Premenopausal and postmenopausal changes in bone mineral density of the proximal femur measured by dual-energy X-ray absorptiometry

Hormonal Control of Bone Architecture Throughout the Lifespan: Implications for Fracture Prediction and Prevention

BACKGROUND

Skeletal modeling in childhood and adolescence and continuous remodeling throughout the lifespan are designed to adapt to a changing environment and resist external forces and fractures. The flux of sex steroids in men and women, beginning from fetal development and evolving through infancy, childhood, puberty, young adulthood, peri/menopause transition, and postmenopause, is critical for bone size, peak bone mass, and fracture resistance.

OBJECTIVE

This review will highlight how changes in sex steroids throughout the lifespan affect bone cells and the consequence of these changes on bone architecture and strength.

METHODS

Literature review and discussion.

RESULTS

The contributions of estrogen and testosterone on skeletal development have been difficult to study due to the reciprocal and intertwining contributions of one on the other. Although orchiectomy in men renders circulating testosterone absent, circulating estrogen also declines due to testosterone being the substrate for estradiol. The discovery of men with absent estradiol or resistance to estrogen and the study of mouse models led to the understanding that estrogen has a larger direct role in skeletal development and maintenance in men and women. The mechanistic reason for larger bone size in men is incompletely understood but related to indirect effects of testosterone on the skeleton, such as higher muscle mass leading to larger mechanical loading. Declines in sex steroids during menopause in women and androgen deprivation therapies in men have profound and negative effects on the skeleton. Therapies to prevent such bone loss are available, but how such therapies can be tailored based on bone size and architecture remains an area of investigation.

CONCLUSION

In this review, the elegant interplay and contribution of sex steroids on bone architecture in men and women throughout the lifespan is described.

Changes in bone quality after switching from a TDF to a TAF based ART: A pilot randomized study

BACKGROUND

The impact of tenofovir disoproxil fumarate (TDF) antiretroviral (ART) regimens on bone health has been characterized mostly by bone mineral density (BMD), but recently also by bone quality (BQ). The aim of this pilot study is to assess the changes in BMD and BQ after switch from TDF to tenofovir alafenamide (TAF) ART.

METHODS

HIV individuals receiving TDF-based ART were randomized to switch to Bictegravir-TAF-Emtricitabine or to remain in the same regimen. At baseline and 24-weeks after randomization, participants underwent bone mineral density (BMD) by DXA and BQ assessment using bone microindentation, a validated technique that measures bone tissue quality expressed as bone material strength index (BMSi). A panel of plasma bone turnover biomarkers were measured by ELISA at the same time-points. Values are expressed as median [interquartile range] and non-parametric tests were used where appropriate.

RESULTS

A total of 24 HIV individuals were included in the study, 19 of which were men (80%). Median age at baseline was 43 years (IQR 38-54). Half of individuals were allocated in the TDF group while the other half changed to TAF treatment. No differences at baseline between both groups were detected in any parameter. Non-significant changes nor in lumbar or femoral BMD at week 24 was found in any regimen. In contrast, there was an increase in BMSi in the TAF arm at 24 weeks, and thus an improvement in BQ[81.6 (79-83) to 86 (80-88) (+5.1%);p=0.041], whereas the TDF arm remained stable from 82 (76-85) at baseline to 82 (73-83);p=0.812. Hence, at week 24 there were significant differences in BQ between arms (p=0.049). A reduction in bone formation markers was found at week 24 in both regimens: N-terminal propeptide of type-1 collagen decreased a 20% (-35 - -0.6); p=0.031 with TAF and -16% (-25 - -5); p=0.032 with TDF. Also a decrease in bone resorption marker C-telopeptide with TAF was detected [-10% (-19 - -5);p=0.028] but not with TDF (p=0.232), suggesting a less metabolically active bone after switching to TAF.

CONCLUSION

A bone quality improvement was found after switching from a TDF to a TAF based ART independently of BMD, suggesting that the bone health benefits of TAF may extend beyond BMD. Future research should be directed to confirm these findings and to identify the underlying mechanisms of ART related bone toxicity.

Obesity and Bone Loss at Menopause: The Role of Sclerostin

Background. Peripheral fat tissue is known to positively influence bone health. However, evidence exists that the risk of non-vertebral fractures can be increased in postmenopausal women with obesity as compared to healthy controls. The role of sclerostin, the SOST gene protein product, and body composition in this condition is unknown. Methods. We studied 28 severely obese premenopausal (age, 44.7 ± 3.9 years; BMI, 46.0 ± 4.2 kg/m²) and 28 BMI-matched post-menopausal women (age, 55.5 ± 3.8 years; BMI, 46.1 ± 4.8 kg/m²) thorough analysis of bone density (BMD) and body composition by dual X-ray absorptiometry (DXA), bone turnover markers, sclerostin serum concentration, glucose metabolism, and a panel of hormones relating to bone health. Results. Postmenopausal women harbored increased levels of the bone turnover markers CTX and NTX, while sclerostin levels were non-significantly higher as compared to premenopausal women. There were no differences in somatotroph, thyroid and adrenal hormone across menopause. Values of lumbar spine BMD were comparable between groups. By contrast, menopause was associated with lower BMD values at the hip (p < 0.001), femoral neck (p < 0.0001), and total skeleton (p < 0.005). In multivariate regression analysis, sclerostin was the strongest predictor of lumbar spine BMD (p < 0.01), while menopausal status significantly predicted BMD at total hip (p < 0.01), femoral neck (p < 0.001) and total body (p < 0.05). Finally, lean body mass emerged as the strongest predictor of total body BMD (p < 0.01). Conclusions. Our findings suggest a protective effect of obesity on lumbar spine and total body BMD at menopause possibly through mechanisms relating to lean body mass. Given the mild difference in sclerostin levels between pre- and postmenopausal women, its potential actions in obesity require further investigation.

Faster Lumbar Spine Bone Loss in Midlife Predicts Subsequent Fracture Independent of Starting Bone Mineral Density

CONTEXT

Bone mineral density (BMD) decreases rapidly during menopause transition (MT), and continues to decline in postmenopause.

OBJECTIVE

This work aims to examine whether faster BMD loss during the combined MT and early postmenopause is associated with incident fracture, independent of starting BMD, before the MT.

METHODS

The Study of Women's Health Across the Nation, a longitudinal cohort study, included 451 women, initially premenopausal or early perimenopausal, and those transitioned to postmenopause. Main outcome measures included time to first fracture after early postmenopause.

RESULTS

In Cox proportional hazards regression, adjusted for age, body mass index, race/ethnicity, study site, use of vitamin D and calcium supplements, and use of bone-detrimental or -beneficial medications, each SD decrement in lumbar spine (LS) BMD before MT was associated with a 78% increment in fracture hazard (P = .007). Each 1% per year faster decline in LS BMD was related to a 56% greater fracture hazard (P = .04). Rate of LS BMD decline predicted future fracture, independent of starting BMD. Women with a starting LS BMD below the sample median, and an LS BMD decline rate faster than the sample median had a 2.7-fold greater fracture hazard (P = .03). At the femoral neck, neither starting BMD nor rate of BMD decline was associated with fracture.

CONCLUSION

At the LS, starting BMD before the MT and rate of decline during the combined MT and early postmenopause are independent risk factors for fracture. Women with a below-median starting LS BMD and a faster-than-median LS BMD decline have the greatest fracture risk.

Bone Health and Osteoporosis Prevention and Treatment

Postmenopausal osteoporosis is a common condition and is associated with increased risk of fracture, including hip and vertebral fractures that in turn can have devastating consequences on morbidity and mortality. In this article, we review the pathogenesis and diagnostic approach to postmenopausal osteoporosis. We review available nonpharmacologic and pharmacologic therapies and we discuss their clinical efficacy and complications, with a detailed discussion of atypical femur fractures and osteonecrosis of the jaw.

Patterns of Age- and Sex-Related Variations in Bone Mineral Density of Lumbar Spine and Total Femur: A Retrospective Diagnostic Laboratory-Based Study

Background:

Osteoporosis is a major public health problem and should be a priority for healthcare providers and policymakers as it is an important reason of morbidity, mortality, and high-cost incurred in the management of its complications such as hip fractures. This study is designed to assess the bone mineral density (BMD) variation with age, site, and sex. Study is based on diagnostic laboratory data of BMD.

Methods:

A retrospective analysis was conducted on a sample population of 935 persons (73.5% women, 26.4% men), who underwent dual-energy X-ray absorptiometry scan between 2015 and 2017 in a National Accreditation Board for Testing and Calibration Laboratories accredited Mumbai (Maharashtra, India) based diagnostic laboratory. Lumbar spine, right and left total femur, BMD were analyzed across age, sex, and sites. The prevalence of low BMD and osteoporosis at these sites has been estimated as per the World Health Organization criteria of osteoporosis diagnosis using T scores.

