Total body and regional bone mineral density in men: effect of age

A randomized, placebo-controlled study of the effects of denosumab for the treatment of men with low bone mineral density

CONTEXT

Men with low bone mineral density (BMD) were treated with denosumab.

OBJECTIVE

Our objective was to investigate the effects of denosumab compared with placebo in men with low BMD after 1 yr of treatment.

DESIGN, SUBJECTS, AND INTERVENTION

This was a placebo-controlled, phase 3 study to investigate the efficacy and safety of denosumab 60 mg every 6 months vs. placebo in men with low BMD.

MAIN OUTCOME MEASURE

The primary endpoint was the percent change from baseline in lumbar spine (LS) BMD at month 12.

RESULTS

Of the 242 randomized subjects (mean age 65 yr), 228 (94.2%) completed 1 yr of denosumab therapy. After 12 months, denosumab resulted in BMD increases of 5.7% at the LS, 2.4% at the total hip, 2.1% at the femoral neck, 3.1% at the trochanter, and 0.6% at the one third radius (adjusted P ≤ 0.0144 for BMD percent differences at all sites compared with placebo). Sensitivity analyses done by controlling for baseline covariates (such as baseline testosterone levels, BMD T-scores, and 10-yr osteoporotic fracture risk) demonstrated that the results of the primary endpoint were robust. Subgroup analyses indicate that treatment with denosumab was effective across a spectrum of clinical situations. Treatment with denosumab significantly reduced serum CTX levels at d 15 (adjusted P < 0.0001). The incidence of adverse events was similar between groups.

CONCLUSIONS

One year of denosumab therapy in men with low BMD was well tolerated and resulted in a reduction in bone resorption and significant increases in BMD at all skeletal sites assessed.

TWO CLINICAL PROBLEMS IN ELDERLY MEN: OSTEOPOROSIS AND ERECTILE DYSFUNCTION

Seventy-six of 108 random men aged 50 years or over were evaluated for erectile dysfunction with interviews of patients using the International Index of Erectile Function Form and minimal evaluation. Serum hormone concentrations were measured. Bone mineral density was measured using dual energy x-ray absorptiometry. Hormone levels did not show significance in terms of erectile dysfunction or bone mineral density results. Erectile dysfunction was determined in 57 (75%) of 76 patients. Ten (13.2%) patients had osteoporosis and 45 (59.2%) had osteopenia at the bone mineral density measurements. The distribution of bone mineral density groups relating to erectile dysfunction did not show significance. The frequencies of osteoporosis and erectile dysfunction increased with age, but the association of these conditions seems to be independent of each other and hormonal changes appear not to be the major determinants for both conditions in elderly men.

Age, gender, and race/ethnic differences in total body and subregional bone density

SUMMARY

Total body bone density of adults from National Health and Nutrition Examination Survey (NHANES) 1999-2004 differed as expected for some groups (men>women and blacks>whites) but not others (whites>Mexican Americans). Cross-sectional age patterns in bone mineral density (BMD) of older adults differed at skeletal sites that varied by degree of weight-bearing.

INTRODUCTION

Total body dual-energy X-ray absorptiometry (DXA) data offer the opportunity to compare bone density of demographic groups across the entire skeleton.

METHODS

The present study uses total body DXA data (Hologic QDR 4500A, Hologic, Bedford MA, USA) from the NHANES 1999-2004 to examine BMD of the total body and selected skeletal subregions in a wide age range of adult men and women from three race/ethnic groups. Total body, lumbar spine, pelvis, right leg, and left arm BMD and lean mass from 13,091 adults aged 20 years and older were used. The subregions were chosen to represent sites with different degrees of weight-bearing.

RESULTS

Mean BMD varied in expected ways for some demographic characteristics (men>women and non-Hispanic blacks>non-Hispanic whites) but not others (non-Hispanic whites>Mexican Americans). Differences in age patterns in BMD also emerged for some characteristics (sex) but not others (race/ethnicity). Differences in cross-sectional age patterns in BMD and lean mass by degree of weight-bearing in older adults were observed for the pelvis, leg, and arm.

