Testosterone dose-response relationships in healthy young men

The relationship between libido and testosterone levels in aging men

CONTEXT

Although it is known that serum testosterone (T) concentrations are related to libido, the strength of that relationship in community-dwelling men has not yet been determined.

OBJECTIVE

Our objective was to assess the strength and significance of the association between aging men's self-reports of libido and serum T concentrations.

DESIGN

Our study was a community-based evaluation of men's health and aging, including three data collection waves: baseline (T1, 1987-1989) and follow-ups (T2, 1995-1997; T3, 2002-2004). Libido was measured on a 14-point scale assessing self-reported frequency of desire and thoughts/fantasies; low libido was defined as a score of less than 7 of 14.

SETTING

We conducted an epidemiological study in greater Boston, Massachusetts.

PARTICIPANTS

There were 1632 men aged 40-70 yr at baseline, with follow-up on 922 (56%) at 9 yr (T2) and 623 (38%) at 15 yr (T3).

MAIN OUTCOME MEASURES

We assessed total and calculated bioavailable T .

RESULTS

Three hundred eighteen (19%) subjects reported low libido at baseline. Libido and T displayed a significant association. However, the difference in mean T levels between those subjects with low libido and those without was small; analyses indicated a 3.4 ng/dl (0.12 nmol/liter) increase in total T per unit increase in libido. Subjects reporting low libido exhibited an increased but modest probability of exhibiting low T. Dividing T concentrations by the number of androgen receptor gene cytosine, adenine, guanine repeats did not enhance associations.

CONCLUSIONS

Libido and T concentrations are strongly related at the population level. However, the value of individual patient reports of reduced libido as indicators of low T levels is open to question.

Anabolic androgenic steroids: a survey of 500 users

PURPOSE

The use of anabolic androgenic steroids (AAS) to increase muscle size and strength is widespread. Information regarding self-administered AAS used nonmedically to enhance athletic performance or improve physical appearance is sparse and poorly documented. The purpose of this study is to identify current trends in the drug-taking habits of AAS users.

METHODS

An anonymous self-administered questionnaire was posted on the message boards of Internet Web sites popular among AAS users.

RESULTS

Of the 500 AAS users who participated in the survey, 78.4% (392/500) were noncompetitive bodybuilders and nonathletes; 59.6% (298/500) of the respondents reported using at least 1000 mg of testosterone or its equivalent per week. The majority (99.2%) of AAS users (496/500) self-administer injectable AAS formulations, and up to 13% (65/500) report unsafe injection practices such as reusing needles, sharing needles, and sharing multidose vials. In addition to using AAS, 25% of users admitted to the adjuvant use of growth hormone and insulin for anabolic effect, and 99.2% (496/500) of users reported subjective side effects from AAS use.

CONCLUSIONS

This survey reveals several trends in the nonmedical use of AAS. Nearly four out of five AAS users are nonathletes who take these drugs for cosmetic reasons. AAS users in this sample are taking larger doses than previously recorded, with more than half of the respondents using a weekly AAS dose in excess of 1000 mg. The majority of steroid users self-administer AAS by intramuscular injection, and approximately 1 in 10 users report hazardous injection techniques. Polypharmacy is practiced by more than 95% of AAS users, with one in four users taking growth hormone and insulin. Nearly 100% of AAS users reported subjective side effects.

Effects of transdermal testosterone administration on insulin sensitivity, fat mass and distribution, and markers of inflammation and thrombolysis in human immunodeficiency virus–infected women with mild to moderate weight loss

OBJECTIVE

To determine the effects of raising serum T levels into the high normal female range by transdermal T administration on insulin sensitivity, fat volume, and markers of inflammation and thrombolysis in HIV-infected women with recent weight loss.

DESIGN

Placebo-controlled, randomized clinical trial.

SETTING

Academic clinical research center.

PATIENT(S)

Fifty-two HIV-infected, menstruating women with >5% weight loss over the prior 6 months and current T<33 ng/dL.

INTERVENTION(S)

Placebo or T patches twice weekly for 24 weeks to achieve nominal delivery of 300 microg T daily.

MAIN OUTCOME MEASURE(S)

Testosterone by liquid chromatography-tandem mass spectrometry, insulin sensitivity by the frequently sampled intravenous glucose tolerance test (FSIVGT), abdominal and thigh fat volumes by magnetic resonance imaging (MRI), and C-reactive protein (CRP) as a measure of inflammation and plasminogen-activated inhibitor-1 (PAI-1) levels as a marker of thrombolysis.

RESULT(S)

Serum and free T levels significantly increased into the high normal female range in T-treated but not placebo-treated women. Insulin sensitivity by FSIVGT, whole body, thigh SC, and intra-abdominal fat volumes, and CRP and PAI-1 levels did not change significantly in either group and were not significantly different between the two groups. Fasting insulin increased in the placebo group and fell slightly in the T group, resulting in significant differences in change between groups.

CONCLUSION(S)

Twenty-four weeks of elevation of serum T levels into the high normal female range in HIV-infected women with mild to moderate weight loss by transdermal T patches did not adversely affect insulin sensitivity, whole-body fat mass or regional fat distribution, or markers of inflammation and thrombolysis. More prolonged and larger studies are needed to determine the effects of higher doses of T on body composition and insulin sensitivity in women.

