Search

Background: Observational studies in cutaneous melanoma have indicated an inverse relationship between levels of 25-hydroxy vitamin D and Breslow thickness, as well as a protective effect of high 25- hydroxy vitamin D levels on clinical outcome., Objectives: To evaluate whether high dose vitamin D supplementation in curatively resected cutaneous melanoma reduces melanoma relapse., Methods: In a prospective, randomized, double-blind, placebo-controlled trial, 436 patients with resected cutaneous melanoma stage IA to III (8th American Joint Committee on Cancer staging) were randomized. Among them, 218 received a placebo while 218 received monthly 100,000 IU cholecalciferol for a minimum of 6 months and a maximum of 42 months (treatment arm). Following randomization, patients were followed for a median of 52 months, with a maximum follow-up of 116 months. The primary endpoint was relapse-free survival. Secondary endpoints were melanoma-related mortality, overall survival, and the evolution of 25-hydroxy vitamin D serum levels over time., Results: In our population (mean age 55 years, 54% female) Vitamin D supplementation increased 25- hydroxy vitamin D serum levels after 6 months of supplementation in the treatment arm by a median 17 ng/ml (95%CI: 9; 26) compared to 0 ng/ml (95%CI: -6; 8) in the placebo arm (P < 0.001; Wilcoxon test) and remained at a steady state during the whole treatment period. The estimated event rate for relapse-free survival at 72 months after inclusion was 26.51% in the vitamin D supplemented arm (95% CI: 19.37; 35.64) versus 20.70% (95%CI: 14.26; 29.52) in the placebo arm, [hazard ratio 1.27 (95%CI 0.79; 2.03), P = 0.32]. After adjusting for confounding factors (including baseline stage, body mass index, age, gender, and baseline season), the hazard ratio was 1.20 (95% CI 0.74; 1.94, P = 0.46). Deaths from progression of cutaneous melanoma and non-melanoma related deaths were similar in both vitamin D supplemented and placebo group (n = 10 and 11 and n = 3 and 2, respectively). No major adverse events were observed during the study., Conclusion: In cutaneous melanoma patients, monthly high dose vitamin D supplementation was safe, resulted in a sustained increase in 25-hydroxy vitamin D levels during the treatment period, but did not improve relapse-free survival, melanoma-related death or overall survival., (© The Author(s) 2024. Published by Oxford University Press on behalf of British Association of Dermatologists. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Transgender youth increasingly present at pediatric gender services. Some of them receive long-term puberty suppression with gonadotropin-releasing hormone analogues (GnRHa) before starting gender-affirming hormones (GAH). The impact of GnRHa use started in early puberty on bone composition and bone mass accrual is unexplored. It is furthermore unclear whether subsequent GAH fully restore GnRHa effects and whether the timing of GAH introduction matters. To answer these questions, we developed a mouse model mimicking the clinical strategy applied in trans boys. Prepubertal 4-week-old female mice were treated with GnRHa alone or with GnRHa supplemented with testosterone (T) from 6 weeks (early puberty) or 8 weeks (late puberty) onward. Outcomes were analyzed at 16 weeks and compared with untreated mice of both sexes. GnRHa markedly increased total body fat mass, decreased lean body mass, and had a modest negative impact on grip strength. Both early and late T administration shaped body composition to adult male levels, whereas grip strength was restored to female values. GnRHa-treated animals showed lower trabecular bone volume and reduced cortical bone mass and strength. These changes were reversed by T to female levels (cortical bone mass and strength) irrespective of the time of administration or even fully up to adult male control values (trabecular parameters) in case of earlier T start. The lower bone mass in GnRHa-treated mice was associated with increased bone marrow adiposity, also reversed by T. In conclusion, prolonged GnRHa use started in prepubertal female mice modifies body composition toward more fat and less lean mass and impairs bone mass acquisition and strength. Subsequent T administration counteracts GnRHa impact on these parameters, shaping body composition and trabecular parameters to male values while restoring cortical bone architecture and strength up to female but not male control levels. These findings could help guide clinical strategies in transgender care. © 2023 American Society for Bone and Mineral Research (ASBMR)., (© 2023 American Society for Bone and Mineral Research (ASBMR).)

The androgen receptor (AR) plays a central role in the development and maintenance of the male phenotype. The binding of androgens to the receptor induces interactions between the carboxyterminal ligand-binding domain and the highly conserved 23FQNLF27 motif in the aminoterminal domain. The role of these so-called N/C interactions in AR functioning is debated. In vitro assays show that mutating the AR in the 23FQNLF27 motif (called ARNoC) attenuates the AR transactivation of reporter genes, has no effect on ligand binding, but does affect protein-protein interactions with several AR coregulators. To test the in vivo relevance of the N/C interaction, we analyzed the consequences of the genomic introduction of the ARNoC mutation in mice. Surprisingly, the ARNoC/Y mice show a normal male development, with unaffected male anogenital distance and normal accessory sex glands, male circulating androgen levels, body composition, and fertility. The responsiveness of androgen target genes in kidney, prostate, and testes was also unaffected. We thus conclude that the N/C interactions in the AR are not essential for the development of a male phenotype under normal physiological conditions., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Failure of bone mass maintenance in spite of functional loading is an important contributor to osteoporosis and related fractures. While the link between sex steroids and the osteogenic response to loading is well established, the underlying mechanisms are unknown, hampering clinical relevance. Androgens inhibit mechanoresponsiveness in male mice, but the cell type mediating this effect remains unidentified. To evaluate the role of neuronal sex steroid receptor signaling in the male bone's adaptive capacity, we subjected adult male mice with an extrahypothalamic neuron-specific knockout of the androgen receptor (N-ARKO) or the estrogen receptor alpha (N-ERαKO) to in vivo mechanical stimulation of the tibia. Loading increased cortical thickness in the control animals mainly through periosteal expansion, as total cross-sectional tissue area and cortical bone area but not medullary area were higher in the loaded than the unloaded tibia. Trabecular bone volume fraction also increased upon loading in the control group, mostly due to trabecular thickening. N-ARKO and N-ERαKO males displayed a loading response at both the cortical and trabecular bone compartments that was not different from their control littermates. In conclusion, we show that the presence of androgen receptor or estrogen receptor alpha in extrahypothalamic neurons is dispensable for the osteogenic response to mechanical loading in male mice., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: erectile dysfunction is associated with mortality, whereas the association between low testosterone (T) and higher mortality remains controversial. Sexual dysfunction and low T often coexist, but the relative importance of sexual symptoms versus low T in predicting mortality is not known. We studied the interrelationships between sex steroids and sexual symptoms with all-cause mortality in a large prospective cohort of European men., Design: survival status was assessed in 1,788 community-dwelling men, aged 40-79, who participated in the European Male Ageing Study (EMAS). Sexual symptoms were evaluated via a validated questionnaire (EMAS-SFQ). Sex steroids were measured by mass spectrometry. Cox proportional hazard models were used to study the association between hormones, sexual symptoms and mortality., Results: about 420 (25.3%) men died during a mean follow-up of 12.6 ± 3.1 years. Total T levels were similar in both groups, but free T was lower in those who died. Men with three sexual symptoms (erectile dysfunction, reduced morning erections and lower libido) had a higher mortality risk compared with men with none of these symptoms (adjusted hazard ratio (HR) and 95% confidence intervals: 1.75 (1.28-2.40, P = 0.001)). Particularly, erectile dysfunction and poor morning erections, but not lower libido, were associated with increased mortality (HR 1.40 (1.13-1.74, P = 0.002), 1.28 (1.04-1.59, P = 0.023) and 1.12 (0.90-1.39, P = 0.312), respectively). Further adjusting for total T, free T or oestradiol did not influence the observed risk., Conclusions: sexual symptoms, in particular erectile dysfunction, predict all-cause mortality independently of sex steroids and can be an early warning sign of a poor health status., (© The Author(s) 2022. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Context: Low total 25-hydroxyvitamin D (25(OH)D) has been associated with mortality. Whether vitamin D in its free form or 1,25-dihydroxyvitamin D (1,25(OH)2D), provide any additional information is unclear., Objective: To determine what level of 25(OH)D is predictive for mortality and if free 25(OH)D or 1,25(OH) 2 D concentrations have any added value., Methods: This prospective cohort comprised 1915 community-dwelling men, aged 40 to 79 years. Intervention included determination of association of total and free 25(OH)D and 1,25(OH) 2 D concentrations with survival status. Vitamin D results were grouped into quintiles. For total 25(OH)D, specific cutoff values were also applied. Cox proportional hazard models were used adjusted for center, body mass index, smoking, alcohol, physical activity, season of blood sample, kidney function, and number of comorbidities., Results: A total of 469 (23.5%) men died during a mean follow-up of 12.3 ± 3.4 years. Compared to those with normal vitamin D values (> 30 µg/L), men with a total 25(OH)D of less than 20 µg/L had an increased mortality (hazard ratio [HR] 2.03 [95% CI, 1.39-2.96]; P < .001). Likewise, men in the lowest 3 free 25(OH)D quintiles (< 4.43 ng/L) had a higher mortality risk compared to the highest quintile (HR 2.09 [95% CI, 1.34-3.25]; P < .01). Mortality risks were similar across all 1,25(OH)2D and vitamin D binding protein quintiles., Conclusion: Aging men with vitamin D deficiency have a 2-fold increased mortality risk. Determinations of either the free fractions of vitamin D or measurement of its active form offer no additional information on mortality risks., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objective: GC/DBP effects on response to vitamin D supplementation have not been well-studied. Thus we assessed free and total 25-OHD after vitamin D treatment across the six common GC haplotypes., Design: This double-blind, randomized study compared two vitamin D3 doses in healthy, urban-dwelling 6-month to 10-year-old children at-risk for vitamin D deficiency. Randomization was stratified by GC haplotype., Methods: Children were randomized to receive 2800 or 7000 International Units of vitamin D3 weekly. 25-OHD and 1,25(OH)2D were sampled at baseline and after 1-6 months of supplementation., Results and Conclusions: One hundred ninety-two of 225 enrolled subjects completed the study. After one month, total 25-OHD increased with both doses and were higher with 7000 IU/week (85.5 ± 22.8 nmol/L) compared to 2800 IU/week (76.8 ± 18.0 nmol/L), despite equivalent baseline levels. No further significant increase occurred at 6 months (89.8 ± 35.5 and 74.3 ± 18.3 nmol/L, respectively). Free 25-OHD similarly changed. 25-OHD differed among GC groups at baseline. Although no significant effects of individual GC haplotypes on incremental changes were evident, a trend toward an effect of combined 'at risk' GC alleles on response was evident (P = 0.06). Total 1,25(OH)2D showed modest increases, moreso with the larger dose. In urban-dwelling children at-risk for vitamin D deficiency, 1 month of vitamin D3 2800 IU/week increased 25-OHD across all GC haplotype groups, and somewhat enhanced with 7000 IU/week with no further significant increases after 6 months of supplementation. Free 25-OHD measures offer no monitoring advantage over total 25-OHD.