CONCLUSION

This information may be useful for generating hypotheses about age, race, and sex differences in fracture risk in the population.

Bone mineral status and bone loss over time in men with chronic systolic heart failure and their clinical and hormonal determinants

AIMS

Bone status has not been comprehensively studied in chronic heart failure (CHF). In CHF men, we evaluated bone status, bone loss over time, and their clinical and hormonal determinants.

METHODS AND RESULTS

Bone mineral content (BMC) and bone mineral density (BMD) of arms, legs, trunk, and total body were examined using dual-energy X-ray absorptiometry in 187 men with CHF [age: 60+/-11 years, left ventricular ejection fraction (LVEF): 32+/-7%, New York Heart Association (NYHA) class (I/II/III/IV): 20/76/76/15] and in 21 age-matched male controls without CHF. Men with CHF had reduced BMD and BMC compared with controls (P < 0.05). Reduced BMD and BMC were independently determined by CHF severity (high NYHA class and impaired LVEF), reduced lean tissue mass, low serum dehydroepiandrosterone sulphate, total testosterone (TT), and estimated free testosterone (eFT) (all P < 0.05). Bone status was reassessed in 60 patients who survived >2 years from the initial evaluation. Significant bone loss over time (a reduction in BMC total > or = 1%/year) occurred in 35% of CHF men. Advanced NYHA class (P < 0.05) and reduced serum TT and eFT (P < 0.0001) at baseline predicted augmented bone loss.

CONCLUSION

In CHF men, reduced BMD and BMC constitute an element of generalized body wasting, determined mainly by advanced heart failure and androgen deficiencies. Significant bone loss over time frequently occurs in CHF men and is related to testosterone depletion and disease severity.

Population-based reference values for bone mineral density in young men

Population-based reference values for peak bone mass density in Danish men. BMD of total hip (1.078 +/- 0,14 g/cm2) differed significantly from values from National Health and Nutrition Examination Survey III and of total lumbar spine ((1.073 +/- 0.125 g/cm2) differed significantly from Hologic values.

INTRODUCTION

Geographic, ethnic, and socio-economic factors are known to affect bone mineral density (BMD) and peak bone mass significantly. Reference values for male peak bone mass are scarce, and the diagnosis of male osteoporosis often relies on values provided by producers of dual-energy X-ray absorptiometry (DXA) equipment.

METHODS

The aim of the present study was 1) to establish population-based reference values for BMD in young men and 2) to study subgroups based on variables with suspected impact on bone metabolism. We included 783 young Caucasian men aged 20 to 30 years in the Odense Androgen Study (OAS).

RESULTS

Peak BMD was attained within the third decade. Obesity (BMI > 30 kg/m2) was associated with higher BMD. Abuse of anabolic steroids as well as chronic illness was associated with lower BMD. Our population-based reference values for BMD of the total hip (1.078 +/- 0.14 g/cm2) differed significantly from published values from National Health and Nutrition Examination Survey III for non-Hispanic white men, while BMD of total lumbar spine (1.073 +/- 0.125 g/cm2) differed significantly from Hologic reference values.

CONCLUSIONS

Locally derived reference values are important to avoid false positive or false negative findings during work-up in patients evaluated for osteoporosis.

Clinical risk indices, prediction of osteoporosis, and prevention of fractures: diagnostic consequences and costs

