Assessing bone density in men

Frailty and bone health in European men

Background

frailty is associated with an increased risk of fragility fractures. Less is known, however, about the association between frailty and bone health.

Methods

men aged 40-79 years were recruited from population registers in eight European centres for participation in the European Male Aging Study. Subjects completed a comprehensive assessment which included quantitative ultrasound (QUS) scan of the heel (Hologic-SAHARA) and in two centres, dual-energy bone densitometry (dual-energy x-ray absorptiometry, DXA). Frailty was defined based on an adaptation of Fried's phenotype criteria and a frailty index (FI) was constructed. The association between frailty and the QUS and DXA parameters was determined using linear regression, with adjustments for age, body mass index and centre.

Results

in total, 3,231 subjects contributed data to the analysis. Using the Fried categorisation of frailty, pre-frail and frail men had significantly lower speed of sound (SOS), broadband ultrasound attenuation (BUA) and quantitative ultrasound index (QUI) compared to robust men (P< 0.05). Similar results were seen using the FI after categorisation into 'high', 'medium' and 'low' levels of frailty. Using the Fried categorisation, frail men had lower femoral neck bone mineral density (BMD) compared to robust men (P < 0.05), but not lower lumbar spine BMD. Using the FI categorisation, a 'high' level of frailty (FI > 0.35) was associated with lower lumbar spine BMD (P < 0.05) when compared to those with low (FI < 0.2), but not lower femoral neck BMD. When analysed as a continuous variable, higher FI was linked with lower SOS, BUA and QUI (P < 0.05).

Conclusions

optimisation of bone health as well as prevention of falls should be considered as strategies to reduce fractures in frail older people.

Study of sex differences in the association between hip fracture risk and body parameters by DXA-based biomechanical modeling

There is controversy about whether or not body parameters affect hip fracture in men and women in the same way. In addition, although bone mineral density (BMD) is currently the most important single discriminator of hip fracture, it is unclear if BMD alone is equally effective for men and women. The objective of this study was to quantify and compare the associations of hip fracture risk with BMD and body parameters in men and women using our recently developed two-level biomechanical model that combines a whole-body dynamics model with a proximal-femur finite element model. Sideways fall induced impact force of 130 Chinese clinical cases, including 50 males and 80 females, were determined by subject-specific dynamics modeling. Then, a DXA-based finite element model was used to simulate the femur bone under the fall-induced loading conditions and calculate the hip fracture risk. Body weight, body height, body mass index, trochanteric soft tissue thickness, and hip bone mineral density were determined for each subject and their associations with impact force and hip fracture risk were quantified. Results showed that the association between impact force and hip fracture risk was not strong enough in both men (r=-0.31,p<0.05) and women (r=0.42,p<0.001) to consider the force as a sole indicator of hip fracture risk. The correlation between hip BMD and hip fracture risk in men (r=-0.83,p<0.001) was notably stronger than that in women (r=-0.68,p<0.001). Increased body mass index was not a protective factor against hip fracture in men (r=-0.13,p>0.05), but it can be considered as a protective factor among women (r=-0.28,p<0.05). In contrast to men, trochanteric soft tissue thickness can be considered as a protective factor against hip fracture in women (r=-0.50,p<0.001). This study suggested that the biomechanical risk/protective factors for hip fracture are sex-specific. Therefore, the effect of body parameters should be considered differently for men and women in hip fracture risk assessment tools. These findings support further exploration of sex-specific preventive and protective measurements to reduce the incidence of hip fractures.

Treatment of osteoporosis in men

SUMMARY

Aspects of osteoporosis in men, such as screening and identification strategies, definitions of diagnosis and intervention thresholds, and treatment options (both approved and in the pipeline) are discussed.

INTRODUCTION

Awareness of osteoporosis in men is improving, although it remains under-diagnosed and under-treated. A European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) workshop was convened to discuss osteoporosis in men and to provide a report by a panel of experts (the authors).

METHODS

A debate with an expert panel on preselected topics was conducted.

RESULTS AND CONCLUSIONS

Although additional fracture data are needed to endorse the clinical care of osteoporosis in men, consensus views were reached on diagnostic criteria and intervention thresholds. Empirical data in men display similarities with data acquired in women, despite pathophysiological differences, which may not be clinically relevant. Men should receive treatment at a similar 10-year fracture probability as in women. The design of mixed studies may reduce the lag between comparable treatments for osteoporosis in women becoming available in men.

Important risk factors and attributable risk of vertebral fractures in the population-based Tromsø study

Background

Vertebral fractures, the most common type of osteoporotic fractures, are associated with increased risk of subsequent fracture, morbidity, and mortality. The aim of this study was to examine the contribution of important risk factors to the variability in vertebral fracture risk.

Methods

Vertebral fracture was ascertained by VFA method (DXA, GE Lunar Prodigy) in 2887 men and women, aged between 38 and 87 years, in the population-based Tromsø Study 2007/2008. Bone mineral density (BMD; g/cm²) at the hip was measured by DXA. Lifestyle information was collected by questionnaires. Multivariable logistic regression model, with anthropometric and lifestyle factors included, was used to assess the association between each or combined risk factors and vertebral fracture risk. Population attributable risk was estimated for combined risk factors in the final multivariable model.

Results

In both sexes, age (odds ratio [OR] per 5 year increase: 1.32; 95% CI 1.19-1.45 in women and 1.21; 95% CI 1.10-1.33 in men) and BMD (OR per SD decrease: 1.60; 95% CI 1.34-1.90 in women and1.40; 95% CI 1.18-1.67 in men) were independent risk factors for vertebral fracture. At BMD levels higher than 0.85 g/cm², men had a greater risk of fracture than women (OR 1.52; 95% CI 1.14-2.04), after adjusting for age. In women and men, respectively, approximately 46% and 33% of vertebral fracture risk was attributable to advancing age (more than 70 years) and low BMD (less than 0.85 g/cm²), with the latter having a greater effect than the former.

Conclusions

These data confirm that age and BMD are major risk factors for vertebral fracture risk. However, in both sexes the two factors accounted for less than half of fracture risk. The identification of individuals with vertebral fracture is still a challenge.

Relationship of femoral neck areal bone mineral density to volumetric bone mineral density, bone size, and femoral strength in men and women

Using combined dual-energy X-ray absorptiometry (DXA) and quantitative computed tomography, we demonstrate that men matched with women for femoral neck (FN) areal bone mineral density (aBMD) have lower volumetric BMD (vBMD), higher bone cross-sectional area, and relatively similar values for finite element (FE)-derived bone strength.

INTRODUCTION

aBMD by DXA is widely used to identify patients at risk for osteoporotic fractures. aBMD is influenced by bone size (i.e., matched for vBMD, larger bones have higher aBMD), and increasing evidence indicates that absolute aBMD predicts a similar risk of fracture in men and women. Thus, we sought to define the relationships between FN aBMD (assessed by DXA) and vBMD, bone size, and FE-derived femoral strength obtained from quantitative computed tomography scans in men versus women.

METHODS

We studied men and women aged 40 to 90 years and not on osteoporosis medications.

RESULTS

In 114 men and 114 women matched for FN aBMD, FN total cross-sectional area was 38% higher (P < 0.0001) and vBMD was 16% lower (P < 0.0001) in the men. FE models constructed in a subset of 28 women and 28 men matched for FN aBMD showed relatively similar values for bone strength and the load-to-strength ratio in the two groups.

CONCLUSIONS

In this cohort of young and old men and women from Rochester, MN, USA who are matched by FN aBMD, because of the offsetting effects of bone size and vBMD, femoral strength and the load-to-strength ratio tended to be relatively similar across the sexes.

Towards a diagnostic and therapeutic consensus in male osteoporosis

The consensus views on osteoporosis in men are reported.

INTRODUCTION

A workshop was convened within a meeting on osteoporosis in men to identify areas of consensus amongst the panel (the authors) and the participants of the meeting.

