Long-term variability of markers of bone turnover in postmenopausal women and implications for their clinical use: the OFELY study

Plasma Cartilage Acidic Protein 1 Measured by ELISA Is Associated With the Progression to Total Joint Replacement in Postmenopausal Women

OBJECTIVE

To investigate the association of plasma cartilage acidic protein 1 (CRTAC1), a novel biochemical marker of osteoarthritis (OA), and total joint replacement (TJR) in postmenopausal women.

METHODS

The association of plasma CRTAC1 with the incidence of TJR was investigated in a prospective cohort including 478 postmenopausal women. A total of 38 women underwent a TJR for OA during a median follow-up of 18 years. Every one of the TJR cases were age- and BMI (kg/m2)-matched with 2 controls with no TJR from the same cohort. Plasma CRTAC1 was measured before TJR. The association between CRTAC1 and TJR incidence was investigated by conditional logistic regression.

RESULTS

Increased CRTAC1 was associated with a higher risk of TJR with an odds ratio (OR) of 1.80 (95% CI 1.11-2.92) for 1 SD increase, which remained significant after adjusting for Western Ontario and McMaster Universities Osteoarthritis Index, knee OA baseline severity (Kellgren-Lawrence grade), hip OA, and hip bone mineral density. Urinary crosslinked C-telopeptide of type II collagen (CTX-II) was also associated with a higher risk of TJR with an adjusted OR of 1.83 (95% CI 1.11-3.00). When CRTAC1 and CTX-II were included in the same model, both markers were significantly associated with TJR with similar ORs.

CONCLUSION

CRTAC1 is a new risk indicator of TJR for OA in postmenopausal women. Combined with knee and hip OA and CTX-II, it may help to identify subjects at risk for TJR.

Bone Turnover Markers for Assessment of Anti-Resorptive Effect in Clinical Practice: A Good Idea Meets the Problem of Measurement Uncertainty

OBJECTIVES

Bone turnover markers (BTM) are measures for understanding the effect of anti-resorptives upon osteoclast activity. Post-hoc trial data suggests reduction in BTM of 40% may represent a target for defining appropriate response to therapy. We modeled clinical application of this target threshold in an individual patient setting where assay measurement uncertainty and biological variation are included.

DESIGN

Using serum C-telo-peptide (ß-CTX), we constructed hypothetical scenarios of ß-CTX measurement pre and post bisphosphonate therapy. Using typical ß-CTX assay characteristics (analytical coefficient of variation, CV 5.0%) and published intra-individual ß-CTX data for post-menopausal women (CV 18.0%), we calculated the post-therapy ß-CTX that must be seen on single repeat measure for 95% confidence that the observed result was ≥40% below baseline. Sensitivity analyses considered greater and lesser variations in the combined sources of variation.

RESULTS

The one-tailed 95% reference change value for any detectable therapeutic decrease in ß-CTX was 22%. However, to have 95% confidence of having achieved a reduction ≥ 40%, an observed ß-CTX decrease of ≥56% is required. Larger decreases are needed for scenarios of greater analytical or intra-individual variation.

CONCLUSIONS

Although population data suggest a ß-CTX decrease of 40% is commensurate with adequate therapeutic response to anti-resorptives, application to an individual patient where measurement and natural variation are present is problematic. ß-CTX decreases much greater than 40% are required to be confident of having achieved the optimal treatment response. It is uncertain whether this is a legitimate change to be expected in all individual patients and therefore clinical application of this threshold is uncertain.

Bone Turnover Markers in Children: From Laboratory Challenges to Clinical Interpretation

Bone turnover markers (BTMs) have been developed many years ago to study, in combination with imaging techniques, bone remodeling in adults. In children and adolescents, bone metabolism differs from adults since it implies both growth and bone remodeling, suggesting an age- and gender-dependent BTM concentration. Therefore, specific studies have evaluated BTMs in not only physiological but also pathological conditions. However, in pediatrics, the use of BTMs in clinical practice is still limited due to these many children-related specificities. This review will discuss about physiological levels of BTMs as well as their modifications under pathological conditions in children and adolescents. A focus is also given on analytical and clinical challenges that restrain BTM usefulness in pediatrics.

Analysis of the molecular mechanisms by flavonoids with potential use for osteoporosis prevention or therapy

BACKGROUND

Osteoporosis is the most common skeletal disorder worldwide. Flavonoids have the potential to alleviate bone alterations in osteoporotic patients with the advantage of being safer and less expensive than the conventional therapies.

OBJECTIVE

The main objective is to analyze the molecular mechanisms triggered in bone by different subclasses of flavonoids. In addition, this review provides an up-to-date overview on the cellular and molecular aspects of osteoporotic bones versus healthy bones, and a brief description of some epidemiological studies indicating that flavonoids could be useful for osteoporosis treatment.

METHODS

The PubMed database was searched in the range of years 2001- 2021 using the keywords osteoporosis, flavonoids, and their subclasses such as flavones, flavonols, flavanols, isoflavones, flavanones and anthocyanins, focusing the data on the molecular mechanisms triggered in bone.

RESULTS

Although flavonoids comprise many compounds that differ in structure, their effects on bone loss in postmenopausal women or in ovariectomized-induced osteoporotic animals are quite similar. Most of them increase bone mineral density and bone strength, which occur through enhancement of osteoblastogenesis and osteoclast apoptosis, decrease in osteoclastogenesis as well as increase in neovascularization on the site of the osteoporotic fracture.

CONCLUSION

Several molecules of signaling pathways are involved in the effect of flavonoids on osteoporotic bone. Whether all flavonoids have a common mechanism or they act as ligands of estrogen receptors remain to be established. More clinical trials are necessary to know better their safety, efficacy, delivery and bioavailability in humans, as well as comparative studies with conventional therapies.

Circulating Carboxylated Osteocalcin Correlates With Skeletal Muscle Mass and Risk of Fall in Postmenopausal Osteoporotic Women

Background

Bone and skeletal muscle represent a single functional unit. We cross-sectionally investigated body composition, risk of fall and circulating osteocalcin (OC) isoforms in osteoporotic postmenopausal women to test the hypothesis of an involvement of OC in the bone-muscle crosstalk.

Materials and Methods

Twenty-nine non-diabetic, non-obese, postmenopausal osteoporotic women (age 72.4 ± 6.8 years; BMI 23.0 ± 3.3 kg/m2) underwent to: 1) fasting blood sampling for biochemical and hormone assays, including carboxylated (cOC) and uncarboxylated (uOC) osteocalcin; 2) whole-body dual energy X-ray absorptiometry (DXA) to assess total and regional body composition; 3) magnetic resonance imaging to determine cross-sectional muscle area (CSA) and intermuscular adipose tissue (IMAT) of thigh muscles; 4) risk of fall assessment through the OAK system.

