Rates of change in bone mineral density of the spine, heel, femoral neck and radius in healthy postmenopausal women

Assessment of age-dependent sexual dimorphism in paediatric vertebral size and density using a statistical shape and statistical appearance modelling approach

This work focuses on the growth patterns of the human fourth lumbar vertebra (L4) in a paediatric population, with specific attention to sexual dimorphism. The study aims to understand morphological and density changes in the vertebrae through age-dependent statistical shape and statistical appearance models, which can describe full three-dimensional anatomy. Results show that the main growth patterns are associated with isotropic volumetric vertebral growth, a decrease in the relative size of the vertebral foramen, and an increase in the length of the transverse processes. Moreover, significant sexual dimorphism was demonstrated during puberty. We observe significant age and sex interaction in the anterior vertebral body height (P = 0.005), where females exhibited an earlier increase in rates of vertebral height evolution. Moreover, we also observe an increase in cross-sectional area (CSA) with age (P = 0.020), where the CSA is smaller in females than in males (significant sex effect P = 0.042). Finally, although no significant increase in trabecular bone density with age is observed (P = 0.363), a trend in the statistical appearance model suggests an increase in density with age.

Playing basketball and volleyball during adolescence is associated with higher bone mineral density in old age: the Bunkyo Health Study

Introduction: Exercise is beneficial for increasing areal bone mineral density (aBMD) in adolescence and maintaining it in old age. Moreover, high-impact sports are more effective than low-impact sports in increasing aBMD. This study aimed to determine the types of adolescent sports played in school-based sports clubs associated with aBMD in old age. Methods: In total, 1,596 older adults (681 men and 915 women, age: 65-84 years) living in an urban area of Japan were evaluated for the femoral neck and lumbar spine aBMD using dual-energy X-ray absorptiometry. The association between adolescent sports played in sports clubs and aBMD in old age was analyzed using multiple regression analysis, with femoral neck and lumbar spine aBMD as dependent variables, and sports type and participant characteristics such as age, body weight, and serum 25-hydroxyvitamin D [25(OH)D] level, as independent variables. Results: For the femoral neck, basketball was associated with aBMD in older men (β = 0.079, p < 0.05) and women (β = 0.08, p < 0.01), whereas current body weight and 25(OH)D level were associated with aBMD in both sexes. For the lumbar spine, volleyball (β = 0.08, p < 0.01) and swimming (β = 0.06, p < 0.05) was significantly associated with lumbar spine aBMD, whereas current body weight, 25(OH)D, and diabetes mellitus were associated with aBMD in older women. Conclusion: Both men and women who played basketball in adolescence had higher femoral neck aBMD in old age. Moreover, women who played volleyball in adolescence had higher lumbar spine aBMD in old age.

The use of alkaline phosphatase as a bone turnover marker after spinal cord injury: A scoping review of human and animal studies

BACKGROUND

Serum alkaline phosphatase (ALP) is measured as an indicator of bone or liver disease. Bone-specific alkaline phosphatase (B-ALP) is an isoform of ALP found in the bone tissue which can predict fractures and heterotopic ossification.

OBJECTIVE

The aim of this scoping review was to explore the current use of ALP and B-ALP in studies using humans or animal models of SCI, and to identify ways to advance future research using ALP and B-ALP as a bone marker after SCI.

RESULTS

HUMAN STUDIES: 42 studies were included. The evidence regarding changes or differences in ALP levels in individuals with SCI compared to controls is conflicting. For example, a negative correlation between B-ALP and total femur BMD was observed in only one of three studies examining the association. B-ALP seemed to increase after administration of teriparatide, and to decrease after treatment with denosumab. The effects of exercise on ALP and B-ALP levels are heterogeneous and depend on the type of exercise performed. ANIMAL STUDIES: 11 studies were included. There is uncertainty regarding the response of ALP or B-ALP levels after SCI; levels increased after some interventions, including vibration protocols, curcumin supplementation, cycles in electromagnetic field or hyperbaric chamber. Calcitonin or bisphosphonate administration did not affect ALP levels.

CONCLUSION

Researchers are encouraged to measure the bone-specific isoform of ALP rather than total ALP in future studies in humans of animal models of SCI.

Characteristics of Long-Term Femoral Neck Bone Loss in Postmenopausal Women: A 25-Year Follow-Up

The aim of this study was to monitor long-term changes in bone mineral density (BMD) after menopause and factors affecting BMD. The study population consisted of a random sample of 3222 women from the Kuopio Osteoporosis Risk Factor and Prevention (OSTPRE) study, of which 62.1% were postmenopausal at the beginning of the study. This group of women underwent dual-energy X-ray absorptiometry (DXA) measurements at the femoral neck every 5 years from baseline (in 1989) up to 25-year follow-up. They also responded to risk-factor questionnaires at 5-year intervals. During the 25-year follow-up, the baseline cohort decreased to 686 women. The women were divided into quartiles based on their baseline BMD. Self-reported hormone replacement therapy (HRT) and corticosteroid use were divided into ever users and never users. Morbidity was assessed as the total number of self-reported diseases and BMD-affecting diseases. The mean 25-year BMD change was found to be -10.1%, p < 0.001. Higher baseline BMD was associated with higher bone loss rate; the reduction in the highest quartile BMD was 11.1% and in the lowest quartile 7.4% (p = 0.0031). Lower baseline body mass index (BMI) and a greater increase in BMI were found to protect against postmenopausal bone loss (p < 0.001). The lowest bone loss quartile included 15.2% more HRT users than the highest bone loss quartile (p = 0.004). The number of diseases/bone-affecting diseases, use of vitamin D/calcium supplementation, use of corticosteroids, smoking or alcohol use had no statistical significance for annual bone loss rate. This study presents hitherto the longest (25-year) BMD follow-up in postmenopausal women. The linear femoral neck bone loss of 10% was less than previously assumed. A 5-year BMD change appeared to predict long-term bone loss in postmenopausal women. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Study of the combined effects of PTH treatment and mechanical loading in postmenopausal osteoporosis using a new mechanistic PK-PD model

One of only a few approved and available anabolic treatments for severe osteoporosis is daily injections of PTH (1-34). This drug has a specific dual action which can act either anabolically or catabolically depending on the type of administration, i.e. intermittent or continuous, respectively. In this paper, we present a mechanistic pharmacokinetic-pharmacodynamic model of the action of PTH in postmenopausal osteoporosis. This model accounts for anabolic and catabolic activities in bone remodelling under intermittent and continuous administration of PTH. The model predicts evolution of common bone biomarkers and bone volume fraction (BV/TV) over time. We compared the relative changes in BV/TV resulting from a daily injection of 20 [Formula: see text]g of PTH with experimental data from the literature. Simulation results indicate a site-specific bone gain of 8.66[Formula: see text] (9.4 ± 1.13[Formula: see text]) at the lumbar spine and 3.14[Formula: see text] (2.82 ± 0.72[Formula: see text]) at the femoral neck. Bone gain depends nonlinearly on the administered dose, being, respectively, 0.68[Formula: see text], 3.4[Formula: see text] and 6.16[Formula: see text] for a 10, 20 and 40 [Formula: see text]g PTH dose at the FN over 2 years. Simulations were performed also taking into account a bone mechanical disuse to reproduce elderly frail subjects. The results show that mechanical disuse ablates the effects of PTH and leads to a 1.08% reduction of bone gain at the FN over a 2-year treatment period for the 20 [Formula: see text]g of PTH. The developed model can simulate a range of pathological conditions and treatments in bones including different PTH doses, different mechanical loading environments and combinations. Consequently, the model can be used for testing and generating hypotheses related to synergistic action between PTH treatment and physical activity.

Connexin 43 hemichannels protect bone loss during estrogen deficiency

Estrogen deficiency in postmenopausal women is a major cause of bone loss, resulting in osteopenia, osteoporosis, and a high risk for bone fracture. Connexin 43 (Cx43) hemichannels (HCs) in osteocytes play an important role in osteocyte viability, bone formation, and remodeling. We showed here that estrogen deficiency reduced Cx43 expression and HC function. To determine if functional HCs protect osteocytes and bone loss during estrogen deficiency, we adopted an ovariectomy model in wild-type (WT) and two transgenic Cx43 mice: R76W (dominant-negative mutant inhibiting only gap junction channels) and Cx43 Δ130–136 (dominant-negative mutant compromising both gap junction channels and HCs). The bone mineral density (BMD), bone structure, and histomorphometric changes of cortical and trabecular bones after ovariectomy were investigated. Our results showed that the Δ130–136 transgenic cohort had greatly decreased vertebral trabecular bone mass compared to WT and R76W mice, associated with a significant increase in the number of apoptotic osteocyte and empty lacunae. Moreover, osteoclast surfaces in trabecular and cortical bones were increased after ovariectomy in the R76W and WT mice, respectively, but not in ∆130–136 mice. These data demonstrate that impairment of Cx43 HCs in osteocytes accelerates vertebral trabecular bone loss and increase in osteocyte apoptosis, and further suggest that Cx43 HCs in osteocytes protect trabecular bone against catabolic effects due to estrogen deficiency.

