Frailty, serum androgens, and the CAG repeat polymorphism: results from the Massachusetts Male Aging Study

Physical frailty is related to oxidative stress through thiol/disulfide homeostasis parameters

AIM

To evaluate relationship between frailty and oxidative stress through thiol/disulfide homeostasis parameters [Native thiol (NT), total thiol (TT), and disulfide levels (D), disulfide-native thiol (D/NT), disulfide-total thiol (D/TT), native thiol-total thiol (NT/TT) ratios, and ischemia-modified albumin levels (IMA)].

MATERIALS AND METHODS

In total, 139 community-dwelling older adults were included. The frailty status, defined by the FRIED frailty index (FFI) and Clinical Frailty Scale (CFS), and comprehensive geriatric assessment results compared with thiol/disulfide homeostasis parameters and ischemia-modified albumin levels.

RESULTS

NT and TT levels were significantly lower in the frail group (respectively; p = 0.014, p = 0.020). The FFI scores were correlated with the levels of NT, TT, D/NT, D/TT, and NT/TT (respectively; r = - 0.25, r = - 0.24, r = 0.17, r = 0.17, r = - 0.17). The significant correlation could not be retained with the CFS scores. In ROC analysis, the AUC for NT was calculated as 0.639 in diagnosing frailty according to the FFI (95% CI 0.542-0.737), AUC was 0.638 for TT (95% CI 0.540-0.735), and AUC was 0.610 for NT/TT (95% CI 0.511-0.780). The AUC was calculated as 0.610 for both D/NT and D/TT in diagnosing physical frailty (95% CI 0.511-0.708).

CONCLUSION

Thiol/disulfide homeostasis parameters can be a potential biomarker in diagnosing physical frailty. However, further studies are needed for diagnosing frailty defined with cumulative deficit models.

Circulating biomarkers characterizing physical frailty: CRP, hemoglobin, albumin, 25OHD and free testosterone as best biomarkers. Results of a meta-analysis

INTRODUCTION

During aging, individuals can be classified as being in one of 3 different states: robust, frail or dependent. Frailty is described as reversible, so early detection offers the potential of returning the subject to a robust status. There are multiple clinical frailty scales but no gold standard and frailty is not systematically assessed in clinicians' daily practice. Reliable biomarkers of frailty are lacking, however, while their identification and systematic use would make this simple scale a useful clinical tool.

OBJECTIVE

To conduct a review of the literature concerning the biomarkers associated with frailty and to compare in a meta-analysis the plasmatic values of each biomarker in the frail with the robust group.

RESULTS

503 articles were identified on PubMed, 467 on Scopus and 369 on Web Of Science. 67 articles were included, collecting a total of 32,934 robust subjects and 6864 frail subjects. C-reactive protein (CRP) (Standardized Mean Difference (SMD): 0.49 CI 95% [0.37-0.61]) was significantly higher in the frail group whereas hemoglobin (SMD: -0.67[-0.90; -0.44]), albumin (SMD: -0.62[-0.84; -0.41]), 25-hydroxyvitamin D (25OHD) (SMD: -0.43 [-0.64; -0.21]) and, in men, free testosterone (SMD: -0.77 [-1.05; -0.49]) were significantly lower in the frail group.

CONCLUSION

We found 5 biomarkers that were associated with frailty (CRP, hemoglobin, albumin, 25OHD and free testosterone in men) belonging to multiple physiological systems. Further cohort studies are needed to verify their ability to screen for frailty.

Androgen Receptor CAG Repeat Length as a Risk Factor of Late-Onset Hypogonadism in a Korean Male Population

Background

Testosterone action is mediated through the androgen receptor (AR), whose sensitivity is influenced by the AR CAG repeat polymorphism. However, the relation between late-onset hypogonadism (LOH) and AR CAG repeat length is unclear and studies of Asian populations are limited.

Aim

To investigate the relation between AR CAG repeat length and LOH in Korean men.

Methods

263 Korean men (mean age = 63.43 ± 10.9 years) were enrolled from 2014 to 2015. LOH diagnosis was based on a serum testosterone level lower than 3.5 ng/mL and positive androgen deficiency according to the Aging Males’ Symptom Scale (AMS). Total testosterone levels and answers to the LOH-related questionnaire were analyzed.

