composition, dimensions and strength were analyzed by pQCT and three-point bending test on tibiae. In addition, detailed bone composition was analyzed by optical emission spectroscopy (ICP-OES) and Fourier transform infrared spectrometry (FTIR). Analysis of the serum bone biomarkers procollagen type-I N-terminal propeptide (PINP) and carboxyterminal cross linking teleopeptide (CTX) were also performed. pQCT-results showed alterations in the metaphysis, with a significant decrease in trabecular bone cross-sectional area (-19%, p<0.05) and a significant increase in total bone mineral density (+7%, p<0.05) in TCDD-exposed rats. Analyses of the bones by ICP-OES and FTIR showed that bones from exposed rats had a higher relative proportion of crystalline phosphate (+13% for a1080 and +11% for a1113, p<0.05) and lower acid phosphate content (-22% for a1145, p<0.05), resembling the composition of more mature bones. Serum analysis showed that the bone formation marker PINP was decreased (-37%, p<0.05) and that the bone resorption marker CTX was increased (+14%, p<0.05) indicating a net loss of bone tissue. In conclusion, 5d of exposure to TCDD was sufficient to negatively affect bone tissue in male rats.

Age-related changes of serum tartrate-resistant acid phosphatase 5b and the relationship with bone mineral density in Chinese women

AIM

Osteoclastic activity is mainly assessed by measurement of urinary markers (eg C-terminal cross-linked telopeptides of type I collagen, N-terminal crosslinked telopeptides of type I collagen, etc), the levels of which could often be affected by renal clearance. Recently, serum tartrate-resistant acid phosphatase 5b (TRACP5b) has been used as an alternative serum marker to evaluate osteoclastic activity. We investigated the age-related changes of TRACP5b level and its association with bone mineral density (BMD) in Chinese women.

METHODS

Seven-hundred and twenty-two Chinese mainland women aged 20-79 years were recruited in the study. Serum TRACP5b level was measured using immunoassay to evaluate the state of bone resorption. Bone mineral density (BMD) (g/cm2) at lumbar spine 1-4 and proximal femur were measured by duelenergy X-ray absorptiometry.

RESULTS

The serum TRACP5b level reached a bottom value in premenopausal women aged 30-39, gradually increased in women aged 40-49, rapidly rose in women aged 50-59, and culminated with a maximum value in women aged 60-69 before a slow drop in women aged 70- 79. The average level of TRACP5b was significantly higher in postmenopausal women [(3.29+/-1.07) U/L] than in premenopausal women ([1.70+/-0.59] U/L). The levels of TRACP5b were inversely correlated with BMD at all measured sites (P<0.001). Furthermore, the level of TRACP5b was obviously higher in women with osteoporosis and osteopenia than those with normal bone mass (P<0.001).

CONCLUSION

We have established the reference values of serum TRACP5b in Chinese mainland women, and found that postmenopausal women had higher TRACP5b concentration than younger women. The results showed that serum TRACP5b was a sensitive and useful parameter for the evaluation of age-related changes of bone absorption.

The amino- and carboxyterminal cross-linked telopeptides of collagen type I, NTX-I and CTX-I: a comparative review

Bone diseases such as osteoporosis or bone metastases are a continuously growing problem in the ageing populations across the world. In recent years, great efforts have been made to develop specific and sensitive biochemical markers of bone turnover that could help in the assessment and monitoring of bone turnover. The amino- and carboxyterminal cross-linked telopeptides of type I collagen (NTX-I and CTX-I, respectively) are two widely used bone resorption markers that attracted great attention due to their relatively high sensitivity and specificity for the degradation of type I collagen, and their rapid adaptation to automated analyzers. However, the clinical performance of both markers differs significantly depending on the clinical situation. These differences have caused considerable confusion and uncertainty. If used correctly, both markers have great potential to improve the management of many bone diseases. We here review the biochemistry, analytical background and clinical performance of NTX-I and CTX-I, as documented in the accessible literature until March 2008.