Channels that form between cells and their extracellular environment help protect bone tissue from the damage wrought by low estrogen levels, a major cause of bone loss in post-menopausal women. Jean Jiang from the UT Health San Antonio and colleagues showed that depleting the estrogen hormone in mouse bone cells reduced levels of connexin 43 and impaired the protein’s ability to forms pores known as ‘hemichannels’. The researchers surgically removed the ovaries of various mouse strains to induce estrogen deficiencies. They found that transgenic mice without working hemichannels had reduced bone mass compared to normal mice or mice that could make hemichannels but lacked the ability for those channels to come together to form complete passageways. The findings highlight the importance of connexin 43 hemichannels in protecting bone tissue against osteoporosis.

A Cross-Sectional Study of the Association between Autoantibodies and Qualitative Ultrasound Index of Bone in an Elderly Sample without Clinical Autoimmune Disease

Bone loss is characteristic of the ageing process and a common complication of many autoimmune diseases. Research has highlighted a potential role of autoantibodies in pathologic bone loss. The confounding effects of immunomodulatory drugs make it difficult to establish the contribution of autoantibodies amongst autoimmune disease sufferers. We attempted to examine the relationship between autoantibodies and bone mass in a population of 2812 elderly participants without clinical autoimmune disease. Serum samples were assayed for a panel of autoantibodies (anti-nuclear, extractable nuclear antigen, anti-neutrophil cytoplasmic, thyroid peroxidase, tissue transglutaminase, anti-cardiolipin, rheumatoid factor, and cyclic citrullinated peptide). Bone mass was measured using quantitative ultrasound (QUS) of the calcaneus. The relationship between each autoantibody and bone mass was determined using linear regression models. Anti-nuclear autoantibodies were the most prevalent, positive in approximately 11%, and borderline in roughly 23% of our sample. They were also the only autoantibody observed to be significantly associated with QUS index in the univariate analysis (n = 1628; r = -0.20; 95% CI: -0.40-0.00; p = 0.046). However, statistical significance was lost after adjustment for various other potential confounders. None of the other autoantibodies was associated with QUS index in either univariate or multivariate analysis. We are limited by the cross-sectional nature of the study and the low prevalence of autoantibodies in our nonclinical sample.

A systematic review and economic evaluation of bisphosphonates for the prevention of fragility fractures

BACKGROUND

Fragility fractures are fractures that result from mechanical forces that would not ordinarily result in fracture.

OBJECTIVES

To evaluate the clinical effectiveness and safety of bisphosphonates [alendronic acid (Fosamax^® and Fosamax^® Once Weekly, Merck Sharp & Dohme Ltd), risedronic acid (Actonel^® and Actonel Once a Week^®, Warner Chilcott UK Ltd), ibandronic acid (Bonviva^®, Roche Products Ltd) and zoledronic acid (Aclasta^®, Novartis Pharmaceuticals UK Ltd)] for the prevention of fragility fracture and to assess their cost-effectiveness at varying levels of fracture risk.

DATA SOURCES

For the clinical effectiveness review, six electronic databases and two trial registries were searched: MEDLINE, EMBASE, The Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, Web of Science and BIOSIS Previews, Clinicaltrials.gov and World Health Organization International Clinical Trials Registry Platform. Searches were limited by date from 2008 until September 2014.

REVIEW METHODS

A systematic review and network meta-analysis (NMA) of effectiveness studies were conducted. A review of published economic analyses was undertaken and a de novo health economic model was constructed. Discrete event simulation was used to estimate lifetime costs and quality-adjusted life-years (QALYs) for each bisphosphonate treatment strategy and a strategy of no treatment for a simulated cohort of patients with heterogeneous characteristics. The model was populated with effectiveness evidence from the systematic review and NMA. All other parameters were estimated from published sources. A NHS and Personal Social Services perspective was taken, and costs and benefits were discounted at 3.5% per annum. Fracture risk was estimated from patient characteristics using the QFracture^® (QFracture-2012 open source revision 38, Clinrisk Ltd, Leeds, UK) and FRAX^® (web version 3.9, University of Sheffield, Sheffield, UK) tools. The relationship between fracture risk and incremental net benefit (INB) was estimated using non-parametric regression. Probabilistic sensitivity analysis (PSA) and scenario analyses were used to assess uncertainty.

RESULTS

Forty-six randomised controlled trials (RCTs) were included in the clinical effectiveness systematic review, with 27 RCTs providing data for the fracture NMA and 35 RCTs providing data for the femoral neck bone mineral density (BMD) NMA. All treatments had beneficial effects on fractures versus placebo, with hazard ratios varying from 0.41 to 0.92 depending on treatment and fracture type. The effects on vertebral fractures and percentage change in BMD were statistically significant for all treatments. There was no evidence of a difference in effect on fractures between bisphosphonates. A statistically significant difference in the incidence of influenza-like symptoms was identified from the RCTs for zoledronic acid compared with placebo. Reviews of observational studies suggest that upper gastrointestinal symptoms are frequently reported in the first month of oral bisphosphonate treatment, but pooled analyses of placebo-controlled trials found no statistically significant difference. A strategy of no treatment was estimated to have the maximum INB for patients with a 10-year QFracture risk under 1.5%, whereas oral bisphosphonates provided maximum INB at higher levels of risk. However, the PSA suggested that there is considerable uncertainty regarding whether or not no treatment is the optimal strategy until the QFracture score is around 5.5%. In the model using FRAX, the mean INBs were positive for all oral bisphosphonate treatments across all risk categories. Intravenous bisphosphonates were estimated to have lower INBs than oral bisphosphonates across all levels of fracture risk when estimated using either QFracture or FRAX.

LIMITATIONS

We assumed that all treatment strategies are viable alternatives across the whole population.

CONCLUSIONS

Bisphosphonates are effective in preventing fragility fractures. However, the benefit-to-risk ratio in the lowest-risk patients may be debatable given the low absolute QALY gains and the potential for adverse events. We plan to extend the analysis to include non-bisphosphonate therapies.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013006883.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

The 24,25 to 25-hydroxyvitamin D ratio and fracture risk in older adults: The cardiovascular health study

25-hydroxyvitamin D [25(OH)D] may not optimally indicate vitamin D receptor activity. Higher concentrations of its catabolic product 24,25-dihydroxyvitmin D [24,25(OH)₂D] and a higher ratio of 24,25(OH)₂D to 25(OH)D (the vitamin D metabolite ratio [VMR]) may provide additional information on receptor activity. We compared the strength of associations of these markers with serum PTH concentrations, hip bone mineral density (BMD), and risk of incident hip fracture in community-living older participants in the Cardiovascular Health Study. Among 890 participants, the mean age was 78years, 60% were women, and the mean 25(OH)D was 28±11ng/ml. In cross-sectional analysis, the strength of association of each vitamin D measure with PTH was similar; a 1% higher 25(OH)D, 24,25(OH)₂D, and VMR were associated with 0.32%, 0.25%, and 0.26% lower PTH, respectively (p<0.05 for all). Among 358 participants with available BMD data, we found no associations of 25(OH)D or VMR with BMD, whereas higher 24,25(OH)₂D was modestly associated with greater hip BMD (1% higher 24,25(OH)₂D associated with 0.04% [95% CI 0.01-0.08%] higher BMD). Risk of incident hip fracture risk was evaluated using a case-cohort design. There were 289 hip fractures during a mean follow up time of 8.4years. Both higher 24,25(OH)₂D and VMR were associated with lower risk of hip fracture (HR per SD higher, 0.73 [0.61, 0.87] and 0.74 [0.61, 0.88], respectively) whereas 25(OH)D was not associated with hip fracture (HR 0.93 [0.79, 1.10]). We conclude that evaluating vitamin D status by incorporating assessment of 24,25(OH)D and the VMR provides information on bone health above and beyond 25(OH)D alone.