Outcomes

The relation between AR CAG repeat length and LOH was determined.

Results

Mean CAG repeat length was 22.1 ± 4.6 and mean serum testosterone levels were 2.6 ± 0.7 and 6.0 ± 2.0 ng/mL in men with and without LOH, respectively. Men with LOH showed significantly longer AR CAG repeat lengths than men without LOH (26.1 vs 21.6, P < .001). Longer CAG repeat lengths were correlated with higher AMS total scores (r = 0.454, P = .001) and AMS psychotic, somatic, and sexual sub-scores (r = 0.276, 0.246, and 0.571, P = .006, .007, .001, respectively) and significantly lower 5-item International Index of Erectile Function scores (r = −0.261, P = .001). Multivariate analysis showed that patient age and CAG repeat length were independently associated with LOH (odds ratio = 1.05 and 1.29, P = .041 and <.001, respectively).

Clinical Implications

A longer CAG repeat length is associated with LOH symptoms and LOH.

Strengths and Limitations

Associations between CAG repeats and LOH were verified in Korean patients. Moreover, a longer CAG repeat length was shown to be an independent risk factor for LOH. Limitations included the small number of LOH patients studied and that other sex hormone-associated factors were not measured.

Conclusions

AR CAG repeat length was associated with LOH prevalence and clinical symptoms in this Korean male population. Thus, it is important to measure CAG repeat length for patients with LOH symptoms with normal testosterone levels.

Kim JW, Bae YD, Ahn ST, et al. Androgen Receptor CAG Repeat Length as a Risk Factor of Late-Onset Hypogonadism in a Korean Male Population. Sex Med 2018;6:203–209.

Effects of 8-Year Treatment of Long-Acting Testosterone Undecanoate on Metabolic Parameters, Urinary Symptoms, Bone Mineral Density, and Sexual Function in Men With Late-Onset Hypogonadism

INTRODUCTION

The long-term effects of long-acting testosterone undecanoate (TU) and androgen receptor CAG repeat lengths in Thai men with late-onset hypogonadism (LOH) have not been reported.

AIM

To analyze the 8-year follow-up effects of intramuscular TU therapy on metabolic parameters, urinary symptoms, bone mineral density, and sexual function and investigate CAG repeat lengths in men with LOH.

METHODS

We reviewed the medical records of 428 men with LOH who had been treated with TU and 5 patients were diagnosed with prostate cancer during TU therapy. There were 120 patients (mean age = 65.6 ± 8.9 years) who had 5 to 8 years of continuous TU supplementation and sufficiently completed records for analysis. Genomic DNA was extracted from peripheral blood and the CAG repeat region was amplified by polymerase chain reaction. Fragment analysis, sequencing, electropherography, and chromatography were performed.

MAIN OUTCOME MEASURES

The main outcome measure was dynamic parameter changes during testosterone supplementation.

RESULTS

TU did not improve all obesity parameters. A statistically significant decrease was found in waist circumference, percentage of body fat, glycated hemoglobin, cholesterol, low-density lipoprotein, and International Prostate Symptom Score (P < .05). TU did not produce differences in body mass index, high-density lipoprotein, triglyceride, or the Aging Male Symptoms score from baseline. However, a statistically significant increase was found in the level of testosterone, prostate-specific antigen, hematocrit, International Index of Erectile Function score, and vertebral and femoral bone mineral density (P < .05). No major adverse cardiovascular events or prostate cancer occurred during this study. The CAG repeat length was 14 to 28 and the median CAG length was 22. There was no association between CAG repeat length and any of the anthropometric measurements.

CONCLUSION

Long-term TU treatment in men with LOH for up to 8 years appears to be safe, tolerable, and effective in correcting obesity parameters.