Activity or mass concentration of bone-specific alkaline phosphatase as a marker of bone formation

BACKGROUND

Recently published data identified bone-specific alkaline phosphatase (BALP) as a good marker of bone formation in different bone diseases and osteoporosis. Two methods are available for BALP determination: one measures enzyme activity, the other its mass concentration. We compared results for BALP activity and its mass concentration in a group of 88 healthy pre- and postmenopausal women to identify which is a more useful marker for detecting early menopausal bone remodelling changes.

METHODS

We measured BALP activity and BALP mass concentration in relation to femoral neck (FN) and lumbar spine (LS) bone mineral density (BMD) and some other widely used bone markers: osteocalcin (OC), procollagen type I N-terminal propeptide (PINP) and serum C-terminal telopeptide cross-links of type I collagen (CTx) in serum samples from 50 premenopausal (age 45.9+/-4.6 years) and 38 postmenopausal (age 54.4+/-4.5 years) women.

RESULTS

Healthy postmenopausal women exhibited 34.2% (p<0.01) and 27.3% (p=0.000) higher levels of BALP activity and mass concentration than premenopausal women, respectively. At the same time, FN and LS BMD were not significantly different between the groups. CTx values were significantly higher in postmenopausal women (p=0.018), while OC and PINP were not. We observed significant correlation between BALP activity and mass concentration (r=0.85, p<0.01). The correlation between BALP activity and FN BMD or LS BMD was insignificant. BALP mass correlated significantly with LS BMD (r=-0.370, p=0.033) but not with FN BMD. As expected, we proved a significant positive correlation for both BALP methods with the other bone markers measured in our study.

CONCLUSIONS

Postmenopausal women have slightly higher bone turnover. Since LS and FN BMD were not significantly lower in our group of healthy postmenopausal women, but BALP and CTx were markedly higher, we suggest that measurements of BALP and CTx might be useful as early markers of higher bone turnover. Finally, our results did not show any differences between the clinical utility of BALP activity and BALP mass concentration measurements.

Reduced incidence of distant metastases and lower mortality in 1072 patients with breast cancer with a history of hormone replacement therapy

OBJECTIVE

Substitution of estrogens (hormone replacement therapy [HRT]) is the most common therapy and prophylaxis of postmenopausal complaints. However, in most studies, long-term HRT has been associated with an increased risk for breast cancer, but the influence on a prognosis of breast cancer has been examined rarely.

STUDY DESIGN

For further investigation, we analyzed 1072 patients aged 45-70 years at the time of first diagnosis of breast cancer with and without preoperative HRT with regard to the incidence of distant metastases and overall survival. Of these, 279 women were premenopausal (mean, 47.8 +/- 3.2 years); 793 women were postmenopausal (mean, 54.5 +/- 3.5 years); 320 women had received HRT over a minimum of 1 year (mean, 5.5 +/- 4.0 years; group HRT+); and 473 women had not received HRT (group HRT-). The median follow-up time was 73.2 months.

RESULTS

Although body mass index, tumor size, and grading of group HRT- were significantly higher than in group HRT+, nodal status, S-phase fraction, hormone-receptor status, and local recurrence showed no significant differences. In regard to the incidence of distant metastases, women without HRT have significantly (P < .001) more metastases to bone (68 vs 20 women), lung (47:13 women), and liver (47:13 women). Overall survival was significantly lower in the HRT- group.

CONCLUSION

We were able to show that the use of HRT before the diagnosis of breast cancer results in more favorable primary tumors, with a lower incidence of recurrences and a better overall survival rate. This might be due to normalized bone metabolism by the use of HRT, which may lower the conditions of tumor cell seeding.