Testosterone (T) reduces male fat mass, but the underlying mechanisms remain elusive, limiting its clinical relevance in hypogonadism-associated obesity. Here, we subjected chemically castrated high-fat diet-induced adult obese male mice to supplementation with T or the nonaromatizable androgen dihydrotestosterone (DHT) for 20 weeks. Both hormones increased lean mass, thereby indirectly increasing oxygen consumption and energy expenditure. In addition, T but not DHT decreased fat mass and increased ambulatory activity, indicating a role for aromatization into estrogens. Investigation of the pattern of aromatase expression in various murine tissues revealed the absence of Cyp19a1 expression in adipose tissue while high levels were observed in brain and gonads. In obese hypogonadal male mice with extrahypothalamic neuronal estrogen receptor alpha deletion (N-ERαKO), T still increased lean mass but was unable to decrease fat mass. The stimulatory effect of T on ambulatory activity was also abolished in N-ERαKO males. In conclusion, our work demonstrates that the fat-burning action of T is dependent on aromatization into estrogens and is at least partially mediated by the stimulation of physical activity via extrahypothalamic ERα signaling. In contrast, the increase in lean mass upon T supplementation is mediated through the androgen receptor and indirectly leads to an increase in energy expenditure, which might also contribute to the fat-burning effects of T., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Endocrine Society.)

Background: Few data have looked at the occurrence and clinical correlates of self-reported shorter than desired ejaculation latency (rapid ejaculation, RE) and its related distress in the general population., Aim: To determine the prevalence and clinical correlates of self-reported RE and RE- related distress in middle age and older European men., Methods: Subjects were recruited from population samples of men aged 40-79 years across 8 European centers., Outcomes: Self-reported RE and its related distress were derived from the European male Aging Study (EMAS) sexual function questionnaire (EMAS-SFQ). Beck's depression Inventory (BDI) was used for the quantification of depressive symptoms, the Short Form 36 health survey (SF-36) for the assessment of the quality of life, the International Prostate Symptom Score (IPSS) for the evaluation of lower urinary tract symptoms., Results: About 2,888 community dwelling men aged 40-79 years old (mean 58.9 ± 10.8 years) were included in the analysis. Among the subjects included, 889 (30.8%) self-reported RE. Among them, 211 (7.3%) claimed to be distressed (5.9% and 1.4% reported mild or moderate-severe distress, respectively). Increasing levels of RE-related distress were associated with a progressive worse sexual functioning, higher risk of ED and with couple impairment, along with a higher prevalence of depressive symptoms (all P < 0.05). Furthermore, a worse quality of life and higher IPSS score were associated with RE-related distress (all P < 0.05). The aforementioned results were confirmed even when patients using drugs possibly interfering with ejaculation or those without a stable relationship were excluded from the analysis., Clinical Implications: RE is a frequent condition in men from the general population; however, its related distress is relatively modest. Nonetheless, men with any degree of self-reported RE show increasing levels of depression, worse quality of life and worse couple satisfaction., Strengths & Limitations: This is the first study estimating the prevalence of self-reported RE and its related distress, along with their biological and psychological correlates, in a population sample of European middle age and older men. However, is should be recognized that the diagnosis of RE was derived from patient reports and not supported by Intra-ejaculatory-Latency-Time (IELT) measurements., Conclusion: Self-reported RE is relatively common in European men aged more than 40 years. The reported limited RE-related distress may explain the relatively low number of medical consultations for RE. RE-related distress is associated with worse sexual function, couple impairment, and more LUTS resulting in a worse quality of life and mood disturbances. Corona G, Rastrelli G, Bartfai G, et al. Self-Reported Shorter Than Desired Ejaculation Latency and Related Distress-Prevalence and Clinical Correlates: Results From the European Male Ageing Study. J Sex Med Rev 2021;18:908-919., (Copyright © 2021. Published by Elsevier Inc.)

Context: Questions regarding the superiority of free and bioavailable 25-hydroxyvitamin D [25(OH)D] in predicting health outcomes remain unresolved., Objective: This study investigates the impact of vitamin D variables-total, bioavailable, or free 25(OH)D-on indices of bone and mineral metabolism, at baseline and in response to 2 vitamin D doses., Design: Our objectives are implemented as exploratory analyses on data collected in a 1-year, double-blind, randomized controlled trial completed in July 2014., Setting: Participants were recruited from 3 major hospitals in an ambulatory setting., Participants: Participants were >65 years of age, overweight, and had a baseline serum 25(OH)D between 10 and 30 ng/mL. A total of 221 participants completed the study., Intervention: Subjects were randomized to receive calcium and oral vitamin D3 (600 IU/day or 3750 IU/day) supplementation., Results: Participants who received the higher vitamin D dose had levels that were 1.3- to 1.4-fold higher than those taking the lower dose, for all variables (P value < 0.001). Serum values of bioavailable and free 25(OH)D were associated with total 25(OH)D, with r values of 0.942 and 0.943, respectively (P value < 0.001). Parathyroid hormone (PTH) was negatively associated with all vitamin D variables, with correlation coefficients ranging from -0.22 to -0.25, while calcium and bone turnover markers (carboxy-terminal collagen crosslinks and osteocalcin) did not. Only total 25(OH)D had a positive relationship with % change bone mineral density (BMD) at the femoral neck at 12 months, while only free and bioavailable 25(OH) had a positive relationship with % change total body BMD at 12 months., Conclusion: Calculated free and bioavailable 25(OH)D do not appear to be superior to total 25(OH)D in predicting indices of bone health in an elderly population., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Context: Serum testosterone concentrations decline with age, while serum sex hormone-binding globulin (SHBG) concentrations increase., Objective: To analyze associations of baseline serum testosterone and SHBG concentrations, and calculated free testosterone (cFT) values, with all-cause and cause-specific mortality in men., Design, Setting, and Participants: The UK Biobank prospective cohort study of community-dwelling men aged 40-69 years old, followed for 11 years., Main Outcome Measures: All-cause, atherosclerotic cardiovascular disease (CVD) and cancer-related mortality. Cox proportional hazards regression was performed, adjusting for age, waist circumference, medical conditions, and other covariates. Models for testosterone included SHBG and vice versa., Results: In a complete case analysis of 149 436 men with 10 053 deaths (1925 CVD and 4927 cancer-related), men with lower testosterone had a higher mortality rate from any cause (lowest vs highest quintile, Q1 vs Q5, fully-adjusted hazard ratio [HR] = 1.14, 95% confidence interval [CI] = 1.06-1.22, overall trend P < 0.001), and cancer (HR = 1.20, CI = 1.09-1.33, P < 0.001), with no association for CVD deaths. Similar results were seen for cFT. Men with lower SHBG had a lower mortality rate from any cause (Q1 vs Q5, HR = 0.68, CI = 0.63-0.73, P < 0.001), CVD (HR = 0.70, CI = 0.59-0.83, P < 0.001), and cancer (HR = 0.80, CI = 0.72-0.89, P < 0.001). A multiply imputed dataset (N = 208 425, 15 914 deaths, 3128 CVD-related and 7468 cancer-related) and analysis excluding deaths within the first 2 years (9261, 1734, and 4534 events) yielded similar results., Conclusions: Lower serum testosterone is independently associated with higher all-cause and cancer-related, but not CVD-related, mortality in middle-aged to older men. Lower SHBG is independently associated with lower all-cause, CVD-related, and cancer-related mortality. Confirmation and determination of causality requires mechanistic studies and prospective trials., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objective: Long-term androgen deprivation therapy (ADT) negatively influences bone. The short-term effects on bone and mineral homeostasis are less known. Therefore, we aimed to investigate the early effects of ADT on calcium/phosphate homeostasis and bone turnover., Design: Prospective cohort study., Methods: Eugonadal adult, male sex offenders, who were referred for ADT to the endocrine outpatient clinic, received cyproterone acetate. Changes in blood markers of calcium/phosphate homeostasis and bone turnover between baseline and first follow-up visit were studied., Results: Of 26 screened patients, 17 were included. The median age was 44 (range 20-75) years. The median time interval between baseline and first follow-up was 13 (6-27) weeks. Compared to baseline, an 81% decrease was observed for median total testosterone (to 3.4 nmol/L (0.4-12.2); P < 0.0001) and free testosterone (to 0.06 nmol/L (0.01-0.18); P < 0.0001). Median total estradiol decreased by 71% (to 17.6 pmol/L (4.7-35.6); P < 0.0001). Increased serum calcium (P < 0.0001) and phosphate (P = 0.0016) was observed, paralleled by decreased PTH (P = 0.0156) and 1,25-dihydroxyvitamin D3 (P = 0.0134). The stable calcium isotope ratio (δ44/42Ca) decreased (P = 0.0458), indicating net calcium loss from bone. Bone-specific alkaline phosphatase and osteocalcin decreased (P < 0.0001 and P = 0.0056, respectively), periostin tended to decrease (P = 0.0500), whereas sclerostin increased (P < 0.0001), indicating suppressed bone formation. Serum bone resorption markers (TRAP, CTX) were unaltered., Conclusions: In adult men, calcium release from the skeleton occurs early following sex steroid deprivation, reflecting early bone resorption. The increase of sclerostin and reduction of bone formation markers, without changes in resorption markers, suggests a dominant negative effect on bone formation in the acute phase.