METHODS

A public debate with an expert panel on preselected topics was conducted.

RESULTS AND CONCLUSIONS

Consensus views were reached on diagnostic criteria and several aspects on the pathophysiology and treatment of osteoporosis in men.

[Prevalence of osteoporosis in male patients with risk factors]

Male osteoporosis is often secondary to other conditions. However the causes of osteoporosis in men are dramatically variable according to the authors. The aim of this observational multicenter study was to assess the main risk factors and causes for male patients with low bone mineral density (LBM).

METHODS

The study was performed in a cohort of rheumatologists who usually prescribe bone mineral density assessment according to HAS criteria (one or more criteria) for bone mineral density (BMD) measurement as defined by: (a): vertebral fracture; (b): non traumatic non vertebral fracture; (c): corticosteroid therapy; (d): hypogonadism or GnRH agonist therapy; (e): endocrine disorders; (f): osteogenesis imperfecta (OI). BMD was measured by dual photon absorptiometry (DXA) at lumbar spine, femoral or total neck sites. Osteoporosis was defined as a T-score value less or equal to 2.5 at one of those region of interest (ROI); LBM as a T-score value between -1 and -2.5.

RESULTS

A total of 431 rheumatologists included 1198 male patients (66.6 ± 12.2 years). According to DXA results, 888 patients (74.1 %) had osteoporosis and 231 (19.3 %) had osteopenia. BMD was considered as normal for 79 patients (6.6 %). A total of 1146 patients (95.7 %) satisfied to the criteria of reimbursement of DXA measurement. Six hundred and eighty-six patients (57.3 %) had suffered from vertebral fractures and 349 patients (29.2 %) from non vertebral fractures. Corticosteroids had been prescribed in 28.7 % of patients and 6.6 % were treated with GnRH agonists for prostate cancer. Hypogonadism was diagnosed in 27 %. Five patients suffered from OI. Other risk factors were detected: alcoholism and smoking in 28.1 % and 42.9 % respectively; rheumatoid arthritis or spondylarthropathy in 12.5 % of patients; chronic pulmonary disorders in 16.1 %. By contrast endocrinopathies were rare (2.5 %). Several risk factors were more frequently encountered for patients with osteoporosis as compared with osteopenia, i.e., smoking, alcohol abuse, low calcium intake, vitamin D insufficiency and maternal history of hip fracture.

CONCLUSION

A diagnosis of osteoporosis (BMD ≤ 2.5) was established by rheumatologists in 74.1 % of patients with clinical risk factors: LBM was found in 93.4 %. In 95.7 % the criteria for reimbursement of DXA measurement were satisfied. DXA is useful in male patients with classical risk factors of osteoporosis to confirm the diagnosis of the disease and start a treatment.

Using the same bone density reference database for men and women provides a simpler estimation of fracture risk

Although low bone mineral density (BMD) predicts fractures, there are postulated sex differences in the fracture "threshold." Some studies demonstrate a higher mean BMD for men with fractures than for women, whereas others note similar absolute risk at the same level of BMD. Our objective was to test the preceding observations in the population-based Canadian Multicentre Osteoporosis Study (CaMOS). We included participants 50+ years of age at baseline. Mean BMD in men was higher than in women among both fracture cases and noncases. Three methods of BMD normalization were compared in age-adjusted Cox proportional hazards models. In a model using the same reference population mean and standard deviation (SD), there were strong effects of age and total-hip BMD for prediction of fractures but no significant effect of sex [hazard ratio (HR) = 0.97, 95% confidence interval (CI) 0.78-1.20] for men versus women. In a model using sex-specific reference means but a common SD, an apparent sex difference emerged (HR = 0.66, 95% CI 0.54-0.81) for men versus women. The sex term in the second model counterbalanced the higher risk introduced by the lower normalized BMD in men. A third model using sex-specific reference means and SDs gave nearly identical results. Parallel results for the three methods of normalization were seen when adjusting for clinical risk factors, excluding antiresorptive users and considering death as a competing risk. We conclude that no adjustment for sex is necessary when using common reference data for both men and women, whereas using sex-specific reference data requires a substantial secondary adjustment for sex.

Male osteoporosis

Osteoporosis develops in males approximately 10 years later than in females. Low vitamin D is a common problem. Decline in testosterone represents a major cause for osteoporosis in men. Bisphosphonates are the treatment of choice for osteoporosis in older males.

Bone loss and the risk of non-vertebral fractures in women and men: the Tromsø study

SUMMARY

We assessed the association between the rate of forearm bone loss and non-vertebral fracture. Bone loss at the distal forearm predicted fractures, independently of baseline BMD, but not independently of follow-up BMD in women. The BMD level where an individual ends up is the significant predictor of fracture risk.

INTRODUCTION

Bone loss may predict fracture risk independently of baseline BMD. The influence of follow-up BMD on this prediction is unknown. The aim of this study was to assess the association between bone loss and fracture risk in both sexes in a prospective population-based study.

METHODS

We included 1,208 postmenopausal women (50 to 74 years), and 1,336 men (55 to 74 years) from the Tromsø Study, who had repeated distal and ultra-distal forearm BMD measurements. Non-vertebral fractures were registered from 2001 to 2005.

RESULTS

A total of 100 women and 46 men sustained fractures during the follow-up time. Independent of baseline BMD, the RR associated with distal site bone loss of 1 SD %/year was 1.23 (1.01-1.50) for low-trauma fractures (excluding hand, foot, skull & high-trauma) and 1.32 (1.07-1.62) for osteoporotic fractures (hip, wrist and shoulder). However, bone loss did not predict fracture after adjusting for follow-up BMD. The BMD level where an individual ends up became the significant predictor of fracture risk and not the rate of bone loss. Follow-up BMD at ultra-distal site was associated with low-trauma fractures in both sexes. While ultra-distal site BMD changes were not associated with fracture risk in both sexes.

CONCLUSION

Bone loss at the distal forearm predicted non-vertebral fractures, independently of baseline BMD, but not independently of follow-up BMD, in women. The BMD level where an individual ends up is the significant predictor of fracture risk and not the rate of bone loss.

Correlates of trabecular and cortical volumetric bone mineral density at the femoral neck and lumbar spine: the osteoporotic fractures in men study (MrOS)

The objective of this cross-sectional analysis was to examine the correlates of trabecular and cortical volumetric bone mineral density (vBMD) in 3670 community-dwelling men, mean age 73.6 ± 5.9 years. vBMD was measured by quantitative computed tomography (QCT) and areal BMD by dual-energy X-ray absorptiometry (DXA). Demographic, historical, and lifestyle information was obtained by interview, and height, weight, and neuromuscular function were determined by examination. To express the strength of the associations, percent differences (95% confidence interval) were calculated from multivariable linear regression models using the formula 100 (β × unit/mean BMD). Units for continuous variables were chosen to approximate 1 standard deviation (SD). The multivariable linear regression models predicted 15%, 21%, and 20% of the overall variance in trabecular and cortical vBMD of the femoral neck and vBMD of the lumbar spine, respectively. Diabetes was associated with a 16.5% greater trabecular vBMD at the femoral neck and 11% at the lumbar spine but less than 2% for cortical vBMD. For femoral neck trabecular vBMD, the strongest negative correlates were past smoking (-9%), fracture history (-15%), kidney stones (-7%), corticosteroids (-11%), and insulin therapy (-26%). For cortical vBMD, the strongest negative correlate was use of thyroid medication (-2.8%). The strongest negative correlates for lumbar spine trabecular vBMD were fracture history (-5%), antiandrogen use (-19%), height (-8%), and thiazoliainedione use (-22%). Bioavailable estradiol and testosterone levels were positively related and sex hormone-binding globulin was negatively related to trabecular vBMD of the spine. There was no relationship between sex hormones and femoral neck trabecular vBMD. Our conclusion is that correlates of trabecular vBMD and cortical vBMD appear to differ in older men.