Biochemical markers of bone turnover in diagnosis of myeloma bone disease

This study was designed to explore the value of markers of bone turnover, macrophage inflammatory protein-1alpha (MIP-1alpha), and osteopontin (OPN) in the diagnosis of myeloma bone disease. Twenty-five patients with newly diagnosed and untreated multiple myeloma (MM), and 22 age-, sex-, and bone mineral density-matched control subjects were enrolled. Levels of MIP-1alpha, OPN, carboxy-terminal telopeptide of Type-1 collagen (C-telopeptide or Ctx), deoxypyridinoline (DPD), Type-1 collagen propeptide (T1Pro), and bone-specific alkaline phosphatase (BALP) were assessed in both groups. Twenty-two of the patients had bone involvement documented by skeletal surveys and lumbar spinal magnetic resonance imaging. Levels of serum Ctx, OPN, MIP-1alpha, and urine DPD were significantly higher in MM patients with bone disease than in controls (P<0.01). Serum Ctx levels were elevated in 90.9% of patients with MM and 40.9% of controls (P<0.001). Urine DPD levels were elevated in 90.4% of the patients and 31.8% of the controls (P<0.001). The serum OPN and MIP-1alpha levels of the patients were significantly correlated with beta2-microglobulin and lactate dehydrogenase levels (P<0.05). Our study indicates that Ctx and DPD are sensitive markers of bone disease in MM, and higher than normal values suggest presence of bone disease rather than benign osteoporosis in MM. The utility of OPN and MIP-1alpha needs to be further investigated.

One-year soy isoflavone supplementation prevents early postmenopausal bone loss but without a dose-dependent effect

It is believed that soy isoflavone has much potential effectiveness on the postmenopausal status; however, the optimal dose for preventing postmenopausal bone loss still remains unclear. This open-labeled, self-controlled pilot study was undertaken to determine the effect of 1-year supplementation of different high dosages of soy isoflavone in postmenopausal Taiwanese women. Forty-three women aged 45-67 years were enrolled and randomly assigned into a control (C), 100 mg/day isoflavone (IF100) and 200 mg/day isoflavone (IF200) groups for 1 year. Dual-energy X-ray absorptiometry and other related biochemical markers of bone metabolism were measured. Results indicated that the decrease in bone mineral density (BMD) was significant for lumbar vertebrae L1-3, L1-4 and the femur neck in the C group; surprisingly, the BMD of L1-3 was significantly elevated in the IF100 group; however, there were no consistent responses in the IF200 group. No significant change except loss of the bone mineral content of Ward's triangle (P=.003) was found in the IF200 group after treatment. The percentage change at L1-3 was less (P=.04) in the IF200 group when compared to the IF100 group. A relatively uniform direction of bone formation in expanding the weight and area with different rates of change resulted in different BMD changes. Both indicated a change of bone formation patterns with the higher-dose supplement. A protective effect of IF100 on estrogen-related bone loss was observed. A lack of a benefit such as high safety in the IF200 group for 1-year administration was ensured and lacked undesirable side effects.

Influence of pattern of menopausal transition on the amount of trabecular bone loss. Results from a 6-year prospective longitudinal study

INTRODUCTION

Bone density is lower in postmenopausal than in premenopausal women. Recent findings have suggested that accelerated bone loss already begins before menopause. Despite numerous cross-sectional studies on menopause-related bone density, longitudinal data on perimenopausal bone density changes are scarce. This study sought to characterize the dynamics of changes leading to postmenopausal osteopenia and to possibly find the time point at which accelerated bone loss begins.

METHODS

We prospectively followed 34 pre-, peri- and early postmenopausal women without prior external hormone use, measuring their lumbar spine trabecular bone density with quantitative computer tomography at 0, 2 and 6 years. The analysis of the changes over time was done in a tri-parted fashion, since menopausal status changed variably for individual subjects: we grouped the participants according to their currently valid menopausal classification for prospective (baseline classification), interim (2 years) and retrospective (6-year classification) analysis.

RESULTS

Six different patterns of menopausal transition were identified in our sample. Bone loss in the groups not reaching postmenopause during 6 years of observation was >50% of the maximum bone loss observed during the study period. Invariably for all analyses, the perimenopausal phase with estrogen levels still adequate was associated with the greatest reduction of trabecular bone mineral density, reaching 6.3% loss annually in the lumbar spine. By comparison, the average rate of loss was slower in the early postmenopause; total bone loss differed by pattern of menopausal transition (one-way ANOVA p<0.05).

CONCLUSION

The presented data for the first time show the perimenopausal course of trabecular bone loss (as measured by QCT of the lumbar spine). Acceleration of bone loss during perimenopause reached half-maximal values of the total bone loss measured around menopause, despite adequate serum estradiol levels.