Context: Vitamin D status is usually assessed by serum total 25-hydroxyvitamin D (t25-OHD). Whether free 25-hydroxyvitamin D measures better correlate with various clinical outcomes is unclear., Objective: To identify correlations between t25-OHD, calculated and direct measures of free 25-OHD, and to identify associations of these measures with other outcomes in children, across the 6 common GC haplotypes., Design: Healthy urban-dwelling children underwent measurement of relevant variables., Setting: Academic medical center., Participants: The study included 203 healthy, urban-dwelling children, aged 6 months to 10 years, predominantly of Hispanic background and representative of all common GC haplotypes., Intervention: None., Main Outcome Measures: Total and free 25-OHD and 1,25(OH)2D, calcium, phosphate, parathyroid hormone (PTH), glucose, insulin, aldosterone, and renin., Results: Mean t25-OHD [26.3 ± 6.7ng/ml; 65.8 ± 16.8nmol/L] were lowest in the GC2 genotype. Mean t1,25(OH)2D [57.6 ± 16.5pg/ml; 143.9 ± 41.3pmol/L], were lowest in GC1f/1f, GC1f/2, and GC2/2 groups. T25-OHD correlated strongly with calculated free 25-OHD (cf25-OHD) (r = 0.89) and moderately with directly measured free 25-OHD (dmf25-OHD) (r = 0.69). Cf25-OHD correlated with dmf25-OHD (r = 0.69) (P < 0.001 for all). t25-OHD inversely correlated with body mass index (BMI) (r=-0.191; P = 0.006), skin reflectometry, and systolic blood pressure. T25-OHD correlated with fasting insulin and the homeostatic model assessment for insulin resistance (HOMA-IR), however significance for these correlations was not evident after adjustment for BMI. PTH inversely correlated with all measures of 25-OHD, but most strongly with t25-OHD., Conclusions: Measures of circulating total and free 25-OHD are comparable measures of vitamin D status in heathy children. Correlations are similar with other outcome variables, however t25-OHD remains the strongest correlate of circulating PTH and other variables. These data argue against routine refinement of the t25-OHD measure using currently available assessments of free 25-OHD., Clinical Trial Information: Clinicaltrials.gov registration no: NCT01050387 (January 15, 2010)., (© Endocrine Society 2019. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Androgens via the androgen receptor (AR) are required for optimal male bone health. The target cell(s) for the effects of androgens on cortical bone remain(s) incompletely understood. In females, estrogen receptor alpha in neurons is a negative regulator of cortical and trabecular bone. Whether neuronal AR regulates bone mass in males remains unexplored. Here, we inactivated AR in neurons using a tamoxifen-inducible CreERT2 under the control of the neuronal promoter Thy1. Tamoxifen induced a 70% to 80% reduction of AR mRNA levels in Thy1-CreERT2-positive brain regions cerebral cortex and brainstem as well as in the peripheral nervous tissue of male neuronal AR knockout (N-ARKO) mice. Hypothalamic AR mRNA levels were only marginally reduced and the hypothalamic-pituitary-gonadal axis remained unaffected, as determined by normal levels of serum testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH). In contrast to orchidectomy, deletion of neuronal AR did not alter body weight, body composition, hindlimb muscle mass, grip strength, or wheel running. MicroCT analysis of the femur revealed no changes in bone accrual during growth in N-ARKO mice. However, 36- and 46-week-old N-ARKO mice displayed an accelerated age-related cortical involution, namely a more pronounced loss of cortical thickness and strength, which occurred in the setting of androgen sufficiency. Neuronal AR inactivation decreased the cancellous bone volume fraction in L 5 vertebra but not in the appendicular skeleton of aging mice. MicroCT findings were corroborated in the tibia and after normalization of hormonal levels. Serum markers of bone turnover and histomorphometry parameters were comparable between genotypes, except for a 30% increase in osteoclast surface in the trabecular compartment of 36-week-old N-ARKO mice. Cortical bone loss in N-ARKO mice was associated with an upregulation of Ucp1 expression in brown adipose tissue, a widely used readout for sympathetic tone. We conclude that androgens preserve cortical integrity in aging male mice via AR in neurons. © 2018 American Society for Bone and Mineral Research., (© 2018 American Society for Bone and Mineral Research.)

Context: Assessment of free testosterone (FT) might help evaluate androgen status in patients with borderline total testosterone (T) and/or altered sex hormone-binding globulin (SHBG) levels. However, the validity of different methods to measure FT is debatable., Methods: Serum from 183 women and 146 men was analyzed using equilibrium dialysis (ED), with FT directly measured by liquid chromatography-tandem mass spectrometry. FT calculation was re-evaluated for the mass action law-based equation according to Vermeulen (cFT-V), empirical equations according to Ly (cFT-L), and a proposed calculation based on a multistep, dynamic, allosteric model according to Zakharov (cFT-Z)., Results: FT level analyzed by ED [median,13 pmol/L (1.2% of T) in women; 248 pmol/L (1.5% of T) in men] was strongly inversely correlated to SHBG level, significantly to albumin level in women, and only weakly to SHBG level in men. The median [percentile (p) range, 2.5 to 97.5] ratios of calculated FT (cFT) over ED-FT (from European Male Aging Study samples) were 1.19 (0.9 to 1.47), 1.00 (0.69 to 1.42), and 2.05 (1.26 to 3.26) for cFT-V, cFT-L, and cFT-Z, respectively. The ratio for cFT-V was not significantly affected by SHBG, T, or albumin levels (ρ range, 0.17 to -0.01); ratios for cFT-L and cFT-Z were affected (P < 0.05 and P < 0.001, respectively) and strongly correlated with SHBG levels (ρ = 0.72 and 0.75, respectively). Rank correlations between cFT% and ED-FT% (for men) were 0.62, 0.74, and 0.89 for cFT-Z, cFT-L, and cFT-V, respectively., Conclusion: FT results by direct ED confirm prior FT data from indirect ED and ultrafiltration methodologies. Calculations have inherent limitations, with clinically important differences among evaluated equations: cFT-V, although overestimating FT level, appears the most robust approximation, largely independent of SHBG, albumin, and T levels.

Context: Serum estradiol (E2) and estrone (E1) levels exhibit substantial heritability., Objective: To investigate the genetic regulation of serum E2 and E1 in men., Design, Setting, and Participants: Genome-wide association study in 11,097 men of European origin from nine epidemiological cohorts., Main Outcome Measures: Genetic determinants of serum E2 and E1 levels., Results: Variants in/near CYP19A1 demonstrated the strongest evidence for association with E2, resolving to three independent signals. Two additional independent signals were found on the X chromosome; FAMily with sequence similarity 9, member B (FAM9B), rs5934505 (P = 3.4 × 10-8) and Xq27.3, rs5951794 (P = 3.1 × 10-10). E1 signals were found in CYP19A1 (rs2899472, P = 5.5 × 10-23), in Tripartite motif containing 4 (TRIM4; rs17277546, P = 5.8 × 10-14), and CYP11B1/B2 (rs10093796, P = 1.2 × 10-8). E2 signals in CYP19A1 and FAM9B were associated with bone mineral density (BMD). Mendelian randomization analysis suggested a causal effect of serum E2 on BMD in men. A 1 pg/mL genetically increased E2 was associated with a 0.048 standard deviation increase in lumbar spine BMD (P = 2.8 × 10-12). In men and women combined, CYP19A1 alleles associated with higher E2 levels were associated with lower degrees of insulin resistance., Conclusions: Our findings confirm that CYP19A1 is an important genetic regulator of E2 and E1 levels and strengthen the causal importance of E2 for bone health in men. We also report two independent loci on the X-chromosome for E2, and one locus each in TRIM4 and CYP11B1/B2, for E1.