Testosterone in older men after the Institute of Medicine Report: where do we go from here?

Despite nearly a half-century of research on aging and sex steroids in men, answers to key questions that would allow us to confidently assess risk:benefit ratios for androgen replacement in older men with the partial androgen deficiency of aging men (PADAM) syndrome remain uncertain. Although it is now reasonably clear that a significant percentage of otherwise healthy older men have decreases in testosterone and bioavailable testosterone to levels consistent with hypogonadism, the clinical implications of this change remain uncertain. Data suggest that low testosterone in older men is correlated to varying degrees with loss of lean body mass and muscle strength, and increased total and central body fat. Less certain, but suggestive, are data relating low testosterone levels to decreased bone density, loss of insulin sensitivity, and cognitive and affective deterioration, as well as reduced sexual function. Replacement of testosterone in older men has shown some positive effects on each of these variables, but findings have been inconsistent, perhaps because studies have employed different preparations and doses of androgens, treated for various durations, and defined their target populations in different ways. As important as beneficial effects is the potential for adverse effects, which may be greater in older men. Possible problems include sleep apnea, erythrocytosis, dyslipidemia with acceleration of atherosclerosis, and, of greatest concern, prostate cancer or hyperplasia. Studies to date have suggested that these outcomes are not major risks, but, in the absence of a large, randomized trial or trials, definitive information is not available. The US National Academies Institute of Medicine's recent report recommends that the National Institutes of Health support small efficacy trials aimed at treatment of androgen deficiency-related clinical conditions, but not a large, randomized trial to elucidate risk:benefit ratios. This recommendation, if adhered to, is likely to delay, rather than foster, progress in this important area.

Intravenous zoledronic acid: what are the indications for male osteoporosis?

Osteoporosis and fractures are under-recognized and undertreated, both in men and women worldwide. Male osteoporosis is not the epidemic problem that female osteoporosis is; however, the National Osteoporosis Foundation estimates that over 14 million American men have osteoporosis or low bone mass, and approximately 25% to 30% of all hip fractures occur in male individuals who incur greater morbidity and mortality than their female counterparts. Until recently, alendronate, risedronate, and teriparatide were the only pharmacologic agents approved by the US Food and Drug Administration for treating male osteoporosis. In December 2008, zoledronic acid was approved for "treatment to increase bone mass in men with osteoporosis." In 2009, zoledronic acid was also approved for "treatment and prevention of glucocorticoid-induced osteoporosis in patients (both men and women) expected to be on glucocorticoids for at least 12 months."

Risk Factors for the Development of Osteoporosis and Osteoporotic Fractures Among Older Men

Objective.

Osteoporotic fractures are associated with significant morbidity and mortality particularly among older men. However, there is little information regarding risk factors among this population. The aims of our study were to determine risk factors for osteoporosis and fragility fractures and the predictive value of bone mineral density (BMD) measurements for development of fragility fractures in a cohort of elderly Caucasian and African American men.

Methods.

We evaluated 257 men aged 70 years or older for risk factors for osteoporosis and fragility fractures using a detailed questionnaire and BMD assessment. Exclusion criteria included conditions known to cause osteoporosis such as hypogonadism and chronic steroid use, current treatment with bisphosphonates, bilateral hip arthroplasties, and inability to ambulate independently.

Results.

Age, weight, weight loss, androgen deprivation treatment, duration of use of dairy products, exercise, and fracture within 10 years prior to study entry were associated with osteoporosis (p ≤ 0.05). Fragility fractures were associated with duration of use of dairy products, androgen deprivation treatment, osteoporosis, and history of fracture within 10 years prior to BMD assessment (p ≤ 0.05). There were some differences in risk factors between the Caucasian and African American populations, suggesting that risk factors may vary between ethnic groups.

Conclusion.

Although men with osteoporosis had a higher rate of fractures, the majority of fractures occurred in men with T-scores > −2.5 standard deviations below the mean, suggesting that factors other than BMD are also important in determining risk.

New Therapies for Osteoporosis

Osteoporosis is a growing health concern in the United States, with an enormous impact on morbidity and mortality. Despite published guidelines to aid clinicians in its management, several controversies remain. Many trials evaluate surrogate measures of bone strength rather than more clinically relevant outcomes, including fracture. Furthermore, the role of combination and sequential therapy remains unclear. Limited data are available regarding appropriate duration of therapy, management of osteoporosis in men, and treatment of glucocorticoid-induced osteoporosis. The development of unique therapeutic agents could potentially revolutionize the treatment of osteoporosis. Once yearly zoledronic acid may provide advantages over existing therapies. Because of limitations with existing selective estrogen receptor modulators, the search for agents with better efficacy and safety profiles has led to the development of several new medications within this class. Finally, denosumab, a monoclonal antibody to receptor activator for nuclear factor-kappa B ligand, also represents a novel therapeutic option for osteoporosis.

First update of the Lebanese guidelines for osteoporosis assessment and treatment

With the demographic explosion, the human, social, and economic costs of osteoporosis in developing countries, including the Middle East, will continue to rise. In 2002, the Lebanese Guidelines for Osteoporosis Assessment and Treatment were developed to optimize quality of osteoporosis care in Lebanon and the region. They were endorsed by 5 Lebanese medical scientific societies, and by the Eastern Mediterranean Regional Office branch of the World Health Organization (WHO). In April 2006, the Lebanese Society for Osteoporosis and Metabolic Bone Disorders (OSTEOS) led an initiative to update several recommendations detailed in the original document, based on relevant new local and international data. Data from a population-based sample of elderly Lebanese validated the following recommendations: fracture risk assessment, expressed as relative risk per standard deviation (RR/SD) decrease, was comparable in Lebanese subjects to similarly derived estimates from Western studies; the use of the NHANES database (hip), and the densitometer American database (spine) was as good, if not superior to the use of a Lebanese database for identifying subjects with prevalent vertebral fractures. The original recommendation regarding the use of a gender-specific western database, densitometer for spine and NHANES for T-score derivation for men, remains unchanged. For skeletal site selection, the update recommends measuring the spine and hip for women < or =65 yr, hip only for subjects >65 yr, and adding the forearm in conditions associated with cortical bone loss or in the case of inability to measure axial sites. The original recommendations for conservative management in premenopausal women were reiterated. This First Update of the Lebanese Osteoporosis Guidelines validates previous recommendations using evidence from a population-based sample of elderly Lebanese, and lays the ground for transitioning the Lebanese Osteoporosis Guidelines to the WHO global fracture risk assessment model.

A reference standard for the description of osteoporosis

In 1994, the World Health Organization published diagnostic criteria for osteoporosis. Since then, many new technologies have been developed for the measurement of bone mineral at multiple skeletal sites. The information provided by each assessment will describe the clinical characteristics, fracture risk and epidemiology of osteoporosis differently. Against this background, there is a need for a reference standard for describing osteoporosis. In the absence of a true gold standard, this paper proposes that the reference standard should be based on bone mineral density (BMD) measurement made at the femoral neck with dual-energy X-ray absorptiometry (DXA). This site has been the most extensively validated, and provides a gradient of fracture risk as high as or higher than that of many other techniques. The recommended reference range is the NHANES III reference database for femoral neck measurements in women aged 20-29 years. A similar cut-off value for femoral neck BMD that is used to define osteoporosis in women can be used for the diagnosis of osteoporosis in men - namely, a value for BMD 2.5 SD or more below the average for young adult women. The adoption of DXA as a reference standard provides a platform on which the performance characteristics of less well established and new methodologies can be compared.

Femoral neck BMD is a strong predictor of hip fracture susceptibility in elderly men and women because it detects cortical bone instability: the Rotterdam Study

We studied HSA measurements in relation to hip fracture risk in 4,806 individuals (2,740 women). Hip fractures (n = 147) occurred at the same absolute levels of bone instability in both sexes. Cortical instability (propensity of thinner cortices in wide diameters to buckle) explains why hip fracture risk at different BMD levels is the same across sexes.