Results

Appendicular skeletal muscle index (ASMMI) was low in 45% of patients. Forty percent got a low OAK score, consistent with moderate-severe risk of fall, which was predicted by low legs lean mass and increased total fat mass. Circulating cOC levels showed significantly correlated with βCTx-I, lean mass parameters including IMAT, and OAK score. Fractured and unfractured women did not differ for any of the analyzed parameters, though cOC and uOC positively correlated with legs lean mass, OAK score and bone markers only in fractured women.

Conclusions

Data supported the relationship between OC and skeletal muscle mass and function in postmenopausal osteoporotic women. Serum cOC, but not uOC, emerges as mediator in the bone-muscle crosstalk. Circulating cOC and uOC levels may be differentially regulated in fractured and unfractured osteoporotic women, suggesting underlying differences in bone metabolism.

European Biological Variation Study (EuBIVAS): within- and between-subject biological variation estimates of β-isomerized C-terminal telopeptide of type I collagen (β-CTX), N-terminal propeptide of type I collagen (PINP), osteocalcin, intact fibroblast growth factor 23 and uncarboxylated-unphosphorylated matrix-Gla protein-a cooperation between the EFLM Working Group on Biological Variation and the International Osteoporosis Foundation-International Federation of Clinical Chemistry Committee on Bone Metabolism

We have calculated the biological variation (BV) of different bone metabolism biomarkers on a large, well-described cohort of subjects. BV is important to calculate reference change value (or least significant change) which allows evaluating if the difference observed between two consecutive measurements in a patient is biologically significant or not.

INTRODUCTION

Within-subject (CV_I) and between-subject (CV_G) biological variation (BV) estimates are essential in determining both analytical performance specifications (APS) and reference change values (RCV). Previously published estimates of BV for bone metabolism biomarkers are generally not compliant with the most up-to-date quality criteria for BV studies. We calculated the BV and RCV for different bone metabolism markers, namely β-isomerized C-terminal telopeptide of type I collagen (β-CTX), N-terminal propeptide of type I collagen (PINP), osteocalcin (OC), intact fibroblast growth factor 23 (iFGF-23), and uncarboxylated-unphosphorylated Matrix-Gla Protein (uCuP-MGP) using samples from the European Biological Variation Study (EuBIVAS).

METHODS

In the EuBIVAS, 91 subjects were recruited from six European laboratories. Fasting blood samples were obtained weekly for ten consecutive weeks. The samples were run in duplicate on IDS iSYS or DiaSorin Liaison instruments. The results were subjected to outlier and variance homogeneity analysis before CV-ANOVA was used to obtain the BV estimates.

RESULTS

We found no effect of gender upon the CV_I estimates. The following CV_I estimates with 95% confidence intervals (95% CI) were obtained: β-CTX 15.1% (14.4-16.0%), PINP 8.8% (8.4-9.3%), OC 8.9% (8.5-9.4%), iFGF23 13.9% (13.2-14.7%), and uCuP-MGP 6.9% (6.1-7.3%).

CONCLUSIONS

The EuBIVAS has provided updated BV estimates for bone markers, including iFGF23, which have not been previously published, facilitating the improved follow-up of patients being treated for metabolic bone disease.

Discovery of potential biomarkers for osteoporosis using LC-MS/MS metabolomic methods

Our study focused on the associations of metabolites with BMD and osteoporosis, finding that several metabolites are associated with BMD, and metabolites combined with bone turnover markers tend to be more sensitive in distinguishing osteoporosis in both males and postmenopausal females, which might be meaningful for the early diagnosis of osteoporosis.

INTRODUCTION

Our study aimed to evaluate the association of metabolites with bone, trying to find new metabolic markers that are distinguishing for low bone mineral density (BMD).

METHODS

Our study recruited 320 participants, including 138 males and 182 postmenopausal females from the Shanghai area. Bone turnover markers (BTMs), including osteocalcin, PINP and β-CTX, and other biochemical traits were tested. BMD values of the lumber spine (L1-4), femoral neck and total hip were determined using dual-energy X-ray absorptiometry and the serum metabolome profiles including 221 metabolites from five groups (acylcarnitines, amino acids, biogenic amines, glycerophospholipids, sphingolipids and hexose) were assessed by mass spectrometry.

RESULTS

No visual separation in the metabolic profiles between different BMD groups was observed in principal component analysis (PCA) or partial least squares discriminant analysis (PLS-DA) models. We compared metabolites in three groups with different BMD levels in males and postmenopausal females separately and further filtering these metabolites via random forest-based feature selection, a commonly applied machine learning algorithm which could select the features with the greatest impact on osteoporosis, then metabolites with the highest importance (≥ 5%) (5 in males and 9 in postmenopausal females) were selected to construct better models for osteoporosis classification. After adding these selected metabolites to the model, the area under the curve (AUC) of receiver operating characteristic (ROC) curves increased significantly (BTMs: AUC 0.729, 95% CI 0.647-0.802, p < 0.0001, model 1: AUC = 0.828, 95% CI 0.754-0.888, p < 0.0001; model 1 versus model of BTMs: p = 0.0158) compared to the AUC of the BTM-only model in males. Similar results were also observed in postmenopausal females (BTMs: AUC = 0.638, 95% CI 0.562-0.708, p = 0.0025; model 2: AUC = 0.741, 95% CI 0.669-0.803, p < 0.0001; model 1 versus model of BTMs: p = 0.0182).

CONCLUSION

Metabolites combined with traditional BTMs tend to better markers for distinguishing osteoporosis in both males and postmenopausal females than BTMs alone.

Contribution of bone turnover markers to the variation in bone mineral density: a study in Vietnamese men and women

The present cross-sectional study constructed reference ranges for bone resorption marker beta isomerized form of C-terminal crosslinking telopeptides of type I collagen (beta-CTX) and bone formation marker procollagen type 1 N-terminal propeptide (PINP) for the Vietnamese population. We have further shown that for a given age and weight, higher levels of beta-CTX were significantly associated with bone mineral density in men and women.

INTRODUCTION

Normal bone is constantly renewed by two opposing processes of resorption and formation which can be reflected by bone turnover markers (BTMs). This study sought to define the contribution of BTMs to the variation in bone mineral density (BMD) in normal individuals.

METHODS

The study involved 205 men and 432 women aged between 18 and 87, who were randomly selected from various districts within Ho Chi Minh City, Vietnam. Fasting serum levels of PINP and beta-CTX were determined by electrochemiluminescence (Roche, ECLIA). BMD at the lumbar spine (LS) and femoral neck (FN) was measured by dual-energy x-ray absorptiometry (Hologic, Waltham, MA, USA).

RESULTS

Among those aged < 50 years, women had lower PINP and beta-CTX levels than men, but among those aged > 50 years, women had higher PINP and beta-CTX levels than men. In the multiple linear regression analysis, beta-CTX-but not PINP-was significantly associated with both femoral neck (P = 0.008) and lumbar spine BMD (P = 0.008) and the association was independent of gender, age, and body weight. The proportion of variance in BMD attributable to beta-CTX was 1% for femoral neck BMD and 2% for lumbar spine BMD.