Results:

Overall the prevalence of osteoporosis was found to be 6.4%, 5.5%, and 16.4%, while the prevalence of low BMD was 32.6%, 32.8%, and 31.2% at right total femur, left total femur, and lumbar spine, respectively. The decline in BMD at lumbar spine is more among women and it was a consistent decline with age, while among men' decline rate was less at all three sites.

Conclusion:

Our study highlighted the variation of BMD at different sites of body and higher vulnerability of spine for fragility fractures. Our study has shown a sharp decline in BMD among women during transition from 5^th to 6^th decade which signifies association of menopause with osteoporosis. Major limitation of the study is unavailability of clinical profiles of the subjects because of which it is difficult to ascertain whether BMD estimation was a diagnostic or screening procedure. In addition, study is conducted in diagnostic lab settings, due to which it is possible to overestimate prevalence of low BMD and osteoporosis by extrapolating these findings to the community.

Association between body weight and proximal tibial bone mineral density after bilateral total knee arthroplasty

BACKGROUND

Proximal tibial bone mineral density (BMD) has been studied for its potential impact on subsidence and loosening of the tibial component after total knee arthroplasty (TKA). However, no known studies of proximal tibial BMD after TKA have evaluated the effect of major impact factors such as body weight (BW), muscle strength, and level of activity. We aim to determine whether factors such as level of activity, quadriceps strength, BW, gender, age, and prosthetic design affect proximal tibial BMD over the mid- to long-term following TKA.

METHODS

We evaluated 36 patients (72 knees) who were undergoing bilateral TKA performed by a single surgeon. Median follow up time was 115months (range, 60-211months) for a minimum of five years. We measured BMD in the proximal tibia and used a hand-held dynamometer to measure quadriceps isometric strength, recording the maximum value of three measurements for each patient.

RESULTS

Univariate analyses using Spearman's correlation coefficient for continuous variables revealed a weak negative correlation between age and BMD (r=-0.316, P=0.007) and a moderate positive correlation between BW and BMD (r=0.430, P<0.001). However, no significant correlations were found between the other factors above and BMD for continuous and discrete variables. Based on multivariate analyses, only BW had a significant effect on BMD (β=0.342, P=0.003).

CONCLUSIONS

BW is the most impact factor on the proximal tibial BMD after mid- to long-term follow up TKA. Therefore, the management of BW may contribute to prevention of decline of tibial BMD for TKA patients owing to aging.

Vitamin K2 (menaquinone-7) prevents age-related deterioration of trabecular bone microarchitecture at the tibia in postmenopausal women

OBJECTIVE

Clinical studies suggest that vitamin K2 protects against bone loss and fractures; however, its effect on bone quality has never been investigated. We investigated the effect of vitamin MK-7 on undercarboxylated osteocalcin (ucOC), and bone mass and quality.

DESIGN

We conducted a randomised, placebo-controlled, double-blinded clinical trial.

METHODS

We investigated the effect of MK-7 375 µg for 12 months on bone mineral density (BMD) measured by dual X-ray absorptiometry (DXA), bone microarchitecture measured by high-resolution peripheral quantitative computed tomography (HRpQCT) and biochemical bone turnover markers in 148 postmenopausal women with osteopenia. All of them were supplemented with calcium and vitamin D.

RESULTS

ucOC decreased in the MK-7 group (-65.6 (59.1; 71.0) %) (median (CI)) compared with the placebo group (-6.4 (-13.5; 1.2) %) after 3 months (P < 0.01). HRpQCT after 12 months demonstrated that trabecular number in tibia was unchanged in the MK-7-group (-0.1 ± 1.9%) (mean ± s.d.) and decreased in the placebo group (-3.5 ± 2.2%), trabecular spacing was unchanged in the MK-7 group (+1.2 ± 8.0%) and increased in the placebo group (+4.5 ± 9.7%), and trabecular thickness was unchanged in the MK-7 group (+0.2 ± 1.7%) and increased in the placebo group (+4.0 ± 2.2%) (between-group changes for all: P < 0.05). There were no significant differences between the groups in HRpQCT-derived parameters at the radius or in BMD at any site.

CONCLUSION

The changes in bone microarchitecture in the placebo group are consistent with the age-related deterioration of trabecular structure, with a loss of trabeculae and a greater mean thickness of the remaining trabeculae. This suggests that vitamin MK-7 preserves trabecular bone structure at the tibia.

Assessment risk of osteoporosis in Chinese people: relationship among body mass index, serum lipid profiles, blood glucose, and bone mineral density

OBJECTIVE

The aim of our study was to investigate the relationship among age, sex, body mass index (BMI), serum lipid profiles, blood glucose (BG), and bone mineral density (BMD), making an assessment of the risk of osteoporosis.

MATERIALS AND METHODS

A total of 1,035 male and 3,953 female healthy volunteers (aged 41-95 years) were recruited by an open invitation. The basic information, including age, sex, height, weight, waistline, hipline, menstrual cycle, and medical history, were collected by a questionnaire survey and physical examination. Serum lipid profiles, BG, postprandial blood glucose, and glycosylated hemoglobin were obtained after 12 hours fasting. BMD in lumbar spine was measured by dual-energy X-ray absorptiometry scanning.

RESULTS

The age-adjusted BMD in females was significantly lower than in males. With aging, greater differences of BMD distribution exist in elderly females than in males (P<0.001), and the fastigium of bone mass loss was in the age range from 51 to 55 in females and from 61 to 65 years in males. After adjustment for sex, there were significant differences in BMD among BMI-stratified groups in both males and females. The subjects with a BMI of <18.5 had a higher incidence of osteoporosis than BMI ≥18.5 in both sexes. BMD in type 2 diabetes mellitus with a BG of >7.0 mmol/L was lower than in people with BG of ≤7.0 mmol/L (P<0.001). People with serum high-density lipoprotein cholesterol levels of ≥1.56 mmol/L had a greater prevalence of osteoporosis compared with high-density lipoprotein cholesterol ≤1.55 mmol/L. Logistic regression with odds ratios showed that no association was found among total cholesterol, triglyceride, low-density lipoprotein cholesterol, glycosylated hemoglobin, postprandial blood glucose and BMD.

CONCLUSION

The present study further confirmed that factors such as age, sex, weight, BMI, high-density lipoprotein cholesterol, and diabetes are significant predictors of osteoporosis in the Chinese people.

Impact of Dietary Habits and Physical Activity on Bone Health among 40 to 60 Year Old Females at Risk of Osteoporosis in India

Osteoporosis is a disorder of bones with increasing risk among women. However, a number of modifiable factors can help in combating this disorder. Present study examined the relationship of diet and physical activity and risk of osteoporosis through biochemical tests, bone mass density (BMD) scores, and standard questionnaires. Genetic risk for osteoporosis, presence of osteoarthritis, and thyroid problems were found among 8%, 7%, and 3% of participants, respectively; and 78% had onset of menopause between 47 to 55 years of age. Results revealed that less intake of proteins, minerals, and diverse fruit and vegetable consumption was significantly (p≤0.05; 0.01) correlated with decreased BMD score and serum calcium. It was concluded that adequate intake of varied fruits and vegetables, good protein, habit of daily physical activity, adequate sun exposure, and dietary calcium, may play a promising role in decreasing the risk of osteoporosis among women of this age group.

Does estrogen play a role in response to adjuvant bone-targeted therapies?

Bone remains the most common site of breast cancer recurrence. The results of population studies, pre-clinical research and clinical studies in patients with metastatic disease provided a rationale for testing bone-targeted agents in the adjuvant setting. Despite the initial optimism, results from eight prospectively designed, randomized control studies powered to assess the value of adjuvant bone-targeted therapy in early breast cancer are conflicting. Data have shown that, where benefit exists, it tends to be in women with a “low estrogen environment”, either through menopause or suppression of ovarian function. In this manuscript, we review clinical data supporting the hypothesis that estrogen levels may play a part in explaining the response of patients to bone-targeted agents in the adjuvant setting. The results presented to date suggest that there may be data supporting a unifying role for estrogen in adjuvant trials. However, in the absence of any prospective randomized trials in which estrogen data has been systematically collected we cannot specifically answer this question. We await the results of the Oxford overview analysis of individual patient data with interest.

Early postmenopausal bone loss and what to do about it

The pattern of lifelong changes in bone mass in women characterized in several publications generally shows that peak adult bone mass is achieved at about the end of adolescence or later, and begins to decline as menopause approaches. Uncertainties remain regarding the exact age at which peak bone mass is reached and when it starts to decline. The data indicate that the onset of rapid bone loss in healthy women begins at about two years before the last menses and is complete at about four to five years after the last menses. The bone loss at the spine, total body, and femoral neck over these years is equal to about one T-score and is largely irreversible after it occurs. This presentation examines the data on these questions and focuses on the perimenopausal pattern of rapid bone loss and the implications for identifying and managing the later-life risk of fracture.