Principal component analysis of three-dimensional face shape: Identifying shape features that change with age

BACKGROUND

The types of shape feature that constitutes a face have not been comprehensively established, and most previous studies of age-related changes in facial shape have focused on individual characteristics, such as wrinkle, sagging skin, etc. In this study, we quantitatively measured differences in face shape between individuals and investigated how shape features changed with age.

METHODS

We analyzed three-dimensionally the faces of 280 Japanese women aged 20-69 years and used principal component analysis to establish the shape features that characterized individual differences. We also evaluated the relationships between each feature and age, clarifying the shape features characteristic of different age groups.

RESULTS

Changes in facial shape in middle age were a decreased volume of the upper face and increased volume of the whole cheeks and around the chin. Changes in older people were an increased volume of the lower cheeks and around the chin, sagging skin, and jaw distortion.

CONCLUSION

Principal component analysis was effective for identifying facial shape features that represent individual and age-related differences. This method allowed straightforward measurements, such as the increase or decrease in cheeks caused by soft tissue changes or skeletal-based changes to the forehead or jaw, simply by acquiring three-dimensional facial images.

Similarities in acquired factors related to postmenopausal osteoporosis and sarcopenia

Postmenopausal population is at increased risk of musculoskeletal impairments. Sarcopenia and osteoporosis are associated with significant morbidity and social and health-care costs. These two conditions are uniquely linked with similarities in pathophysiology and diagnostic methods. Uniform diagnostic criteria for sarcopenia are still evolving. Postmenopausal sarcopenia and osteoporosis share many environmental risk- and preventive factors. Moreover, geriatric frailty syndrome may result from interaction of osteoporosis and sarcopenia and may lead to increased mortality. The present paper reviews the factors in evolution of postmenopausal sarcopenia and osteoporosis.

Improved precision with Hologic Apex software

The precision of Hologic Apex v2.0 analysis software is significantly improved from Hologic Delphi v11.2 software and is comparable to GE Lunar Prodigy v7.5 software. Apex and Delphi precisions were, respectively, 1.0% vs. 1.2% (L1-L4 spine), 1.l % vs. 1.3% (total femur), 1.6% vs. 1.9% (femoral neck), and 0.7% vs. 0.9% (dual total femur).

INTRODUCTION

Precision of bone mineral density (BMD) measurements by dual-energy X-ray absorptiometry (DXA) is known to vary by manufacturer, model, and technologist. This study evaluated the precision of three analysis versions: Apex v2.0 and Delphi v11.2 (Hologic, Inc.), and Prodigy v7.5 (GE Healthcare, Inc.) independent of technologist skill.

METHODS

Duplicate spine and dual hip scans on 90 women were acquired on both Delphi and Prodigy DXA systems at three clinics. BMD measures were converted to standardized BMD (sBMD) units. Precision errors were described as a root-mean-square (RMS) standard deviations and RMS percent coefficients of variation across the population.

RESULTS

Apex and Delphi values were highly correlated (r ranged from 0.90 to 0.99). Excluding the right neck, the Apex precision error was found to be 20% to 25% lower than the Delphi (spine: 1.0% versus 1.2% (p < 0.05), total hip: 1.1% versus 1.3% (p < 0.05), right neck: 2.3% versus 2.6% (p > 0.1)). No statistically significant differences were found in the precision error of the Apex and Prodigy (p > 0.05) except for the right neck (2.3% versus 1.8% respectively, p = 0.03).

CONCLUSION

The Apex software has significantly lower precision error compared to Delphi software with similar mean values, and similar precision to that of the Prodigy.

Oral bioavailability and bone-sparing effects of estetrol in an osteoporosis model

OBJECTIVES

To measure the oral bioavailability of estetrol (E(4)) in rats relative to its subcutaneous administration and to test the bone-sparing effect of oral E(4) compared to that of ethinylestradiol (EE).

METHODS

In the bioavailability study, E(4) was administered as a single dose of 0.05, 0.5 or 5.0 mg/kg orally or subcutaneously to female rats. Plasma was analyzed using an LC-MS/MS method. The bone study was conducted in 3-month-old female rats assigned to the following seven treatment groups of ten animals each: no treatment; sham-operated + vehicle; bilaterally ovariectomized (OVX) + vehicle; OVX + E(4) 0.1, 0.5, or 2.5 mg/kg/day and OVX + EE 0.1 mg/kg/day. Once-daily treatment by oral gavage was given for 4 weeks and the following measurements were performed: serum osteocalcin, bone mineral density, bone mineral content and bone mineral area of lumbar vertebrae L3-L6, peripheral quantitative computed tomography of the left tibiae and the biomechanical properties of the distal femora.

RESULTS

Oral bioavailability of E(4), relative to that of subcutaneous dosing, was 70% and above at the 0.05 and 0.5 mg/kg doses based on the AUC(0-t last). Subcutaneous dosing provided significantly higher E(4) levels at the 1-h time point only, and was comparable to oral dosing after 0.5, 2, 4 and 8 h. In the bone study, E(4) dose-dependently and significantly (1) inhibited the OVX-related increase in osteocalcin levels, (2) increased bone mineral density and content, and (3) increased bone strength, all attenuated by ovariectomy. In this rat model, the relative potency of the highest dose of E(4) (2.5 mg/kg/day) was comparable to the EE dose, used as positive control.

CONCLUSIONS

Estetrol exhibits high oral bioavailability in the rat, a species considered relevant for pharmacological studies that are predictive for effects on human bone. Oral administration of E(4) conveys dose-dependent bone-sparing effects of high-quality bone in estrogen-depleted OVX rats. Based on its bone-sparing effects, its oral bioavailability and its preclinical safety and efficacy profile, E(4) may be superior to other estrogens and is a potential drug for the prevention of osteoporosis in postmenopausal women.

The magnitude and rate of bone loss in ovariectomized mice differs among inbred strains as determined by longitudinal in vivo micro-computed tomography

Osteoporosis is characterized by low bone mass and a deterioration of bone architecture and likely is influenced by genetic factors. The ovariectomized (OVX) mouse is well suited for osteoporosis research, as shown to date by cross-sectional studies. Here, we investigate longitudinal changes by in vivo micro-computed tomography (micro-CT) to examine the skeletal response to OVX and patterns of change in three inbred strains of mice. We address whether higher baseline bone mass among the strains of mice provides protection against bone loss and if there is a common base level of bone quantity despite genetic background after the effects of OVX have stabilized. Groups of mice (n = 7 or 8/group) from three inbred strains (C3H/HeJ, C57BL/6J, BALB/cByJ) were subjected to OVX or sham OVX surgery at 12 weeks of age. Weekly in vivo micro-CT scans were performed for 5 weeks at the proximal tibia (skipping week 4). Femurs were harvested after week 5 for analysis of the distal metaphysis and midshaft. The baseline bone architecture differed among the three inbred strains of mice, as did the longitudinal patterns of change due to OVX. At the end point, all three strains retained different bone architecture at the proximal tibia, distal femur, and femur midshaft. Rate of bone loss was correlated to amount of baseline bone volume (R = 0.82, P < 0.001). Morphological analysis indicated that trabecular bone loss due to OVX was manifested through reduced connectivity instead of overall thinning and that the quantity and rate of bone loss due to estrogen deficiency were in part genetically regulated.

Two-year randomized controlled trial of vitamin K1 (phylloquinone) and vitamin D3 plus calcium on the bone health of older women

Dietary supplementation with vitamin K(1), with vitamin D(3) and calcium or their combination, was examined in healthy older women during a 2-year, double-blind, placebo-controlled trial. Combined vitamin K with vitamin D plus calcium was associated with a modest but significant increase in BMC at the ultradistal radius but not at other sites in the hip or radius.

INTRODUCTION

The putative beneficial role of high dietary vitamin K(1) (phylloquinone) on BMD and the possibility of interactive benefits with vitamin D were studied in a 2-year double-blind, placebo-controlled trial in healthy Scottish women > or =60 years of age.

MATERIALS AND METHODS

Healthy, nonosteoporotic women (n = 244) were randomized to receive either (1) placebo, (2) 200 microg/day vitamin K(1), (3) 10 microg (400 IU) vitamin D(3) plus 1000 mg calcium/day, or (4) combined vitamins K(1) and D(3) plus calcium. Baseline and 6-month measurements included DXA bone mineral scans of the hip and wrist, markers of bone turnover, and vitamin status. Supplementation effects were tested using multivariate general linear modeling, with full adjustment for baseline and potential confounding variables.