CONCLUSION

The elevation in bone formation marker PINP and bone resorption marker beta-CTX in postmenopausal women was greater than in elderly men. However, only beta-CTX was modestly but significantly associated with BMD.

Biochemical Testing Relevant to Bone

Laboratory biochemical testing is critical to the clinical understanding of bone disorders. Patients with skeletal diseases have underlying themes in their pathophysiology that would be impossible to detect without biochemical assessment of serum and urine minerals, vitamin D, parathyroid hormone, parathyroid hormone-related peptide, and bone turnover markers. Bone disorders are caused by abnormalities in signaling pathways that affect bone formation and resorption. Therapies for common bone diseases were developed in direct response to underlying biochemical abnormalities.

Association between the metabolome and bone mineral density in pre- and post-menopausal Chinese women using GC-MS

The present study describes for the first time, a metabolic profile reflecting the osteoporosis progression in 364 pre- and postmenopausal Chinese women using GC-MS. In order to accurately evaluate the dynamic changes of metabolites along with estrogen deficiency and osteoporosis progression, we divided these subjects into the following four groups: premenopausal women with normal bone mass density (BMD, group I), postmenopausal women with normal BMD (group II), postmenopausal women with osteopenia (group III) and postmenopausal women with osteoporosis (group IV), according to their menopause or low BMD status. Principal component analysis (PCA) and Partial least squares-discriminant analysis (PLS-DA) were used to evaluate the associations of metabolic changes with low BMD or estrogen deficiency. Twelve metabolites identified by the PLS-DA model were found to be able to differentiate low BMD groups from normal BMD groups. Of the 12 metabolites, five free fatty acids (LA, oleic acid, AA and 11,14-eicosadienoic acid) have the most potential to be used as osteoporosis biomarkers due to their better correlations with BMD, and high sensitivity and specificity in distinguishing the low BMD groups from the normal BMD groups calculated by the receiver operating characteristic curve (ROC). The lipid profile may be useful for osteoporosis prediction and diagnosis.

A serum metabolomics-based profile in low bone mineral density postmenopausal women

Osteoporosis is characterized as a metabolic disorder of bone tissue, and various metabolic markers are now available to support its diagnosis and evaluate treatment effects. Substances produced as end products of metabolomic activities are the correlated factors to the biological or metabolic status, and thus, metabolites are considered highly sensitive markers of particular pathological states, including osteoporosis. Here we undertook comprehensive serum metabolomics analysis in postmenopausal women with or without low bone mineral density (low BMD vs controls) for the first time using capillary electrophoresis/mass spectrometry. Among the metabolites tested, 57 were detected in sera. Levels of hydroxyproline, Gly-Gly and cystine, differed significantly between groups, with Gly-Gly and cystine significantly lower in the low BMD group and hydroxyproline, a reported marker of osteoporosis, significantly higher. Levels of TRACP5b, a bone resorption marker, were significantly higher in the low BMD group, supporting the study's validity. Taken together, our findings represent novel metabolomic profiling in low BMD in postmenopausal women.

Metabolomics and Its Application in the Development of Discovering Biomarkers for Osteoporosis Research

Osteoporosis is a progressive skeletal disorder characterized by low bone mass and increased risk of fracture in later life. The incidence and costs associated with treating osteoporosis cause heavy socio-economic burden. Currently, the diagnosis of osteoporosis mainly depends on bone mineral density and bone turnover markers. However, these indexes are not sensitive and accurate enough to reflect the osteoporosis progression. Metabolomics offers the potential for a holistic approach for clinical diagnoses and treatment, as well as understanding of the pathological mechanism of osteoporosis. In this review, we firstly describe the study subjects of osteoporosis and bio-sample preparation procedures for different analytic purposes, followed by illustrating the biomarkers with potentially predictive, diagnosis and pharmaceutical values when applied in osteoporosis research. Then, we summarize the published metabolic pathways related to osteoporosis. Furthermore, we discuss the importance of chronological data and combination of multi-omics in fully understanding osteoporosis. The application of metabolomics in osteoporosis could provide researchers the opportunity to gain new insight into the metabolic profiling and pathophysiological mechanisms. However, there is still much to be done to validate the potential biomarkers responsible for the progression of osteoporosis and there are still many details needed to be further elucidated.

Effects of Pegylated Interferon/Ribavirin on Bone Turnover Markers in HIV/Hepatitis C Virus-Coinfected Patients

HIV/hepatitis C virus (HCV) patients have a 3-fold increased fracture incidence compared to uninfected patients. The impact of HCV therapy on bone health is unclear. We evaluated bone turnover markers (BTM) in well-controlled (HIV RNA <50 copies/ml) HIV/HCV-coinfected patients who received pegylated interferon-α and ribavirin (PEG-IFN/RBV) in ACTG trial A5178. Early virologic responders (EVR: ≥2 log HCV RNA drop at week 12) continued PEG-IFN/RBV and non-EVRs were randomized to continuation of PEG-IFN alone or observation. We assessed changes in C-terminal telopeptide of type 1 collagen (CTX; bone resorption marker) and procollagen type I intact N-terminal propeptide (P1NP; bone formation marker), and whether BTM changes were associated with EVR, complete early virologic response (cEVR: HCV RNA <600 IU/ml at week 12), or PEG-IFN treatment. A total of 192 subjects were included. After 12 weeks of PEG-IFN/RBV, CTX and P1NP decreased: −120 pg/ml and −8.48 μg/liter, respectively (both p < 0.0001). CTX declines were greater in cEVR (N = 91; vs. non-cEVR (N = 101; p = 0.003). From week 12 to 24, CTX declines were sustained among EVR patients who continued PEG-IFN/RBV (p = 0.027 vs. non-EVR) and among non-EVR patients who continued PEG-IFN alone (p = 0.022 vs. Observation). Median decreases of P1NP in EVR vs. non-EVR were similar at weeks 12 and 24. PEG-IFN-based therapy for chronic HCV markedly reduces bone turnover. It is unclear whether this is a direct IFN effect or a result of HCV viral clearance, or whether they will result in improved bone mineral density. Further studies with IFN-free regimens should explore these questions.