Bone and the perimenopause

Loss of ovarian function has a profound impact on female skeletal health. Bone mineral density findings from the Study of Women's Health Across the Nation demonstrate an accelerated rate of bone loss during the menopausal transition. The greatest reduction occurs in the year before the final menstrual period and the first 2 years thereafter. Clinical management includes maintenance of adequate dietary calcium and vitamin D intake, attention to modifiable risk factors, and osteoporosis screening. Indications, benefits, and risks of pharmacologic osteoporosis therapy should be assessed individually; there are currently no established guidelines addressing the treatment and prevention of osteoporosis in perimenopausal women.

Menopausal bone changes and incident fractures in diabetic women: a cohort study

SUMMARY

The purpose of this study was to evaluate the rate of bone loss and incident fractures in women with diabetes mellitus (DM) across menopause. During menopause, DM women experienced bone mineral density (BMD) loss that was faster at hip and slower at spine and had a higher risk of fractures, perhaps because of their earlier menopause. The increasing DM epidemic will contribute to higher fracture burden.

INTRODUCTION

Women with DM have a higher risk of fractures independent of age, body mass index (BMI), and BMD. Our objective is to evaluate if women with DM experience greater bone loss and more fractures across menopause.

METHODS

Two thousand one hundred seventy one women, aged 42 to 52 years at baseline (1996), enrolled in the Study of Women's Health Across the Nation (SWAN), a prospective study, with 8 years of annual follow up. One thousand three hundred forty six (62%) completed annual visit 7 (2004). Women with baseline fasting blood glucose level of ≥126 mg/dl and those being treated for diabetes were designated as DM. Annual assessment of menopausal stage, BMD, and urinary N-telopeptide (NTx) were carried out. Rate of change in BMD across menopause and annual self-report data for risk of incident fractures by DM status were determined.

RESULTS

Despite higher baseline BMD at hip (p = <0.001), and lumbar spine (p = <0.001), rate of decline in BMD was faster at hip (β = -0.45 vs. -0.11 gm/cm(2)/year, p = <0.001) for DM women, compared to non-DM. However, lumbar spine bone loss was slower in women with DM as compared to non-DM women (β = 0.04 vs. -0.25 gm/cm(2)/year, p = 0.004). DM women experienced menopause 3 years earlier than non-DM women (p = 0.002), and age adjusted incident fractures were two fold higher in women with DM compared to non-DM (RR = 2.20, 95% CI: 1.26-3.85, p = <0.006).

CONCLUSIONS

BMD loss is greater in hip and slower at spine in DM women during menopausal transition. Women with DM have a higher risk of fractures, perhaps because of their earlier menopause.

Mechanical stimulation of the pro-angiogenic capacity of human fracture haematoma: involvement of VEGF mechano-regulation

Compromised angiogenesis appears to be a major limitation in various suboptimal bone healing situations. Appropriate mechanical stimuli support blood vessel formation in vivo and improve healing outcomes. However, the mechanisms responsible for this association are unclear. To address this question, the paracrine angiogenic potential of early human fracture haematoma and its responsiveness to mechanical loading, as well as angiogenic growth factors involved, were investigated in vitro. Human haematomas were collected from healthy patients undergoing surgery within 72 h after bone fracture. The haematomas were embedded in a fibrin matrix, and cultured in a bioreactor resembling the in vivo conditions of the early phase of bone healing (20% compression, 1 Hz) over 3 days. Conditioned medium (CM) from the bioreactor was then analyzed. The matrices were also incubated in fresh medium for a further 24 h to evaluate the persistence of the effects. Growth factor (GF) concentrations were measured in the CM by ELISAs. In vitro tube formation assays were conducted on Matrigel with the HMEC-1 cell line, with or without inhibition of vascular endothelial growth factor receptor 2 (VEGFR2). Cell numbers were quantified using an MTS test. In vitro endothelial tube formation was enhanced by CM from haematomas, compared to fibrin controls. The angiogenesis regulators, vascular endothelial growth factor (VEGF) and transforming growth factor beta1 (TGF-beta1), were released into the haematoma CM, but not angiopoietins 1 or 2 (Ang1, 2), basic fibroblast growth factor (bFGF) or platelet-derived growth factor (PDGF). Mechanical stimulation of haematomas, but not fibrin controls, further increased the induction of tube formation by their CM. The mechanically stimulated haematoma matrices retained their elevated pro-angiogenic capacity for 24 h. The pro-angiogenic effect was cancelled by inhibition of VEGFR2 signalling. VEGF concentrations in CM tended to be elevated by mechanical stimulation; this was significant in haematomas from younger, but not from older patients. Other GFs were not mechanically regulated. In conclusion, the paracrine pro-angiogenic capacity of early human haematomas is enhanced by mechanical stimulation. This effect lasts even after removing the mechanical stimulus and appears to be VEGFR2-dependent.

Amount of bone loss in relation to time around the final menstrual period and follicle-stimulating hormone staging of the transmenopause

BACKGROUND AND OBJECTIVE

The objective of the study was to describe bone loss rates across the transmenopause related to FSH staging and the final menstrual period (FMP).

DESIGN AND SETTING

This was a population-based cohort of 629 women (baseline age 24-44 yr) with annual data points over 15 yr.

MEASUREMENTS

Measures were bone mineral density (BMD), FSH to define four FSH stages, and menstrual bleeding cessation to define the FMP. Bone loss rates were reported by obesity status.

RESULTS

Annualized rates of lumbar spine bone loss began in FSH stage 3, which occurs approximately 2 yr prior to the FMP (1.67%/yr); bone loss continued into FSH stage 4 (1.21%/yr). Mean spine BMD in FSH stage 4 was 6.4% less than spine BMD value in FSH stage 1. Annualized rates of femoral neck (FN) bone loss began in FSH stage 3 (0.55%/yr) and continued into FSH stage 4 (0.72%/yr). The FN difference between mean values in FSH stage 1 and FSH stage 4 was 5%. Annualized rates of spine bone loss in the 2 yr prior to the FMP were 1.7%/yr, 3.3%/yr in the 2 yr after the FMP, and 1.1%/yr in the 2- to 7-yr period after the FMP. Nonobese women had lower BMD levels and greater bone loss rates.

CONCLUSIONS

Spine and FN bone loss accelerates in FSH stage 3. Bone loss also began to accelerate 2 yr before the FMP with the greatest loss occurring in the 2 yr after the FMP. Bone loss rates in both spine and FN BMD were greater in nonobese women than obese women.

High bone matrix turnover predicts blood levels of lead among perimenopausal women

Skeletal bone is the primary endogenous source of lead in circulating blood, particularly under conditions of accelerated bone turnover and mineral loss, such as pregnancy and postmenopausal osteoporosis. We studied the influence of bone turnover rate on the release of lead from bone in 1225 female farmers from 5 districts in Japan. We collected peripheral blood and urine samples and medical nutritional information, and measured forearm bone mineral density (BMD). We found that blood lead levels in perimenopausal women were highest among all groups studied. Analysis of data for subjects grouped by level of markers of bone metabolism suggested that, in perimenopausal women, blood lead levels were higher in groups with high levels of N-telopeptide cross-linked collagen type I (NTx) and high levels of bone-specific alkaline phosphates (BALP) or osteocalcin (OC) compared with groups with low NTx and low BALP or OC levels. Linear multivariate models showed that markers of bone turnover were significantly positively related to blood lead levels. These results provide evidence that high bone turnover rates increase the release of lead stored in bone into the circulation. It is likely that markers of bone metabolism can be used to predict blood lead levels.

Variation in bone mineral density by anatomical site in patients with proximal humeral fractures

Low-energy fractures of the proximal humerus indicate osteoporosis and it is important to direct treatment to this group of patients who are at high risk of further fracture. Data were prospectively collected from 79 patients (11 men, 68 women) with a mean age of 69 years (55 to 86) with fractures of the proximal humerus in order to determine if current guidelines on the measurement of the bone mineral density at the hip and lumbar spine were adequate to stratify the risk and to guide the treatment of osteoporosis. Bone mineral density measurements were made by dual-energy x-ray absorptiometry at the proximal femur, lumbar spine (L2-4) and contralateral distal radius, and the T-scores were generated for comparison. Data were also collected on the use of steroids, smoking, the use of alcohol, hand dominance and comorbidity.

The mean T-score for the distal radius was −2.97 (sd 1.56) compared with −1.61 (sd 1.62) for the lumbar spine and −1.78 (sd 1.33) for the femur. There was a significant difference between the mean lumbar and radial T scores (1.36 (1.03 to 1.68); p < 0.001) and between the mean femoral and radial T-scores (1.18 (0.92 to 1.44); p < 0.001). The inclusion of all three sites in the determination of the T-score increased the sensitivity to 66% compared with that of 46% when only the proximal femur and lumbar spine were used. This difference between measurements in the upper limb compared with the axial skeleton and lower limb suggests that basing risk assessment and treatment on only the bone mineral density taken at the hip or lumbar spine may misrepresent the extent of osteoporosis in the upper limb and the subsequent risk of fracture at this site.

The assessment of osteoporosis must include measurement of the bone mineral density at the distal radius to avoid underestimation of osteoporosis in the upper limb.