Context: Clinical sequelae of androgen deficiency share common features with frailty. Evidence supporting the role of androgens in the development of frailty is limited and conflicting., Objective: To determine associations between male reproductive hormones and prospective changes in frailty status., Design/setting: A 4.3-year prospective cohort study of community-dwelling men participating in the European Male Ageing Study., Participants: A total of 3369 men aged 40 to 79 from eight European centers., Intervention: None., Main Outcome Measure: Frailty status was determined using frailty index (FI; n = 2278) and frailty phenotype (FP; n = 1980)., Results: After adjusting for baseline frailty, age, center, and smoking, the risk of worsening FI decreased with higher testosterone (T), free T, and dihydrotestosterone (DHT) [percentage change (95% confidence interval) in FI associated with 1 standard deviation higher hormone level: -3.0 (-5.9, -1.0) for total T; -3.9 (-6.8, -2.0) for free T; and -3.9 (-6.8, -2.0) for DHT]. After further adjustment for body mass index, only free T remained a significant predictor of FI change. In fully adjusted models, higher luteinizing hormone and follicle-stimulating hormone were positively related to worsening FI only in men <60 years, and higher estradiol predicted lower likelihood of improving FP [odds ratio: 0.68 (0.52, 0.88)]., Conclusions: These prospective data support the hypothesis that higher androgen levels may protect elderly men from worsening frailty. However, the causal nature of these relationships requires further investigation. Whereas raised gonadotropins in men <60 years might be an early marker of frailty, the role of estradiol in frailty needs further clarification., (Copyright © 2017 Endocrine Society)

Context: Low levels of nonandrogenic anabolic hormones have been linked with frailty, but evidence is conflicting and prospective data are largely lacking., Objective: To determine associations between nonandrogenic anabolic hormones and prospective changes in frailty status., Design/setting: A 4.3-year prospective observational study of community-dwelling men participating in the European Male Ageing Study., Participants: Men (n = 3369) aged 40 to 79 years from eight European centers., Main Outcome Measures: Frailty status was determined using frailty phenotype (FP; n = 2114) and frailty index (FI; n = 2444)., Analysis: Regression models assessed relationships between baseline levels of insulinlike growth factor 1 (IGF-1), its binding protein 3 (IGFBP-3), dehydroepiandrosterone sulfate (DHEA-S), 25-hydroxyvitamin D (25OHD), and parathyroid hormone (PTH), with changes in frailty status (worsening or improving frailty)., Results: The risk of worsening FP and FI decreased with 1 standard deviation higher IGF-1, IGFBP-3, and 25OHD in models adjusted for age, body mass index, center, and baseline frailty [IGF-1: odds ratio (OR) for worsening FP, 0.82 (0.73, 0.93), percentage change in FI, -3.7% (-6.0, -1.5); IGFBP-3: 0.84 (0.75, 0.95), -4.2% (-6.4, -2.0); 25OHD: 0.84 (0.75, 0.95); -4.4%, (-6.7, -2.0)]. Relationships between IGF-1 and FI were attenuated after adjusting for IGFBP-3. Higher DHEA-S was associated with a lower risk of worsening FP only in men >70 years old [OR, 0.57 (0.35, 0.92)]. PTH was unrelated to change in frailty status., Conclusions: These longitudinal data confirm the associations between nonandrogenic anabolic hormones and the changes in frailty status. Interventional studies are needed to establish causality and determine therapeutic implications.

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., (© The Author 2016. Published by Oxford University Press on behalf of the British Geriatrics Society.)

Context: The androgen receptor (AR) gene exon 1 CAG repeat length has been proposed to be a determinant of between-individual variations in androgen action in target tissues, which might regulate phenotypic differences of human ageing. However, findings on its phenotypic effects are inconclusive., Objective: To assess whether the AR CAG repeat length is associated with longitudinal changes in endpoints that are influenced by testosterone (T) levels in middle-aged and elderly European men., Design: Multinational European observational prospective cohort study., Participants: A total of 1887 men (mean ± s.d. age: 63 ± 11 years; median follow up: 4.3 years) from centres of eight European countries comprised the analysis sample after exclusion of those with diagnosed diseases of the hypothalamic-pituitary-testicular (HPT) axis., Main Outcome Measures: Longitudinal associations between the AR CAG repeat and changes in androgen-sensitive endpoints (ASEs) and medical conditions were assessed using regression analysis adjusting for age and centre. The AR CAG repeat length was treated as both a continuous and a categorical (6-20; 21-23; 24-39 repeats) predictor. Additional analysis investigated whether results were independent of baseline T or oestradiol (E 2 ) levels., Results: The AR CAG repeat, when used as a continuous or a categorical predictor, was not associated with longitudinal changes in ASEs or medical conditions after adjustments. These results were independent of T and E 2 levels., Conclusion: Within a 4-year time frame, variations in the AR CAG repeat do not contribute to the rate of phenotypic ageing, over and above, which might be associated with the age-related decline in T levels., (© 2016 European Society of Endocrinology.)

Background: Phosphorus control is generally considered to be better in peritoneal dialysis (PD) patients as compared with haemodialysis (HD) patients. Predialysis phosphorus concentrations are misleading as a measure of phosphorus exposure in HD, as these neglect significant dialysis-related fluctuations., Methods: Parameters of mineral metabolism, including parathyroid hormone (PTH) and fibroblast growth factor-23 (FGF-23), were determined in 79 HD and 61 PD patients. In PD, phosphorus levels were determined mid-morning. In HD, time-averaged phosphorus concentrations were modelled from measurements before and after the mid-week dialysis session. Weekly renal, dialytic and total phosphorus clearances as well as total mass removal were calculated from urine and dialysate collections., Results: Time-averaged serum phosphorus concentrations in HD (3.5 ± 1.0 mg/dL) were significantly lower than the mid-morning concentrations in PD (5.0 ± 1.4 mg/dL, P < 0.0001). In contrast, predialysis phosphorus concentrations (4.6 ± 1.4 mg/dL) were not different from PD. PTH and FGF-23 levels were significantly higher in PD. Despite higher residual renal function, total phosphorus clearance was significantly lower in PD (P < 0.0001). Total phosphorus mass removal, conversely, was significantly higher in PD (P < 0.05)., Conclusions: Our data suggest that the time-averaged phosphorus concentrations in patients treated with PD are higher as compared with patients treated with HD. Despite a better preserved renal function, total phosphorus clearance is lower in patients treated with PD. Additional studies are needed to confirm these findings in a population with a different demographic profile and dietary background and to define clinical implications., (© The Author 2016. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.)

Context: During aging, total testosterone (TT) declines and SHBG increases, resulting in a greater decrease in calculated free T (cFT). Currently, guidelines suggest using TT to diagnose androgen deficiency and to reserve cFT only for men with borderline TT., Objective: Our objective was to investigate if either low cFT or low TT is more strongly associated with androgen-related clinical endpoints., Methods: A total of 3334 community-dwelling men, aged 40-79 years, were included in this study. Differences in clinical variables between the referent group of men with both normal TT (≥10.5 nmol/liter) and normal cFT (≥220 pmol/liter) with those who had normal TT/low cFT, low TT/normal cFT, and low TT/low cFT were assessed by regression models adjusted for age, center, body mass index, and comorbidities., Results: A total of 2641 men had normal TT (18.4 ± 5.5 [mean ± SD] nmol/liter)/normal cFT (326 ± 74 pmol/liter), 277 men had normal TT (14.2 ± 3.7)/low cFT (194 ± 23), 96 men had low TT (9.6 ± 0.7)/normal cFT (247 ± 20), and 320 men had low TT (7.8 ± 2.5)/low cFT (160 ± 55). Men with normal TT/low cFT were older and in poorer health. They had higher SHBG and LH and reported more sexual and physical symptoms, whereas hemoglobin and bone ultrasound parameters were lower compared to the referent group. Men with low TT/normal cFT were younger and more obese. They had lower SHBG, but LH was normal, whereas features of androgen deficiency were lacking., Conclusions: Low cFT, even in the presence of normal TT, is associated with androgen deficiency-related symptoms. Normal cFT, despite low TT, is not associated with cognate symptoms; therefore, cFT levels should be assessed in men with suspected hypogonadal symptoms.