INTRODUCTION

Despite the sexual dimorphism of bone, hip fracture risk is very similar in men and women at the same absolute BMD. We aimed to elucidate the main structural properties of bone that underlie the measured BMD and that ultimately determines the risk of hip fracture in elderly men and women.

MATERIALS AND METHODS

This study is part of the Rotterdam Study (a large prospective population-based cohort) and included 147 incident hip fracture cases in 4,806 participants with DXA-derived hip structural analysis (mean follow-up, 8.6 yr). Indices compared in relation to fracture included neck width, cortical thickness, section modulus (an index of bending strength), and buckling ratio (an index of cortical bone instability). We used a mathematical model to calculate the hip fracture distribution by femoral neck BMD, BMC, bone area, and hip structure analysis (HSA) parameters (cortical thickness, section modulus narrow neck width, and buckling ratio) and compared it with prospective data from the Rotterdam Study.

RESULTS

In the prospective data, hip fracture cases in both sexes had lower BMD, thinner cortices, greater bone width, lower strength, and higher instability at baseline. In fractured individuals, men had an average BMD that was 0.09 g/cm(2) higher than women (p < 0.00001), whereas no significant difference in buckling ratios was seen. Modeled fracture distribution by BMD and buckling ratio levels were in concordance to the prospective data and showed that hip fractures seem to occur at the same absolute levels of bone instability (buckling ratio) in both men and women. No significant differences were observed between the areas under the ROC curves of BMD (0.8146 in women and 0.8048 in men) and the buckling ratio (0.8161 in women and 0.7759 in men).

CONCLUSIONS

The buckling ratio (an index of bone instability) portrays in both sexes the critical balance between cortical thickness and bone width. Our findings suggest that extreme thinning of cortices in expanded bones plays a key role on local susceptibility to fracture. Even though the buckling ratio does not offer additional predictive value, these findings improve our understanding of why low BMD is a good predictor of fragility fractures.

Osteoporosis in men

Osteoporosis has long been considered to be a disease of the aging female skeleton. As awareness of the pervasiveness of this disorder increases, it is clear that men are also at risk for this disorder. Recent epidemiological studies have confirmed that osteoporosis in men is an increasing health problem. This development not only has its roots in increased longevity but also in increased awareness of this problem in men. The purpose of this article is to review what is known about the factors in men that lead to acquisition, maintenance, and loss of bone, as well as new insights about the causes, pathogenesis, and treatment of osteoporosis in men.

Association of kidney function with incident hip fracture in older adults

Kidney dysfunction is associated with bone loss, and patients with ESRD have an increased risk for hip fracture. However, the association of mild to moderate kidney disease with hip fracture has not been studied previously. The association of kidney function with incident hip fracture was examined among participants in the Cardiovascular Health Study, a community-based cohort of older individuals. The primary measure of kidney function was serum cystatin C, a measure that does not depend on lean mass. Hip fractures were identified using International Classification of Diseases, Ninth Revision codes for hospitalizations. A total of 4699 individuals had cystatin C measured in 1992 to 1993 and did not have a hip fracture before cystatin C measurement. The association of kidney function with hip fracture was analyzed with Cox proportional hazards models. Analyses were conducted separately for men and women. After a mean follow-up of 7.1 yr, 195 incident hip fractures occurred in women and 79 occurred in men. Higher cystatin C levels were associated with a higher risk for fracture in women (hazard ratio [HR] 1.26; 95% confidence interval [CI] 1.14 to 1.38 per SD) and in men (HR 1.27; 95% CI 1.11 to 1.46). After multivariable adjustment, higher cystatin C levels were significantly associated with hip fracture in women (HR 1.16; 95% CI 1.01, 1.33) but not in men (HR 1.14; 95% CI 0.86 to 1.52), although the magnitude of the association was similar. Kidney dysfunction, as assessed by cystatin C, is associated with an increased risk for hip fracture. Further studies are needed to evaluate potential mediators of this relationship and to assess whether interventions can decrease this risk.

Osteoporosis: differences and similarities in male and female patients

Osteoporosis is associated with decreased bone strength as a consequence of decreased bone density and altered quality. It is a result of a disruption of balance between bone breakdown and bone formation, caused by increased bone resorption by osteoclasts or without appropriate screening, one's first awareness of the disease is a fracture. It results in increased mortality and significant morbidity. In the last decade, great strides have been made in defining the diagnosis and establishing effective modes of treatment for this disorder. Our current state of knowledge indicates that although this disease affects both sexes, there are clear differences that have clinical importance.

Office practice of osteoporosis evaluation

Osteoporosis is a metabolic disease characterized by low bone mass and microarchitectural deterioration of bone tissue, leading to enhanced bone fragility and a consequent increase in fracture risk. Bone fragility depends on bone density, turnover and microarchitectural features, such as relative trabecular volume, spacing, number and connectivity. Previous fragility fractures increase the fracture risk irrespective of bone density. Other risk factors must also be considered as many fractures occur in patients with osteopenia on densitometry. On the other hand, the diagnosis of osteoporosis and increased fracture risk should not be based on densitometric data alone when young populations such as men below 65 years, premenopausal women, adolescents and children are considered.

Association between level of frailty and bone mineral density in community-dwelling men

The goal of this study is to determine the associations between the components of a frailty definition and bone mineral density (BMD) in older men. A total of 392 community dwelling men (age range: 58-95 yr) with a mean age of 73+/-8 yr were evaluated. Femoral neck BMD T-scores ranged from -5.78 to +2.50, with 48.7% who had T-scores between -1 and -2.5 (low bone mass) and 8.7% who had T scores < or = -2.5 (osteoporosis). Participants were characterized as normal (39%), intermediate (55%), or frail (6%). Hand grip strength was 31.5+/-9.1 kg in those with normal BMD compared with 26.5+/-7.9 kg in those with osteoporotic BMD (p=0.0026). Walk speed (8 ft) was 2.32+/-0.49 s in those with normal BMD compared with 2.87+/-1.30 s with osteoporotic BMD (p=0.0015). Femoral neck T-score declined significantly with increasing level of frailty (p=0.014), but significance of decline was lost when corrected for age. Increasing frailty was associated with lower femoral neck BMD, although the association was not independent of age. Two components of the frailty model (i.e., hand grip strength and walking speed) were independently associated with lower femoral neck BMD, a finding that has not previously been reported in men.

Femoral bone mineral density in patients with heart failure

INTRODUCTION

Heart failure and osteoporosis are common conditions in older, frail individuals. It is important to investigate interactions of the common problems in the aging population to devise relevant interventions.

METHODS

Sixty individuals (43 men, mean age 77+/-9 years, and 17 women, mean age 78+/-12 years) with heart failure (HF) and 23 age- and gender-matched non-HF controls (15 men, eight women; mean age 77+/-9 years) underwent hip and bone mineral density (BMD) assessments; frailty assessment; physical performance assessment including 6-min walk, grip strength, and self-reported physical activity; and biochemical assessment including calcium, parathyroid hormone (PTH), 25-hydroxy vitamin D (25-OHD), estradiol, creatinine (Cr), and blood urea nitrogen levels (BUN).

RESULTS

Significant differences between HF and control groups were found for BMD Z-scores of the femoral neck, total femur, and trochanteric region at the femur (p<.05). Further differences between groups included frailty score (p=.02), 6-min walking distance (p<.001), and self-reported physical activity (p=.001). In addition, several differences between groups were present for calcium (p=.054), PTH (p<.001), 25-OHD (p=.01), Cr (p=.04), and BUN (p=.01). In regression analysis, HF (defined as case, by ejection fraction, or by New York Heart Association class), frailty status, and vitamin D were significant predictors of lower bone mass at the femur.