Associations of genetic lactase non-persistence and sex with bone loss in young adulthood

Some studies have reported that after attainment of peak bone mass (PBM), slow bone loss may occur in both men and women; however, findings are inconsistent. Genetic factors play a significant role in bone loss, but the available evidence is conflicting. Genetic lactase non-persistence (lactase C/C(-13910) genotype) is suggested to increase risk for inadequate calcium intake predisposing to poorer bone health. We investigated whether this genotype is associated with PBM and bone loss in young Finnish adults. Subjects belong to the Cardiovascular Risk in Young Finns Study that is an ongoing multi-centre follow-up of atherosclerosis risk factors. From the original cohort, randomly selected subjects aged 20-29 participated in baseline bone mineral density (BMD) measurements (n=358), and in follow-up measurements 12 years later (n=157). Bone mineral content (BMC) and BMD at lumbar spine (LS) and femoral neck (FN) were measured at baseline and follow-up with dual energy X-ray absorptiometry (DXA). Lactase C/T(-13910) polymorphism was determined by PCR and allele-specific fluorogenic probes. Information on lifestyle was elicited with questionnaires. During the follow-up, bone loss at both bone sites was greater in males (LS BMD: -1.1%, FN BMD: -5.2%) than in females (LS BMD: +2.1%, FN BMD: -0.7%) (both bone sites p=0.001). Younger age predicted greater loss of FN BMC and BMD in females (p=0.013 and p=0.001, respectively). Increased calcium intake predicted FN BMD gain in both sexes (in females B=0.007 g/cm(2)/mg, p=0.002; in males B=0.006, p=0.045), and increased physical activity LS BMD gain in females (B=0.091 g/cm(2)/physical activity point, p=0.023). PBM did not differ between the lactase genotypes, but males with the CC(-13910) genotype seemed to be prone to greater bone loss during the follow-up (LS BMD: C/C vs. T/T p=0.081). In conclusion, bone loss in young adulthood was more common in males than in females and seemed to occur mainly at the femoral neck. Young males with the lactase CC(-13910) genotype may be more susceptible to bone loss; however, calcium intake predicts changes in bone mass more than the lactase genotype.

Change in bone mineral density and its determinants in pre- and perimenopausal Chinese women: the Hong Kong Perimenopausal Women Osteoporosis Study

This 30-month study investigating bone change and its determinants in 438 perimenopausal Chinese women revealed that the fastest bone loss occurred in women undergoing menopausal transition but maintenance of body weight and physical fitness were beneficial for bone health. Soy protein intake also seemed to exert a protective effect.

INTRODUCTION

This 30-month follow-up study aims to investigate change in bone mineral density and its determinants in Hong Kong Chinese perimenopausal women.

METHODS

Four hundred and thirty-eight women aged 45 to 55 years were recruited through random telephone dialing and primary care clinic. Bone mass, body composition, lifestyle measurements were obtained at baseline and at 9-, 18- and 30-month follow-ups. Univariate and stepwise multiple regression analyses were performed with the regression coefficients of BMD/C (derived from baseline and follow-up measurements) as the outcome variables. Menopausal status was classified as pre- or postmenopausal or transitional.

RESULTS

Menopausal status was the strongest determinant of bone changes. An annual bone loss of about 0.5% was observed among premenopausal, 2% to 2.5% among transitional, and about 1.5% in postmenopausal women. Multiple regression analyses, revealed that a positive regression slope of body weight was protective for follow-up bone loss at all sites. Number of pregnancy, soy protein intake and walking were protective for total body BMC. Higher baseline LM was also protective for neck of femur BMD.

CONCLUSION

Maintenance of body weight and physical fitness were observed to have a protective effect on for bone loss in Chinese perimenopausal women.

Bone mineral density changes during the menopause transition in a multiethnic cohort of women

CONTEXT

Rates of bone loss across the menopause transition and factors associated with variation in menopausal bone loss are poorly understood.

OBJECTIVE

Our objective was to assess rates of bone loss at each stage of the transition and examine major factors that modify those rates.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a longitudinal cohort study of 1902 African-American, Caucasian, Chinese, or Japanese women participating in The Study of Women's Health Across the Nation. Women were pre- or early perimenopausal at baseline.

OUTCOME MEASURE

We assessed bone mineral density (BMD) of the lumbar spine and total hip across a maximum of six annual visits.

RESULTS

There was little change in BMD during the pre- or early perimenopause. BMD declined substantially in the late perimenopause, with an average loss of 0.018 and 0.010 g/cm2.yr from the spine and hip, respectively (P<0.001 for both). In the postmenopause, rates of loss from the spine and hip were 0.022 and 0.013 g/cm2.yr, respectively (P<0.001 for both). During the late peri- and postmenopause, bone loss was approximately 35-55% slower in women in the top vs. the bottom tertile of body weight. Apparent ethnic differences in rates of spine bone loss were largely explained by differences in body weight.

CONCLUSIONS

Bone loss accelerates substantially in the late perimenopause and continues at a similar pace in the first postmenopausal years. Body weight is a major determinant of the rate of menopausal BMD loss, whereas ethnicity, per se, is not. Healthcare providers should consider this information when deciding when to screen women for osteoporosis.

Effects of isoflavone and exercise on BMD and fat mass in postmenopausal Japanese women: a 1-year randomized placebo-controlled trial

The combined intervention of isoflavone intake and walking exercise over 1 year in postmenopausal Japanese women exhibited a trend for a greater effect on prevention of bone loss at the total hip and Ward's triangle regions.

INTRODUCTION

The additive effects of isoflavones and exercise on bone and lipid metabolism have been shown in estrogen-deficient animals. In this study, we determined the effects of isoflavone intake, walking exercise, and their interaction on bone, fat mass, and lipid metabolism over 1 year in postmenopausal Japanese women.

MATERIALS AND METHODS

A total of 136 postmenopausal women at <5 years after the onset of menopause were randomly assigned to four groups: (1) placebo, (2) walking (45 minutes/day, 3 days/week) with placebo, (3) isoflavone intake (75 mg of isoflavone conjugates/day), and (4) combination of isoflavone plus walking. BMD, fat mass, serum lipid, and serum and urinary isoflavone concentrations were assessed.

RESULTS

A significant main effect of isoflavone on the reduction in trunk fat mass was obtained at 12 months. Significant main effects of walking on the reduction in fat mass in the whole body and the trunk were observed at 3, 6, and 12 months and that in the legs and arms at 6 and 12 months. Serum high-density lipoprotein (HDL)-cholesterol concentration significantly increased by 12 months after the walking and the combined intervention. After 12 months, a significant main effect of isoflavone on BMD was observed only at Ward's triangle. Walking prevented bone loss at the total hip and the Ward's triangle to significant degrees. The effect of the combined intervention on BMD at total hip and Ward's triangle regions was greater than that of either alone. No significant interaction was observed between isoflavone and walking in any measurements recorded during the study.

CONCLUSIONS

Our study suggest that combined intervention of 75 mg/day of isoflavone intake and walking exercise 3 times/week for 1 year showed a trend for a greater effect on BMD at total hip and Ward's triangle regions than either alone. Intervention with isoflavone in postmenopausal Japanese women showed a modest effect on BMD compared with those in Westerners. Further studies over longer treatment duration that include assessment of BMD at various regions are necessary to ascertain the clinical significance of the combined intervention of isoflavone plus walking in postmenopausal women.

The use of micro-CT to evaluate cortical bone geometry and strength in nude rats: correlation with mechanical testing, pQCT and DXA

In both clinical and experimental settings, access to quantitative methods enabling the objective evaluation of cortical bone mass, structure, geometry and strength are essential for the assessment of efficacy and safety of different treatments aimed to improve bone strength. The ability of non-invasive methodologies (DXA, pQCT and micro-CT) to assess and quantify cortical bone mass and geometry was tested in a nude rat model in which bone loss was induced by surgical castration. Treatment with a bone antiresorptive (alendronate) or a bone forming (PTH) drug was used to: (A) validate the nude rat model in terms of bone metabolism, (B) test the ability of each technology to detect change in cortical bone geometry and (C) correlate cortical bone geometry with bone strength data obtained by 3-point bending method. Our observations regarding effect of castration and treatment with PTH and alendronate on cortical bone parameters in nude rats is in general agreement with previously published data obtained in immunocompetent male rats under similar experimental conditions. Data presented here support the hypothesis that nude rats have similar bone physiology and response to known bone therapies to that observed in normal rats and therefore could be effectively used to predict skeletal response in humans. All three technologies deployed in this study (DXA, pQCT and micro-CT) proved useful in describing cancellous and/or cortical bone parameters and positive correlations were demonstrated between data obtained by different methods. The cross-sectional area of a bone structure is crucial for resisting loads in bending or torsion and is described as "areal moment of inertia" for bending, and as "polar moment of inertia" in torsion. Novel, three-dimensional micro-CT methodology used in this study to assess geometry of cortical bone provides data that accurately describes cortical bone geometry and parallels cortical bone strength results obtained by the 3-point bending method. Our micro-CT data meet the criteria of providing quick, reproducible and accurate answers regarding cortical bone geometry as a predictor of cortical bone strength.