Effects of de-escalated bisphosphonate therapy on bone turnover biomarkers in breast cancer patients with bone metastases

While de-escalation of bisphosphonates from 4 to 12-weekly dosing has been shown to be clinically non-inferior to standard dosing, there is evidence the de-escalation is associated with increased bone turnover biomarkers. Here we evaluated the effect of de-escalated dosing on a panel of biomarkers and determined their association with incidence of skeletal related events (SREs) in breast cancer patients with ‘low risk’ bone metastases. As part of a pilot randomized trial, women with baseline C-telopeptide levels <600 ng/L after >3 months of 3–4 weekly pamidronate were randomized to continue pamidronate every 4 weeks or de-escalation to 12-weekly treatment. Serum was analysed for bone biomarkers (C-telopeptide, N-telopeptide, bone-specific alkaline phosphatase, transforming growth factor-β, procollagen type 1 N-propeptide, activinA and bone sialoprotein) using ELISA. The associations between changes in biomarkers, pain scores and SREs were assessed by univariable logistic regression. Numerical increases in all biomarkers were observed between baseline and 12 weeks but were of higher magnitude in the de-escalated arm. Pain scores in the de-escalated treatment arm showed a greater magnitude of pain reduction from baseline to 12 weeks. Neither baseline levels nor changes in biomarkers from baseline to 12 weeks on treatment were associated with on study SREs. Baseline pain as measured by the FACT-BP was associated with increased risk of SRE. In conclusion, biomarkers of bone activity do not appear to predict for SREs in ‘low risk’ cohorts. However, baseline bone pain appears to be associated with SRE occurrence, a finding which warrants evaluation in larger cohorts.

Intervention timing of strontium treatment on estrogen depletion-induced osteoporosis in rats: bone microstructure and mechanics

PURPOSE

To evaluate the effect of intervention timing of Sr treatment on trabecular bone microstructure and mechanics.

METHODS

Ninety female rats were randomly divided into three batches with three groups in each batch. Each group was divided according to the initiation timing of vehicle or strontium compound (SrC), which was at week 0 (early), 4 (mid-term) and 8 (late) after the ovariectomy, respectively. The treatment lasted for 12 weeks. The trabecular bone biomechanical properties, trabecular bone tissue mechanical properties, trabecular bone microstructure, and bone remodeling were analyzed with mechanical testing, nanoindentation, microCT, and histomorphometry, respectively. The osteoblast and osteoclast phenotypic genes were analyzed with real-time polymerase chain reaction (PCR).

RESULTS

Early and mid-term Sr treatment significantly increased biomechanical properties of trabecular bone, which was associated with increased microarchitecture parameters, increased bone formation parameters and up-regulation of osteoblast-related gene expression. Late Sr treatment failed to exert a beneficial effect on any of those parameters.

CONCLUSIONS

The beneficial effect of Sr was dependent on the intervention timing in ovariectomized rats.

Association between the metabolome and low bone mineral density in Taiwanese women determined by (1)H NMR spectroscopy

Osteoporosis is related to the alteration of specific circulating metabolites. However, previous studies on only a few metabolites inadequately explain the pathogenesis of this complex syndrome. To date, no study has related the metabolome to bone mineral density (BMD), which would provide an overview of metabolism status and may be useful in clinical practice. This cross-sectional study involved 601 healthy Taiwanese women aged 40 to 55 years recruited from MJ Health Management Institution between 2009 and 2010. Participants were classified according to high (2nd tertile plus 3rd tertile) and low (1st tertile) BMD groups. The plasma metabolome was evaluated by proton nuclear magnetic resonance spectroscopy ((1) H NMR). Principal components analysis (PCA), partial least-squares discriminant analysis (PLS-DA), and logistic regression analysis were used to assess the association between the metabolome and BMD. The high and low BMD groups could be differentiated by PLS-DA but not PCA in postmenopausal women (Q(2)  = 0.05, ppermutation  = 0.04). Among postmenopausal women, elevated glutamine was significantly associated with low BMD (adjusted odds ratio [AOR] = 5.10); meanwhile, elevated lactate (AOR = 0.55), acetone (AOR = 0.51), lipids (AOR = 0.04), and very low-density lipoprotein (AOR = 0.49) protected against low BMD. To the best of our knowledge, this study is the first to identify a group of metabolites for characterizing low BMD in postmenopausal women using a (1) H NMR-based metabolomic approach. The metabolic profile may be useful for predicting the risk of osteoporosis in postmenopausal women at an early age.

Odanacatib reduces bone turnover and increases bone mass in the lumbar spine of skeletally mature ovariectomized rhesus monkeys

Odanacatib (ODN) is a selective and reversible inhibitor of cathepsin K (CatK) currently being developed as a once-weekly treatment for osteoporosis. In this study, we evaluated the effects of ODN on bone turnover, bone mineral density (BMD), and bone strength in the lumbar spine of estrogen-deficient, skeletally mature rhesus monkeys. Ovariectomized (OVX) monkeys were treated in prevention mode for 21 months with either vehicle, ODN 6 mg/kg, or ODN 30 mg/kg (p.o., q.d.) and compared with intact animals. ODN treatment persistently suppressed the bone resorption markers (urinary NTx [75% to 90%] and serum CTx [40% to 55%]) and the serum formation markers (BSAP [30% to 35%] and P1NP [60% to 70%]) versus vehicle-treated OVX monkeys. Treatment with ODN also led to dose-dependent increases in serum 1-CTP and maintained estrogen deficiency-elevated Trap-5b levels, supporting the distinct mechanism of CatK inhibition in effectively suppressing bone resorption without reducing osteoclast numbers. ODN at both doses fully prevented bone loss in lumbar vertebrae (L₁ to L₄) BMD in OVX animals, maintaining a level comparable to intact animals. ODN dose-dependently increased L₁ to L₄ BMD by 7% in the 6 mg/kg group (p < 0.05 versus OVX-vehicle) and 15% in the 30 mg/kg group (p < 0.05 versus OVX-vehicle) from baseline. Treatment also trended to increase bone strength, associated with a positive and highly significant correlation (R = 0.838) between peak load and bone mineral content of the lumbar spine. Whereas ODN reduced bone turnover parameters in trabecular bone, the number of osteoclasts was either maintained or increased in the ODN-treated groups compared with the vehicle controls. Taken together, our findings demonstrated that the long-term treatment with ODN effectively suppressed bone turnover without reducing osteoclast number and maintained normal biomechanical properties of the spine of OVX nonhuman primates.

Remodeling markers are associated with larger intracortical surface area but smaller trabecular surface area: a twin study

All postmenopausal women become estrogen deficient but not all remodel their skeleton rapidly or lose bone rapidly. As remodeling requires a surface to be initiated upon, we hypothesized that a volume of mineralized bone assembled with a larger internal surface area is more accessible to being remodeled, and so decayed, after menopause. We measured intracortical, endocortical and trabecular bone surface area and microarchitecture of the distal tibia and distal radius in 185 healthy female twin pairs aged 40 to 61 years using high-resolution peripheral quantitative computed tomography (HR-pQCT). We used generalized estimation equations to analyze (i) the trait differences across menopause, (ii) the relationship between remodeling markers and bone surface areas, and (iii) robust regression to estimate associations between within-pair differences. Relative to premenopausal women, postmenopausal women had higher remodeling markers, larger intracortical and endocortical bone surface area, higher intracortical porosity, smaller trabecular bone surface area and fewer trabeculae at both sites (all p<0.01). Postmenopausal women had greater deficits in cortical than trabecular bone mass at the distal tibia (-0.98 vs. -0.12 SD, p<0.001), but similar deficits at the distal radius (-0.45 vs. -0.39 SD, p=0.79). A 1 SD higher tibia intracortical bone surface area was associated with 0.22-0.29 SD higher remodeling markers, about half the 0.53-0.67 SD increment in remodeling markers across menopause (all p<0.001). A 1 SD higher porosity was associated with 0.20-0.30 SD higher remodeling markers. A 1 SD lower trabecular bone surface area was associated with 0.15-0.18 SD higher remodeling markers (all p<0.01). Within-pair differences in intracortical and endocortical bone surface areas at both sites and porosity at the distal tibia were associated with within-pair differences in some remodeling markers (p=0.05 to 0.09). We infer intracortical remodeling may be self perpetuating by creating intracortical porosity and so more bone surface for remodeling to occur upon, while remodeling upon the trabecular bone surface is self limiting because it removes trabeculae with their surface.