RESULTS

Significant bone mineral loss was seen only at the mid-distal radius but with no significant difference between groups. However, women who took combined vitamin K and vitamin D plus calcium showed a significant and sustained increase in both BMD and BMC at the site of the ultradistal radius. Serum status indicators responded significantly to respective supplementation with vitamins K and D. Over 2 years, serum vitamin K(1) increased by 157% (p < 0.001), the percentage of undercarboxylated osteocalcin (%GluOC) decreased by 51% (p < 0.001), serum 25-hydroxyvitamin D [25(OH)D] increased by 17% (p < 0.001), and PTH decreased by 11% (p = 0.049).

CONCLUSIONS

These results provide evidence of a modest synergy in healthy older women from nutritionally relevant intakes of vitamin K(1) together with supplements of calcium plus moderate vitamin D(3) to enhance BMC at the ultradistal radius, a site consisting of principally trabecular bone. The substantial increase in gamma-carboxylation of osteocalcin by vitamin K may have long-term benefits and is potentially achievable by increased dietary intakes of vitamin K rather than by supplementation.

Measurement of spinal bone mineral density on a Hologic Discovery DXA scanner with and without leg elevation

Although it is generally recommended that patients keep their hips flexed by 90 degrees during the measurement of spinal bone mineral density (BMD), there is no uniform agreement among the manufacturers of dual-energy X-ray absorptiometry (DXA) scanners regarding the positioning of legs while scanning the spine. We measured spinal BMD in 54 postmenopausal women, from L1 to L4 in posterior-anterior projection, using a Hologic Discovery scanner, first with their legs elevated as recommended by the manufacturer and then with their legs flat on the scanning table. Differences of bone mineral content (BMC), area of the region of interest (ROI), BMD, and T-score of the total spine between the 2 scans were compared. The mean (SD) age of the women was 54.3 yr (15 yr). Between the 2 scans, BMC, area of the ROI, BMD, and T-scores showed high correlations (r=0.98, 0.94, 0.99, and 0.99, respectively). BMC and the area of the ROI changed significantly between the 2 scans, but the changes of BMD and T-scores were not significant. The percentage changes of BMC and the area of the ROI were similar (2.6% and 2.4%, respectively), whereas T-scores showed no change and change of BMD was only 0.6%. The absolute difference in BMD between the 2 scans was only 0.005 (p=0.09). When spinal BMD was measured with their legs elevated, 31 women were found to have osteoporosis and further 13 were found to have osteopenia. When spinal BMD was measured with their legs flat, 32 women were found to have osteoporosis and further 12 were found to have osteopenia. In conclusion, no clinically or statistically significant difference in the total spinal BMD was found when the BMD in a group of women was measured on a Hologic Discovery DXA scanner with their legs positioned flat.

Smokeless tobacco use accelerates age-related loss of bone mineral density among older women in a multi-ethnic rural community

Cigarette smoking is a recognized risk factor for low bone mineral density (BMD) and osteoporosis. Despite the prevalence of smokeless tobacco (ST) use by women in some areas of the United States, minority groups in the United Kingdom, and populations in South Asia and Africa, no data exist to evaluate its effect on bone health. The objective of the study is to identify risk factors for low BMD among older women in a multi-ethnic population, with particular attention to smoking and ST use. Data were collected in Robeson County, North Carolina. ST use from childhood is common among women in this community. Two hundred-forty women aged 60 years and older (approximately equal numbers of African Americans, Native Americans and whites) were recruited at a variety of community events to obtain a cross-section of the demographic composition of the county. The main outcome was BMD measured in the heel using a portable dual energy x-ray absorptiometry. Twenty-nine percent of women were current or former smokers, and 26% current or former ST users. Increased BMD was predicted by greater body mass index, estrogen use in the past year, and African American and Native American ethnicity. There was a significant interaction between ST use and age, and between smoking and nutritional supplement use. BMD declined with age; the decline with age was greater for women who were current or former ST users than for those who never used ST. Women who formerly smoked and did not use supplements had a decreased BMD. ST should be considered as an additional risk factor for osteoporosis in populations where its use is prevalent.

Association of grip strength change with menopausal bone loss and related fractures: a population-based follow-up study

The aim of the present study was to investigate the association between grip strength change and bone health according to menopausal status. A random sample of 971 pre- to postmenopausal women from the Kuopio Osteoporosis Risk Factor and Prevention (OSTPRE) study cohort was measured with dual X-ray absorptiometry in the lumbar spine (LS) and femoral neck (FN) and grip strength with pneumatic squeeze dynamometer at baseline (1989-1991), 5 years (1994-1997), and 10 years (1999-2001). Fractures were recorded based on self-reports and validated from medical records. Women were divided into two groups according to change in grip strength quartile from baseline to 5-year follow-up: not improved (n = 735) and improved (n = 236). In the total population, the greatest bone loss was observed in perimenopausal (beginning of menopause during follow-up, n = 311) women [P < 0.001 vs. premenopausal women (n = 139)], and it declined in postmenopausal (n = 521) women [P < 0.001 by analysis of covariance (ANCOVA)]. The perimenopausal bone loss rate was significantly lower in women in the improved group in comparison to the not improved group (P < 0.01) in contrast to the pre- and postmenopausal groups (P > 0.05). Accordingly, there was a greater decline in perimenopausal LS and FN T-scores in the improved group vs. the not improved group over the first 5-year follow-up interval (P < 0.05 by ANCOVA) and remained unchanged over the 10-year follow-up. In perimenopausal women, there was a trend toward higher fracture-free survival rate in the improved group (82%) vs. the not improved group (88%) after 10 years. Adjustments did not change the results. In conclusion, maintenance of grip strength is associated with menopausal bone loss and future fractures.

Ovariectomy-induced bone loss varies among inbred strains of mice

There is a subset of women who experience particularly rapid bone loss during and after the menopause. However, the factors that lead to this enhanced bone loss remain obscure. We show that patterns of bone loss after ovariectomy vary among inbred strains of mice, providing evidence that there may be genetic regulation of bone loss induced by estrogen deficiency.

INTRODUCTION

Both low BMD and increased rate of bone loss are risk factors for fracture. Bone loss during and after the menopause is influenced by multiple hormonal factors. However, specific determinants of the rate of bone loss are poorly understood, although it has been suggested that genetic factors may play a role. We tested whether genetic factors may modulate bone loss subsequent to estrogen deficiency by comparing the skeletal response to ovariectomy in inbred strains of mice.

MATERIALS AND METHODS

Four-month-old mice from five inbred mouse strains (C3H/HeJ, BALB/cByJ, CAST/EiJ, DBA2/J, and C57BL/6J) underwent ovariectomy (OVX) or sham-OVX surgery (n = 6-9/group). After 1 month, mice were killed, and microCT was used to compare cortical and trabecular bone response to OVX.

RESULTS

The effect of OVX on trabecular bone varied with mouse strain and skeletal site. Vertebral trabecular bone volume (BV/TV) declined after OVX in all strains (-15 to -24%), except for C3H/HeJ. In contrast, at the proximal tibia, C3H/HeJ mice had a greater decline in trabecular BV/TV (-39%) than C57BL/6J (-18%), DBA2/J (-23%), and CAST/EiJ mice (-21%). OVX induced declines in cortical bone properties, but in contrast to trabecular bone, the effect of OVX did not vary by mouse strain. The extent of trabecular bone loss was greatest in those mice with highest trabecular BV/TV at baseline, whereas cortical bone loss was lowest among those with high cortical bone parameters at baseline.

CONCLUSIONS

We found that the skeletal response to OVX varies in a site- and compartment-specific fashion among inbred mouse strains, providing support for the hypothesis that bone loss during and after the menopause is partly genetically regulated.

Trabecular bone is more deteriorated in spinal cord injured versus estrogen-free postmenopausal women

The prevalence of osteoporosis is high among postmenopausal women and individuals sustaining a spinal cord injury (SCI). We assessed the effects of estrogen loss and unloading on the trabecular bone of the knee in women. Pre- and postmenopausal ambulatory women (n=17) were compared to pre- and postmenopausal women with SCI (n=20). High-resolution magnetic resonance imaging was used to compare groups on apparent measures of trabecular bone volume, trabecular number, trabecular spacing, and trabecular thickness in the distal femur and proximal tibia, regions with a high proportion of trabecular bone and the most common fracture site for SCI patients. Trabecular bone was deteriorated in women with SCI compared to ambulatory women. SCI groups had fewer, (-19 and -26% less) and thinner trabeculae (-6%) that were spaced further apart (40% and 62% more space between structures) resulting in less trabecular bone volume (-22% and -33%) compared to the ambulatory groups (tibia and femur, respectively). Postmenopausal women with SCI also had 34% greater trabecular spacing in the tibia compared to the 40-year-old premenopausal women with SCI, showing an interaction between unloading and estrogen loss. Middle-aged postmenopausal, ambulatory women, not taking estrogen or medications that affect bone, did not show the deteriorated trabeculae that were evident in women with SCI, nor did they show differences in distal femur and proximal tibia trabeculae compared to a premenopausal group. We conclude that the effect of unloading on bone architecture is greater than that of estrogen loss in middle-aged women.