CONCLUSIONS

Individuals with HF have lower BMD, in part related to lower vitamin D status and higher frailty rates. Interventions to optimize vitamin D and physical activity should be explored to prevent bone loss in individuals with heart failure.

Pharmacotherapy of osteoporosis in men

Osteofragility fractures occur in men due to a compromise in bone strength, coupled with either trauma or a fall. In men >or= 65years of age, osteoporosis can be defined as bone mineral density (at the proximal femur, spine or distal forearm) of 2.5 standard deviations or less below the mean for a normal young adult man, using a male reference database (i.e., T-score value of <or=-2.5) [1,2]. In men 50 - 65 years of age, a similar definition is used if other risk factors for a fracture are present. Osteoporosis is increasingly recognised in men [3-11]. One in three men aged > 60 years will suffer an osteoporotic fracture [3]. Spinal fractures occur in 5% of men (compared with 16% of women) and hip fractures in 6% of men (compared with 18% of women) > 50 years of age [8]. The risk of hip fracture increases by approximately 2.6-fold for each standard deviation decrease in bone density measured at the hip [12,13]. At present, the life expectancy for men has increased to a mean age of 76.8 years. With men now living longer, they can be expected to develop multiple coexisting illnesses contributing to bone loss and an increased likelihood of falling and fragility fractures [5,14,15]. It is estimated that 30 - 60% of men presenting with spinal fractures have another illness contributing to their bone disease [4,6-10,16-20]. The ideal therapy for men with osteoporosis should include an intervention which significantly increases bone strength and reduces fracture rates, is safe, easy to administer and economical. This review outlines the current treatment strategies available for men with osteoporosis.

Quality and performance measures in bone densitometry: part 1: errors and diagnosis

INTRODUCTION

Bone densitometry is one of the main pillars in the assessment of osteoporosis. The most important modalities are dual x-ray absorptiometry (DXA), quantitative computed tomography (QCT), and quantitative ultrasound (QUS).

MATERIALS AND METHODS

For each modality a variety of technical solutions and numerous commercial devices are available and widely used for patient measurements. While the field of bone densitometry may be considered mature, new modalities and devices are being introduced. Consequently, there is a constant need to assess and compare the quality of bone densitometry approaches and devices in a rigorous way.

RESULTS

The International Commission on Radiation Units has commissioned a report on bone densitometry to address some of these issues, in particular to provide clear definitions of quantities and units used and to describe parameters and methods that can be used to compare and standardize densitometric equipment and measurements. One of the core chapters of the report summarizes quality and performance measures in bone densitometry. It is divided into four sections: physical performance measures, diagnosis, fracture risk, and monitoring. Here we publish part 1 of this chapter containing the first two sections: physical performance measures and issues in diagnosing osteoporosis.

CONCLUSION

Following the international standard (ISO 5725-1), trueness, bias, repeatability, and reproducibility are defined along with terms common to osteoporosis research, such as accuracy and precision. Building on the conceptual definition of osteoporosis, diagnostic criteria are defined and discussed including criteria for reference data. Based on this, clinical performance measures commonly used for the diagnosis of osteoporosis are reviewed and discussed.

The fracture risk index and bone mineral density as predictors of vertebral structural failure

Structural failure becomes increasingly likely as the load on bone approximates or exceeds the bone's ability to withstand it. The vertebral fracture risk index (FRI) expresses the risk for structural failure as a ratio of compressive stress (load per unit area) to estimated failure stress, and so should be a more sensitive and specific predictor of vertebral fracture than spine areal BMD (aBMD) or volumetric BMD (vBMD), surrogates of bone strength alone. To address this issue, we analyzed the results of a case-control study of 89 postmenopausal women with vertebral fractures and 306 controls in Melbourne, Australia, and a 10-year community-based prospective study in which 30 postmenopausal women who had incident vertebral fractures were compared with 150 controls in Lyon, France. The FRI and vBMD of the third lumbar vertebral body and spine aBMD were derived using dual X-ray absorptiometry. In the cross-sectional analysis, each SD increase in FRI was associated with 2.1-fold (95% confidence interval [CI], 1.55-2.73) increased vertebral fracture risk, while each SD decrease in aBMD or vBMD was associated with 4.0-fold (95% CI, 2.69-6.18 and 2.65-6.94, respectively) increase in risk. Using receiver operating characteristic (ROC) analysis, the FRI was less sensitive and specific than aBMD in discriminating cases and controls (area under ROC, 0.76 vs 0.84, p<0.01). The area under ROC curve did not differ between FRI and vBMD (0.76 vs 0.79, NS). In the prospective data set, the FRI was not predictive [hazard ratio, HR, 1.20 (95% CI, 0.9-1.7)] and was in contrast to aBMD [HR, 2.4 (95% CI, 1.5-3.8)] and vBMD [HR, 2.1 (95% CI, 1.39-3.17)]. There was also lower sensitivity using a cutoff value of FRI>or=1 compared with aBMD T-score of -2.5 SD in both studies. There was poor agreement (kappa=0.13-0.18) between FRI and aBMD T -scores in detecting fractures; each method only identified around 50% of fractured cases. Within the constraints of the sample size, we concluded that applying a biomechanical index such as FRI at the spine is no better in discriminating fracture cases and controls than conventional aBMD or vBMD. The FRI may not predict incident vertebral fractures.

A comparison between peripheral BMD and central BMD measurements in the prediction of spine fractures in men

INTRODUCTION

Most of the research on osteoporosis has been conducted on women. Few studies have compared central and peripheral densitometry and their association with vertebral fractures in men. The present study was designed to compare peripheral bone mineral density (BMD) measurements with central BMD measurements, and to examine their association with radiographic spine fracture in men.

METHODS

We studied 402 community-dwelling men aged 45-92 years (mean: 70 years) from the Rancho Bernardo Study cohort who attended a clinic visit between 1988 and 1992 when BMD measurements of the midshaft radius, ultradistal wrist, lumbar spine, and total hip were obtained, and who returned for lateral X-rays of the thoracic and lumbar spine an average of 4 years later. Logistic regression, T-scores, and quintiles were used to analyze BMD and its association with vertebral fractures.

RESULTS

The prevalence of osteoporosis defined by the National Osteoporosis Foundation criteria (for women) was 14.2% at the spine and 13% at the hip. Because there are no validated definitions of osteoporosis based on the ability to predict fracture risk for peripheral densitometry, the frequency of overlap by bone site was calculated among men in the lowest quintile of each site. Of the 402 men, 82 men (20.3%) had at least two sites with BMD measurements in the lowest quintile. After an average of 4 years, 33 (8.2%) men had at least one radiographic vertebral fracture, and ten (2.5%) men had at least two vertebral fractures. Low BMD at the spine (with and without covariate adjustment) was associated with having one or more vertebral fractures, whether using NOF T-score-defined osteoporosis [Odds ratio (OR): 3.81; confidence interval (CI): 1.52, 9.57] or the lowest quintile versus all others (OR: 2.53; CI: 1.03, 6.19). After age and/or other covariate adjustments, neither BMD at the total hip nor at the peripheral sites was associated with spine fractures using either NOF women-based criteria or male quintiles from this cohort.

CONCLUSION

Although different men had osteoporosis defined by quintiles at different sites, only low BMD at the spine was associated with vertebral fracture.