A phase 2 trial exploring the effects of high-dose (10,000 IU/day) vitamin D(3) in breast cancer patients with bone metastases

BACKGROUND

Vitamin D deficiency has potential roles in breast cancer etiology and progression. Vitamin D deficiency has also been associated with increased toxicity from bisphosphonate therapy. The optimal dose of vitamin D supplementation is unknown, but daily sunlight exposure can generate the equivalent of a 10,000-IU oral dose of vitamin D(3). This study therefore aimed to assess the effect of this dose of vitamin D(3) in patients with bone metastases from breast cancer.

METHODS

Patients with bone metastases treated with bisphosphonates were enrolled into this single-arm phase 2 study. Patients received 10,000 IU of vitamin D(3) and 1000 mg of calcium supplementation each day for 4 months. The effect of this treatment on palliation, bone resorption markers, calcium metabolism, and toxicity were evaluated at baseline and monthly thereafter.

RESULTS

Forty patients were enrolled. No significant changes in bone resorption markers were seen. Despite no change in global pain scales, there was a significant reduction in the number of sites of pain. A small but statistically significant increase in serum calcium was seen, as was a significant decrease in serum parathyroid hormone. Treatment unmasked 2 cases of primary hyperparathyroidism, but was not associated with direct toxicity.

CONCLUSIONS

Daily doses of 10,000 IU vitamin D(3) for 4 months appear safe in patients without comorbid conditions causing hypersensitivity to vitamin D. Treatment reduced inappropriately elevated parathyroid hormone levels, presumably caused by long-term bisphosphonate use. There did not appear to be a significant palliative benefit nor any significant change in bone resorption.

Urinary levels of pentosidine and the risk of fracture in postmenopausal women: the OFELY study

The aim of the study was to investigate prospectively whether the levels of urinary pentosidine could predict fractures in postmenopausal women from the OFELY cohort. The results of the study suggest that urine pentosidine concentration is not an independent risk factor for fractures in postmenopausal women from a French cohort.

INTRODUCTION

Pentosidine has been described as an independent risk factor for hip and vertebral fracture in postmenopausal Japanese women. We investigated the prediction of urinary pentosidine on all fragility fracture risk in healthy untreated postmenopausal women from the OFELY cohort.

METHODS

Urinary pentosidine was assessed at baseline in 396 healthy untreated postmenopausal women aged 63.3 +/- 8.4 years from the OFELY cohort using high-performance liquid chromatography method. Incident clinical fractures were recorded during annual follow-up and confirmed by radiographs, and vertebral fractures were assessed on radiographs performed every 4 years. Multivariate Cox's regression analysis was used to calculate the risk of urinary pentosidine levels after adjustment for age, prevalent fractures, and total hip bone mineral density (BMD).

RESULTS

During a mean follow-up of 10 years, 88 of the 396 postmenopausal women have undergone incident vertebral (n = 28) and peripheral (n = 60) fractures. Fracture risk was higher in postmenopausal women with pentosidine in the highest quartile (p = 0.02), but it did not remain significant after adjustment for age, BMD, and prevalent fracture.

CONCLUSIONS

Urine pentosidine concentration is not an independent risk factor of osteoporotic fracture in healthy postmenopausal women from the OFELY cohort.

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.

Use of biochemical markers of bone turnover in the management of postmenopausal osteoporosis

BACKGROUND

We currently have guidelines that allow us to use bone densitometry in the diagnosis and management of osteoporosis. The role of biochemical markers of bone turnover (BTMs) is less well defined. Serum and urine BTM patterns in treated and untreated osteoporotic patients have been studied to help us define their role. The aim of this review is to present data which helps elucidate the current role and limitation of BTMs in the management of osteoporosis.

METHOD

A search of the literature on BTMs was performed. References with keywords, such as bone turnover markers, biochemical markers, monitoring therapy and monitoring osteoporosis, were used.

RESULTS

Literature describing the nature and limitation of currently available BTMs was reviewed. The clinical use and limitation of BTMs in assessing fracture risk reduction, bone mineral density (BMD) and response to therapy is available, whereas definitive guidelines have not yet been created.

CONCLUSIONS

BTMs offer a potential non-invasive and reliable way of assessing skeletal activity, studying drug effects and response to therapies, assessing fracture risk and predicting other skeletal parameters, such as bone loss, BMD and bone mass. A 30%-70% reduction in bone resorption markers can be achieved with antiresorptive therapy, and 30%-50% increase in bone formation markers with anabolic therapy. We recommend that clinicians understand and incorporate the measurement of BTMs in the management of osteoporosis.

Biochemical markers of bone turnover: potential use in the investigation and management of postmenopausal osteoporosis

INTRODUCTION

The aim was to analyse data on the use of biochemical bone turnover markers (BTM) in postmenopausal osteoporosis.

METHODS

We carried out a comparative analysis of the most important papers concerning BTM in postmenopausal osteoporosis that have been published recently.

RESULTS

The BTM levels are influenced by several factors. They are moderately correlated with BMD and subsequent bone loss. Increased levels of bone resorption markers are associated with a higher risk of fracture. Changes in the BTM during the anti-osteoporotic treatment (including combination therapy) reflect the mechanisms of action of the drugs and help to establish their effective doses. Changes in the BTM during the anti-resorptive treatment are correlated with their anti-fracture efficacy.

CONCLUSION

Biological samples should be obtained in a standardised way. BTM cannot be used for prediction of the accelerated bone loss at the level of the individual. BTM help to detect postmenopausal women who are at high risk of fracture; however, adequate practical guidelines are lacking. BTM measurements taken during the anti-resorptive therapy help to identify non-compliers. They may improve adherence to the anti-resorptive therapy and the fall in the BTM levels that exceeds the predefined threshold improves patients' persistence with the treatment. There are no guidelines concerning the use of BTM in monitoring anti-osteoporotic therapy in postmenopausal women.