Quantitative ultrasound measurements at the calcaneus in natural and surgically induced menopause

OBJECTIVE

The aim of the study was to assess skeletal status in natural and surgically induced menopausal women regarding the presence of previous osteoporotic fracture.

METHODS

Ninety-three females after bilateral oophorectomy in mean age of 56.8+/-8.3y. (48 without and 45 with fracture, groups 1 and 2, respectively) and 285 females with natural menopause in mean age of 56.4+/-7.0y (176 without and 109 with fracture, groups 3 and 4, respectively) were studied. Mean age, age of menopause, years since menopause (YSM), duration of fertile period (durFER) and body size did not differ between women after surgical and natural menopause and between non-fractured and fractured groups. No additional factors known to influence bone metabolism (either diseases or medications) or osteoporosis treatment were noted in the subjects studied. Skeletal status was evaluated by quantitative ultrasound (QUS) of the calcaneum using the Achilles system (Lunar, USA).

RESULTS

Calcaneal QUS results were significantly higher: in women after natural than surgical menopause (p<0.05), in non-fractured females after natural menopause than in non-fractured females after surgical menopause (p<0.001) and in women after natural menopause without fracture compared with those with fracture (p<0.000001). The same comparisons between fractured groups and between women after surgical menopause with and without fracture revealed no significant differences. QUS parameters were regressed in a stepwise, multiple regression analysis on age, YSM, durFER, weight and height for all groups. In group 1, YSM had a negative influence and durFER was a protective factor; in group 2, age and durFER were a negative factors and YSM had no influence; in group 3, age and YSM were a negative factors (no role of durFER) and in group 4, only YSM had a negative influence, and durFER was a protective factor.

CONCLUSION

Surgical menopause seems to be a risk factor for osteoporotic fracture because of low ultrasound values.

Physical activity in the prevention and amelioration of osteoporosis in women : interaction of mechanical, hormonal and dietary factors

Osteoporosis is a serious health problem that diminishes quality of life and levies a financial burden on those who fear and experience bone fractures. Physical activity as a way to prevent osteoporosis is based on evidence that it can regulate bone maintenance and stimulate bone formation including the accumulation of mineral, in addition to strengthening muscles, improving balance, and thus reducing the overall risk of falls and fractures. Currently, our understanding of how to use exercise effectively in the prevention of osteoporosis is incomplete. It is uncertain whether exercise will help accumulate more overall peak bone mass during childhood, adolescence and young adulthood. Also, the consistent effectiveness of exercise to increase bone mass, or at least arrest the loss of bone mass after menopause, is also in question. Within this framework, section 1 introduces mechanical characteristics of bones to assist the reader in understanding their responses to physical activity. Section 2 reviews hormonal, nutritional and mechanical factors necessary for the growth of bones in length, width and mineral content that produce peak bone mass in the course of childhood and adolescence using a large sample of healthy Caucasian girls and female adolescents for reference. Effectiveness of exercise is evaluated throughout using absolute changes in bone with the underlying assumption that useful exercise should produce changes that approximate or exceed the absolute magnitude of bone parameters in a healthy reference population. Physical activity increases growth in width and mineral content of bones in girls and adolescent females, particularly when it is initiated before puberty, carried out in volumes and at intensities seen in athletes, and accompanied by adequate caloric and calcium intakes. Similar increases are seen in young women following the termination of statural growth in response to athletic training, but not to more limited levels of physical activity characteristic of longitudinal training studies. After 9-12 months of regular exercise, young adult women often show very small benefits to bone health, possibly because of large subject attrition rates, inadequate exercise intensity, duration or frequency, or because at this stage of life accumulation of bone mass may be at its natural peak. The important influence of hormones as well as dietary and specific nutrient abundance on bone growth and health are emphasised, and premature bone loss associated with dietary restriction and estradiol withdrawal in exercise-induced amenorrhoea is described. In section 3, the same assessment is applied to the effects of physical activity in postmenopausal women. Studies of postmenopausal women are presented from the perspective of limitations of the capacity of the skeleton to adapt to mechanical stress of exercise due to altered hormonal status and inadequate intake of specific nutrients. After menopause, effectiveness of exercise to increase bone mineral depends heavily on adequate availability of dietary calcium. Relatively infrequent evidence that physical activity prevents bone loss or increases bone mineral after menopause may be a consequence of inadequate calcium availability or low intensity of exercise in training studies. Several studies with postmenopausal women show modest increases in bone mineral toward the norm seen in a healthy population in response to high-intensity training. Physical activities continue to stimulate increases in bone diameter throughout the lifespan. These exercise-stimulated increases in bone diameter diminish the risk of fractures by mechanically counteracting the thinning of bones and increases in bone porosity. Seven principles of bone adaptation to mechanical stress are reviewed in section 4 to suggest how exercise by human subjects could be made more effective. They posit that exercise should: (i) be dynamic, not static; (ii) exceed a threshold intensity; (iii) exceed a threshold strain frequency; (iv) be relatively brief but intermittent; (v) impose an unusual loading pattern on the bones; (vi) be supported by unlimited nutrient energy; and (vii) include adequate calcium and cholecalciferol (vitamin D3) availability.

Ovarian aging and bone metabolism in menstruating women aged 35–50 years

OBJECTIVES

The aim of this study was to investigate the relationships between the levels of gonadotrophins, estradiol, inhibin-b and bone mass and turn-over in regularly menstruating women aged 35-50 years.

METHODS

The study group included 87 healthy volunteers from the community aged 35-50 years. Bone mineral density of lumbar vertebras, wards triangle, throchanter, femur neck, bone resorption and formation markers were studied as well as the serum levels of gonadotrophins, estradiol and inhibin-b on the day 3 of menstrual cycle.

RESULTS

The gonadotrophin levels showed significant positive relation with age, whereas inhibin-b and estradiol levels showed significant negative correlation with age. The gonadotrophins and estradiol levels had no significant association with bone mass and bone formation markers. Increased gonadotrophin (p < 0.001) levels and decreased inhibin-b (p < 0.01) levels independent from age were correlated with increased bone resorption. Gonadotrophins, estradiol, age, inhibin-b, body mass index (BMI) were the confounding factors for bone resorption (p = 0.015, R(2) = 0.190) and lumbar bone mass (p = 0.041, R(2) = 0.148). Multivariate analysis showed an independent contribution of inhibin-b and BMI in the prediction of lumbar bone mass.

CONCLUSION

This findings suggested that estradiol was not the only factor responsible for bone loss and decrease in reproductive function because increased gonadotrophins and decreased inhibin-b levels might trigger some changes in bone metabolism prior to the menopause.

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.

Ward's triangle bone mineral density determined by dual-energy x-ray absorptiometry is a sensitive indicator of osteoporosis

OBJECTIVE

To assess the clinical utility of bone mineral density (BMD) of Ward's triangle by dual-energy absorptiometry (DEXA) as an indicator of osteoporosis in comparison with quantitative computed tomography (QCT) of the lumbar spine and DEXA of the lumbar spine and hip sites (trochanter and femoral neck).

METHODS

We conducted a retrospective study of all patients (28 men and 17 women) with decreased BMD by QCT (T-score less than -1.0) who had DEXA BMD performed at the lumbar spine and hip between October 1993 and January 1995 in our Endocrine Clinic.

RESULTS

Osteoporosis based on the World Health Organization criteria (T-score less than -2.5) was defined by QCT lumbar spine BMD in 78% of the study subjects and by DEXA of Ward's triangle in 53%, of the femoral neck in 22%, of the trochanter in 7%, and of the lumbar spine in 2%. In the men, the only DEXA BMD measurement that was sensitive for detecting osteoporosis was Ward's triangle. Of the 24 men with osteoporosis by QCT BMD, 14 were defined as having osteoporosis by DEXA exclusively at Ward's triangle. The DEXA lumbar spine BMD measurement was actually above the mean for young normal control subjects in 8 of the 24 men with osteoporosis by QCT BMD. In the 11 women with osteoporosis by QCT BMD, the DEXA BMD at Ward's triangle and the femoral neck were equally sensitive in detecting osteoporosis, whereas the DEXA lumbar spine and trochanter BMD measurements were insensitive.

CONCLUSION

DEXA BMD of Ward's triangle is a sensitive indicator of osteoporosis, particularly in men, and should be used to identify patients at increased risk for osteoporosis-related fractures.

Prevention of Bone Loss in Ovariectomized Rats: The Effect ofSalvia miltiorrhizaExtracts

The preventive effect of Salvia miltiorrhiza extracts (SMEs) on the progress of bone loss induced by ovariectomy (OVX) was studied in rats. We measured body weight and bone histomorphometry in sham, OVX or SMEs-administered OVX rats. From light microscopic analyses, a porous or erosive appearances were observed on the surface of trabecular bone of tibia in OVX rats, whereas those of the same bone in sham rats and in SMEs-administered rats were composed of fine particles. The trabecular bone area and trabecular thickness in OVX rats decreased by 50% from those in sham rats, these decreases were completely inhibited by administration of SMEs for 7 weeks. In this study, the mechanical strength in femur neck was significantly enhanced by the treatment of SMEs for 7 weeks. In OVX rats, free T3 was normal in all cases, whereas free T4 was significantly increased. Although there was no difference between OVX and SMEs-administered rats in T3 level, we have found significant difference between them in T4 level. These results strongly suggest that SMEs are effective in preventing the development of bone loss induced by OVX in rats.