The primary aim of this study was to validate the Osteoporosis Self-Assessment Tools for Asians (OSTA) instrument in Thai women, and to evaluate its utility in terms of economic costs and fracture prediction. Femoral neck and lumbar spine BMD was measured by dual energy X-ray absorptiometry in 322 Thai women, aged 60+/-10 years (mean+/-SD; range: 45-84 years). The women were classified as having osteoporosis if their BMD T-scores were < or =-2.5. The OSTA score was calculated for each woman using her age and weight according to the formula: 0.2(weight-age). Women with OSTA scores < or =-1 and >-1 were classified as "high risk" and "low risk," respectively. The prevalence of osteoporosis was 33% by femoral neck or lumbar spine BMD. Using the OSTA score, 165 (51.2%) women were classified as high risk. The sensitivity, specificity and positive predictive value of OSTA was 82% 64% and 53%, respectively. If the OSTA score is used to identify women with high risk of fracture, and assuming that the incidence of fracture among osteoporotic and non-osteoporotic women are 2% and 1% per year, respectively, the OSTA score can identify 59% of fracture cases correctly, and 41% are expected to be missed. Furthermore, if the high-risk subjects identified by OSTA are to be treated, and if the treatment reduces fracture incidence by 50%, and assuming that the treatment cost is $1 per day, then the cost to prevent one fracture is estimated to be $48,530. Results of this study suggest that, in the Thai population, the OSTA score had high sensitivity but low specificity and low positive predictive value in the identification of osteoporotic women. Its use in the general population can result in a high false-positive rate and incur significant cost to the community.

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.

Testosterone increases bone mineral density in female-to-male transsexuals: a case series of 15 subjects

OBJECTIVE

Testosterone therapy for osteoporosis has not been studied extensively in women because of its potential to cause virilization. Female-to-male transsexuals are genetic females who suffer from gender dysphoria and thus take supra-physiologic doses of testosterone to change from the female to male phenotype. The aim of this study is to examine the effects of testosterone treatment on the genetic female skeleton.

PATIENTS AND DESIGN

A group of 15 female-to-male transsexuals was prospectively enrolled for observation over a 2-year period. The subjects had a mean age of 37.0 +/- 3.0 years. All of the subjects self-administered testosterone esters intramuscularly at a mean dose of 70.7 +/- 4.5 mg weekly.

MEASUREMENTS

The subjects had measurements of bone mineral density (BMD) by dual X-ray absorptiometry (DXA) of the femoral neck and spine (L2-L4) at 12-month intervals. They had determinations of serum oestradiol, testosterone, soluble RANKL (sRANKL), osteoprotegerin (OPG) and urine N-telopeptide (NTX) at the date of enrolment and at the end of 2 years. results There was a significant positive increase in mean BMD of 7.8% at the femoral neck and a nonsignificant increase in mean BMD of 3.1% at the spine over 2 years. The levels of testosterone reached the upper normal range for males and the levels of oestradiol declined to near the postmenopausal range. sRANKL levels decreased significantly in female-to-male transsexuals who newly initiated testosterone therapy. There was no significant change in urine NTX or serum OPG during the study.

CONCLUSIONS

We conclude that supra-physiologic testosterone therapy increases BMD at the hip while maintaining BMD at the spine in female-to-male transsexuals. The effects of testosterone may be the result of testosterone hormone directly acting on the bone or indirectly through aromatization to oestradiol. Lower RANKL levels coupled with unchanged OPG levels results in an increased OPG/RANKL ratio, which may be beneficial to the bone by inhibiting osteoclastogenesis.

Osteoporosis in men: epidemiology, diagnosis, prevention, and treatment

BACKGROUND

Osteoporosis and fragility fractures in men account for substantial health care expenditures and decreased quality of life.

OBJECTIVE

This article reviews the most current information about the epidemiology, diagnosis, prevention, and treatment of osteoporosis in men.

METHODS

Relevant literature was identified through a search of MEDLINE (1966-June 2003) limited to English-language studies in men. The search terms included fractures, bone density, or osteoporosis plus either epidemiology, diagnosis, prevention, control, or therapy. Additional search terms included specific subtopics (eg, bisphosphonates, calcium, exercise, parathyroid hormone). The authors contributed additional relevant publications.