Within-Subject Variability and Analytic Imprecision of Insulinlike Growth Factor Axis and Collagen Markers: Implications for Clinical Diagnosis and Doping Tests

Background: The utility of insulinlike growth factor (IGF) axis and collagen markers for a growth hormone (GH) doping test in sport depends on their stability and reproducibility. We sought to determine short-term within-subject variability of these markers in a large cohort of healthy individuals.

Methods: We measured IGF-I, IGF binding protein 3 (IGFBP-3), acid labile subunit (ALS), and the collagen markers N-terminal propeptide of type I procollagen (PINP), C-terminal telopeptide of type I collagen (ICTP), and N-terminal propeptide of type III procollagen (PIIINP) in serum samples obtained on multiple occasions (median 3 per participant) over a 2- to 3-week period from 1103 elite athletes (699 men, 404 women) ages 22.2 (5.2) years [mean (SD)]. We estimated between-subject and within-subject variances by mixed–effects ANOVA.

Results: Within-subject variance accounted for 32% to 36% and 4% to 13% of the total variance in IGF markers and collagen markers, respectively. The within-subject CV ranged from 11% to 21% for the IGF axis markers and from 13% to 15% for the collagen markers. The index of individuality for the IGF axis markers was 0.66–0.76, and for the collagen markers, 0.26–0.45. For each marker, individuals with initial extreme measured values tended to regress toward the population mean in subsequent repeated measurements. We developed a Bayesian model to estimate the long-term probable value for each marker.

Conclusions: These results indicate that in healthy individuals the within-subject variability was greater for IGF-I than for the collagen markers, and that where a single measurement is available, it is possible to estimate the long-term probable value of each of the markers by applying the Bayesian approach. Such an application can increase the reliability and decrease the cost of detecting GH doping.

Serial assessment of serum bone metabolism markers identifies women with the highest rate of bone loss and osteoporosis risk

CONTEXT

One of the important challenges in the management of osteoporosis is to identify women who are at high risk of developing osteoporosis and fragility fractures.

OBJECTIVE

Our objective was to evaluate whether assessment of bone metabolism at multiple occasions can identify women with the highest risk for bone loss.

DESIGN

The Malmö Osteoporosis Prospective Risk Assessment study is an ongoing longitudinal study. Participants have been evaluated at baseline and after 1, 3, and 5 yr.

SETTING

We conducted a population-based study.

PARTICIPANTS

Participants included 1044 women, all 75 yr old at baseline.

MAIN OUTCOME MEASURES

Seven bone turnover markers were assessed at baseline and at 1, 3, and 5 yr (n = 573). The 5-yr change in areal bone mineral density (aBMD) was also determined.

RESULTS

Baseline markers correlated weakly to change in total body aBMD. The associations were more pronounced when the average of the baseline and 1-yr measurements was used (standardized regression coefficients -0.12 to -0.23, P < 0.01). Adding the 3-yr and 5-yr measurement further strengthened the correlation (regression coefficients up to -0.30, P < 0.001). Women with constantly high turnover lost significantly more bone at total body assessment (-2.6%) than women with intermediate (-1.6%) or low turnover (-0.2%, P for trend < 0.001). They also had a greater decrease in hip BMD (-8.3, -6.0, and -5.1%, respectively, P = 0.010). Results were similar also in the subgroup of women with osteopenia.

CONCLUSIONS

Our results suggest that serial assessment of bone turnover improves the identification of women with the highest rate of bone loss and osteoporosis risk.

Treatment of postmenopausal osteoporosis

Osteoporosis is a skeletal disease characterized by low bone mass and microarchitectural deterioration with a resulting increase in bone fragility and hence susceptibility to fracture. Calcium and vitamin D are the most commonly used therapies for osteoporosis, although their efficacy in osteoporotic fracture prevention remains uncertain. Biphosphonates are the most frequently prescribed medication for treatment of osteoporosis and are often considered as first-line therapy for the treatment of osteoporosis. Currently, hormone replacement therapy is only approved by the Food and Drug Administration (FDA) for short-term treatment of severe postmenopausal symptoms with the lowest dose used for the shortest time. In view of its lack of effect on the prevention of nonvertebral fractures, the use of raloxifene should be limited to women with spinal osteoporosis. Most experts agree that it is preferable to treat osteoporosis with a more potent agent than calcitonin and manage the pain separately. Currently, the FDA recommends the use of parathyroid hormone for treatment of osteoporosis for a maximum of 2 years because of the concern of development of osteosarcoma.

Moderate alcohol consumption and increased bone mineral density: potential ethanol and non-ethanol mechanisms

Mounting epidemiological evidence indicates an association between the moderate ingestion of alcoholic beverages and higher bone mineral density (v. abstainers). More limited findings provide some evidence for translation of this association into reduced fracture risk, but further studies are required. Here, these data are reviewed and caveats in their assimilation, comparison and interpretation as well as in the use and application of bone health indices are discussed. Whilst it is concluded that evidence is now strong for the moderate alcohol-bone health association, at least in relation to bone mineral density, mechanisms are less clear. Both ethanol and non-ethanol components have been implicated as factors that positively affect bone health in the light of moderate consumption of alcoholic beverages, and four particular areas are discussed. First, recent findings suggest that moderate ethanol consumption acutely inhibits bone resorption, in a non-parathyroid hormone- and non-calcitonin-dependent fashion, which can only partly be attributed to an energy effect. Second, critical review of the literature does not support a role for moderate ethanol consumption affecting oestrogen status and leading to a knock-on effect on bone. Third, Si is present at high levels in certain alcoholic beverages, especially beer, and may have a measurable role in promoting bone formation. Fourth, a large body of work indicates that phytochemicals (e.g. polyphenols) from alcoholic beverages could influence bone health, but human data are lacking. With further work it is hoped to be able to model epidemiological observations and provide a clear pathway between the magnitude of association and the relative contribution of these mechanisms for the major classes of alcoholic beverage.

Association of 12 serum biochemical markers of angiogenesis, tumour invasion and bone turnover with bone metastases from breast cancer: a crossectional and longitudinal evaluation

Complex biological pathways including angiogenesis, invasion, osteoclastic activation and bone matrix degradation are involved in the formation of bone metastasis (BM). The aim of our study was to investigate the cross-sectional and longitudinal associations of a panel of 12 serum biochemical markers reflecting biological pathways underlying BM development. In a cross-sectional study, we investigated 29 patients with primary breast carcinoma without BM (BC/BM-), 28 patients with breast carcinoma and BM (BC/BM+) and 15 healthy women. In longitudinal analyses, we investigated 34 patients for whom serum was obtained a two different time points: at the time of primary BC diagnosis and after a median time of 3 years. During this follow-up, 15 patients developed BM, whereas the other 19 remained free of BM. In patients who developed BM, the second samples were obtained before BM was documented by bone scan. The cross-sectional analyses have shown all biochemical markers to be significantly elevated in patients with BM, when compared to the patients without BM and healthy controls, except TGFbeta1 that was significantly decreased. Multivariable analyses showed that only the bone resorption markers TRACP 5b, CTX and ICTP, and the marker of angiogenesis VEGF were independently associated with BM. Those markers correctly distinguished 85% of BC patients with or without BM from normal individuals. Longitudinal analyses showed that patients with primary BC who developed BM during follow-up had higher levels of TRACP5b (+95%, P=0.08) at the time of primary diagnosis, those patients had also a higher increases of ICTP (P=0.006), MMP-7 (P=0.004) and TIMP-1 (P=0.017) during follow-up than patients who did not progress toward bone metastasis. This study provides evidence of increase and interrelationship of circulating markers of angiogenesis, invasion and bone resorption in patients with BC with and without BM. Markers of bone resorption have the highest independent diagnostic value for detecting and potentially predicting BM in breast carcinoma patients.