Testosterone and androgen receptor gene polymorphism are associated with confidence and competitiveness in men

A contribution to a special issue on Hormones and Human Competition. Studies in non-human animals and humans have demonstrated the important role of testosterone in competitive interactions. Here, we investigated whether endogenous testosterone levels predict the decision to compete, in a design excluding spite as a motive underlying competitiveness. In a laboratory experiment with real monetary incentives, 181 men solved arithmetic problems, first under a noncompetitive piece rate, followed by a competition incentive scheme. We also assessed several parameters relevant to competition, such as risk taking, performance, and confidence in one's own performance. Salivary testosterone levels were measured before and 20min after the competition task using mass spectrometry. Participants were also genotyped for the CAG repeat polymorphism of the androgen receptor gene, known to influence the efficacy of testosterone signaling in a reciprocal relationship to the number of CAG repeats. We observed a significant positive association between basal testosterone levels and the decision to compete, and that higher testosterone levels were related to greater confidence in one's own performance. Whereas the number of CAG repeats was not associated with the choice to compete, a lower number of CAG repeats was related to greater confidence in those who chose to compete, but this effect was attributable to the polymorphism's effect on actual performance. An increase in testosterone levels was observed following the experiment, and this increase varied with self-reported high-school math grades. We expand upon the latest research by documenting effects of the androgen system in confidence in one's own ability, and conclude that testosterone promotes competitiveness without spite.

Estrogens and Androgens in Skeletal Physiology and Pathophysiology

Estrogens and androgens influence the growth and maintenance of the mammalian skeleton and are responsible for its sexual dimorphism. Estrogen deficiency at menopause or loss of both estrogens and androgens in elderly men contribute to the development of osteoporosis, one of the most common and impactful metabolic diseases of old age. In the last 20 years, basic and clinical research advances, genetic insights from humans and rodents, and newer imaging technologies have changed considerably the landscape of our understanding of bone biology as well as the relationship between sex steroids and the physiology and pathophysiology of bone metabolism. Together with the appreciation of the side effects of estrogen-related therapies on breast cancer and cardiovascular diseases, these advances have also drastically altered the treatment of osteoporosis. In this article, we provide a comprehensive review of the molecular and cellular mechanisms of action of estrogens and androgens on bone, their influences on skeletal homeostasis during growth and adulthood, the pathogenetic mechanisms of the adverse effects of their deficiency on the female and male skeleton, as well as the role of natural and synthetic estrogenic or androgenic compounds in the pharmacotherapy of osteoporosis. We highlight latest advances on the crosstalk between hormonal and mechanical signals, the relevance of the antioxidant properties of estrogens and androgens, the difference of their cellular targets in different bone envelopes, the role of estrogen deficiency in male osteoporosis, and the contribution of estrogen or androgen deficiency to the monomorphic effects of aging on skeletal involution.

Estrogens and Androgens in Skeletal Physiology and Pathophysiology

Estrogens and androgens influence the growth and maintenance of the mammalian skeleton and are responsible for its sexual dimorphism. Estrogen deficiency at menopause or loss of both estrogens and androgens in elderly men contribute to the development of osteoporosis, one of the most common and impactful metabolic diseases of old age. In the last 20 years, basic and clinical research advances, genetic insights from humans and rodents, and newer imaging technologies have changed considerably the landscape of our understanding of bone biology as well as the relationship between sex steroids and the physiology and pathophysiology of bone metabolism. Together with the appreciation of the side effects of estrogen-related therapies on breast cancer and cardiovascular diseases, these advances have also drastically altered the treatment of osteoporosis. In this article, we provide a comprehensive review of the molecular and cellular mechanisms of action of estrogens and androgens on bone, their influences on skeletal homeostasis during growth and adulthood, the pathogenetic mechanisms of the adverse effects of their deficiency on the female and male skeleton, as well as the role of natural and synthetic estrogenic or androgenic compounds in the pharmacotherapy of osteoporosis. We highlight latest advances on the crosstalk between hormonal and mechanical signals, the relevance of the antioxidant properties of estrogens and androgens, the difference of their cellular targets in different bone envelopes, the role of estrogen deficiency in male osteoporosis, and the contribution of estrogen or androgen deficiency to the monomorphic effects of aging on skeletal involution.

The androgen receptor gene CAG repeat in relation to 4-year changes in androgen-sensitive endpoints in community-dwelling older European men

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 (E₂) 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 E₂ 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.