Limited diagnostic agreement of quantitative sonography of the radius and phalanges with dual-energy x-ray absorptiometry of the spine, femur, and radius for diagnosis of osteoporosis

OBJECTIVE

The aim of our study was to evaluate the diagnostic agreement of quantitative sonography of the radius and proximal phalanx and dual-energy X-ray absorptiometry (DXA) of the radius, lumbar spine, and femoral neck for the detection of osteoporosis.

MATERIALS AND METHODS

In 95 women (mean age, 53 +/- 13 years) and 26 men (mean age, 53 +/- 13 years), DXA measurements of the lumbar spine (posterior-anterior, L1-L4) and the femoral neck, as well as quantitative sonography of the radius and proximal phalanx of the third finger were obtained. The percentage of patients below a given threshold was calculated for each imaging technique. A T score of less than -2.5 indicated presence of osteoporosis. Diagnostic agreement in identifying individuals with osteoporosis was assessed using kappa scores.

RESULTS

Between 14% and 22% of the patients were classified as osteoporotic after DXA of the various regions of interest of the radius, 31% after DXA of the spine, 43% after DXA of the femoral neck, 32% after quantitative sonography of the distal radius, and 34% after quantitative sonography of the phalanx of the third finger. Correlation coefficients between T values for quantitative sonography and those for DXA varied between not significant and 0.54 at the different regions. Kappa analysis showed the diagnostic agreement among quantitative sonography and DXA to be fair to moderate (kappa = 0.38-0.48). The highest agreement was between quantitative sonography of the proximal phalanx of the third finger and DXA of the total radius (kappa 0.48; p < 0.05).

CONCLUSION

Considerable diagnostic disagreement exists between quantitative sonography and DXA of the forearm, as is true for most quantitative techniques in the assessment of skeletal status. The lack of correlation makes quantitative sonography impractical for routine diagnostic use but might characterize different parameters related to bone quality.

Relationships between muscle strength and bone mineral density of three body regions in sedentary postmenopausal women

This cross-sectional study was designed to investigate correlations between muscle strength and regional bone mineral density (BMD) in sedentary postmenopausal women. Sixty-two women who ranged in age from 41 to 76 years were investigated. Hip and trunk muscle strength was measured by isokinetic dynamometry. Grip strength of the nondominant hand was measured using a hand-held dynamometer. Bone mineral density of the lumbar spine, femur, and distal radius was measured by dual-energy X-ray absorptiometry. Only the correlation between hip abductor strength and femoral BMD was significant (P = 0.009, r = 0.327). There was no correlation between trunk muscle strength and lumbar vertebral BMD or between grip strength and distal radius BMD. Subjects with osteoporosis (T score < -2.5) or osteopenia T (-2.5 to -1) and normal subjects (T > -1) exhibited similar isokinetic hip and trunk muscle strength. Women with osteoporotic distal radii had significantly lower grip strength than subjects who were osteopenic or normal at this site, but the osteoporotic group was also significantly older. In conclusion, our results indicate that the isokinetic strength of hip abductors weakly correlates with femoral BMD in postmenopausal women with and without osteoporosis. Trunk muscle strength did not correlate with lumbar vertebral BMD in either of these groups. The weaker handgrip we observed in the women with osteoporotic radii may be attributed to older age.

Influence of weight and weight change on bone loss in perimenopausal and early postmenopausal Scottish women

Weight is recognized as an important factor in determining an individual's risk of osteoporosis. However, little is known about whether weight or weight change influences bone loss around the time of the menopause, and the relationship with energy intake and physical activity level remains largely undefined. Healthy premenopausal women (1,064 selected from a random population of 5,119 women aged 45-54 years at baseline) each had bone mineral density (BMD), weight and height measurements, and completed a food frequency and physical activity questionnaire. Of the original participants, 907 women (85.2%) returned 6.3 +/- 0.6 years later for repeat BMD measurements, and 896 women completed the questionnaires. Bone loss at the hip (FN) and spine (LS) occurred before the menopause. Weight change rather than weight was associated with FN BMD loss (r=0.102, p=0.002), but weight at follow-up was associated with LS BMD change (r=0.105, p=0.002). Although an increase in physical activity level (PAL) appeared to be beneficial for FN BMD in women who were heavy weight gainers, PAL was associated with increased LS BMD loss in women who lost weight. For current HRT users, neither weight nor weight change was associated with change in BMD. Postmenopausal women not taking HRT should be made aware that low body weight or losing weight during this particularly vulnerable period may worsen bone loss.

Bone densitometry in premenopausal women: synthesis and review

Bone loss prior to menopause is being increasingly identified in women. Clearly, low bone mineral density (BMD) is a significant risk factor for fracture in the estrogen-deficient female postmenopause. The significance of low bone density prior to menopause needs to be addressed. Low bone density in the premenopausal female may reflect attainment of a lower peak bone mass. It may also be secondary to progressive bone loss following achievement of peak bone density. The etiology of low bone density in the premenopausal female needs to be clarified with meticulous exclusion of secondary causes of bone loss. Menstrual status is an important determinant of peak bone mass as well as the development of bone loss in women prior to the onset of menopause. Subclinical decreases in circulating gonadal steroids may be associated with a lower peak bone mass as well as progressive bone loss in otherwise reproductively normal women. Elevations of follicle-stimulating hormone (FSH) of greater than 20 miu/L are associated with evidence of increased bone turnover marker activity and correlate with progressive bone loss in perimenopausal women. This transitional period requires further study with respect to the magnitude of bone loss experienced and the potential benefits of antiresorptive therapy. Detailed assessment of menstrual status is necessary in the evaluation of low bone density in premenopausal women. The majority of the cross-sectional and longitudinal studies completed evaluating BMD in the premenopausal years suggest that minimal bone loss does occur prior to menopause after attainment of peak bone mass. The magnitude of premenopausal bone loss, however, is controversial and may be site-dependent. More rapid rates of bone loss are seen in the transitional period beginning 2-3 yr prior to the onset of menopause. Prospective data are needed to understand further the relationship between BMD and fracture in the premenopausal period. Women with steroid-induced bone loss as well as other secondary causes of osteoporosis respond to antiresorptive therapy with documented improvements in BMD. Biomarkers can identify perimenopausal women with increased bone turnover. Lifestyle modification can improve BMD in the pre- and the perimenopausal period. Antiresorptive therapy has not been evaluated in pre- or perimenopausal women with low BMD in the absence of secondary causes of osteoporosis. As new treatment options are evaluated and become available, biomarker assessment may be of value in identifying women at risk of fracture.

Endogenous hormones and bone turnover markers in pre- and perimenopausal women: SWAN

We tested the hypothesis that higher serum osteocalcin and urinary N-telopeptide of type I collagen (NTx) concentrations would be found in women with increasing cycle irregularity or increased follicle stimulating hormone concentrations. We studied 2,375 pre- and early perimenopausal women from the Study of Women's Health Across the Nation (SWAN), aged 42-52 years, who self-identified their race/ethnic origin as African-American (28.3%), Caucasian (49.4%), Japanese (10.5%) or Chinese (11.8%). Outcome measures were serum osteocalcin, a measure of bone formation, and NTx, a measure of bone resorption. The explanatory variables were menopausal status, based on self-reported regularity of menstrual bleeding, and circulating endogenous hormone concentrations including estradiol (E(2)), testosterone (T), sex hormone binding globulin (SHBG) and follicle stimulating hormone (FSH) concentrations. Additionally, we evaluated the association of the bone turnover markers with the Free Androgen Index (FAI) and the Free Estradiol Index (FEI), ratios of total testosterone and estradiol concentrations to SHBG, respectively. Higher FSH concentrations were associated with higher NTx concentrations ( beta=0.003, partial r2=2.1%, p<0.0001), both before and after adjusting for other covariates (total explained variability of 9%). Higher FSH concentrations were also associated with higher osteocalcin concentrations ( beta=-0.216, partial r2=4.1%, p<0.0001, total explained variability of 15.4%). There were no significant associations of the bone turnover markers with other endogenous hormones, following adjustment for covariates. Mean osteocalcin and NTx values were not significantly different in premenopausal women compared to early perimenopausal women. In these pre- and early perimenopausal women, higher FSH concentrations, but not other serum reproductive hormone concentrations, are positively associated with greater bone turnover prior to the last menstrual period.