Physical training and hormone replacement therapy reduce the decrease in bone mineral density in perimenopausal women: a pilot study

The effects of physical training and hormone replacement therapy (HRT) on bone mineral density in perimenopausal women were studied. Sixty perimenopausal women were randomized to either physical training (n = 20), HRT (n = 20), or control group (n = 20). The study period was 18 months. Bone mineral density (BMD) in the femoral neck and lumbar spine was measured using dual-energy X-ray absorptiometry (DXA). DXA was performed before treatment and after 6 and 18 months. Blood samples for analysis of the bone markers U-deoxypyridinoline and osteocalcin were collected at the same time points. After 18 months, BMD in the spine had not decreased in either the training group or in the HRT group. In the control group, spine BMD had significantly decreased (p = 0.0014). U-Deoxypyridinoline and osteocalcin were increased significantly in the control group (p = 0.0198, p = 0.0295, respectively). No significant changes in bone marker levels were found in the training group or the HRT group. We found that both HRT and physical training can prevent loss of spine BMD in perimenopausal women over a period of 18 months. HRT remains a cornerstone in the treatment of vasomotor symptoms and preservation of BMD. However, HRT can only be used for limited periods of time due to the potential serious adverse effects. This study indicates a beneficial effect of physical activity on spine BMD in the perimenopausal period, and highlights its potential as an alternative to HRT during this period.

Tartrate-Resistant Acid Phosphatase 5b is a Useful Serum Marker for Extensive Bone Metastasis in Breast Cancer Patients

Purpose: Previous studies showed that serum tartrate-resistant acid phosphatase 5b (TRACP5b) activity was increased in 70% to 94% of breast cancer (BC) patients with bone metastasis (BM). This study aims to determine whether serum TRACP5b is useful for identifying limited or extensive BM in BC patients.

Experimental Design: Serum TRACP5b activity was measured in 168 BC patients, including 81 who were newly diagnosed with early BC, 20 with extraosseous metastasis, 24 with limited BM, and 43 with extensive BM. Serum TRACP5b activity was also measured monthly in 151 patients with early BC until they developed BM. Four hundred and twenty-seven (427) healthy women ages 18 to 90 served as control. One-way ANOVA was used to compare serum TRACP5b among groups. The sensitivity and specificity of serum TRACP5b as a marker for BM were estimated by receiver operator characteristic (ROC) curves.

Results: Serum TRACP5b increased with age in healthy women ( P &lt; 0.0001). It was significantly elevated in patients with extensive BM compared with all other groups ( P &lt; 0.0001). ROC analysis established a cutoff value of 4.026 units/L to identify patients with extensive BM with a specificity of 98% and a sensitivity of 93% (area under the curve = 0.9807; 95% CI = 0.9698-0.9915). Among the 151 patients with early BC, 6 developed limited BM and 2 developed extensive BM during the follow-up period. Serum TRACP5b remained below the cutoff value in patients with limited BM, but became significantly increased in those whose BM became extensive.

Conclusion: Serum TRACP5b activity is a useful diagnostic marker for extensive BM in patients with BC.

Estrogen receptor alpha gene analysis in osteoporosis and familial osteoporosis

Estrogens are important determinants of bone mineral density (BMD) mediating their effects via estrogen receptor alpha (ERalpha) and beta (ERbeta). The strong genetic predisposition to osteoporosis, and the fact that alterations in the aminoterminal region of ERalpha have been linked to bone disturbances, prompted us to identify genetic alterations in exon 1 and exon 2 of ERalpha in osteoporotic individuals. Sixty-two unrelated normal subjects (age 46.1+/-9.5 years) and 72 unrelated osteoporotic subjects (age 52.3+/-7.9 years) were studied. Their menopausal status was pre- and perimenopausal. We also included 30 related osteoporotic individuals (mother-daughter or sister-sister relationship) (age 46.2+/-12.8 years) belonging to 14 families who where also pre- and perimenopausal. DNA was extracted from peripheral blood, exons 1 and 2 were amplified by polymerase chain reaction (PCR) and were further submitted to denaturing gradient gel electrophoresis (DGGE), single stranded conformational polymorphism (SSCP), restriction fragment length polymorphism (RFLP) and sequence analysis. Bone turnover markers were also determined. Two polymorphisms were identified in exon 1 (codons 10 and 87) in both normal and osteoporotic women. Statistical analysis revealed no difference (P>0.05) in the ERalpha genotype frequencies within osteoporotic families as compared with the same genotypes in the unrelated normal or osteoporotic subjects. Codon 10, codon 87 polymorphisms were not related to BMD or bone turnover markers. No other mutations were found in exons 1 and 2 in all subjects studied. Genetic alterations in exons 1 and 2 of ERalpha are not associated to osteoporosis and familial osteoporosis. Moreover, the codon 10 and codon 87 polymorphisms do not seem to be correlated with BMD and bone turnover markers.