Context: Total 25-hydroxyvitamin D (25OHD) is a marker of vitamin D status and is lower in African Americans than in whites. Whether this difference holds for free 25OHOD (f25OHD) is unclear, considering reported genetic-racial differences in vitamin D binding protein (DBP) used to calculate f25OHD., Objectives: Our objective was to assess racial-geographic differences in f25OHD and to understand inconsistencies in racial associations with DBP and calculated f25OHD., Design: This study used a cross-sectional design., Setting: The general community in the United States, United Kingdom, and The Gambia were included in this study., Participants: Men in Osteoporotic Fractures in Men and Medical Research Council studies (N = 1057) were included., Exposures: Total 25OHD concentration, race, and DBP (GC) genotype exposures were included., Outcome Measures: Directly measured f25OHD, DBP assessed by proteomics, monoclonal and polyclonal immunoassays, and calculated f25OHD were the outcome measures., Results: Total 25OHD correlated strongly with directly measured f25OHD (Spearman r = 0.84). Measured by monoclonal assay, mean DBP in African-ancestry subjects was approximately 50% lower than in whites, whereas DBP measured by polyclonal DBP antibodies or proteomic methods was not lower in African-ancestry. Calculated f25OHD (using polyclonal DBP assays) correlated strongly with directly measured f25OHD (r = 0.80-0.83). Free 25OHD, measured or calculated from polyclonal DBP assays, reflected total 25OHD concentration irrespective of race and was lower in African Americans than in US whites., Conclusions: Previously reported racial differences in DBP concentration are likely from monoclonal assay bias, as there was no racial difference in DBP concentration by other methods. This confirms the poor vitamin D status of many African-Americans and the utility of total 25OHD in assessing vitamin D in the general population.

Background: we hypothesised that chronic widespread pain (CWP), by acting as a potential stressor, may predispose to the development of, or worsening, frailty., Setting: longitudinal analysis within the European Male Ageing Study (EMAS)., Participants: a total of 2,736 community-dwelling men aged 40-79., Methods: subjects completed a pain questionnaire and shaded a manikin, with the presence of CWP defined using the American College of Rheumatology criteria. Physical activity, smoking, alcohol consumption and depression were measured. Repeat assessments took place a median of 4.3 years later. A frailty index (FI) was used, with frail defined as an FI >0.35. The association between CWP at baseline and the new occurrence of frailty was examined using logistic regression; the association between CWP at baseline and change in FI was examined using negative binomial regression., Results: at baseline, 218 (8.3%) men reported CWP. Of the 2,631 men who were defined as non-frail at baseline, 112 (4.3%) were frail at follow-up; their mean FI was 0.12 (SD 0.1) at baseline and 0.15 (SD 0.1) at follow-up, with a mean change of 0.03 (SD 0.08) P ≤ 0.001. Among men who were non-frail at baseline, those with CWP were significantly more likely to develop frailty. After adjustment for age and centre, compared with those with no pain, those with CWP at baseline had a 70% higher FI at follow-up; these associations remained significant after further adjustment for smoking, body mass index, depression, physical activity and FI at baseline., Conclusion: the presence of CWP is associated with an increased risk of frailty in older European men., (© The Author 2015. Published by Oxford University Press on behalf of the British Geriatrics Society.)

Androgen deficiency is associated with obesity, metabolic syndrome, and type 2 diabetes mellitus in men, but the mechanisms behind these associations remain unclear. In this study, we investigated the combined effects of androgen deficiency and high-fat diet (HFD) on body composition and glucose homeostasis in C57BL/6J male mice. Two models of androgen deficiency were used: orchidectomy (ORX) and androgen receptor knockout mice. Both models displayed higher adiposity and serum leptin levels upon HFD, whereas no differences were seen on a regular diet. Fat accumulation in HFD ORX animals was accompanied by increased sedentary behavior and occurred in spite of reduced food intake. HFD ORX mice showed white adipocyte hypertrophy, correlated with decreased mitochondrial content but not function as well as increased lipogenesis and decreased lipolysis suggested by the up-regulation of fatty acid synthase and the down-regulation of hormone-sensitive lipase. Both ORX and androgen receptor knockout exacerbated HFD-induced glucose intolerance by impairing insulin action in liver and skeletal muscle, as evidenced by the increased triglyceride and decreased glycogen content in these tissues. In addition, serum IL-1β levels were elevated, and pancreatic insulin secretion was impaired after ORX. Testosterone but not dihydrotestosterone supplementation restored the castration effects on body composition and glucose homeostasis. We conclude that sex steroid deficiency in combination with HFD exacerbates adiposity, insulin resistance, and β-cell failure in 2 preclinical male mouse models. Our findings stress the importance of a healthy diet in a clinical context of androgen deficiency and may have implications for the prevention of metabolic alterations in hypogonadal men.

Androgens increase skeletal muscle mass, but their clinical use is hampered by a lack of tissue selectivity and subsequent side effects. Selective androgen receptor modulators elicit muscle-anabolic effects while only sparingly affecting reproductive tissues. The selective androgen receptor modulator, GTx-024 (enobosarm), is being investigated for cancer cachexia, sarcopenia, and muscle wasting diseases. Here we investigate the role of muscle androgen receptor (AR) in the anabolic effect of GTx-024. In mice lacking AR in the satellite cell lineage (satARKO), the weight of the androgen-sensitive levator ani muscle was lower but was decreased further upon orchidectomy. GTx-024 was as effective as DHT in restoring levator ani weights to sham levels. Expression of the muscle-specific, androgen-responsive genes S-adenosylmethionine decarboxylase and myostatin was decreased by orchidectomy and restored by GTx-024 and DHT in control mice, whereas the expression was low and unaffected by androgen status in satARKO. In contrast, insulin-like growth factor 1Ea expression was not different between satARKO and control muscle, decreased upon castration, and was restored by DHT and GTx-024 in both genotypes. These data indicate that GTx-024 does not selectively modulate AR in the satellite cell lineage and that cells outside this lineage remain androgen responsive in satARKO muscle. Indeed, residual AR-positive cells were present in satARKO muscle, coexpressing the fibroblast-lineage marker vimentin. AR positive, muscle-resident fibroblasts could therefore be involved in the indirect effects of androgens on muscle. In conclusion, both DHT and GTx-024 target AR pathways in the satellite cell lineage, but cells outside this lineage also contribute to the anabolic effects of androgens.

Relationships between 1,25-dihydroxyvitamin D (1,25(OH)2 D) and skeletal outcomes are uncertain. We examined the associations of 1,25(OH)2 D with bone mineral density (BMD), BMD change, and incident non-vertebral fractures in a cohort of older men and compared them with those of 25-hydroxyvitamin D (25OHD). The study population included 1000 men (aged 74.6 ± 6.2 years) in the Osteoporotic Fractures in Men (MrOS) study, of which 537 men had longitudinal dual-energy X-ray absorptiometry (DXA) data (4.5 years of follow-up). A case-cohort design and Cox proportional hazards models were used to test the association between vitamin D metabolite levels and incident nonvertebral and hip fractures. Linear regression models were used to estimate the association between vitamin D measures and baseline BMD and BMD change. Interactions between 25OHD and 1,25(OH)2 D were tested for each outcome. Over an average follow-up of 5.1 years, 432 men experienced incident nonvertebral fractures, including 81 hip fractures. Higher 25OHD was associated with higher baseline BMD, slower BMD loss, and lower hip fracture risk. Conversely, men with higher 1,25(OH)2 D had lower baseline BMD. 1,25(OH)2 D was not associated with BMD loss or nonvertebral fracture. Compared with higher levels of calcitriol, the risk of hip fracture was higher in men with the lowest 1,25(OH)2 D levels (8.70 to 51.60 pg/mL) after adjustment for baseline hip BMD (hazard ratio [HR] = 1.99, 95% confidence interval [CI] 1.19-3.33). Adjustment of 1,25(OH)2 D data for 25OHD (and vice versa) had little effect on the associations observed but did attenuate the hip fracture association of both vitamin D metabolites. In older men, higher 1,25(OH)2 D was associated with lower baseline BMD but was not related to the rate of bone loss or nonvertebral fracture risk. However, with BMD adjustment, a protective association for hip fracture was found with higher 1,25(OH)2 D. The associations of 25OHD with skeletal outcomes were generally stronger than those for 1,25(OH)2 D. These results do not support the hypothesis that measures of 1,25(OH)2 D improve the ability to predict adverse skeletal outcomes when 25OHD measures are available. © 2015 American Society for Bone and Mineral Research., (© 2015 American Society for Bone and Mineral Research.)