RESULTS

Morbidity after fragility fracture is at least as high in men as in women, and the rate of fracture-related mortality 1 year hip fracture is approximately double in men compared with women. The bioavailable fraction of testosterone slowly declines into the ninth decade in men. There is evidence that the effect of estrogen on bone is greater than that of testosterone in men. Diagnosing osteoporosis in men is complicated by a lack of consensus on how it should be defined. Significant risk factors for osteoporosis or fracture include low bone mineral density, previous fragility fracture, maternal history of fracture, marked hypogonadism, smoking, heavy alcohol intake or alcoholism, low calcium intake, low body mass or body mass index, low physical activity, use of bone-resorbing medication such as glucocorticoids, and the presence of such conditions as hyperthyroidism, hyperparathyroidism, and hypercalciuria. Prevention is paramount and should begin in childhood. During adulthood, calcium (1000-1500 mg/d), vitamin D (400-800 IU/d), and adequate physical activity play crucial preventive roles. When treatment is indicated, the bisphosphonates are the first choice, whereas there is less support for the use of calcitonin or androgen therapy. Parathyroid hormone (1-34) is a promising anabolic therapy. There is also strong evidence for the use of bisphosphonates for the treatment of glucocorticoid-induced osteoporosis.

Superiority of age and weight as variables in predicting osteoporosis in postmenopausal white women

Identification of women at risk for osteoporosis is of great importance for the prevention of osteoporotic fractures. Routine BMD measurement of all women is not feasible for most populations, hence identification of a high-risk subset of women is an important element of effective preventive strategies.

METHODS

We identified 959 postmenopausal non-Hispanic women aged 51 years and above from the NHANES III study to assess the relative contribution of risk predictors for low BMD at the whole proximal femur and the femoral neck regions. Based on recognized risk factors for osteoporosis identified by a systematic literature search, we ran several multiple linear regression models based on the results of preceding bivariate analyses. We show several models based on their explanatory ability assessed by adjusted r(2), ROC, and C-value analyses rather than on the coefficients and P values. We furthermore examined the sensitivity, specificity, and predictive values of our preferred models for various cutoff T-scores-the choice of which will vary depending on different study goals and population characteristics.

RESULTS

Age and weight were by far the most informative predictors for low bone mineral density out of a list of 20 candidate risk predictors. Our preferred prediction models for the two regions hence contained only two variables: i.e., age and measured weight. The resulting parsimonious model to predict BMD at whole proximal femur had an adjusted r(2) of 0.43, an area under the ROC curve of 0.85, and a C-value of 0.70. Similarly, prediction for BMD at the femoral neck had adjusted r(2), area under the curve, and C-value of 0.39, 0.83, and 0.66, respectively.

CONCLUSIONS

The model equations, predicted T-score = -1.332-0.0404 x (age) + 0.0386 x (measured weight) and predicted T-score = -1.318-0.0360 x (age) + 0.0314 x (measured weight) for whole proximal femur and femoral neck, respectively, can be used in field conditions for screening purposes. More complex prediction equations add little explanatory power. Based on the study goals and the population characteristics, specific cutoff T-scores have to be decided before using these equations.

Biomechanical testing of cadaveric specimens: importance of bone mineral density assessment

The bone density of cadaveric specimens is highly variable and has a significant effect on the results of biomechanical testing but it is not often assessed before testing is performed in the lab. Bone mineral density (BMD) tests such as dual X-ray absorptiometry (DXA) are widely available, easy to perform and correlate highly and significantly with bone strength in many modes of failure. We present the results of two different studies performed on cadaveric foot and ankle specimens. In these studies the results vary significantly according to BMD, and this effect is not always eliminated with the use of matched pairs of cadaveric specimens.

Clinical review 144: Estrogen and the male skeleton

Because estrogen (E) and T are the major sex steroids in women and men, respectively, the traditional view had been that E primarily regulated bone turnover in women and T played the analogous role in men. The description of ER- deficient and aromatase-deficient males, however, initiated a major shift in our thinking on the relative roles of T and E in regulating the male skeleton, because these individuals all had unfused epiphyses, high bone turnover, and osteopenia. Similar, albeit less striking, findings were noted in mouse models with knock-out of either the ER-alpha or the aromatase genes. Although these human experiments of nature and mouse knock-out models clearly demonstrated an important role for E in the growth and maturation of the male skeleton, they did not define the role of E vs. T in regulating the adult male skeleton. The past several years have witnessed an accumulation of evidence from observational as well as direct interventional studies that now clearly indicates that E plays a major, and likely dominant, role in bone metabolism in men. These data also suggest that a threshold level of bioavailable (or non-SHBG bound) E is needed for skeletal E sufficiency in the male, and that with aging, an increasing percentage of elderly men begin to fall below this level. It is this subset of men who may be at greatest risk for the development of age-related bone loss and osteoporosis. Moreover, these men may also be the ones most likely to respond favorably to treatment with selective E receptor modulators, or perhaps even to T replacement, because the skeletal effects of the latter may be mediated largely via aromatization to E.