The effects of antifracture therapies on the components of bone strength: assessment of fracture risk today and in the future

OBJECTIVE

To summarize the current knowledge regarding the impact of the most common antifracture medications on the various determinants of bone strength.

METHODS

Relevant English-language articles acquired from Medline from 1966 to January 2005 were reviewed. Searches included the keywords bone AND 1 of the following: strength, remodeling, microcrack, structure, mineralization, collagen, organic, crystallinity, osteocyte, porosity, diameter, anisotropy, stress risers, or connectivity AND alendronate, estrogen, etidronate, hormone replacement therapy, parathyroid hormone, risedronate, OR teriparatide. Abstracts from relevant conference proceedings were also reviewed for pertinent information.

RESULTS

Antiresorptive therapies increase bone strength through decreasing bone turnover. This lower bone turnover results in a higher mean mineralization and decreases the number of active resorption pits within bone at any given time. These resorption pits are speculated to be areas of focal weakness and a higher number of them would, if all other things were equal, result in greater fragility. Parathyroid hormone therapy increases the rate of bone remodeling, which introduces many resorption pits, but this source of strength loss is thought to be compensated by rapid increases in bone mass.

CONCLUSIONS

Both the antiresorptives, particularly bisphosphonates, and the parathyroid hormone therapy increase bone strength; however, the changes that are elicited to achieve this differ significantly.

Efficacy and tolerability of once-monthly oral ibandronate in postmenopausal osteoporosis: 2 year results from the MOBILE study

BACKGROUND

Reducing bisphosphonate dosing frequency may improve suboptimal adherence to treatment and therefore therapeutic outcomes in postmenopausal osteoporosis. Once-monthly oral ibandronate has been developed to overcome this problem.

OBJECTIVE

To confirm the 1 year results and provide more extensive safety and tolerability information for once-monthly dosing by a 2 year analysis.

METHODS

MOBILE, a randomised, phase III, non-inferiority study, compared the efficacy and safety of once-monthly ibandronate with daily ibandronate, which has previously been shown to reduce vertebral fracture risk in comparison with placebo.

RESULTS

1609 postmenopausal women were randomised. Substantial increases in lumbar spine bone mineral density (BMD) were seen in all treatment arms: 5.0%, 5.3%, 5.6%, and 6.6% in the daily and once-monthly groups (50 + 50 mg, 100 mg, and 150 mg), respectively. It was confirmed that all once-monthly regimens were at least as effective as daily treatment, and in addition, 150 mg was found to be better (p<0.001). Substantial increases in proximal femur (total hip, femoral neck, trochanter) BMD were seen; 150 mg produced the most pronounced effect (p<0.05 versus daily treatment). Independent of the regimen, most participants (70.5-93.5%) achieved increases above baseline in lumbar spine or total hip BMD, or both. Pronounced decreases in the biochemical marker of bone resorption, sCTX, observed in all arms after 3 months, were maintained throughout. The 150 mg regimen consistently produced greater increases in BMD and sCTX suppression than the 100 mg and daily regimens. Ibandronate was well tolerated, with a similar incidence of adverse events across groups.

CONCLUSIONS

Once-monthly oral ibandronate is at least as effective and well tolerated as daily treatment. Once-monthly administration may be more convenient for patients and improve therapeutic adherence, thereby optimising outcomes.

Osteopenia and osteoporosis in patients with HIV: a review of current concepts

Since the advent of potent antiretroviral therapy in combination regimens, multiple epidemiologic studies have shown that osteopenia and osteoporosis are common among patients with HIV infection. However, there remain many areas of uncertainty about this potential complication, which can be confusing for the HIV clinician. This review summarizes the epidemiology, pathophysiology, suggested screening strategies, and management options of decreased bone mineral density in patients with HIV. Our aims are to review the available data, highlight controversial issues, and provide guidance for clinicians where supporting data are unavailable.

What is the role of DXA, QUS and bone markers in fracture prediction, treatment allocation and monitoring?

There is evidence that treatment can decrease the risk of fractures in osteoporotic patients, and screening of these patients is therefore relevant. Diagnosis of osteoporosis is based on the T-score calculated from bone mineral density (BMD) measurements. BMD measurements have been widely used for the management of osteoporosis, and a low BMD is a strong risk factor for fractures. But BMD measurement has several limitations in both diagnosis, prediction of fracture risk, and treatment follow-up. Quantitative ultrasound (QUS) parameters, an alternative to BMD in the assessment of bone, are independent risk factors for osteoporotic fracture. However, the use of QUS cannot be recommended for both allocation and monitoring of treatment. Biochemical markers of bone remodelling can be useful for both prediction of fracture risk and monitoring of treatment if sources of variability are controlled.

Common biochemical markers of bone turnover predict future bone loss: a 5-year follow-up study

BACKGROUND

Bone mineral density (BMD) is used to follow gain or loss of bone mass but cannot detect changes within a short period of time. Biochemical markers of bone turnover may be of value for prediction of individual bone loss.

METHODS

We studied the relation between common inexpensive markers of bone turnover (serum alkaline phosphatase (ALP), osteocalcin (OC), urinary hydroxyproline (OHPr), and calcium (Ca)), BMD, age, and menopause in a combined cross-sectional and longitudinal design comprising 429 pre- and postmenopausal randomly selected women aged 21-79 years (mean 50 years). A follow-up was initiated after 5 years (including 192 of these women), which focused on changes in bone mass and the ability of these four common markers of bone turnover (sampled at baseline) to predict future bone loss.

RESULTS

A marked increase was observed for all markers at the beginning of menopause. During the postmenopausal period ALP and Ca decreased to near premenopausal levels, while OC and OHPr remained high even 15 years after menopause. We also found inverse correlations at baseline between the bone markers and BMD, independent of the selected marker or skeletal site, r=-0.14 to -0.46, P<0.05. The correlations between ALP, OC, OHPr, and subsequent bone loss over 5 years, was significant for arm, r=-0.23 to -0.36, P<0.01. Baseline levels of all bone markers correlated significantly at group level with the 5-year follow-up of BMD for all sites. The ability of markers to predict individual bone loss was estimated by a multivariate regression model, which included baseline BMD, age, and body mass index as independent variables. ROC analysis showed a validity of approximately 76% for the forearm model, but was lower for the hip (55%) and lumbar spine (65%).