Repeat polymorphisms in ESR2 and AR and colorectal cancer risk and prognosis: results from a German population-based case-control study

Background

Evidence has accumulated which suggests that sex steroids influence colorectal cancer development and progression. We therefore assessed the association of repeat polymorphisms in the estrogen receptor β gene (ESR2) and the androgen receptor gene (AR) with colorectal cancer risk and prognosis.

Methods

The ESR2 CA and AR CAG repeat polymorphisms were genotyped in 1798 cases (746 female, 1052 male) and 1810 controls (732 female, 1078 male), matched for sex, age and county of residence. Colorectal cancer risk associations overall and specific for gender were evaluated using multivariate logistic regression models adjusted for sex, county of residence and age. Associations with overall and disease-specific survival were evaluated using Cox proportional hazard models adjusted for established prognostic factors (diagnosis of other cancer after colorectal cancer diagnosis, detection by screening, treatment with adjuvant chemotherapy, tumour extent, nodal status, distant metastasis, body mass index, age at diagnosis and year of diagnosis) and stratified for grade of differentiation. Heterogeneity in gender specific associations was assessed by comparing models with and without a multiplicative interaction term by means of a likelihood ratio test.

Results

The average number of ESR2 CA repeats was associated with a small 5% increase in colorectal cancer risk (OR = 1.05, 95% CI 1.01-1.10) without significant heterogeneity according to gender or tumoural ESR2 expression. We found no indication for an association between the AR CAG repeat polymorphisms and risk of colorectal cancer. The ESR2 CA and AR CAG repeat polymorphisms were not associated with overall survival or disease specific survival after colorectal cancer diagnosis.

Conclusions

Higher numbers of ESR2 CA repeats are potentially associated with a small increase in colorectal cancer risk. Our study does not support an association between colorectal cancer prognosis and the investigated repeat polymorphisms.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-817) contains supplementary material, which is available to authorized users.

CAGn repeat of the androgen receptor is linked to proopiomelanocortin promoter methylation-relevance for craving of male alcohol-dependent patients?

RATIONALE

Previous findings of the Franconian Alcoholism Research Studies showed that both the CAGn of the androgen receptor (AR) and the promoter methylation of the hypothalamic peptide proopiomelanocortin (POMC) were associated with craving of male alcohol-dependent patients.

OBJECTIVES

Based on the strong interactions between the hypothalamic-pituitary-gonadal (HPG) and the hypothalamic-pituitary-adrenal axis (HPA), this study investigated the relationships between the CAGn repeat of the AR, POMC promoter methylation and craving of male alcohol-dependent patients.

METHODS

This analysis covers 84 male patients with a diagnosis of alcohol dependence (DSM-IV). We sequenced the POMC gene promoter using bisulfite modified DNA to display the methylation status. Furthermore, we sequenced the CAGn repeat within exon 1 of the AR gene. Craving was quantified by the Obsessive Compulsive Drinking Scale.

RESULTS

We found an inverse correlation between the number of CAGn repeats of the AR and the POMC methylation status in this study. Altogether, the POMC promoter methylation accounted for 33 % of the relationship between CAGn AR polymorphism and craving.

CONCLUSIONS

This work shows that the AR and the POMC gene might functionally interact with each other and subsequently mediate craving in alcohol-dependent patients. The paper discusses different mechanisms which might underlie our findings involving sex hormones' and sex determining region of Y-gene's regulatory function on DNA-methyltransferase activity. In conclusion, the results give insight in the interaction between HPG and HPA axis. This study is a further step on the way to a better understanding of genetic and non-genetic factors underlying craving for alcohol.

A preliminary case study of androgen receptor gene polymorphism association with impulsivity in women with alcoholism

OBJECTIVE

The androgen receptor (AR) gene, located on the X chromosome, contains a common polymorphism involving cytosine-adenine-guanine (CAG) repeats, which impacts disease and could contribute to the unequal sex ratio in alcoholism. CAG repeats in the AR gene are known to correlate with impulsivity in males. We report the first preliminary study examining the association between the number of CAG repeats and measures of impulsivity in females with chronic alcoholism.