Association of quantitative heel ultrasound with history of osteoporotic fractures in elderly men: the ESOPO study

In order to evaluate the usefulness of calcaneal quantitative ultrasound (QUS) in the assessment of male osteoporosis, a cross-sectional, population-based study was performed. A cohort of 4,832 men, randomly selected, community-dwelling, aged 60-80 years and representative of the general older male Italian population was recruited. QUS measurements were assessed in 83 centers distributed all over Italy and equipped with an Achilles device (GE-Lunar, Madison, Wisconsin, USA). All participants were administered a questionnaire covering lifestyle variables and medical history. Low-energy fractures that had occurred since age 50 were recorded. Overall, 43 subjects reported a previous hip fracture and 455 subjects reported other non-spinal fractures. Univariate analysis showed that fractured subjects were older, with a lower level of outdoor physical activity and a more frequent history of prolonged bedridden periods in comparison with unfractured subjects. Men reporting non-spinal fractures showed a higher prevalence of smoking, while no difference was found among groups in anthropometric measures and calcium intake. QUS measurements showed that all QUS parameters were significantly lower in both fracture groups (p<0.001). Multiple logistic regression analysis demonstrated that each SD reduction in QUS measures was associated with an approximate doubling of the risk for hip fracture, independent of age and other clinical variables (broadband ultrasound attenuation [BUA]: odds ratio [OR]=2.24; 95% confidence interval [CI] 1.61-3.08; stiffness index: OR=2.19; CI 1.56-3.11; speed of sound [SOS]: OR=1.71; CI 1.18-3.24) and with an increase of the risk of other non-spinal fractures (BUA: 1.38; CI 1.22-1.59; stiffness index: OR=1.27; CI 1.17-1.38; SOS: OR=1.14; CI 0.96-1.40). It can be concluded that calcaneal QUS measurement is associated with the risk for hip fracture and any non-spinal fractures among a community-dwelling cohort of elderly men. The strength of the association between QUS measurement and fracture is similar to that observed in elderly women.

Quantitative ultrasound and dual-energy X-ray absorptiometry in the prediction of fragility fracture in men

Fragility fractures in men represent a major health problem, and this prompts a necessity for reliable tools for the identification of men at risk of fracture. In order to assess the ability of dual-energy X-ray absorptiometry (DXA) and quantitative ultrasound (QUS) in the prediction of fracture risk in men and whether their combination might be useful in a clinical setting, we studied 401 men (age range 45-82 years, mean 60.3+/-12.5), of whom 133 had osteoporotic fractures and 268 did not. In all subjects we measured bone mineral density at the lumbar spine (BMD-LS) and at the femur, calculating thereafter the standard femoral subregions: neck (BMD-FN), total hip (BMD-T), trochanter (BMD-TR), intertrochanter (BMD-ITR), and Ward's triangle (BMD-W), by DXA. We also performed ultrasound parameters at the calcaneus: speed of sound (SOS), broadband ultrasound attenuation (BUA) and Stiffness, by Achilles plus, and at the phalanxes: amplitude dependent speed of sound (AD-SoS) and the parameters of the graphic trace: bone transmission time (BTT), fast wave amplitude (FWA), signal dynamic (SDy) and ultrasound bone profile index (UBPI), by Bone Profiler. All DXA and QUS parameters, apart from FWA, were significantly (P<0.001) lower in patients with a history of fracture. BMD at the proximal femur showed the best ability in discriminating men with or without fractures. QUS at the heel showed discriminatory ability significantly better than QUS at the fingers. By logistic regression analysis, adjusted for age and BMI, BMD-T showed the best association with fragility fracture [odds ratio (OR)=3.43, 95% confidence interval (CI)=2.47-4.77]. Among QUS parameters, the highest value of the OR was shown by stiffness (OR=3.18, CI=2.27-4.48). FWA and SDy were not associated with fragility fractures in men. If DXA and QUS were combined, the prediction of the OR of fragility fracture events in men increases; in fact Stiffness was able to increase the OR when added to BMD-LS (OR=5.44, CI=3.16-10.13) and BMD-T (OR=6.08, CI=2.63-14.27). SOS and BUA showed a similar pattern. AD-SoS improved the prediction of fracture only when combined with BMD-LS (OR=4.36, CI=1.99-9.57). If BMD-LS and BMD-FN or BMD-T were combined, the value of the OR increases (OR=4.59, CI=2.27-9.25 and OR=4.68, CI=2.24-9.76), respectively. Our study supports the effectiveness of QUS in the identification of osteoporotic fractures in men. QUS seems to play an independent and complementary role, with respect to DXA, in order to enhance the power for predicting osteoporotic fractures in men.

Forearm bone mineral density in an unselected population of 2,779 men and women--the HUNT Study, Norway

The fracture incidence in Norway is among the highest in Europe, presumably due to osteoporosis. As part of a multipurpose health study in the county of Nord-Trondelag, Norway (the HUNT study), a 5% randomly selected sample (n=4,646) of the population >19 years of age was invited to undergo single X-ray absorptiometry (SXA) of the forearm. A total of 1,274 men (50.5 years) and 1,505 women (49.9 years) participated (60%). The aim of the study was to describe the variation in bone mineral density (BMD) and the prevalence of forearm BMD 2.5 standard deviations (SD) below the mean value for young adults in an unselected population sample. In women the BMD remained stable until the age of 50 years, whereupon a strong decline in BMD was observed. In men, a BMD increase was observed until about the age of 40 years; the decline after the age of 65 was, however, similar to that in women. Based on age and gender-specific reference values, the age-adjusted prevalence of T-scores <-2.5 SD in women and men aged 50-69 years was 16.0% and 5.6%, respectively. In the age group of 70 years or older the prevalence was 65.8% and 30.6% for women and men, respectively. The accelerated BMD reduction in women aged 50-65 explains the higher prevalence of T-score <-2.5 SD in elderly women than in men. Further studies on bone loss and falls are required to explain the high fracture incidence in Norway.

Lebanese guidelines for osteoporosis assessment and treatment: who to test? What measures to use? When to treat?

With the demographic explosion of the population worldwide, the human, social, and economic costs of osteoporosis will continue to rise. It is estimated that the magnitude of the problem might be even larger in developing countries, including those in the Middle East. Although several organizations and countries have developed or adapted guidelines to their local needs, as of today there are no guidelines for osteoporosis assessment in the Middle East. In April 2002, a panel of osteoporosis experts met and discussed practice guidelines for osteoporosis assessment and treatment in Lebanon. The process, which involved an overview of international guidelines as well as local data on osteoporosis, resulted in a draft for Lebanese guidelines that addressed three main questions: "Who to test?" "What measures to use?" and "When to treat?". Representatives from five major Lebanese societies (Endocrinology, Rheumatology, Orthopedics, Obstetrics and Gynecology, and Radiology) subsequently reviewed, discussed, and officially endorsed the guidelines after revisions. The Lebanese guidelines were also endorsed by the Eastern Mediterranean branch of the World Health Organization.

Women's conditions occurring in men: breast cancer, osteoporosis, male menopause, and eating disorders

Each of the four disorders discussed in this article emphasizes its significance in the morbidity and mortality of men. Recent research has improved the ability to identify many of the key risk factors that could predispose men to breast cancer, osteoporosis, male menopause, and eating disorders. There is a significant need for further research into each of these conditions, as most studies have been conducted on women. The myths that these disorders are just a feminist issue can be ignored no longer. Nurses are in a prime position to help men identify and analyze their risks and help them select appropriate prevention and screening strategies to improve their knowledge and quality of life.

Risk assessment and screening for low bone mineral density in a multi-ethnic population of women and men: does one approach fit all?

Screening for osteoporosis is currently recommended for all women aged 65 years and older in the USA. How to address screening of non-white women and all men is unclear. Osteoporosis risk assessment questionnaires have been designed and tested mostly among postmenopausal white women, and there is a lack of consensus on appropriate bone mineral density (BMD) cut-off values for defining osteoporosis in non-white persons. The objectives of the present study were to identify a set of risk factors from published population-based studies in white women and men and determine the ability of these risk factors to predict osteoporosis and low BMD in African-American (AA), Mexican-American (MA), and white women and men, and to assess the diagnostic accuracy of this set of risk factors for identifying osteoporosis separately in AA, MA, and white women and men by the use of data for 2,590 women and 2,391 men 50-79 years of age from the third National Health and Nutrition Examination Survey (NHANES III). We employed the World Health Organisation (WHO) definition of osteoporosis, using race/ethnic and gender-specific young adult mean values when calculating the T scores. Low body-mass index, low calcium intake, current cigarette smoking, and physical inactivity were independent risk factors identified from population-based studies. The presence of one or more risk factors was associated with having osteoporosis and low BMD in all groups. The strength of these associations was greater when two or more risk factors were present but varied with race/ethnicity, gender, and age. We conclude that this set of osteoporosis risk factors predicts osteoporosis in non-white women and men. Furthermore, as a risk assessment tool, this set of risk factors might be useful for reducing the number of unnecessary BMD tests performed in older women as well as identifying non-white men who do not require BMD testing.