When should densitometry be repeated in healthy peri- and postmenopausal women: the Danish osteoporosis prevention study

Intervention should be considered in postmenopausal women with bone mineral density (BMD) > or = 1 SD below the reference (T or Z score < -1). However, it is unclear when densitometry should be repeated. This study aimed at determining the need for repeat DXA within 5 years in untreated peri-/postmenopausal women to detect declines of T or Z score to below -1 with 85% confidence. A cohort of 925 healthy women (aged 51.2 +/- 2.9 years) were followed within the Danish Osteoporosis Prevention Study (DOPS) for 5 years without hormone-replacement therapy (HRT). DXA of spine, hip, and forearm was done at 0,1, 2, 3, and 5 years (Hologic QDR-1000/2000). The annual loss in SD units was 0.12 +/- 0.10 at the spine (1.3%), 0.10 +/- 0.09 at the femoral neck (1.2%), and 0.07 +/- 0.09 at the ultradistal (UD) forearm (1.0%). Accordingly, T scores below -1 developed earlier at the spine. The need for a future DXA scan to predict declines of T and Z scores below -1 depended strongly on baseline BMD. In subjects with a positive T score, the risk of developing T < -1 remained at <15% for 5 years at all measured sites. A new scan was needed after 1 year if the T score was below -0.5, and after 3 years if the T score was between 0 and -0.5. Slightly longer intervals apply if Z scores are used. Follow-up densitometry in untreated women should be individually targeted from baseline BMD rather than scheduled at fixed time intervals. An algorithm for planning repeat densitometry in perimenopausal women is provided.

A longitudinal study of bone density in midlife women

A longitudinal study of 386 healthy Black and White women aged 35-60 years was conducted to determine the effects of physical activity and other related factors on lumbar bone mineral density over 24 months. Bone mineral density of the lumbar spine, L2-L4, was measured using dual energy x-ray (Hologic 1000). Physical activity levels in three dimensions (leisure, household, and occupational) from both a lifelong and current perspective were obtained by questionnaire. Body mass index was calculated from measured weight in kilograms divided by measured height in meters squared. Calcium, caffeine, and alcohol intake was estimated using a food frequency questionnaire. Age, race, and smoking were determined by self-report. Radioimmunoassays of follicle stimulating hormone (FSH) and estradiol were used to validate self-reports of menopausal status. Multiple regression analysis revealed that race, age, weight, FSH, calcium, and years of tobacco intake formed the best model at baseline (r(2) = 0.32) and at 24 months (r(2) = 0.303). Physical activity was not a significant predictor for bone mineral density at either time point. There were cross-sectional changes of bone mineral density with race, age, and menopausal status. Black women had significantly higher bone mineral density than White women. However, an age-related decline in bone mineral density was exhibited in both Black and White women. Perimenopausal women had significantly lower bone mineral density as compared with premenopausal women. Furthermore 37 (9.6%) women at baseline and 34 (11%) at 24 months were designated at risk for fracture.

Number of years since menopause: spontaneous bone loss is dependent but response to hormone replacement therapy is independent

In this study we examine the influence of number of years since menopause on spontaneous bone loss and response to hormone replacement therapy (HRT) in 274 women (56.1 +/- 4.2 years) completing two placebo-controlled HRT studies of 2 or 3 year duration. Both cross sectionally and longitudinally, bone loss in untreated women was greatest closest to menopause and declined thereafter (r = 0.34, p < 0.01 for lumbar spine bone loss and r = 0.25, p < 0.05 for femoral neck bone loss when correlated with number of years since menopause), such that the loss was eliminated in the femoral neck and bone mass increased in the spine in women >10 years after menopause. In contrast, bone turnover was consistently elevated throughout postmenopause, both cross-sectionally and longitudinally. The association with number of years since menopause was counteracted by both 1 and 2 mg estradiol combined with gestodene, piperazine, estrone sulfate in combination with norethisterone, and a combination of 2 mg estradiol and 1 mg norethisterone acetate. In addition, the response to various HRT regimens was independent of baseline bone mass. Whereas bone loss was significantly related to number of years since menopause, all HRT regimens applied arrested bone loss in healthy postmenopausal women, regardless of number of years since menopause.

Hormone replacement therapy and fractures in older adults

Estrogen deficiency in women is associated with accelerated bone loss, and estrogen replacement therapy has been proven to be effective in preventing osteoporosis and fractures in postmenopausal women. The introduction of selective estrogen receptor modulators that have an estrogen-like effect on the skeleton but have a different pattern of effects on other tissues may have an important role in the management of osteoporosis in women in the near future. In men, androgen deficiency has been shown to be associated with osteoporosis. Although androgen replacement in hypogonadal men may decrease bone resorption and increase bone mass, long-term placebo-controlled trials are needed to better define the benefits and risks of such therapy before it can be recommended. Sex hormone deficiency is linked to the development of osteoporosis in both women and men. In women, hormonal replacement by estrogen or the newly developed selective estrogen receptor modulators may prevent the development of osteoporosis and its related fractures. In men, there is early evidence that testosterone replacement therapy may enhance bone mass in hypogonadal men.

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.

Gynecological factors and body mass index as determinants of bone mass in normal postmenopausal women. A study with peripheral quantitative computed tomography (pQCT)

OBJECTIVE

This paper studied the influence of several gynecological factors (years since menopause (YSM), age at menarche and gynecological age or reproductive life) simultaneously with anthropometric factors as determinants of bone mass in 189 healthy postmenopausal women.

METHODS

Bone mass was determined by peripheral quantitative computed tomography.

RESULTS

An overall evaluation showed that YSM correlated negatively with trabecular and cortical bone density (BMDTrab and BMDCorti) (P<0.05 in both cases). Age at menarche correlated negatively with BMDCorti (P<0.05) and gynecological age correlated positively with BMDTrab (P<0.05). Classifying the women according to their body mass index (BMI), the YSM correlation persisted in those subjects whose BMI was >25 kg/m(2), and in age at menarche and gynecological age of women whose BMI was <25 kg/m(2) (P<0.05). After separating women according to their age at menarche, their gynecological age and BMI, the only significant difference that persisted was in BMDTrab which was lower in the group with gynecological age <33 years, with a BMI <25 kg/m(2) (P=0.020). Parity and smoking had no impact on our results. By multiple regression, with BMD as the dependent variable and the gynecological factors as independent variables, we only observed significance between YSM and BMDCorti (P<0.005). The same was observed after separating women according to their BMI in the >25 kg/m(2) group (P<0.05).

CONCLUSIONS

Our data stress the importance of YSM on BMDTrab and BMDCorti, of age at menarche on BMDCorti and of gynecological age on BMDTrab. However, YSM is the gynecological factor that mainly determines BMD. The differences observed between measurements taken with pQCT and other methods commonly used to estimate bone mass indicate that results obtained with one technique cannot be extrapolated to other methods.

Digital X-ray radiogrammetry: a new appendicular bone densitometric method with high precision

The precision of any given method for measurement of bone mineral density (BMD) is important in relation to the interpretation of repeated measurements over time, e.g. to monitor the course of suspected osteoporosis or follow the effect of therapy. In the present study a new bone densitometer using the digital X-ray radiogrammetry (DXR) method (Pronosco X-posure Systemtrade mark) is investigated with respect to its short-term precision. The study was carried out on two groups of females, one consisting of 20 women between the ages of 30 and 40, and the other of 20 post-menopausal women above the age of 64. The mean age of the premenopausal women was 35.2 years and the mean DXR BMD was 0.578 g cm-2. The mean age of the post-menopausal women was 68.2 years and the mean DXR BMD was 0.489 g cm-2. The short-term precision of the two groups was evaluated using the coefficient of variation (CV%) and corresponding 90% confidence intervals. The coefficient of variation in the premenopausal group was 0.68% with a 90% confidence interval of 0. 57%-0.83%. The coefficient of variation in the postmenopausal group was 0.61% with a 90% confidence interval of 0.52-0.75%. It can be concluded from the present study that the short-term in vivo precision error of the DXR method is low in both pre- and post-menopausal women. When the results of the study are compared to data reported in the literature, the performance of the DXR method seems to be at least equivalent with peripheral DXA.

A lifetime of fitness. Exercise in the perimenopausal and postmenopausal woman

The peri- and postmenopausal woman experiences physiologic changes of aging that include alterations in hormone levels. Research has shown that the perimenopausal and postmenopausal woman can benefit significantly from exercise, whether endurance or strength training. Exercise can improve the quality of life and attenuate some of the physiologic changes associated with aging. Additionally, exercise can ameliorate the decline in fitness and bone, prevent chronic disease, and promote functional independence. Women who exercise regularly throughout life are physiologically 20 to 30 years younger than their sedentary counterparts. Fitness is a lifetime endeavor that has many positive benefits. Weightbearing activities are especially important as bone loss increases in the perimenopausal phase of life. Women should perform aerobic exercise 3 to 7 days per week for 15 to 60 minutes at 65% to 70% HRreserve. Strengthening exercises should be done 2 to 3 days per week at 40% to 80% 1RM with appropriately selected exercises. An exercise program should be functional and enjoyable. There is no better motivation to exercise than having a partner to work out with and keep the motivation alive. Most important, age itself is not a deterrent to exercise.