METHODS

A total of 35 women and 85 men with chronic alcoholism were previously recruited for a nutritional clinical trial, and 26 well-characterized females (19 African-American and seven Caucasian) with alcoholism agreed to participate for genetic testing. Genomic deoxyribonucleic acid (DNA) was isolated from peripheral blood and CAG repeats determined by analyzing polymerase chain reaction (PCR)-amplified products, using the polymorphic AR gene assay. CAG repeat length was correlated with raw scores from the Barratt Impulsivity Scale, version 11 and the Alcoholism Severity Scale.

RESULTS

CAG repeat lengths were significantly longer in Caucasian alcoholic women compared with African-Americans, and the average number of CAG repeats were significantly, positively correlated (P<0.05) with impulsivity scores. Women with average CAG repeat length (CAGave) ≥18, representing the upper quartile of the repeat range, showed significantly greater mean raw impulsivity scores. CAG repeat length appeared to have less effect in African-American compared with Caucasian women, possibly due to a shorter average repeat length.

CONCLUSION

We found an association between the number of CAG repeats and impulsivity in females with chronic alcoholism, specifically in women with CAGave ≥18, seen more commonly in Caucasian compared with African-American women.

Genome-wide association studies on serum sex steroid levels

Even though the levels of circulating sex steroid hormones are to a large extent heritable, their genetic determinants are largely unknown. With the advent of genome-wide association studies (GWAS), much progress has been made and several genetic loci have been identified to be associated with serum levels of dehydroepiandrosterone sulfate, testosterone and sex hormone-binding globulin. The variants identified so far only explain a small amount of the overall heritability, but may help to elucidate the role of sex steroid hormones in common disorders such as hypogonadism, type 2 diabetes and hormone-sensitive cancers. This review provides an overview of the current state of knowledge of the genetic determinants of sex steroid hormones, with a focus on recent GWAS and brief directions for elucidating the remaining heritability.

Measures of frailty in population-based studies: an overview

Background

Although research productivity in the field of frailty has risen exponentially in recent years, there remains a lack of consensus regarding the measurement of this syndrome. This overview offers three services: first, we provide a comprehensive catalogue of current frailty measures; second, we evaluate their reliability and validity; third, we report on their popularity of use.

Methods

In order to identify relevant publications, we searched MEDLINE (from its inception in 1948 to May 2011); scrutinized the reference sections of the retrieved articles; and consulted our own files. An indicator of the frequency of use of each frailty instrument was based on the number of times it had been utilized by investigators other than the originators.

Results

Of the initially retrieved 2,166 papers, 27 original articles described separate frailty scales. The number (range: 1 to 38) and type of items (range of domains: physical functioning, disability, disease, sensory impairment, cognition, nutrition, mood, and social support) included in the frailty instruments varied widely. Reliability and validity had been examined in only 26% (7/27) of the instruments. The predictive validity of these scales for mortality varied: for instance, hazard ratios/odds ratios (95% confidence interval) for mortality risk for frail relative to non-frail people ranged from 1.21 (0.78; 1.87) to 6.03 (3.00; 12.08) for the Phenotype of Frailty and 1.57 (1.41; 1.74) to 10.53 (7.06; 15.70) for the Frailty Index. Among the 150 papers which we found to have used at least one of the 27 frailty instruments, 69% (n = 104) reported on the Phenotype of Frailty, 12% (n = 18) on the Frailty Index, and 19% (n = 28) on one of the remaining 25 instruments.

Conclusions

Although there are numerous frailty scales currently in use, reliability and validity have rarely been examined. The most evaluated and frequently used measure is the Phenotype of Frailty.

Androgen receptor CAG repeat length is associated with body fat and serum SHBG in boys: a prospective cohort study

BACKGROUND

Longer androgen receptor gene CAG trinucleotide repeats, AR (CAG)n, have been associated with reduced sensitivity of the androgen receptor (AR) in vitro as well as in humans. Furthermore, short AR (CAG)n have been associated with premature adrenarche.

OBJECTIVE

The aim of the study was to evaluate associations between the AR (CAG)n polymorphism and development of pubic hair, levels of androgens, and body fat content in healthy boys.

METHODS

A longitudinal study of 78 healthy boys (age 6.2-12.4 years at inclusion) from the COPENHAGEN Puberty Study was conducted with clinical examinations and blood samples drawn every 6 months. The AR (CAG)n length was established by direct DNA sequencing and reproductive hormones were measured in serum by standardized analyses.