Effect of hip flexion on the measurement of spinal bone mineral density in the Norland Eclipse XR

It is recommended that the hip joints be flexed to 90 degrees during dual-energy X-ray absorptiometry scanning of the lumbar spine in the anteroposterior projection; however, some patients are unable to maintain this position because of the presence of degenerative changes in lower limb joints. This study examines the effect of a lesser degree of hip flexion on the lumbar spine bone mineral density (BMD) measurement and its interpretation. Fifty women were scanned on the Norland Eclipse XR, initially in the standard position with the hips flexed to 90 degrees and then in the adjusted position after allowing for some degree of hip extension to keep them comfortable (hip flexion of 60 degrees -70 degrees ). Higher bone mineral content (BMC), surface area, and BMD values were seen in the standard position compared to the adjusted position, but none of the differences was statistically significant. There were strong correlations for BMC,surface area, and BMD measured in the two positions. In the standard position, 26 women were found to have osteoporosis and 18 had osteopenia. In the adjusted position, osteoporosis was noted in 27 women, and 18 had osteopenia. Four women showed a reduction, whereas 12 women showed an increase in BMD in excess of the least significant change at the 95% confidence level, defined as 2.77 times the precision error (0.008 g/cm(2) x 2.77 = 0.120 g/cm(2)). Our study demonstrates that a lesser degree of hip flexion in women who find it difficult to maintain the recommended 90 degrees hip flexion during the lumbar spine BMD measurement would not affect the patient classification based on T-scores recommended by the World Health Organization; however, variation in hip flexion can be a major confounding factor when interpreting a change in BMD over time.

Soy and Bone

Interest in the use of plant estrogens (phytoestrogens) to attenuate postmenopausal bone loss has increased during the past 10 years as healthcare consumers, practitioners, and scientists have searched for alternative treatments to the use of hormone replacement therapy. Promising research has emerged regarding the potential benefit of increased consumption of phytoestrogens, primarily from dietary soy products. Dietary phytoestrogens, primarily isoflavones found in soy foods, may alter bone turnover in postmenopausal women by decreasing bone resorption and increasing bone formation.

Factors affecting bone loss around menopause in women without HRT: a prospective study

OBJECTIVES

The present study evaluated the effects of menopause and other putative bone loss modifying factors on bone mineral density (BMD) change.

METHODS

The study population, 396 healthy women aged 48-59 years with no history of hormone replacement therapy (HRT) use or any bone affecting disease or medications, was selected from a random sample (n=2025) of the OSTPRE-study cohort (n=13100) in Kuopio, Finland. BMD at lumbar spine (LS) and three areas of proximal femur (femoral neck (FN), Ward's triangle (W), trochanter (T)) was measured with dual X-ray absorptiometry at baseline in 1989-1991 and at 5 years in 1994-1997.

RESULTS

116 women who reported the beginning of menopause during the follow-up (perimenopausal) had the greatest mean annual bone loss (-1.22%/year (LS), -0.87% year (FN), -1.14%/year (W), -0.36%/year (T)). In women under 5 years postmenopausal at baseline (early postmenopausal, n=172) bone loss rate was significantly lower than in perimenopausal women. In women over 5 years postmenopausal at baseline (late postmenopausal, n=108) bone loss rate was significantly further decreased only at lumbar spine. In peri- and postmenopausal women the annual BMD change was best described as a trinomial function of the duration of menopause at all sites (P<0.03). Of the life-style factors studied protective effects were found in weight increase in both spinal and femoral bone (P=0.010/P<0.001), high baseline weight in spine (P<0.001) and high grip strength in femoral neck (P=0.002).

CONCLUSION

The beginning of menopause is accompanied by significant bone loss, which decreases in later menopause. Few other physiological and life-style factors were found to significantly contribute to this phenomenon.

Nutrition education for the healthy elderly population: isn't it time?

In the United States, people are living longer, healthier lives. A major goal of our public health system is to maintain health among successful agers and prevent or delay chronic disease morbidity. Major strides are being made in identifying the dietary needs of elderly people that are different from those of younger adults. However, nutrition education programs to promote those dietary needs have lagged behind. This report reviews dietary needs, demographic information, and recent nutrition policies for older adults as a basis for nutrition education programs. This report suggests that it is time to keep pace with recent findings and develop national and state-sponsored programs that will provide nutrition education and information transference to older people in the communities.

Long-term impact of chemotherapy-induced ovarian failure on bone mineral density (BMD) in premenopausal breast cancer patients. The effect of adjuvant clodronate treatment

We present the 5-year results of the effect of adjuvant chemotherapy on bone mineral density (BMD) and the efficacy of clodronate in the prevention of bone loss in 73 premenopausal women with primary breast cancer. All patients were treated with cyclophosphamide, methotrexate, 5-fluorouracil (CMF) chemotherapy. The patients were randomised to oral clodronate 1600 mg daily for 3 years or to a control group. At 5 years, patients were divided into those with preserved menstruation and those with amenorrhoea. Changes in BMD correlated significantly with the menstrual function after chemotherapy. The change in the lumbar spine BMD at 3 and 5 years were +0.6 and -1.3% in the menstruating group and -7.5 and -10.4% in the amenorrhoeic group (P=0.0001 and 0.0001, respectively), and in femoral neck +1.7 and -0.3%, and -3.5 and -5.8% (P=0.002 and P=0.001, respectively). Three-year clodronate treatment significantly reduced the bone loss in the lumbar spine -3.0% compared with controls -7.4% at three years (P=0.003), but no significant difference was found in the femoral neck: -1.7% versus -2.8%, respectively (P=0.86). These differences between the study groups were still seen at 5 years: in the lumbar spine -5.8% versus -9.7% (P=0.008) and femoral neck -3.5% versus -5.1% (P=0.91). In conclusion, chemotherapy-induced ovarian failure in premenopausal women caused a temporary accelerated bone loss of the lumbar spine. Adjuvant clodronate treatment significantly reduced this bone loss. Two years after the termination of treatment, the bone loss was still significantly less in the clodronate group compared with the control group.

Update on bone density measurement

Bone densitometry is a clinically accepted technique for assessing fracture risk and evaluating skeletal change. The proper clinical use of densitometry requires an understanding of the available techniques, their appropriate application, and the potential sources of measurement error. Recent clinical guidelines recommend that all women over the age of 65 years and all postmenopausal women with risk factors should have their bone density assessed. With the advent of smaller portable devices, bone density measurements are now widely available. In particular, ultrasound techniques, which do not use radiation, have particular promise for widespread screening applications. Peripheral densitometry alone cannot adequately address all clinical questions, particularly the question of monitoring subtle changes in bone density. For this purpose, central densitometers are still preferred. For any bone density measurement to be clinically useful, it must be performed with careful attention to detail, particularly with regard to instrument calibration, patient positioning, measurement analysis, and interpretation.

Characterization of perimenopausal bone loss: a prospective study

This study characterized the change in bone mass, bone markers, pituitary/gonadal hormones, vitamin D, parathyroid hormone, and anthropometric variables in a cohort of healthy women as they passed through normal menopause. We recruited 75 women > 46 years old who had premenopausal estradiol (E2) and gonadotropin levels and regular menses. During 9.5 years of observation, 54 experienced normal menopause (PM group) and 21 remained estrogen replete (ER group). Before the beginning of the menopausal drop and after its completion, the slope of bone mass on time in the PM group was 0% for the spine, -0.61% per year for the total body, and -0.45 % per year for the femoral neck. Designating these losses as "age related," there were 0, 4.88, and 3.40% losses for spine, total body bone mineral (TBBM), and femoral neck, respectively, in the 8-year period for which the data were analyzed. Across menopause, we found a sigmoid pattern of bone loss in the PM group beginning about 2-3 years before the last menses and ending about 3-4 years after the last menses. The total estrogen-deprivation bone losses were 10.50, 7.73, and 5.30% for the spine, TBBM, and femoral neck, respectively. In the ER group, we found a 0, 0.59, and 0.93% per year loss in spine, TBBM, and femoral neck, respectively. Serum osteocalcin rose 77%, serum total alkaline phosphatase rose 34%, and urinary hydroxyproline/creatinine (Hypro/Cr) ratio rose 44% in the PM group, while remaining stable in the ER group. We conclude that menopausal bone loss is a composite of loss caused by estrogen deprivation and age per se for the hip and total body, but is caused by estrogen deprivation alone for the spine.