CONCLUSIONS

These data show that the common inexpensive biochemical markers of bone turnover ALP, OC, OHPr, and Ca were related to the current bone mass and, moreover, provides information about future bone loss at the individual level. Future investigations should include an evaluation of the clinical relevance of markers of bone turnover in relation to fracture risk.

Treatment with once-weekly alendronate 70 mg compared with once-weekly risedronate 35 mg in women with postmenopausal osteoporosis: a randomized double-blind study

Once-weekly alendronate 70 mg and once-weekly risedronate 35 mg are indicated for the treatment of postmenopausal osteoporosis. These two agents were compared in a 12-month head-to-head trial. Greater gains in BMD and greater reductions in markers of bone turnover were seen with alendronate compared with risedronate with similar tolerability.

INTRODUCTION

The nitrogen-containing bisphosphonates, alendronate and risedronate, are available in once-weekly (OW) formulations for the treatment of postmenopausal osteoporosis. A 12-month, head-to-head study was performed to compare these agents in the treatment of postmenopausal women with low BMD.

MATERIALS AND METHODS

A total of 1053 patients from 78 U.S. sites were randomized to OW alendronate 70 mg (N = 520) or risedronate 35 mg (N = 533), taken in the morning after fasting. Endpoints included BMD changes over 6 and 12 months at the hip trochanter, total hip, femoral neck, and lumbar spine (LS); percent of patients with predefined levels of change in trochanter and LS BMD at 12 months; and change in biochemical markers of bone turnover at 3, 6, and 12 months. Tolerability was evaluated by adverse experience (AE) reporting.

RESULTS

Significantly greater increases in hip trochanter BMD were seen with alendronate (3.4%) than risedronate (2.1%) at 12 months (treatment difference, 1.4%; p < 0.001) as well as 6 months (treatment difference, 1.3%; p < 0.001). Significantly greater gains in BMD were seen with alendronate at all BMD sites measured (12-month difference: total hip, 1.0%; femoral neck, 0.7%; LS, 1.2%). Significant differences were seen as early as 6 months at all sites. A greater percentage of patients had > or =0% (p < 0.001) and > or =3% (p < 0.01) gain in trochanter and spine BMD at 12 months with alendronate than risedronate. Significantly greater (p < 0.001) reductions in all biochemical markers of bone turnover occurred with alendronate compared with risedronate by 3 months. No significant differences were seen between treatment groups in the incidence of upper gastrointestinal AEs or AEs causing discontinuation.

CONCLUSIONS

In this 12-month, head-to-head trial of alendronate and risedronate, given in accordance with the approved OW regimens for treatment of osteoporosis in postmenopausal women, alendronate produced greater gains in BMD and greater reductions in markers of bone turnover than risedronate. The greater antiresorptive effect of alendronate was seen as early as 3 months, and the tolerability profiles were similar.

Association between spine disc degeneration and type II collagen degradation in postmenopausal women: the OFELY study

OBJECTIVE

To investigate whether radiologic spine disc degeneration is associated with increased type II collagen (CII) degradation products in the urine of postmenopausal women, independently of radiologic knee osteoarthritis (OA) and clinical hand OA.

METHODS

The study group comprised 324 postmenopausal women ages 58-94 years who had no treatment or disease that could alter bone metabolism. Lateral radiographs of the thoracic and lumbar spine were obtained in each woman and scored for disc space narrowing (DSN) and osteophytes. Fixed-flexion posteroanterior radiographs of the knee were obtained to assess femorotibial knee OA. In all women, hand OA was assessed by clinical examination, and the level of urinary C-terminal crosslinking telopeptide of CII (CTX-II), a biologic marker of CII degradation, was measured.

RESULTS

The prevalences of radiographic lumbar and thoracic spine disc degeneration, knee OA, and clinical hand OA were 84%, 88%, 35%, and 58%, respectively. After adjustment for age and body mass index (BMI), patients with lumbar spine DSN grade > or = 1 had, on average, 34% higher CTX-II levels compared with the other women (P = 0.0005), whereas no association was observed with lumbar spine osteophytes. No significant association between thoracic spine DSN or osteophytes and urinary CTX-II levels was observed. Multivariate analysis of variance showed that, after adjustment for age and BMI, lumbar spine DSN (P = 0.0049), knee OA (P = 0.0055), and clinical hand OA (P = 0.0060) were, independently of each other, associated with CTX-II levels. Thus, patients with lumbar spine DSN, knee OA, and clinical hand OA had CTX-II levels 80% higher (P < 0.0001 after adjustment for age and BMI) than those of patients with no lumbar spine DSN, no radiologic knee OA, and no clinical hand OA.

CONCLUSION

Postmenopausal women with lumbar spine disc degeneration are characterized by increased CII degradation. The contribution of lumbar spine DSN to CII degradation was similar to, and independent of, the contribution of radiologic knee OA or clinical hand OA. Lumbar spine disc degeneration in elderly patients should be assessed when analyzing levels of CTX-II in studies of knee, hip, and hand OA.

Once-weekly alendronate 70 mg and raloxifene 60 mg daily in the treatment of postmenopausal osteoporosis*

OBJECTIVE

To compare the efficacy and tolerability of once-weekly (OW) alendronate (ALN) 70 mg and raloxifene (RLX) 60 mg daily in the treatment of postmenopausal osteoporosis.

DESIGN

This 12-month, randomized, double-blind study enrolled 456 postmenopausal women with osteoporosis (223 ALN, 233 RLX) at 52 sites in the United States. Efficacy measurements included lumbar spine (LS), total hip, and trochanter bone mineral density (BMD) at 6 and 12 months, biochemical markers of bone turnover, and percent of women who maintained or gained BMD in response to treatment. The primary endpoint was percent change from baseline in LS BMD at 12 months. Adverse experiences were recorded to assess treatment safety and tolerability.

RESULTS

Over 12 months, OW ALN produced a significantly greater increase in LS BMD (4.4%, P < 0.001) than RLX (1.9%). The percentage of women with > or = 0% increase in LS BMD (ALN, 94%; RLX, 75%; P < 0.001) and > or =3% increase in LS BMD (ALN, 66%; RLX, 38%; P < 0.001) were significantly greater with ALN than RLX. Total hip and trochanter BMD increases were also significantly greater (P < or =0.001) with ALN. Greater (P < 0.001) reductions in N-telopeptide of type I collagen and bone-specific alkaline phosphatase were achieved with ALN compared with RLX at 6 and 12 months. No significant differences in the incidence of upper gastrointestinal or vasomotor adverse experiences were seen.

CONCLUSION

ALN 70 mg OW produced significantly greater increases in spine and hip BMD and greater reductions in markers of bone turnover than RLX over 12 months. A greater percentage of women maintained or gained BMD on ALN than RLX. Both medications had similar safety and tolerability profiles.