Context: Secondary hypogonadism is common in aging men; its natural history and predisposing factors are unclear., Objectives: The objectives were 1) to identify factors that predispose eugonadal men (T ≥ 10.5 nmol/L) to develop biochemical secondary hypogonadism (T < 10.5 nmol/L; LH ≤ 9.4 U/L) and secondary hypogonadal men to recover to eugonadism; and 2) to characterize clinical features associated with these transitions., Design: The study was designed as a prospective observational general population cohort survey., Setting: The setting was clinical research centers., Participants: The participants were 3369 community-dwelling men aged 40-79 years in eight European centers., Intervention: Interventions included observational follow-up of 4.3 years., Main Outcome Measure: Subjects were categorized according to change/no change in biochemical gonadal status during follow-up as follows: persistent eugonadal (n = 1909), incident secondary hypogonadal (n = 140), persistent secondary hypogonadal (n = 123), and recovered from secondary hypogonadism to eugonadism (n = 96). Baseline predictors and changes in clinical features associated with incident secondary hypogonadism and recovery from secondary hypogonadism were analyzed by regression models., Results: The incidence of secondary hypogonadism was 155.9/10 000/year, whereas 42.9% of men with secondary hypogonadism recovered to eugonadism. Incident secondary hypogonadism was predicted by obesity (body mass index ≥ 30 kg/m(2); odds ratio [OR] = 2.86 [95% confidence interval, 1.67; 4.90]; P < .0001), weight gain (OR = 1.79 [1.15; 2.80]; P = .011), and increased waist circumference (OR = 1.73 [1.07; 2.81], P = .026; and OR = 2.64 [1.66; 4.21], P < .0001, for waist circumference 94-102 and ≥102 cm, respectively). Incident secondary hypogonadal men experienced new/worsening sexual symptoms (low libido, erectile dysfunction, and infrequent spontaneous erections). Recovery from secondary hypogonadism was predicted by nonobesity (OR = 2.28 [1.21; 4.31]; P = .011), weight loss (OR = 2.24 [1.04; 4.85]; P = .042), normal waist circumference (OR = 1.93 [1.01; 3.70]; P = .048), younger age (< 60 y; OR = 2.32 [1.12; 4.82]; P = .024), and higher education (OR = 2.11 [1.05; 4.26]; P = .037), but symptoms did not show significant concurrent improvement., Conclusion: Obesity-related metabolic and lifestyle factors predispose older men to the development of secondary hypogonadism, which is frequently reversible with weight loss.

Androgens are well known to enhance exercise-induced muscle hypertrophy; however, whether androgens also influence bone's adaptive response to mechanical loading remains unclear. We studied the adaptive osteogenic response to unilateral in vivo mechanical loading of tibia in adult male mice in both a long- and a short-term experimental set-up. Mice were divided into four groups: sham operated, orchidectomized (ORX), T (ORX+T), or nonaromatizable dihydrotestosterone (ORX+DHT) replacement. Significant interactions between androgen status and osteogenic response to mechanical loading were observed. Cortical thickness increased by T (0.14 vs 0.11 mm sham, P<.05) and DHT (0.17 vs 0.11 mm sham, P<.05). However, T partially (+36%) and DHT completely (+10%) failed to exhibit the loading-related increase observed in sham (+107%) and ORX (+131%, all P<.05) mice. ORX decreased periosteal bone formation, which was restored to sham levels by T and DHT. However, both androgens completely suppressed the loading-related increase in periosteal bone formation. Short-term loading decreased the number of sclerostin-positive osteocytes in sham, whereas in control fibulas, ORX decreased and T increased the number of sclerostin-positive osteocytes. Loading no longer down-regulated sclerostin in the ORX or T groups. In conclusion, both T and DHT suppress the osteogenic response to mechanical loading.

Context: Low testosterone (T) has been associated with incident metabolic syndrome (MetS), but it remains unclear if this association is independent of sex hormone binding globulin (SHBG). Estradiol (E2) may also be associated with MetS, but few studies have investigated this., Objective: To study the association between baseline sex steroids and the development of incident MetS and to investigate the influence of SHBG, body mass index (BMI) and insulin resistance on this risk., Methods: Three thousand three hundred sixty nine community-dwelling men aged 40-79 years were recruited for participation in EMAS. MetS was defined by the updated NCEP ATP III criteria. Testosterone and E2 levels were measured by liquid and gas chromatography/mass spectrometry, respectively. Logistic regression was used to assess the association between sex steroids and incident MetS., Results: One thousand six hundred fifty one men without MetS at baseline were identified. During follow-up, 289 men developed incident MetS, while 1362 men did not develop MetS. Men with lower baseline total T levels were at higher risk for developing MetS [odds ratio (OR) = 1.72, P < .001), even after adjustment for SHBG (OR = 1.43, P = .001), BMI (OR = 1.44, P < .001) or homeostasis model assessment of insulin resistance (HOMA-IR) (OR = 1.64, P < .001). E2 was not associated with development of MetS (OR = 1.04; P = .56). However, a lower E2/T ratio was associated with a lower risk of incident MetS (OR = 0.38; P < .001), even after adjustment for SHBG (OR = 0.48; P < .001), BMI (OR = 0.60; P = .001) or HOMA-IR (OR = 0.41; P < .001)., Conclusions: In men, lower T levels, but not E2, are linked with an increased risk of developing MetS, independent of SHBG, BMI or insulin resistance. A lower E2/T ratio may be protective against developing MetS.

Sex steroids are chief regulators of gender differences in the skeleton, and male gender is one of the strongest protective factors against osteoporotic fractures. This advantage in bone strength relies mainly on greater cortical bone expansion during pubertal peak bone mass acquisition and superior skeletal maintenance during aging. During both these phases, estrogens acting via estrogen receptor-α in osteoblast lineage cells are crucial for male cortical and trabecular bone, as evident from conditional genetic mouse models, epidemiological studies, rare genetic conditions, genome-wide meta-analyses, and recent interventional trials. Genetic mouse models have also demonstrated a direct role for androgens independent of aromatization on trabecular bone via the androgen receptor in osteoblasts and osteocytes, although the target cell for their key effects on periosteal bone formation remains elusive. Low serum estradiol predicts incident fractures, but the highest risk occurs in men with additionally low T and high SHBG. Still, the possible clinical utility of serum sex steroids for fracture prediction is unknown. It is likely that sex steroid actions on male bone metabolism rely also on extraskeletal mechanisms and cross talk with other signaling pathways. We propose that estrogens influence fracture risk in aging men via direct effects on bone, whereas androgens exert an additional antifracture effect mainly via extraskeletal parameters such as muscle mass and propensity to fall. Given the demographic trends of increased longevity and consequent rise of osteoporosis, an increased understanding of how sex steroids influence male bone health remains a high research priority.

Context: Despite common use of supplemental vitamin D2 in clinical practice, the associations of serum vitamin D2 concentrations with other vitamin D metabolites and total vitamin D are unclear., Objective: The aim of the study was to measure vitamin D2 and D3 levels and examine their associations with each other and with total vitamin D., Design: We performed a cross-sectional analysis of 679 randomly selected participants from the Osteoporotic Fractures in Men Study. 25-Hydroxyvitamin D2 [25(OH)D2], 25(OH)D3, 1,25-dihydroxyvitamin D2 [1,25(OH)2D2], and 1,25(OH)2D3 were measured using liquid chromatography-tandem mass spectrometry and were summed to obtain total 25(OH)D and 1,25(OH)2D. Associations between all metabolites (D2, D3, and total levels) were examined using Wilcoxon rank-sum tests and Spearman correlations., Results: 25(OH)D2 and 1,25(OH)2D2 were detectable in 189 (27.8%) and 178 (26.2%) of the men, respectively. Higher 25(OH)D2 levels did not correlate with higher total 25(OH)D (r = 0.10; P = .17), although median total 25(OH)D was slightly higher in those with detectable vs undetectable 25(OH)D2 (25.8 vs 24.3 ng/mL; P < .001). 25(OH)D2 was not positively associated with total 1,25(OH)2D levels (r = -0.11; P = .13), and median 1,25(OH)2D level was not higher in those with detectable vs undetectable 25(OH)D2. Higher 25(OH)D2 was associated with lower 25(OH)D3 (r = -0.35; P < .001) and 1,25(OH)2D3 (r = -0.32; P < .001), with median levels of both D3 metabolites 18-35% higher when D2 metabolites were undetectable., Conclusions: In a cohort of older men, 25(OH)D2 is associated with lower levels of 25(OH)D3 and 1,25(OH)2D3, suggesting that vitamin D2 may decrease the availability of D3 and may not increase calcitriol levels.