North American male reference population for speed of sound in bone at multiple skeletal sites

Alternatives to dual-energy X-ray absorptiometry (DXA) have been sought to increase access to low-cost osteoporosis risk assessment. Early quantitative ultrasound (QUS) systems measured speed of sound (SOS) and broadband ultrasound attenuation (BUA) at the calcaneus, and these were demonstrated to be good predictors of hip fracture risk. Recent studies have demonstrated the usefulness of other peripheral sites to assess bone status. The Sunlight Omnisense (Sunlight Medical, Rehovot, Israel) is a portable, inexpensive QUS device capable of multiple-site SOS measurement. To provide a robust male reference database, 588 healthy Caucasian males aged 20-90 yr were recruited from 6 centers across North America. SOS measurements were taken at the distal 1/3 radius, proximal third phalanx, midshaft tibia, and fifth metatarsal. A female reference database has previously been collected at North American sites. The results indicate that SOS in males exhibits an age-related decline beginning in the fifth decade at the radius, phalanx, and metatarsal, whereas the tibial SOS remains nearly constant until the ninth decade. Although females reach a higher-peak SOS than males at most sites, SOS is higher in males at all sites after the sixth decade, as a result of a more gradual decline in SOS. Longitudinal monitoring of healthy men should be performed to confirm these cross-sectional results.

Age-related changes in bone mineral content and density in intact male F344 rats

This study was undertaken to determine whether age-related bone loss occurs in intact male F344 rats. Bone loss was assessed in male F344 rats aged 3 to 27 months by scanning different bones using peripheral quantitative computed tomography (pQCT) densitometry. Cancellous and cortical bones were analyzed at the vertebra, proximal tibial metaphysis (PTM), and the neck of the femur. Cortical bone was also analyzed at the tibial and femoral diaphysis and at the tibio-fibula junction. In the vertebra, cancellous bone mineral content (Cn. BMC) did not change significantly with age. Cancellous bone mineral density (Cn. BMD) gradually decreased from 9 months onwards; and at 27 months of age, there was a 29% (p < 0.0001) decrease, when compared with 9-month-old animals. No significant change was observed in cortical bone mineral content (Ct. BMC) and cortical bone mineral density (Ct. BMD) with age. In the PTM, bone loss started to occur after 18 months of age. At 27 months of age, Cn. BMC decreased by 58% (p < 0.0001) and Cn. BMD also decreased by 58% (p < 0.0001). Ct. BMC decreased by 28% (p < 0.0001) in 27-month-old animals, whereas Ct. BMD was not affected by aging. At the tibio-fibula junction, Ct. BMC and Ct. BMD decreased after 18 months of age. At 27 months, Ct. BMC and Ct. BMD had decreased by 8% (p < 0.001) and 3% (p < 0.0001), respectively. Ct. BMC in the tibial diaphysis did not change significantly with age, whereas Ct. BMD decreased by 1% (p < 0.05) at 27 months. In the neck of the femur, Cn. BMC increased up to 24 months of age. Cn. BMD increased up to 18 months of age and decreased by 9% (p < 0.05) at 24 months and 11% (p < 0.001) at 27 months of age when compared with 18-month-old animals. Ct. BMC and Ct. BMD increased with age. In conclusion, although some components of the PTM decreased appreciably with age, in this study, most of the bone parameters analyzed either increased or did not change significantly with age. We conclude that unlike male Sprague Dawley rats, male F344 rats appear not to be a good model for studying age-related bone loss as occurs in aging men.