RESULTS

Median AR (CAG)n length was 22 (range, 17-30). Before puberty (at 10 years of age), boys with long CAG repeats (CAG ≥ 24) had lower levels of SHBG (88 vs 125 nmol/L) (P < .05) and a nonsignificant trend toward higher median skinfold thickness (41 vs 31 mm) (P = .06) compared with boys with an average number of CAG repeats (CAG 21-23). In contrast, the inverse association was observed at puberty (at 12 years of age) in boys with short CAG repeats (CAG 17-20) (P < .05). Serum levels of LH and testosterone (at 12 years) were significantly higher in boys with long CAG repeats compared with boys with an average number of CAG repeats (P = .05).

CONCLUSION

The observed associations between AR (CAG)n and peripubertal fat accumulation and serum SHBG concentrations indicate that this genetic polymorphism may influence the androgen-dependent fine-tuning of metabolic and reproductive factors at a young age.

Genes, physical fitness and ageing

Persons aged 80 years and older are the fastest growing segment of the population. As more individuals live longer, we should try to understand the mechanisms involved in healthy ageing and preserving functional independence in later life. In elderly people, functional independence is directly dependent on physical fitness, and ageing is inevitably associated with the declining functions of systems and organs (heart, lungs, blood vessels, skeletal muscles) that determine physical fitness. Thus, age-related diminished physical fitness contributes to the development of sarcopenia, frailty or disability, all of which severely deteriorate independent living and thus quality of life. Ageing is a complex process involving many variables that interact with one another, including - besides lifestyle factors or chronic diseases - genetics. Thus, several studies have examined the contribution of genetic endowment to a decline in physical fitness and subsequent loss of independence in later life. In this review, we compile information, including data from heritability, candidate-gene association, linkage and genome-wide association studies, on genetic factors that could influence physical fitness in the elderly.

Hormone replacement therapy and physical function in healthy older men. Time to talk hormones?

Improving physical function and mobility in a continuously expanding elderly population emerges as a high priority of medicine today. Muscle mass, strength/power, and maximal exercise capacity are major determinants of physical function, and all decline with aging. This contributes to the incidence of frailty and disability observed in older men. Furthermore, it facilitates the accumulation of body fat and development of insulin resistance. Muscle adaptation to exercise is strongly influenced by anabolic endocrine hormones and local load-sensitive autocrine/paracrine growth factors. GH, IGF-I, and testosterone (T) are directly involved in muscle adaptation to exercise because they promote muscle protein synthesis, whereas T and locally expressed IGF-I have been reported to activate muscle stem cells. Although exercise programs improve physical function, in the long-term most older men fail to comply. The GH/IGF-I axis and T levels decline markedly with aging, whereas accumulating evidence supports their indispensable role in maintaining physical function integrity. Several studies have reported that the administration of T improves lean body mass and maximal voluntary strength in healthy older men. On the other hand, most studies have shown that administration of GH alone failed to improve muscle strength despite amelioration of the detrimental somatic changes of aging. Both GH and T are anabolic agents that promote muscle protein synthesis and hypertrophy but work through separate mechanisms, and the combined administration of GH and T, albeit in only a few studies, has resulted in greater efficacy than either hormone alone. Although it is clear that this combined approach is effective, this review concludes that further studies are needed to assess the long-term efficacy and safety of combined hormone replacement therapy in older men before the medical rationale of prescribing hormone replacement therapy for combating the sarcopenia of aging can be established.

Androgen receptor CAG and GGN polymorphisms in boys with isolated hypospadias

BACKGROUND

The etiology of hypospadias is multifactorial. Abnormal androgenic secretion and/or action during the development of external genitalia may be involved in the etiology of this congenital malformation. This study explored CAG and GGN polymorphisms in the androgen receptor (AR) gene, which may affect its transcriptional activity, in patients with isolated hypospadias.

METHODS

The length of the CAG/GGN polymorphisms was determined in 44 boys with non-severe (glandular) or severe (penile or penoscrotal) isolated hypospadias and with a normal hormonal evaluation. In addition, 79 healthy men, as controls, were studied.