Background: vitamin D deficiency has been associated with an increased risk of mortality, but whether this relationship is causal or linked to co-existent comorbidity and adverse life factors remains uncertain. Our objective was to determine whether endogenous 25-hydroxyvitamin D (25(OH)D), 1,25-dihydroxyvitamin D (1,25(OH)2D) and parathyroid hormone (PTH) levels predicted all-cause, cardiovascular and cancer mortality independently of health and lifestyle factors., Setting: : prospective cohort analysis within the European Male Ageing Study., Participants: : 2,816 community-dwelling men aged 40-79 years at baseline., Methods: : Cox regression was used to examine the association of all-cause mortality with 25(OH)D, 1,25(OH)2D and PTH; cardiovascular and cancer mortality were modelled using competing-risks regression. Results were expressed as hazard ratios (HR) and 95% confidence intervals (CIs) for Cox models; sub-hazard ratios (SHR) and 95% CIs for competing-risks models., Results: : a total of 187 men died during a median of 4.3 years of follow-up. Serum levels of 25(OH)D (per 1 SD decrease: HR = 1.45; 95% CI = 1.16, 1.81) and 1,25(OH)2D (per 1 SD decrease: HR = 1.20; 95% CI = 1.00, 1.44) were associated with an increased risk of all-cause mortality after adjusting for age, centre, smoking, self-reported morbidities, physical activity and functional performance. Only levels of 25(OH)D <25 nmol/l predicted cancer mortality (SHR = 3.33; 95% CI = 1.38, 8.04)., Conclusion: : lower 25(OH)D and 1,25(OH)2D levels independently predicted all-cause mortality in middle-aged and older European men. Associations with cancer mortality were only observed among men with very low levels of 25(OH)D. These associations were only partially explained by the range of adverse health and lifestyle factors measured here., (© The Author 2013. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Introduction: We previously reported that in male patients consulting for sexual dysfunction, low prolactin (PRL) levels were associated with metabolic syndrome (MetS), arteriogenic erectile dysfunction, and incident major cardiovascular events., Aim: The aim of this study is to assess the clinical associations of PRL levels in the European Male Ageing Study (EMAS)., Methods: EMAS is a prospective, observational cohort of community-dwelling men aged 40-79 years old (mean age 60 ± 11 years old). PRL was available for 2,948 men., Main Outcome Measures: Different parameters were evaluated including the Short Form-36 questionnaire, Becks Depression Inventory, the Adverse Life Events Scale, the Physical Activity Scale for the Elderly, and the EMAS sexual function questionnaire (EMAS-SFQ)., Results: After the adjustment for confounders, PRL levels were inversely related with worsening of sexual function as compared with the previous year, as derived from change in sexual functioning domain of the EMAS-SFQ (adj. r = -0.043; P = 0.029). The strongest correlation (Wald = 6.840; P = 0.009) was observed between lower PRL levels and reduced enjoyment of orgasmic experiences. Furthermore, an inverse relationship between PRL levels and stressful life events or depressive symptoms was observed. Low PRL was also negatively associated with an unhealthy metabolic phenotype as well as with the MetS (Wald = 5.229; P = 0.022). In line with these data, low PRL was associated with a lower level of physical activity and feeling unhealthier., Conclusions: Low PRL is related to several metabolic, psychological, and sexual unhealthy characteristics in European men. Checking PRL might be useful to stratify men for cardiovascular risk and to encourage appropriate lifestyle changes., (© 2013 International Society for Sexual Medicine.)

Context: Public health authorities around the world recommend widely variable supplementation strategies for adults, whereas several professional organizations, including The Endocrine Society, recommend higher supplementation., Methods: We analyzed published randomized controlled clinical trials to define the optimal intake or vitamin D status for bone and extraskeletal health., Conclusions: The extraskeletal effects of vitamin D are plausible as based on preclinical data and observational studies. However, apart from the beneficial effects of 800 IU/d of vitamin D3 for reduction of falls in the elderly, causality remains yet unproven in randomized controlled trials (RCTs). The greatest risk for cancer, infections, cardiovascular and metabolic diseases is associated with 25-hydroxyvitamin D (25OHD) levels below 20 ng/mL. There is ample evidence from RCTs that calcium and bone homeostasis, estimated from serum 1,25-dihydroxyvitamin D and PTH, calcium absorption, or bone mass, can be normalized by 25OHD levels above 20 ng/mL. Moreover, vitamin D supplementation (800 IU/d) in combination with calcium can reduce fracture incidence by about 20%. Such a dose will bring serum levels of 25OHD above 20 ng/mL in nearly all postmenopausal women. Based on calculations of the metabolic clearance of 25OHD, a daily intake of 500-700 IU of vitamin D3 is sufficient to maintain serum 25OHD levels of 20 ng/mL. Therefore, the recommendations for a daily intake of 1500-2000 IU/d or serum 25OHD levels of 30 ng or higher for all adults or elderly subjects, as suggested by The Endocrine Society Task Force, are premature. Fortunately, ongoing RCTs will help to guide us to solve this important public health question.

Context: Immunoassay-based techniques, routinely used to measure serum estradiol (E2), are known to have reduced specificity, especially at lower concentrations, when compared with the gold standard technique of mass spectrometry (MS). Different measurement techniques may be responsible for the conflicting results of associations between serum E2 and clinical phenotypes in men., Objective: Our objective was to compare immunoassay and MS measurements of E2 levels in men and evaluate associations with clinical phenotypes., Design and Setting: Middle-aged and older male subjects participating in the population-based Osteoporotic Fractures in Men (MrOS) Sweden study (n = 2599), MrOS US (n = 688), and the European Male Aging Study (n = 2908) were included., Main Outcome Measures: Immunoassay and MS measurements of serum E2 were compared and related to bone mineral density (BMD; measured by dual energy x-ray absorptiometry) and ankle-brachial index., Results: Within each cohort, serum E2 levels obtained by immunoassay and MS correlated moderately (Spearman rank correlation coefficient rS 0.53-0.76). Serum C-reactive protein (CRP) levels associated significantly (albeit to a low extent, rS = 0.29) with immunoassay E2 but not with MS E2 levels. Similar associations of immunoassay E2 and MS E2 were seen with lumbar spine and total hip BMD, independent of serum CRP. However, immunoassay E2, but not MS E2, associated inversely with ankle-brachial index, and this correlation was lost after adjustment for CRP., Conclusions: Our findings suggest interference in the immunoassay E2 analyses, possibly by CRP or a CRP-associated factor. Although associations with BMD remain unaffected, this might imply for a reevaluation of previous association studies between immunoassay E2 levels and inflammation-related outcomes.

Background: the link between the vitamin D endocrine axis and frailty remains undefined, with few studies examining the joint effect of vitamin D and parathyroid hormone (PTH) levels. Our objective was to determine the association of frailty with serum 25-hydroxyvitamin D (25(OH)D) and PTH., Setting: cross-sectional analysis within the European Male Ageing Study (EMAS)., Participants: a total of 1,504 community-dwelling men aged 60-79 years., Methods: frailty was classified using a frailty phenotype (FP) and frailty index (FI). The association of frailty with 25(OH)D and PTH was examined using multinomial logistic regression; individual FP criteria with 25(OH)D and PTH using binary logistic regression. Results were expressed as relative odds ratios (ROR) and 95% confidence intervals (CIs) for multinomial; odds ratios (OR) and 95% CIs for binary models., Results: using the FP, 5.0% of subjects were classified as frail and 36.6% as prefrail. Lower levels of 25(OH)D were associated with being prefrail (per 1 SD decrease: ROR = 1.45; 95% CI: 1.26-1.67) and frail (ROR = 1.89; 95% CI: 1.30-2.76), after adjusting for age, centre and health and lifestyle confounders (robust group = base category). Higher levels of PTH were associated with being frail after adjustment for confounders (per 1 SD increase: ROR = 1.24; 95% CI: 1.01-1.52). Comparable results were found using the FI. Among the five FP criteria only sarcopenia was not associated with 25(OH)D levels, while only weakness was associated with PTH., Conclusion: lower 25(OH)D and higher PTH levels were positively associated with frailty in older men. Prospective data would enable the temporal nature of this relationship to be explored further.

The European Male Ageing Study (EMAS) was designed to examine the hypothesis that inter-individual and regional variability in symptomatic dysfunctions, alterations in body composition and health outcomes in ageing men can be explained by different rates of decline in anabolic hormones, the most important of which being testosterone. Between 2003 and 2005, 3369 community-dwelling men, aged between 40 and 79 years, were recruited from population-based registers in eight European centres to participate in the baseline survey, with follow-up investigations performed a median of 4.3 years later. Largely, identical questionnaire instruments and clinical investigations were used in both phases to capture contemporaneous data on general health (including cardiovascular diseases and chronic conditions), physical and cognitive functioning, mental health, sexual function, quality of life, bone health, chronic pain, disease biomarkers, hormones (sex hormones and metabolic hormones) and genetic polymorphisms. EMAS actively encourages new collaborations, data sharing for validation studies and participation in genetic study consortia. Potential collaborators should contact the principal investigator (F.C.W.W.) in the first instance.

Context: There is little information on the potential impact of serum 1,25-dihydroxyvitamin D [1,25(OH)2D] on bone health including turnover., Objective: The objective of the study was to determine the influence of 1,25(OH)2D and 25-hydroxyvitamin D [25(OH)D] on bone health in middle-aged and older European men., Design, Setting, and Participants: Men aged 40-79 years were recruited from population registers in 8 European centers. Subjects completed questionnaires that included questions concerning lifestyle and were invited to attend for quantitative ultrasound (QUS) of the heel, assessment of height and weight, and a fasting blood sample from which 1,25(OH)2D, 25(OH)D, and PTH were measured. 1,25(OH)2D was measured using liquid chromatography tandem mass spectrometry. Bone markers serum N-terminal propeptide of type 1 procollagen (P1NP) and crosslinks (β-cTX) were also measured. Dual-energy x-ray absorptiometry (DXA) of the hip and lumbar spine was performed in 2 centers., Main Outcome Measure(s): QUS of the heel, bone markers P1NP and β-cTX, and DXA of the hip and lumbar spine were measured., Results: A total of 2783 men, mean age 60.0 years (SD 11.0) were included in the analysis. After adjustment for age and center, 1,25(OH)2D was positively associated with 25(OH)D but not with PTH. 25(OH)D was negatively associated with PTH. After adjustment for age, center, height, weight, lifestyle factors, and season, 1,25(OH)2D was associated negatively with QUS and DXA parameters and associated positively with β-cTX. 1,25(OH)2D was not correlated with P1NP. 25(OH)D was positively associated with the QUS and DXA parameters but not related to either bone turnover marker. Subjects with both high 1,25(OH)2D (upper tertile) and low 25(OH)D (lower tertile) had the lowest QUS and DXA parameters and the highest β-cTX levels., Conclusions: Serum 1,25(OH)2D is associated with higher bone turnover and poorer bone health despite being positively related to 25(OH)D. A combination of high 1,25(OH)2D and low 25(OH)D is associated with the poorest bone health.