Identification of men with reduced bone density at the lumbar spine and femoral neck using BMD of the os calcis

We assessed the utility of os calcis (OC) bone mineral density (BMD) measurements to identify men with low BMD at the lumbar spine (LS) and femoral neck (FN). BMD was measured by dual X-ray absorptiometry (DXA). Receiver operator characteristics (ROC) analysis was applied to determine the risk of osteoporosis at the lumbar spine or femoral neck. [A total of 230 men with an average age of 59 yr were studied.] The most common reasons for referral were fracture (47%) and steroid use (46%). Twenty-six percent were osteoporotic at the LS, 21% at the FN, and 15% at the OC. Optimal classification with respect to osteoporotic measurements at the LS or FN was obtained at an OC T-score of -1.9 (BMD = 0.45 g/cm2). Osteoporosis was only weakly related to a simple cumulative risk factor score, but was strongly related to a T-score OC categorized into quartiles. Regression analysis of BMD on the major risk factors alone explained only 17% of the variance in BMD at the LS and 5% at the FN. The combination of the T-score at the OC, age, and weight provided the best model. BMD OC is superior to risk factors alone in the clinical evaluation and selection of men referred for axial densitometry.

Bone mineral density and prevalent vertebral fractures in men and women

To test the hypothesis that the association between bone mineral density (BMD) and estimated volumetric BMD and prevalent vertebral fractures differs in men and women, we studied 317 Caucasian men and 2,067 Caucasian women (average age 73 years). A total of 43 (14%) men and 386 (19%) women had a vertebral fracture identified on lateral spine radiographs using vertebral morphometry. Hip and spine areal BMD was about 1/3 standard deviation lower among men and women with a vertebral fracture. A 0.10 g/cm(2) decrease in areal BMD was associated with 30-40% increased odds of having a fracture in men and 60-70% increased likelihood in women. Low bone mineral apparent density (BMAD) was also associated with 40-50% increased odds of a vertebral fracture in both genders. The probability of a man having a fracture was observed at higher absolute areal BMD values than observed for women (P=values for interaction of BMD x gender: trochanter, P=0.05; femoral neck, P=0.10; total hip, P=0.09). In contrast, the probability of fracture was similar in men and women across the range of estimated volumetric BMD (BMAD). In conclusion, low BMD and low BMAD are associated with increased odds of vertebral fracture in both men and women. Measures of bone mass that partially correct for gender differences in bone size may yield universal estimates of fracture risk. Prospective studies are needed to confirm this observation.

Racial differences in bone mineral density in older men

Studies have examined factors related to BMD in older white, but not black, men. We measured BMD in older white and black men and examined factors related to racial differences in BMD. Black men had significantly higher adjusted BMD at all sites. These results may explain, in part, the lower incidence of fractures in older black men.

INTRODUCTION

Several studies have examined factors associated with bone mineral density (BMD)in older men. None, however, have had sufficient numbers of black men to allow for meaningful comparisons by race.

MATERIALS AND METHODS

A total of 503 white and 191 black men aged 65 and older(75.1 +/- 5.8 and 72.2 +/- 5.7 years, respectively) were recruited from the Baltimore metropolitan area. All men completed a battery of self-administered questionnaires, underwent a standardized examination, and had BMD measured at the femoral neck, lumbar spine, and total body. Data were analyzed using multiple variable linear regression models, adjusted for potential confounding variables; two-way interactions with main effects were included in models where appropriate.

RESULTS

Black men had significantly higher adjusted BMD at the femoral neck (difference 0.09 [95% CI: 0.07, 0.12] mg/cm2), lumbar spine (0.07 [0.04, 0.10] mg/cm2), and total body (0.06 [0.03, 0.08] mg/cm2) than white men.

CONCLUSIONS

Older black men have significantly higher BMD than older white men, even after adjustment for factors associated with BMD. These differences, especially at the femoral neck, may explain the reduced incidence of hip fracture in black compared with white men.

Secondary screening for osteoporosis in patients admitted with minimal-trauma fracture to a major teaching hospital

AIMS

The aim of the present study was to determine: (i) the prevalence of the investigation and treatment of osteoporosis in patients admitted to hospital with a minimal-trauma fracture, (ii) the prevalence of osteoporosis using bone mineral density assessment by dual X-ray absorptiometry (DEXA) in such patients and (iii) a clinical pathway for the management of osteoporosis in such patients.

METHODS

A cross-sectional study was undertaken involving all patients admitted with a fracture to Westmead Hospital, Sydney, Australia, between January 1999 and June 2000 (n = 327). Of these, 264 were excluded because of: (i) the fracture following significant trauma (n = 83), (ii) unavailability of medical records for review (n = 38), (iii) nursing home status (n = 37), (iv) previous malignancy (n = 18), (v) deceased (n = 11), (vi) recent osteoporosis screening and/or treatment (n = 18), (vii) refusal to participate (n = 37), (viii) uncontactable (n = 16) and (ix) inadequate English (n = 6). The remaining 63 patients underwent DEXA assessment and the following laboratory investigations: (i) liver function tests, (ii) urea, (iii) electrolytes, (iv) calcium, (v) phosphate, (vi) full blood count, (v) 25-hydroxyvitamin D level and (vi) thyroid-function tests. In men, levels of serum free testosterone, luteinizing hormone, follicle-stimulating hormone and prolactin were also obtained.

RESULTS

Of the 63 study participants, 87% of the 47 women were either osteoporotic (T <-2.5) or osteopenic (-2.5 <T <-1) at a mean of 12.7 +/- 5.4 months post-fracture. Of the 16 men screened, 75% had a T-score < or =-1. Forty-four per cent of the study sample had a low 25-hydroxyvitamin D level, 6% were biochemically hyperthyroid and 40% of the men had a low serum free testosterone. Only 16% had an effective anti-osteoporotic medication added following the fracture.

CONCLUSIONS

Secondary screening and treatment of osteoporosis in patients following minimal-trauma fracture are low. The implementation of a clinical pathway for osteoporosis management in these patients may be useful.

Age, gender, and body mass effects on quantitative trait loci for bone mineral density: the Framingham Study

A genome-wide scan was performed in participants from the Framingham Osteoporosis Study (1557 members of 330 mostly Caucasian pedigrees), with 401 microsatellite markers spaced on average at 10 cM. Bone mineral density (BMD) was measured at the femoral neck, trochanter, Ward's area, and lumbar spine with DXA. Our recent study (J Bone Mines Res 17 (2002), 1718) reported a number of regions with suggestive linkage to possible quantitative trait loci (QTL). The current study estimates the heterogeneity of linkage in these regions in subsamples of our pedigrees, stratified on the known biological contributors to bone mass of sex, age, and body mass index (BMI). The pedigree sample was stratified into three sets of subgroups by sex [males (age range 35- 96 years), females (29-91 years)], by age [60 or younger (29-60 years) and older than 60 (61-96 years)], and by BMI [stratified into low or high BMI, by median cut-off 27.7 in males (BMI range 17-53) and 25.8 in females (14-54)]. Heritability estimates of BMD (adjusted for age, anthropometry, nutrition, physical activity, and, in females, estrogen use) in subsamples ranged from 0.47 to 0.69. Two-point and multipoint variance component linkage analyses of BMD (using SOLAR) in subsamples supported findings of previously reported suggestive linkage results in the total sample on 8q24.13 and 14q31 (LODs>2.0). However, heterogeneity of linkage was observed on 6p21.2 and 21qter, where findings in the total sample were not supported by subsamples. On the other hand, subsample-specific maxima were found, on 4q34.1 (males), 9q22-9q31 (younger), 16p13.2 (high BMI), and 17p13.3 (older), which were not reflected by the total sample results. In conclusion, heterogeneity of QTL effects was revealed in pedigree members stratified by sex, age, and BMI; in some instances new loci were identified in subgroups. These findings may suggest that effects of genes on the determination of BMD differ between men and women, younger and older, and lean and obese adults. Evaluation of family members stratified in homogeneous groups may be warranted in genetic studies of bone mass.