Annual skeletal balance and metabolic bone marker changes in healthy early postmenopausal women: results of a prospective study

The aim of this study was to establish the duration and annual rate of menopause-related bone loss and to investigate the relationship between bone turnover and bone loss in early healthy postmenopausal women. The rate of change in bone mineral density (BMD) at the lumbar spine and in bone turnover was measured twice at the exact interval of 12 months by dual-energy X-ray absorptiometry (DXA) and by the determination of plasma alkaline phosphatase levels (ALP) and fasting urinary hydroxyproline/creatinine ratio (OHPr/Cr), respectively, in 123 healthy premenopausal and postmenopausal women 45-60 years of age. The subjects were divided into nine groups according to their menstrual status and years since menopause (YSM). Annual bone loss at the lumbar spine of women who were menopausal for 1, 2, 3, 4, and 5 years was -2.62 +/- 0.37 (95% confidence interval -3.66, -1.58), -3.87 +/- 0.96 (-6.02, -1.73), -2.50 +/- 0. 37 (-3.29, -1.70), -2.86 +/- 0.73 (-4.44, -1.27), and -1.54 +/- 0.41 (-2.42, -0.66), respectively, and was significantly less than zero. But, the annual bone loss of women who were premenopausal or menopausal for 6, 7, and 8 years was -0.76 +/- 0.60 (-2.04, +0.53), -1.16 +/- 0.68 (-2.61, +0.29), 0.24 +/- 0.48 (-0.78, +1.26), and 0. 16 +/- 0.63 (-1.18, -1.49), respectively, and was not significantly different from zero. These results demonstrate that the early hormone-dependent bone loss commences in the first year after menopause and is arrested within 6 years after the onset of menopause. The overall bone loss for this phase is estimated to be approximately 15%. Annual change in ALP and OHPr/Cr seems to indicate that bone resorption prevails on bone formation in the first 2 YSM, whereas osteoblastic activity relatively prevails from YSM 3 to YSM 5, which explains the progressive repairing of the imbalance between bone resorption and formation.

Ovariectomy does not induce osteopenia through interleukin-6 in rhesus monkeys (Macaca mulatta)

To characterize the role of interleukin-6 (IL-6) in estrogen (E2)-depletion bone loss, we utilized a nonhuman primate model of human skeletal physiology. Adult female rhesus monkeys were sham-operated (S; n = 5), ovariectomized (ovx; n = 10), or ovx followed by E2 replacement (ovx + E2; n = 10) and evaluated for the indicated parameters at 0, 3, 6, and 9 months post-ovx. Lumbar spine bone mineral density (BMD) decreased by 3 months and continued to decline through 9 months in the ovx, but not in the ovx + E2 or S groups. Middle and distal radius BMD was decreased at 9 months in the ovx, but not in the ovx + E2 or S groups. The S group had marked fluctuations in bone remodeling parameters, and cytokine levels in S animals were consistent with menstrual cycling, and therefore only those values in the ovx and ovx + E2 groups are reported. Serum osteocalcin and skeletal-specific alkaline phosphatase were elevated in the ovx group compared with the ovx + E2 group. There was no difference in serum or bone marrow plasma IL-6 levels between the ovx and ovx + E2 groups. Similarly, there was no difference in basal or phorbol ester-stimulated IL-6 levels of peripheral blood mononuclear cell or bone marrow cell culture supernatants between groups. There was no difference in serum or bone marrow soluble IL-6 receptor between groups. However, the bone marrow plasma soluble IL-6 receptor levels were transiently increased from baseline at 3 months in the ovx but not in the ovx + E2 group. In summary, there was no bone loss in the ovx + E2 group, although the serum and bone marrow IL-6 levels were similar to those of the ovx group. These data suggest that modulation of IL-6 is not the key mechanism through which estrogen deprivation mediates bone loss in rhesus monkeys.

Determinants of bone loss from the femoral neck in women of different ages

An age-stratified sample of 304 women from Rochester, Minnesota, aged 30-94 years (median 60 years) at baseline underwent measurement of femoral neck bone mineral density (BMD) over a follow-up period extending to 16 years. The average rate of change in femoral neck BMD was -1.0% per year (range -10.0% to +13.4%) and did not vary significantly with age. Because there was no marked increase in the rate of loss around the time of menopause, nor convincing evidence of there being a subset of fast losers, there was fairly good tracking of individual values over time; the correlation of baseline with femoral neck BMD values 16 years later was 0.83. Although a large number of potential determinants was assessed, the only consistent predictor of femoral neck bone loss in women of different ages was baseline femoral neck BMD (r = -0.15; p = 0.023). Otherwise, different sets of risk factors were identified for premenopausal women, women within 20 years of menopause, and women 20 years or more postmenopausal, but the predictive power of these different multivariate models was modest. Nonetheless, these data indicate that femoral neck BMD is quite predictable for extended periods of time. This is reassuring with respect to the use of statistical models that incorporate such data to estimate future fracture risk.

Bone mineral density 6 years after a hip fracture: a prospective, longitudinal study

The purpose of this prospective study was to extend the results of previous studies to determine if an accelerated rate of loss of bone mineral density (BMD) continues for 6 years after a hip fracture. Eighty-five elderly patients who had sustained a hip fracture had determinations of BMD made at the time of fracture; 55 of these patients were available for reassessment of BMD 1 year later, and 21 were available for reassessment of BMD 6 to 7 years later. The change in BMD from injury to 1 year and from 1 to 6 years was determined and correlated with pre- and postinjury variables, such as ambulatory ability, dietary intake of calcium, serum vitamin D levels, and mental status. There was a marked decrease in BMD in the in the first year after fracture, with the mean change in BMD being -4.3% at the femoral neck and -1.8% at the lumbar spine. Between 1 and 6 years after fracture, however, there was a dramatic increase in the BMD at both the femoral neck and lumbar spine measurement sites. Relative to 1 year after fracture, the mean increases were 7.7% at the femoral neck and 4.5% at the lumbar spine. In many cases, the loss of bone mineral that occurred in the first year after fracture was completely recouped in the subsequent 5 years. Five of the 21 patients (24%) sustained a contralateral hip fracture in the 6 years after the index fracture. Lumbar spine BMD was lower at baseline (p = 0.112), 1 year after fracture (p = 0.007), and 6 years after fracture (p = 0.003) in patients who sustained a second hip fracture than in those who did not. There was a general decrease in the functional activity level of patients in the 6 years after a hip fracture, but there were no statistically significant relationships between changes in BMD and the functional mobility of patients. The mean calcium intake in patients improved remarkably in the 6 years after fracture, but there was no correlation between daily calcium intake and changes in BMD. During the first year after a hip fracture, there is a rapid loss of bone mineral from the lumbar spine and contralateral femoral neck. Between 1 and 6 years after fracture, however, BMD is likely to increase, perhaps to levels greater than those at baseline. Although this investigation is small, the findings of this study point to the importance of further larger studies to further clarify the natural history of BMD after a hip fracture and the potential impact of pharmacological intervention on that natural history.

Menstrual history and bone density in young women

Adequate levels of reproductive and pituitary hormones are needed for the initiation and maintenance of regular menstrual cycles as well as for the achievement of peak bone mineral density (BMD). Therefore, in the absence of direct hormone measures, menstrual history may serve as a surrogate for the adequacy of hormonal functioning and be a marker for bone status in young women. In our cross-sectional study of white college women aged 19-26 years, we examined the association of six characteristics of menstrual history with bone density at the lumbar spine and the femoral neck. To characterize associations, we used multiple linear regression models that also accounted for the contribution of body mass index, dietary calcium intake, height, level of physical activity, smoking, and alcohol use. The associations between each of the six menstrual characteristics and BMD were stronger at the lumbar spine than at the femoral neck. Age at menarche explained the most variance at both the lumbar spine (partial r2 x 100 = 5.9%) and the femoral neck (partial r2 x 100 = 2.1%). For each year that menarche was delayed, bone density was lower by -0.023 g/cm2 (p = 0.0024) at the lumbar spine and -0.0129 g/cm2 (p = 0.0565) at the femoral neck. At the lumbar spine, a higher number of lifetime menstrual cycles was also significantly associated with increased bone density (adjusted beta = 0.0010, p = 0.0052, partial r2 x 100 = 4.4%). This association was not significant after adjusting for age at menarche. Neither reproductive years (age - age at menarche) nor a history of irregular cycles (either at menarche, in the past year, or ever) was associated with bone density at either site. Menstrual function appears to affect the bone density of these young women. Studies that include measures of reproductive and pituitary hormones are needed to further explore the role of hormones in the potential link between menstrual history and bone density.