Ability of peripheral bone assessments to predict areal bone mineral density at hip in community-dwelling elderly men

We present cross-sectional data on bone mineral density (BMD) and quantitative ultrasound (QUS) indices in an ambulatory elderly male population (n = 235). Dual X-ray absorptiometry (DXA) at the proximal femur was considered the reference assessment site and was compared with DXA at the forearm and heel and to QUS at the heel and midtibia. Correlations and weighted kappa analysis indicate an only moderate concordance of absolute values between peripheral bone assessment and total hip DXA (weighted kappas: 0.31-0.45). Discrepancies are even more important when T-scores and prevalence rates of osteoporosis are considered, owing to factors related to the reference populations used. Predictive value of peripheral measurements for osteoporosis diagnosed on the basis of hip BMD by DXA, as assessed by receiver operator characteristic analysis, was moderate and comparable for all peripheral measurements (area under the curve: 0.708-0.870), with the exception of a clearly lower predictive value for QUS at the tibia. Discrimination of male subjects with a history of at least one fragility fracture was significant for DXA at the proximal femur and QUS at the heel. It is concluded that peripheral measurements cannot be used as a substitute for hip DXA. However, they might be useful to guide patient referral for central DXA.

Relationship of serum sex steroid levels to longitudinal changes in bone density in young versus elderly men

Estrogen appears to play an important role in determining bone mineral density in men, but it remains unclear whether estrogen primarily determines peak bone mass or also affects bone loss in elderly men. Thus, we assessed longitudinal rates of change in bone mineral density in young (22-39 yr; n = 88) vs. elderly (60-90 yr; n = 130) men and related these to circulating total and bioavailable estrogen and testosterone levels. In young men bone mineral density increased significantly over 4 yr at the mid-radius and ulna and at the total hip (by 0.32-0.43%/yr), whereas it decreased in the elderly men at the forearm sites (by 0.49-0.66%/yr), but did not change at the total hip. The rate of increase in bone mineral density at the forearm sites in the young men was significantly correlated to serum total and bioavailable estradiol and estrone levels (r = 0.22-0.35), but not with total or bioavailable testosterone levels. In the elderly men the rates of bone loss at the forearm sites were most closely associated with serum bioavailable estradiol levels (r = 0.29-0.33) rather than bioavailable testosterone levels. Moreover, elderly men with bioavailable estradiol levels below the median [40 pmol/liter (11 pg/ml)] had significantly higher rates of bone loss and levels of bone resorption markers than men with bioavailable estradiol levels above 40 pmol/liter. These data thus indicate that estrogen plays a key role both in the acquisition of peak bone mass in young men and in bone loss in elderly men. Moreover, our findings suggest that age-related decreases in bioavailable estradiol levels to below 40 pmol/liter may well be the major cause of bone loss in elderly men. This subset of men is perhaps most likely to benefit from preventive therapy.

Relative contributions of testosterone and estrogen in regulating bone resorption and formation in normal elderly men

Young adult males who cannot produce or respond to estrogen (E) are osteopenic, suggesting that E may regulate bone turnover in men, as well as in women. Both bioavailable E and testosterone (T) decrease substantially in aging men, but it is unclear which deficiency is the more important factor contributing to the increased bone resorption and impaired bone formation that leads to their bone loss. Thus, we addressed this issue directly by eliminating endogenous T and E production in 59 elderly men (mean age 68 years), studying them first under conditions of physiologic T and E replacement and then assessing the impact on bone turnover of withdrawing both T and E, withdrawing only T, or only E, or continuing both. Bone resorption markers increased significantly in the absence of both hormones and were unchanged in men receiving both hormones. By two-factor ANOVA, E played the major role in preventing the increase in the bone resorption markers, whereas T had no significant effect. By contrast, serum osteocalcin, a bone formation marker, decreased in the absence of both hormones, and both E and T maintained osteocalcin levels. We conclude that in aging men, E is the dominant sex steroid regulating bone resorption, whereas both E and T are important in maintaining bone formation.