Fracture prediction from bone mineral density in Japanese men and women

In a cohort of 2356 Japanese elderly, after adjusting for age and prevalent vertebral fracture, baseline BMD predicted the risk of spine and hip fracture with similar RR to that obtained from previous reports in whites. The RR per SD decrease in BMD for fracture declined with age.

INTRODUCTION

Low bone mineral density (BMD) is one of the most important predictors of a future fracture. However, we are not aware of any reports among Japanese in Japan.

MATERIALS AND METHODS

We examined the association of BMD with risk of fracture of the spine or hip among a cohort of 2356 men and women aged 47-95 years, who were followed up by biennial health examinations. Follow-up averaged 4 years after baseline measurements of BMD that were taken with the use of DXA. Vertebral fracture was assessed using semiquantitative methods, and the diagnosis of hip fracture was based on medical records. Poisson and Cox regression analysis were used.

RESULTS

The incidence was twice as high in women as in men, after adjusting for age. After adjusting for baseline BMD and prevalent vertebral fracture, however, the gender difference was no longer significant. Age, baseline BMD of spine and femoral neck, and prior vertebral fracture predicted vertebral fracture and hip fracture. Loss of absolute BMD of the femoral neck predicted spine fracture, after adjusting for baseline BMD; rates of change in percent BMD, weight, height, body mass index, and age at menopause did not. The predictive value of baseline BMD for vertebral fracture risk was similar in men and women. The relative risk (RR) for vertebral fracture and hip fracture per SD decrease in BMD declined with age, after adjustment for prevalent vertebral fractures.

CONCLUSIONS

Baseline BMD, loss of femoral neck BMD, and prior vertebral fracture predict the risk of spine and hip fracture in Japanese with similar RR to that obtained from previous reports in whites. The RR per SD decrease in BMD for fracture declined with age, suggesting that factors other than BMD might play a greater role in the elderly.

Randomized controlled trial of zoledronic acid to prevent bone loss in men receiving androgen deprivation therapy for nonmetastatic prostate cancer

PURPOSE

A multicenter double-blind, randomized, placebo controlled clinical trial was performed to assess the effect of zoledronic acid, a potent new bisphosphonate, on bone mineral density during androgen deprivation therapy for nonmetastatic prostate cancer.

MATERIALS AND METHODS

Men with M0 (no distant metastases) prostate cancer beginning androgen deprivation therapy were randomly assigned to receive 4 mg. zoledronic acid or placebo intravenously every 3 months for 1 year. The primary efficacy variable was the percent change from baseline to 1 year in bone mineral density of the lumbar spine as measured by dual energy x-ray absorptiometry.

RESULTS

A total of 106 men were enrolled in the trial. Mean bone mineral density in the lumbar spine increased by 5.6% in men receiving zoledronic acid and decreased by 2.2% in those given placebo (mean difference 7.8%, 95% confidence interval 5.6%-10.0%, p <0.001). Mean bone mineral density of the femoral neck, trochanter and total hip also increased in the zoledronic acid group and decreased in the placebo group. Zoledronic acid was well tolerated.

CONCLUSIONS

Zoledronic acid increases bone mineral density in the hip and spine during androgen deprivation therapy for nonmetastatic prostate cancer.

Bone mass measurements

The clinical application of bone densitometry is one of the advances in the field of osteoporosis that has led to the increased patient awareness of this increasingly prevalent disease. Bone densitometry has made it possible for clinicians to diagnose osteoporosis before the first fracture has occurred; predict risk for fracture in postmenopausal women, men, and in patients who are receiving glucocorticoids; and can be used as a surrogate marker to follow the efficacy of therapies and to examine those patients that might be osteoporosis-specific therapeutic nonresponders.

Deficient acquisition of bone during maturation underlies idiopathic osteoporosis in men: evidence from a three-generation family study

To address the issue whether deficient acquisition of bone during maturation or adult-onset bone loss is primarily to blame for idiopathic osteoporosis in men, we assessed indices of bone mineral density and size, as well as biochemical markers of bone turnover in 61 probands (ages 20-65 years) with idiopathic osteoporosis (z-score < or = -2.0 at the spine or hip), their first-degree relatives (n = 130), and age-matched controls. There was no indication of accelerated bone loss. Indeed, in probands, the observed bone deficit versus controls was unrelated to the age of probands, and indices of bone turnover were not significantly different from controls. On the other hand, a specific deficit in bone acquisition was suggested by findings of lower bone mineral density values in three generations of male and female relatives of the probands, including their offspring; bone turnover in relatives was not different from controls. The bone mineral density deficit was more pronounced in male compared with female relatives; approximately 60% of the sons had a spinal bone mineral density z-score of less than -2.0. There also was a skeletal site-specificity in probands and their male relatives with a larger areal bone mineral density deficit at the spine compared with the hip and the forearm. The deficit at the spine corresponded to a reduction of both volumetric bone mineral density and bone size; a similar less pronounced deficit in volumetric bone mineral density, but not in bone size, was observed at the femoral neck. These findings in probands and their first-degree relatives point toward a major contributory role of a genetically determined maturational defect in bone acquisition in the pathogenesis of idiopathic osteoporosis in men.

Osteoporosis in men and women: a story about bone mineral density thresholds and hip fracture risk

In postmenopausal women, the T score for bone mineral density (BMD) is a well-accepted diagnostic criterion for osteoporosis. It is also used to assess fracture risk. However, it is unclear whether in elderly men similar BMD thresholds should be used. Different hypotheses have been proposed for the relation of BMD with hip fracture risk in men. In this study, we tested those hypotheses using a mathematical model and we compared the calculated results with observed prospective data from the Rotterdam study. In the model, we combined the observed femoral neck BMD distribution for men and women with previously derived hip fracture risk functions based on age and BMD. For men, we tested different hypotheses for the relation of BMD with hip fracture risk. The relation of BMD with hip fracture risk is similar in men and women (scenario 1) or the relative risk (RR) per standard deviation (SD) decrease of BMD is either larger or smaller in men than in women (scenario 2a and 2b), or, at a similar absolute fracture risk, men have a higher BMD (scenario 3). In the prospective data, men with a hip fracture had an average BMD that was 0.070 g/cm2 higher than women with a hip fracture. The calculated results from the first scenario were consistent with those data and were also consistent with the observed hip fracture incidence and the observed female-to-male (F/M) risk ratio (1.7). When the RR for each SD decrease of BMD was assumed to be either larger or smaller in men than in women (second scenario), the calculated average BMD difference in men and women became respectively smaller or larger than observed. When men would have a higher fracture risk at similar BMD levels (third scenario), the calculated total number of hip fractures increased and even exceeded that in women, with an F/M risk ratio of 0.94 in our example. In women, a larger proportion of hip fractures occurs at a T score below -2.5 than in men using the same absolute BMD threshold, but using a male-specific T score largely solves this diagnostic problem. Taken together, the average hip fracture risk in men is much lower than in women but appeared to be similar at the same BMD. Therefore, we propose the use of the same absolute BMD thresholds for decisions about interventions.