Osteoporosis for the allergist

OBJECTIVE

This review is intended to be an authoritative summary of the pathogenesis of osteoporosis, a problem that may be encountered in allergy practice. It also provides an outline for identification of subjects at high risk and directions for their appropriate evaluation, management, and prevention of the disease.

DATA SOURCES

References were obtained through a MEDLINE literature search as well as from previous reviews. Relevant articles were critically reviewed and their conclusions were included.

RESULTS

Osteoporosis is a relatively common disease that is associated with significant morbidity and mortality. The management and prevention of osteoporosis have been improved by an increased awareness of the magnitude of the problem, a better understanding of the pathogenesis, development of a better technique for assessment of bone mineral density, and the availability of specific medications. With the increase in human life-span and the increasing use of glucocorticosteroids for a wide variety of diseases, the incidence of osteoporosis has been on the rise.

CONCLUSION

Glucocorticosteroids are the most common medications that cause or contribute to the pathogenesis of osteoporosis and have been widely used in allergy practice. It is important for physicians to appreciate the current basic understanding of osteoporosis and to be able to identify patients at high risk for this serious disorder, and to initiate appropriate intervention at a sufficiently early time to be effective. Medications for treatment and prevention of osteoporosis include: calcium, vitamin D, estrogen, bisphosphonates, calcitonin, and others are reviewed in this article.

How to get the most out of bone densitometry. Results can help assess fracture risk and guide therapy

Bone densitometry has well-established usefulness in assessing fracture risk. Anyone with a condition that might reduce bone mass or accelerate bone loss should undergo testing, as should postmenopausal women and perimenopausal women who are undecided about starting estrogen replacement therapy. When stratifying a patient's risk of fracture, clinicians should consider not only BMD but also age, lifestyle, concurrent illness, and family history. Almost all patients with BMD in the osteoporotic range on densitometry should be considered for pharmacologic therapy, and so should many of those with values in the osteopenic range. Periodic retesting with bone densitometry is appropriate to monitor the progress of age-related bone loss and response to therapy. There are differences among skeletal sites used in BMD measurement, particularly regarding response to therapy. In addition, there are differences in calibration among densitometry machines, so whenever possible, serial studies should be done on the same machine and by the same technologist.

Risk factors for osteoporotic fracture

Fracture prevention requires the identification of individuals at risk prior to fracture. Bone density, a history of previous fractures, biochemical markers, and the frequency and types of falls are important risk factors for fractures. There are also many other risk factors for bone loss, falls, and fractures. When considered alone or in combination, risk factors can identify a wide range of fracture risk among individuals. Persons with multiple risk factors are at greater risk than are those with either a single risk factor or none. It is not possible to modify some risk factors such as age and gender. Although it is possible in theory to modify other risk factors such as calcium or vitamin D deficiency, the resulting benefits are often small. In contrast, the determination of BMD provides a precise, noninvasive measure of fracture risk, and effective treatments are available to prevent bone loss and increase BMD. Current BMD represents the cumulative, combined influence of all past and current risk factors for bone loss, and prospective changes in biochemical markers and BMD can be used to monitor treatment efficacy. Persons with low BMD and those with multiple risk factors may benefit the most from treatments to preserve or increase BMD. Bone density should always be measured directly, because it is not possible to predict this parameter and fracture risk from other risk factors for bone loss.

The long-term effect of menopause on postmenopausal bone loss in Japanese women: results from a prospective study

The aim of this study was to elucidate perimenopausal bone loss in relation to menstrual conditions and to investigate the long-term effect of menopause on bone loss in aged women. The rate of change in bone mineral density (BMD) was measured twice at an exact interval of 12 months by dual-energy X-ray absorptiometry (DXA) at the lumbar spine in 176 pre- and postmenopausal healthy women 41-65 years of age. Serum follicle-stimulating hormone, intact and N-fragment osteocalcin (OC), three types of vitamin D3, parathyroid hormone (PTH), and calcitonin were also determined. Women who exercised regularly or had anatomical changes at the lumbar spine were excluded from this study. The subjects were divided into eight groups based on their menstrual status and years since menopause. Annual bone loss at the lumbar spine of premenopausal women with regular menstruation was -0.2+/-1.9% (95% confidence interval, -0.9 approximately -0.4%) and was not statistically different from zero, while that of women with irregular menstruation or at menopausal transition was -2.1+/-3.4% (-3.4 approximately -0.8%), and -3.3+/-2.3% (-5.2 approximately -0.3%), respectively, and was significantly different from zero. Serum OC levels of women at menopausal transition were significantly higher than those of women with regular menstruation, suggesting that bone loss had commenced in these women. The rate of annual change in BMD of women who were menopausal for 1-3, 4-6, 10-12, and more than 13 years was -3.1+/-4.0% (-4.7 approximately -1.5%), -1.2+/-2.6% (-2.2 approximately -0.2%), -1.0+/-3.0% (-2.3 approximately -0.3%), and -2.3+/-2.1% (-3.7 approximately -1.0%), respectively, and was significantly less than zero. But the annual bone loss of women who were menopausal for 7-9 years was -1.5+/-2.6% (-3.0 approximately -0.1%) and was not statistically significant from zero. These results indicate that postmenopausal women lose BMD in two phases. The early bone loss is rapid and commences during irregular menstruation, then is attenuated within 6 years after the onset of menopause. The second bone loss commences after the attenuation of the first bone loss. Among bone metabolic hormones, intact PTH alone showed an age-related increase and was suggested as being a causal factor of bone loss in women who were menopausal for 13 years or more.

Bone densitometry: choosing the proper skeletal site to measure

In the last several years, many new techniques have been introduced for the measurement of bone density. At present, the clinician is faced with a choice between various technologies that provide measurements of different skeletal sites. Each of these techniques offer advantages and disadvantages for clinical use. Currently, no single technique ideally addresses all clinical requirements. Although all bone density techniques have clinical utility for assessing fracture risk, some devices offer advantages in terms of versatility (i.e., the number of skeletal sites which can be measured), ability to monitor response, cost, availability, and ease of use. Still, the question often is asked, which technique is the best to use? In clinical practice, the answer to this question will depend on the purpose of the bone density measurement. Different indications for bone mass evaluation will necessitate the measurement of different skeletal sites, which will in turn dictate which technique should be ideally used. In this article, the common clinical questions surrounding bone density measurements are reviewed, together with data supporting the appropriate skeletal site to measure to best answer these clinical questions.

Estrogen receptor gene polymorphism and bone mineral density at the lumbar spine of pre- and postmenopausal women

In order to analyze the role of the estrogen receptor (ER) gene allelic polymorphisms on bone mineral density (BMD), 173 pre- and postmenopausal women were divided into four groups according to their menstrual status (group A: premenopausal women; group B: late premenopausal women; group C: postmenopausal women who had menopause for 5 years or less; and group D: postmenopausal women who had menopause for more than 5 years), and the relationship between ER gene polymorphism and lumbar spine BMD, the percent annual change in BMD and biochemical markers were studied. The restriction fragment length polymorphism (RFLPs) were represented as Xx (XbaI) and Pp (PvuII), with upper case and lower case letters signifying the absence or presence of restriction sites, respectively. In group A, the Xx genotype had significantly higher BMD (p < 0.01) than the xx genotype, but the difference was lost in groups B, C, and D. Because the percent annual change in BMD of group A was 0.052% and was not statistically different among genotypes, it is suggested that RFLP by Xba I is closely linked with peak bone mass that was attained during the subject's late thirties. In group B, serum N-region osteocalcin (N-OC) levels and the percent annual change in BMD showed a significantly larger increase than that of group A, indicating postmenopausal bone loss had commenced. Because the N-OC level of the Xx genotype was significantly higher than that of the xx genotype (p < 0.05), and the percent annual change in BMD of the Xx genotype showed a tendency to increase (p = 0.072), it is suggested that the high BMD of the Xx genotype is rapidly lost during menopausal transition. There were no significant relationships between RFLP and BMD in groups C and D, and between RFLP and BMD in groups C and D, and between RFLP by PvuII and BMD. The present study suggests that the Xx genotype is involved in accretion of BMD during young adulthood, but the effect was lost during menstrual transition.