Effect of polymyxin B-immobilized fiber on bone resorption in patients with sepsis

OBJECTIVE

To analyze the effects of polymyxin B-immobilized fiber (PMX-F) on bone resorption in septic patients.

DESIGN AND SETTING

Observational prospective study in intensive care units of a general hospital.

PATIENTS AND PARTICIPANTS

25 patients with severe sepsis and 20 healthy controls.

MEASUREMENTS AND RESULTS

Septic patients were randomly assigned to two groups: PMX-F treatment group (n=15) and conventional treatment group (n=10). Total pyridinium crosslink pyridinoline (PYD) and deoxypyridinoline (DPD) in urine were determined by modified high-performance liquid chromatography. Nitric oxide production was assessed by measuring the ratio of the nitric oxide breakdown products to urinary creatinine (NOx/Cr). Plasma endotoxin levels were determined by endospecy test. The blood albumin, ionized calcium, and parathyroid hormone were also measured. PMX-F treatment was performed twice separated by 24 h. Urinary NOx/Cr, PYD/Cr, and DPD/Cr were significantly increased in septic patients compared with those in healthy controls. Blood ionized calcium in septic patients was lower than in healthy controls, while parathyroid hormone levels in septic patients were higher than in healthy controls (P<0.01). PMX-F treatment reduced plasma endotoxin, urinary NOx/Cr, PYD/Cr, DPD/Cr, and serum parathyroid hormone levels and increased blood ionized calcium significantly; however, conventional treatment did not affect these levels.

CONCLUSIONS

Septic patients increased nitric oxide production and bone resorption, and PMX-F treatment is effective in reducing nitric oxide levels and bone resorption markers.

An update on the antiestrogenic effect of smoking: a literature review with implications for researchers and practitioners

OBJECTIVE

To draw attention to the implications of smoking in the pathogenesis of osteoporosis and for the effectiveness and safety of hormone therapy. DESIGN Summary of own research and a MEDLINE search of English-language literature on the antiestrogenic effect of smoking in pre- and postmenopausal women published during the past two decades.

RESULTS

Numerous observations suggest that part of the detrimental effect of smoking on bone metabolism is mediated by an adverse influence on sex-steroid metabolism, and in particular by an estrogen-lowering effect. Furthermore, in smokers, serum concentrations of estradiol and estrone during oral, but not parenteral, hormone therapy (HT) reach only half the concentrations of nonsmokers. Thus, cigarette smoking may reduce the favorable effects of HT significantly and may even negate the protective effects. In such cases, the failure of preventive therapy is a failure of dosing rather than of HT per se.

CONCLUSIONS

We urge colleagues to take the antiestrogenic effect of smoking into account when drawing conclusions from population-based trials, as well as when prescribing HT to their patients for the prevention of menopause-related health problems.

Identification of novel proteolytic forms of osteocalcin in human urine

In this study, we report the isolation and characterization of osteocalcin in human urine using mass spectrometry and N-terminal sequencing. Multiple proteolytic forms of osteocalcin were found, which consisted of 16-27 residues from the middle region of the molecule. Several fragments had residue Gly7 at the N-terminus and the most predominant was fragment 7-31. Additional fragments starting from residue Asp14 were detected in the samples of children and young adults. Immunochemical detection of urine osteocalcin fragments had a statistically significant negative correlation to bone mineral density in evaluation of urine samples from 75-year-old women. Thus, the measurement of osteocalcin fragments in urine may have potential applications in diagnostics related to disorders of bone metabolism.