Androgens play a key role in the maintenance of male skeletal integrity. The regulation of this integrity by androgen receptor (AR) signaling has been mainly attributed to osteoblasts. Although osteocytes have emerged as key regulators of bone remodeling, the influence of sex steroids on these cells has been poorly studied. We aimed to investigate the role of AR signaling, specifically in osteocytes using the Cre/LoxP system in male mice (driven by dentin matrix protein 1 [ocy-ARKOs]). Osteocyte fractions of control (AR(ex2)/Y) and ocy-ARKO (ARflox(ex2)/Y; DMP1-cre) mice isolated through sequential collagenase digestion showed increasing AR expression toward the mature osteocyte fraction of control males compared with the more immature fractions, whereas this was reduced by >80% in ocy-ARKO osteocytes. The skeletal phenotype of mutant mice was further assessed by histomorphometry and quantitative micro-computed tomography at 12 and 32 weeks of age. Ocy-ARKOs had significantly lower trabecular bone volume and number in femora and tibias at 32 weeks as well as decreased trabecular number in the L(5) vertebra at 12 weeks. Biomechanical testing showed that ocy-ARKO femora were also stiffer and required a lower ultimate force to induce failure at 32 weeks. However, femoral cortical structure was not significantly different at any time point. The absence of AR in osteocyte also did not appear to affect trabecular bone formation nor its response to mechanical loading. In conclusion, selective inactivation of the AR in osteocytes of male mice accelerates age-related deterioration of skeletal integrity. These findings provide evidence for a direct role of androgens in the maintenance of trabecular bone through actions of the AR in osteocytes., (Copyright © 2012 American Society for Bone and Mineral Research.)

Oral bisphosphonates reduce fracture risk in osteoporotic patients but are often associated with poor compliance, which may impair their antifracture effects. This post hoc analysis assessed the time to onset and persistence of the antifracture effect of zoledronic acid, a once-yearly bisphosphonate infusion, in women with osteoporosis. Data from 9355 women who were randomized in two placebo-controlled pivotal trials were included. Endpoints included reduction in the rate of any clinical fracture at 6, 12, 18, 24, and 36 months in the zoledronic acid group compared with placebo, and the year-by-year incidence of all clinical fractures over 3 years. Cox proportional hazards regression was used to determine the timing of onset of antifracture efficacy. A generalized estimating equation model was used to assess fracture reduction for the 3 consecutive years of treatment, thereby evaluating persistence of effect. Safety results from women in the two studies were collated. Zoledronic acid reduced the risk of all clinical fractures at 12 months (hazard ratio [HR] = 0.75, 95% confidence interval [CI] 0.61-0.92, p = 0.0050) with significant reductions maintained at all subsequent time points. Year-by-year analysis showed that zoledronic acid reduced the risk for all clinical fractures compared with the placebo group in each of the 3 years (year 1: odds ratio [OR] = 0.74, 95% CI 0.60-0.91, p = 0.0044; year 2: OR = 0.53, 95% CI 0.42-0.66, p < 0.0001; year 3: OR = 0.61, 95% CI 0.48-0.77, p < 0.0001). This antifracture effect was persistent over 3 years, with the reductions in years 2 and 3 slightly larger than in year 1 (p = 0.097). This analysis shows that zoledronic acid offered significant protection from clinical fractures as early as 12 months. When administered annually, its beneficial effects persisted for at least 3 years., (Copyright © 2012 American Society for Bone and Mineral Research.)

Background: The limitations of serum testosterone and estradiol (E(2)) measurements using non-extraction platform immunoassays (IAs) are widely recognized. Switching to more specific mass spectrometry (MS)-based methods has been advocated, but directly comparative data on the two methods are scarce., Methods: We compared serum testosterone and E(2) measurements in a large sample of middle-aged/elderly men using a common platform IA and a gas chromatography (GC)-MS method, in order to assess their limitations and advantages, and to diagnose male hypogonadism. Of subjects from the European Male Aging Study (n=3174; age 40-79 years), peripheral serum testosterone and E(2) were analyzed using established commercial platform IAs (Roche Diagnostics E170) and in-house GC-MS methods., Results: Over a broad concentration range, serum testosterone concentration measured by IA and MS showed high correlation (R=0.93, P<0.001), which was less robust in the hypogonadal range (<11 nmol/l; R=0.72, P<0.001). The IA/MS correlation was weaker in E(2) measurements (R=0.32, P<0.001, at E(2) <40.8 pmol/l, and R=0.74, P<0.001, at E(2) >40.8 pmol/l). Using MS as the comparator method, IA ascertained low testosterone compatible with hypogonadism (<11 nmol/l), with 75% sensitivity and 96.3% specificity. The same parameters with IA for the detection of low E(2) (<40.7 pmol/l) were 13.3 and 99.3%, and for high E(2) (>120 pmol/l) 88.4 and 88.6%., Conclusion: A validated platform IA is sufficient to detect subnormal testosterone concentrations in the diagnosis of male hypogonadism. The IA used for E(2) measurements showed poor correlation with MS and may only be suitable for the detection of high E(2) in men.

Osteoporosis may be a lifelong condition. Robust data regarding the efficacy and safety of both long-term osteoporosis therapy and therapy discontinuation are therefore important. A paucity of clinical trial data regarding the long-term antifracture efficacy of osteoporosis therapies necessitates the use of surrogate endpoints in discussions surrounding long-term use and/or discontinuation. Long-term treatment (beyond 3-4 years) may produce further increases in bone mineral density (BMD) or BMD stability, depending on the specific treatment and the skeletal site. Bisphosphonates, when discontinued, are associated with a prolonged reduction in bone turnover markers (BTMs), with a very gradual increase to pretreatment levels within 3 to 60 months of treatment cessation, depending on the bisphosphonate used and the prior duration of therapy. In contrast, with nonbisphosphonate antiresorptive agents, such as estrogen and denosumab, BTMs rebound to above pretreatment values within months of discontinuation. The pattern of BTM change is generally mirrored by a more or less rapid decrease in BMD. Although the prolonged effect of some bisphosphonates on BTMs and BMD may contribute to residual benefit on bone strength, it may also raise safety concerns. Adequately powered postdiscontinuation fracture studies and conclusive evidence on maintenance or loss of fracture benefit is lacking for bisphosphonates. Similarly, the effects of rapid reversal of bone turnover upon discontinuation of denosumab on fracture risk remain unknown. Ideally, studies evaluating the effects of long-term treatment and treatment discontinuation should be designed to provide head-to-head "offset" data between bisphosphonates and nonbisphosphonate antiresorptive agents. In the absence of this, a clinical recommendation for physicians may be to periodically assess the benefits/risks of continuation versus discontinuation versus alternative management strategies., (Copyright © 2012 American Society for Bone and Mineral Research.)

Context: Late-onset hypogonadism (LOH) has been defined as a syndrome in middle-aged and elderly men reporting symptoms in the presence of low testosterone (T)., Objective: The objective of the study was to seek objective biochemical and end-organ evidence of androgen deficiency in men classified as having LOH according to our previously published criteria., Design, Setting, and Participants: The design of the study included cross-sectional data from the European Male Aging Study on 2966 community-dwelling men aged 40-79 years in eight European countries., Main Outcome Measure(s): Waist circumference, body mass index, muscle mass, estimated heel bone mineral density (eBMD), hemoglobin, insulin sensitivity, physical activity, metabolic syndrome, insulin resistance index, and cardiovascular disease were measured., Results: Sixty-three men (2.1%) were classified as having LOH: 36 moderate and 27 severe. They were older and more obese than eugonadal men and had, in proportion to the graded T deficiency, lower muscle mass, eBMD, and hemoglobin, with poorer general health. Both moderate and severe LOH was associated with lower hemoglobin, mid-upper arm circumference, eBMD, physical function (measured by the Short Form-36 questionnaire), slower gait speed and poorer general health. Only men with severe LOH showed significant associations with larger waist circumference (β=1.93 cm; 0.04-3.81), insulin resistance (β=2.81; 1.39-4.23), and the metabolic syndrome (odds ratio 9.94; 2.73-36.22) after adjustments for confounders. Men with low testosterone only (irrespective of symptoms) showed lesser magnitudes of association with the same end points., Conclusions: LOH is associated with multiple end-organ deficits compatible with androgen deficiency. These data support the existence of a syndrome of LOH in only a minority of aging men, especially those with T below 8 nmol/liter.