The prevention of early postmenopausal bone loss by cyclical etidronate therapy: a 2-year, double-blind, placebo-controlled study

PURPOSE

To determine whether intermittent cyclical etidronate therapy can prevent early postmenopausal bone loss.

PATIENTS AND METHOD

This was a 2-year outpatient, randomized, double-blind, placebo-controlled clinical trial. The subjects were 152 women within 1 to 10 years of the onset of menopause and bone mineral density (BMD) between 0 and -2 SD of normal values for a 50 year old woman. The women were stratified according to years since the menopause (1 to 3 years: n = 43; 4 to 6 years: n = 53; 7 to 10 years: n = 56). Measurements of lumbar spine, proximal femur and total body BMD were performed at baseline, 12 and 24 months by dual x-ray absorptiometry. Biochemical markers of bone resorption and bone formation were measured on the same visits.

RESULTS

One hundred thirty-five subjects completed the study. Mean percentage change in lumbar spine BMD (and SEM) at 2 years was +2.14 (0.47)% in the etidronate group and -1.72 (0.41)% in the placebo group. Results for lumbar spine BMD in the treated and control groups stratified according to years since the menopause were: 1 to 3 years: +1.73 (0.84)% and -3.30 (0.70)%; 4 to 6 years: +1.37 (0.88)% and -1.80 (0.61)%; 7 to 10 years: +3.42 (0.61)% and -0.38 (0.70)%. The effect of both treatment group and menopausal stratum were highly statistically significant for lumbar spine and total body BMD. Treatment group, but not stratum, was significant for BMD in the proximal femur. Markers of bone resorption and bone formation were significantly decreased by etidronate therapy.

CONCLUSIONS

Cyclical etidronate prevents bone loss in the total skeleton and at the clinically relevant sites (spine and proximal femur) even in the early postmenopausal years. Hence, it appears to be an effective and safe nonhormonal therapy in postmenopausal women with normal or low BMD.

Accelerated bone mineral loss following a hip fracture: a prospective longitudinal study

The purpose of this prospective study was to monitor the bone mineral density (BMD) of the lumbar spine and contralateral femoral neck in the first year following an osteoporosis-related fracture of the hip. Eighty-three elderly patients (mean age 77 years) who had sustained a hip fracture had determinations of BMD made at the time of fracture; 49 of these patients were available for reassessment of BMD 1 year later. The change in BMD was correlated with pre- and postinjury variables, such as ambulatory ability, dietary intake of calcium, serum vitamin D levels, mental status, and routine serologies. The mean decrease in BMD in the year following fracture was 5.4% from the contralateral femoral neck and 2.4% from the lumbar spine. Calcium intake correlated with the loss of BMD from the femoral neck (p = 0.015), but not the lumbar spine. Patients with daily calcium intakes of less than 500 mg/day had a more than 10% decrease in femoral neck BMD in the year following their hip fracture. Serum 1,25-dihydroxy vitamin D level correlated with loss of MBD from the lumbar spine (p = 0.001), but not from the femoral neck. There was no correlation between the loss of bone mineral from either measurement site and age, sex, level of ambulation, or mental status. The loss of BMD from the femoral neck in the year following a hip fracture is more than five times that reported in the nonfractured population. This accelerated rate of loss can have drastic consequences in an elderly population already exhibiting osteopenia and propensity to fall. Investigation of pharmacologic or other interventions in the first critical year following a hip fracture may potentially blunt this accelerated rate of bone loss and lessen the risk of subsequent fractures.

The pathophysiology and treatment of postmenopausal osteoporosis. An evidence-based approach to estrogen replacement therapy

Osteoporosis is one of the most common and debilitating diseases of postmenopausal women. Recent advances in understanding the bone remodeling unit have clarified the pathophysiologic processes that contribute to bone loss after the onset of estrogen deprivation. Epidemiologic studies have suggested a protective effect from long-term estrogen replacement therapy on fracture risk. This article examines the key role estrogens play in bone remodeling and the current evidence that estrogen treatment in postmenopausal women reduces the likelihood of osteoporotic fractures.

Increased risk of tooth loss is related to bone loss at the whole body, hip, and spine

Increased systemic bone loss may be a risk factor for tooth loss by contributing to the resorption of tooth-supporting alveolar bone. Concurrent longitudinal associations between tooth loss and bone loss at the whole body, femoral neck, and spine were examined in 189 healthy, white, dentate, postmenopausal women who participated in three intervention trials conducted within a 7-year period. None of the subjects was taking estrogen. Bone mineral density (BMD) was measured by dual photon or dual energy X-ray absorptiometry. Teeth were counted at baseline; number and timing of teeth lost over the observation period were assessed by questionnaire. All analyses were controlled for years since menopause, body mass index, number of teeth at baseline, smoking status, and the assigned treatment during each study. These interventions were calcium (Ca) or placebo (P) in Study I, vitamin D+Ca or P+Ca in Study II, and 1 of 2 doses of vitamin D+Ca in Study III. Age at baseline (mean +/- SD) was 59 +/- 6 years and the number of teeth remaining was 23 +/- 7. Women who lost teeth during the 7-year follow-up (n = 45) experienced less favorable changes in BMD at all sites compared with 144 women who lost no teeth (whole body mean +/- SE, -0.35 +/- 0.08%/year versus -0.11 +/- 0.05, P < 0.01; femoral neck -0.48 +/- 0.38%/year versus -0.14 +/- 0.35, P < 0.05; and spine, +0.05 +/- 0.21%/year versus +0. 45 +/- 0.16, P < 0.05). For each 1%/year decrement in BMD, relative risks (and 95% CI) of losing a tooth were significantly elevated at the whole body (RR = relative risks, CI = confidence interval) (RR = 4.83, CI = 1.72-13.52, n = 180), femoral neck (1.50, 1.02 to 2.22, n = 189), and spine (1.45, 1.00 to 2.11, n = 167). These results provide support for a role of systemic bone loss in the development of tooth loss among postmenopausal women.

Prediction of fracture risk. II: Other risk factors

Many osteoporotic fractures are probably preventable-by definition, prevention requires identification of those at risk prior to fracture. There is a continuum in fracture risk and a very wide range in risk among individuals. Bone density, previous fractures, and the frequency and types of falls are important risk factors for fractures. There are also many other risk factors for bone loss, falls, and fractures. People with multiple risk factors are at greater risk than those with either a single risk factor or none. Identification of risk factors can help when planning interventions. For example, dietary deficiencies are amenable to dietary modification or supplementation; however, the effects of many risk factors have not been quantified separately, making it difficult to determine the importance. In addition, it is not possible to accurately predict current bone density and fracture risk from risk factors for bone loss; bone density should always be measured directly.

Quantification of remodeling parameter sensitivity--assessed by a computer simulation model

During normal aging and menopause, cancellous bone is lost at all skeletal sites due to remodeling-related factors: negative formation balance; temporarily increased remodeling space; and osteoclastic perforations. The relative importance of the various factors in inducing bone mass loss and perforations is still controversial. We have previously used a computer simulation model to describe the effect of several bone remodeling parameters on vertebral cancellous bone loss. The model focused on two different scenarios for the menopause and three different treatment regimens. The aim of the present study was to extend the previous study by quantifying remodeling parameter sensitivity for changes in the bone mass with the use of the computer model we had previously formulated. The menopause scenario, with increased activation frequency and increased resorption depth, was chosen as the base case scenario, and the following parameters were investigated in the sensitivity analysis: activation frequency; formation balance; resorption depth; and critical trabecular thickness. Simulations were performed for a period of 20 years starting at the age of 48 years. The analysis showed that the number of perforations and the perforation-related mass loss both exhibited a large sensitivity toward variations in the final resorption depth. However, the formation balance was the factor that was responsible for the greater part of the bone mass loss. The computer model allowed us to quantify the sensitivity of different output variables with respect to changes in some of the model parameters. This can give information about the biological mechanisms responsible for bone mass loss around the surgically induced or natural menopause and also provide an indication of the type of treatment that would be most useful in preventing the deterioration of the cancellous network.