Prevalence of osteoporosis in women: variation with skeletal site of measurement of bone mineral density

OBJECTIVE

To determine retrospectively the prevalence of osteoporosis in a referral population of female patients and to compare the sensitivity for diagnosing osteoporosis by dual-energy x-ray absorptiometry (DXA) measurements of bone mineral density (BMD) at multiple skeletal sites.

METHODS

We studied the data from 625 consecutive women (mean age, 57.3 +/- 13.9 years), who had been referred to our center for lumbar spine (anteroposterior [AP] and lateral region) and hip (femoral neck [FN], Ward's triangle [WT], trochanter, intertrochanteric region, and total hip) BMD measurements with use of DXA (Hologic QDR-2000) between June 1994 and July 1998.

RESULTS

Osteoporosis (based on the World Health Organization definition--T-score of -2.5 or lower for BMD) was diagnosed by DXA at the following sites: AP spine in 21.7%, lateral spine in 43.2%, FN in 33.6%, WT in 49.1%, trochanter in 26.1%, intertrochanteric region in 25.9%, and total hip in 28.4% of study patients. Significant site differences were found in the prevalence of osteoporosis between the lateral and AP spine (P < 0.001), as well as between WT and the FN, trochanter, intertrochanteric region, and total hip (P < 0.001). In a subgroup of 71 women, forearm (ultradistal radius and radius 1/3 region) BMD results indicated low sensitivity for diagnosing osteoporosis, similar to that seen at the AP spine, trochanter, and intertrochanteric region. Not surprisingly, the prevalence of osteoporosis increased with advancing age (15.5% in patients younger than 50 years, in comparison with 59.6% in those older than 69 years of age). The frequency of misclassification of patients (osteoporosis at one site and normal BMD at another) with use of the seven measurement sites was 16.6% (104 of the 625 patients).

CONCLUSIONS

For diagnosis of osteoporosis, DXA BMD measurements are significantly more sensitive at the lateral spine than at the AP spine, as well as at WT than at the FN, trochanter, intertrochanteric region, and total hip sites.

Cross-sectional and longitudinal assessment of pre- and postmenopausal bone loss with a portable forearm X-ray device: the Ofely study

The aim of our study was to describe cross-sectional and longitudinal bone mineral decrease in pre-, peri-, and postmenopausal healthy women using a monoenergy X-ray densitometer specifically designed for forearm assessement. Measurements were performed on the most distal part of the radius (ultradistal, 55% of trabecular bone and 45% of trabecular bone), and on the distal part (distal, 13% of trabecular bone and 87% of cortical bone). A specific trabecular-rich region of interest (nROI) comprising two trapezoids regions of interest located proximally to the endplates of the radius and ulna was also investigated. From a large prospective study (OFELY study), 455 women were measured once a year for 2 years (three measurements). The proportion of postmenopausal women classified as having osteoporosis (i.e., a T score <-2.5) was 33% for the distal region, 44% for the ultradistal region, and 45% for the nROI. No significant bone mineral decrease was found over the 2-year period in premenopausal women (n = 138). In perimenopausal (n = 48) women, a bone loss of 1% was found at the distal site. In the 269 postmenopausal women, a significant decrease was observed at all sites, ranging from 2.14% for the nROI to 2.68% for the ultradistal part. Bone loss was greater in the first 5 years after menopause in trabecular sites and decreased thereafter. For the distal site, bone loss remained stable during the postmenopausal period. We conclude that this small and portable forearm densitometer is suitable for the diagnosis of osteoporosis, and provides information on the rate of bone loss in peri- and postmenopausal women in trabecular and cortical compartments of bone.

The type and time of menopause as decisive factors for bone mass changes

BACKGROUND

Early menopause, whether it be natural or surgical, is one of the established risk factors for osteoporosis. Surgical menopause, however, differs from natural menopause owing to the abrupt cessation of estrogen secretion. This study attempts to investigate the influence of menopause type on bone mineral density (BMD) changes.

METHODS

Four groups, each consisting of 30 women, were compared: early menopause (EMP), surgical menopause (SUMP) and two groups of natural menopause. The two groups share a similar number of years since menopause (YSM) but have a different chronological age (NMPO), or share a similar age but different YSM (NMPY) to the EMP and SUMP. BMD was measured by the DXA method at L2-L4 vertebrae and proximal femur.

RESULTS

Mean vertebral BMD of EMP was lower than that of SUMP (P < 0.05) and of NMPY (P < 0.001) women. Femoral neck BMD did not differ between SUMP and EMP women but both exhibited significantly lower BMD than either natural menopause groups. BMD of SUMP and vertebral BMD of NMPY women was inversely correlated to chronological age and to number of YSM. Pertaining to T-score values according to the osteoporotic range, NMPO, EMP and SUMP women being homogeneous exhibited significantly lower values than NMPY in the vertebrae (F-ratio = 7.84, P < 0.001). Whereas, in the femoral neck and the trochanter major, EMP and SUMP categories presented significantly lower T-score values than the NMPO and NMPY (F = 3.61, P < 0.01 and 2.8, P < 0.05 respectively).

CONCLUSION

Women with early menopause exhibit lower vertebral BMD than women of similar age after either surgical or natural menopause. In women of similar age, surgical menopause results in lower vertebral and femoral neck densities compared to natural menopause. Chronological age and the interval after menopause negatively affects bone density in women with similar age whether in surgical or natural menopause.

Osteoporosis and years since menopause

In Fukuoka Prefecture, in south-western Japan, a regional screening program for osteoporosis was conducted from 1994 to 1995. The screening level in the bone mineral density (BMD) at the distal non-dominant radius was equal to or less than two standard deviations below age-specific mean (< or = -2.0 SD). In 1177 examinees with natural menopause (mean age: 61.4, range: 42-88), 56 of those who were screened were subsequently radiologically confirmed by orthopedic specialists to have osteoporosis (case group). They were then compared with 802 normal BMD (> or =-1.0 SD) women (reference group) with their lifestyle and reproductive characteristics. The adjusted odds ratio (OR) and its 95% confidence interval (CI) were calculated using a logistic regression model. A significant increase in the ORs for osteoporosis based on the number of years since menopause was observed for 7-13 years since menopause (OR = 2.3; 95% CI: 1.0-5.4) compared with <7 years, however, no increasing trend in risk was evident in 14+ years since menopause (OR = 1.4; 95% CI: 0.4-5.1). Thus, the elevated risk continued up to around 10 years since menopause. These findings are consistent with previous studies that reported an alternation in the calcium metabolism and bone loss related to the length of time after menopause. Both the childhood and current milk consumption were also associated with a decreased risk: ORs were 0.4 (95% CI: 0.2-0.9) and 0.5 (95% CI: 0.3-1.0), respectively.

Changes in biochemical markers and bone mass after withdrawal of ibandronate treatment: prediction of bone mass changes during treatment

The study was a 1 year randomized, double-blind, placebo-controlled study of ibandronate treatment in postmenopausal, osteopenic women. Participants were followed for 1 year after withdrawal of treatment. All women were at least 10 years past menopause and had a baseline bone mineral density (BMD) at the distal forearm at least 1.5 standard deviations below the premenopausal mean peak value. A total of 141 women (78%) completed the first year, and 119 women (66%) the second year of the study. The dose-response data of the first year have been published previously (Ravn et al. Bone 19:527-533;1996). In this study, we analyzed the biochemical markers as predictors of response in bone mass during ibandronate treatment, and report withdrawal data from the last year of the study, when ibandronate was discontinued. The relative change in the biochemical markers was significantly correlated to the response in BMD. At 12 months, the r values ranged from -0.29 to -0.47 (p < 0.01) and were highest for CrossLaps (uCL) and osteocalcin (OC(N-MID)). The quartiles of women with the most reduced concentrations of uCL and OC(N-MID) during treatment showed a 360-430% higher response in BMD compared to quartiles with less reduced concentrations (p < 0.01). During the withdrawal period, uCL and alkaline phosphatase (AP) returned to baseline values 12 months after discontinuation of treatment in all groups, whereas OC(N-MID) and bone-specific AP were still reduced 10%-25% in the groups previously treated with the highest doses of ibandronate (1.0-5.0 mg) (p < 0.01). In the withdrawal period, BMD decreased equally in all groups (analysis of variance; not significant); with a linear rate of 2%/year on average (p < 0.05 to < 0.001) at the spine and femur. In conclusion, uCL and OC(N-MID) can be used to predict the response in bone mass during ibandronate treatment. The bone loss that resumes after withdrawal of ibandronate treatment is of a magnitude similar to that of normal postmenopausal bone loss.

Update on primary osteoporosis

Osteoporosis is the most common bone disorder encountered in clinical practice. It is also one of the most important diseases facing our aging population. In the United States alone, an estimated 1.5 million fractures that occur annually are attributed to osteoporosis, and they account for an estimated $13 billion annually. With the projected increase in life expectancy for the global population, osteoporosis and osteoporosis-related fractures have the potential to become an even larger health-care problem in the future. This article focuses on the evaluation and treatment of primary osteoporosis in women.