RESULTS

Mean CAG repeats were significantly higher in total and severe cases compared to controls (24.4 +/- 2.8 and 24.7 +/- 3.1 vs. 22.7 +/- 3.3, respectively; p<0.05, Student's t and Bonferroni test). In addition, a frequency of CAG alleles >23 was significantly different in total and severe cases compared to controls (70.5% and 74.1% vs. 39.2%, respectively, p<0.05, chi2 and Bonferroni test). The median number and the distribution of GGN polymorphisms were similar in cases and controls.

CONCLUSION

Boys with isolated hypospadias have longer CAG alleles in their AR, which may be related with the development of this congenital malformation.

Low testosterone in ageing men: a modifiable risk factor for frailty?

There is substantial interest in the role of testosterone (T) in male ageing. Studies suggest that low T may be a risk factor for frailty, the vulnerable health status that occurs at advanced ages. However, T deficiency is relatively rare in ageing men and, importantly, is linked to modifiable risk factors including body weight and concurrent illnesses. These observations shift the focus away from hormone replacement and towards potential preventative strategies to help maintain T levels in ageing men. Furthermore, the effects of T on physical function remain inconsistent, and studies examining the safety of T treatment in ageing males raise concerns. Further research may usefully focus on novel pro-anabolic pharmaceutical agents, which together with other interventions will allow for optimal management of frailty.

Sex hormone activity in alcohol addiction: integrating organizational and activational effects

There are well-known sex differences in the epidemiology and etiopathology of alcohol dependence. Male gender is a crucial risk factor for the onset of alcohol addiction. A directly modifying role of testosterone in alcohol addiction-related behavior is well established. Sex hormones exert both permanent (organizational) and transient (activational) effects on the human brain. The sensitive period for these effects lasts throughout life. In this article, we present a novel early sex hormone activity model of alcohol addiction. We propose that early exposure to sex hormones triggers structural (organizational) neuroadaptations. These neuroadaptations affect cellular and behavioral responses to adult sex hormones, sensitize the brain's reward system to the reinforcing properties of alcohol and modulate alcohol addictive behavior later in life. This review outlines clinical findings related to the early sex hormone activity model of alcohol addiction (handedness, the second-to-fourth-finger length ratio, and the androgen receptor and aromatase) and includes clinical and preclinical literature regarding the activational effects of sex hormones in alcohol drinking behavior. Furthermore, we discuss the role of the hypothalamic-pituitary-adrenal and -gonadal axes and the opioid system in mediating the relationship between sex hormone activity and alcohol dependence. We conclude that a combination of exposure to sex hormones in utero and during early development contributes to the risk of alcohol addiction later in life. The early sex hormone activity model of alcohol addiction may prove to be a valuable tool in the development of preventive and therapeutic strategies.

The relationship between testosterone deficiency and frailty in elderly men

The vulnerable health status usually preceding the onset of overt disability is often referred to as frailty. A stringent definition is elusive but it can be viewed as a physiological syndrome, characterized by decreased reserve and diminished resistance to stressors, resulting from a cumulative decline across multiple physiological systems and causing vulnerability to adverse outcomes. Elements of frailty are related to the neurological system, metabolism, joints, bones, and muscles. Sarcopenia seems to be the major determinant of frailty. Several components of the frailty syndrome are related to loss of physiological actions of testosterone (T). T and/or its aromatized metabolite, estradiol, are necessary for maintenance of bone mineral density. Furthermore, T stimulates erythrocyte formation. T has a profound effect on body composition. Androgens promote differentiation of mesenchymal pluripotent cells into the myogenic lineage and inhibit differentiation into the adipogenic lineage. Skeletal muscles of older men are as responsive to the anabolic effects of T as of younger men. Thus, although frailty is obviously a complex syndrome, some elements are androgen-associated and these can improve in men with subnormal T levels when treated with T. Evidence suggests that T treatment in frail elderly men with low T improves body composition, quality of life, and physical function, including increased axial bone mineral density and body composition. The data available to date strongly suggest a relationship between T-deficiency and frailty and warrant further basic and clinical investigations to extend these observations to the management of elderly men with frailty.