REVIEWS: Are Androgens Critical for Penile Erections in Humans? Examining the Clinical and Preclinical Evidence

Androgens are deemed critical for penile-tissue development, growth, and maintenance of erectile function, however, their role in erection, especially in humans, remains controversial. In this review, we summarize information from clinical and animal model studies to provide a comprehensive and rational argument for the role of androgens, or lack thereof, on penile erection ability in humans. The goal of this review is to present the clinical and preclinical evidence available in the literature with regard to testosterone and erectile physiology and engage the reader in this discussion. Ultimately, each reader will have to form his or her own conclusions based on the existing evidence. In humans, androgen-deficiency manifestations are noted in clinical situations such as: (i) inadequate development of the penis; and (ii) loss of erectile function in prostate cancer and benign prostatic hyperplasia patients managed with medical or surgical castration or antiandrogen therapy. Androgen treatment causes: (i) improvement in sexual function in hypogonadal patients treated with androgen supplementation; (ii) improvement in nocturnal penile tumescence in hypogonadal patients treated with androgens; (iii) improvement in erectile function with androgen supplementation in patients who did not respond to phosphodiesterase type 5 inhibitor therapy initially; and (iv) improvement in the well-being, mood, energy, and sexual function in aging men who have testosterone deficiency treated with androgen therapy. In contrast to animals, especially rodents in which the adrenal cortex does not synthesize androgens, the human adrenal is a source of peripherally circulating androgen precursors, thus, complete androgen insufficiency may not be observed in men at a younger age. Furthermore, in light of the concept that a threshold of androgen levels exists in animals and humans below which sexual function is diminished, further contributes to the complexity of understanding androgens role in erections, especially in humans. Nevertheless, based on the preclinical and clinical data available in the literature, to date, we infer that androgens play a critical role in maintaining erectile physiology in humans.

Oxandrolone in the treatment of HIV-associated weight loss in men: a randomized, double-blind, placebo-controlled study

OBJECTIVE

To evaluate the efficacy and safety of oxandrolone in promoting body weight and body cell mass (BCM) gain in HIV-associated weight loss.

METHODS

Randomized, double-blind, placebo-controlled trial. Two hundred sixty-two HIV-infected men with documented 10% to 20% weight loss or body mass index < or =20 kg/m were randomized to placebo or to 20, 40, or 80 mg of oxandrolone daily. After 12 weeks, subjects were allowed to receive open-label oxandrolone at a dose of 20 mg for another 12 weeks.

RESULTS

Body weight increased in all groups, including the group receiving placebo, during the double-blind phase (1.1 +/- 2.7, 1.8 +/- 3.9, 2.8 +/- 3.3, and 2.3 +/- 2.9 kg in placebo and 20-, 40-, and 80-mg oxandrolone groups, respectively; all P < 0.014 vs. baseline). BCM increased from baseline in all groups (0.45 +/- 1.7, 0.91 +/- 2.2, 1.5 +/- 2.5, and 1.8 +/- 1.8 kg in placebo and 20-, 40-, and 80-mg oxandrolone groups, respectively). At 12 weeks, only the gain in weight at the 40-mg dose of oxandrolone and the gain in BCM at the 40- and 80-mg doses of oxandrolone were greater than those in the placebo group, however. Oxandrolone treatment was associated with significant suppression of sex hormone-binding globulin, luteinizing hormone, follicle-stimulating hormone, and total and free testosterone levels. Treatment was generally well tolerated but accompanied by significant increases in transaminases and low-density lipoprotein as well as decreases in high-density lipoprotein.

CONCLUSION

Oxandrolone administration is effective in promoting dose-dependent gains in body weight and BCM in HIV-infected men with weight loss.

Predictors of South African male testosterone levels: the THUSA study

The process of urbanization occurring in many developing countries may have consequences for reproductive endocrine function. Here, we test predictions concerning variation in South African male testosterone levels among subgroups across an urbanization gradient representing differences in both geography and socioeconomic status. Subjects included 364 males aged between 20 and 82 comprising a cross-sectional study conducted between 1996 and 1998. Testosterone levels were measured from serum samples obtained between 08:00 and 11:00. In ANCOVA analysis, male testosterone levels differed significantly along this rural-to-urban gradient, with members of the most urban group having higher testosterone levels than groups of farmers and inhabitants of informal housing areas adjacent to towns. Testosterone levels declined with age and were negatively related to body mass index (BMI). Testosterone levels did not differ according to HIV status. Further exploratory ANCOVA analyses revealed that physical activity levels, depression, affect, and hostility were not significantly associated with variation in testosterone levels. These data help document causes of variation in male testosterone levels in a context of urbanization and may have implications for clinical outcomes such as the development of a male hormonal contraceptive or prostate cancer.

Male hormonal contraception: concept proven, product in sight?

Current male hormonal contraceptive (MHC) regimens act at various levels within the hypothalamic pituitary testicular axis, principally to induce the withdrawal of the pituitary gonadotrophins and in turn intratesticular androgen production and spermatogenesis. Azoospermia or severe oligozoospermia result from the inhibition of spermatogonial maturation and sperm release (spermiation). All regimens include an androgen to maintain virilization, while in many the suppression of gonadotrophins/spermatogenesis is augmented by the addition of another anti-gonadotrophic agent (progestin, GnRH antagonist). The suppression of sperm concentration to 1 x 10(6)/ml appears to provide comparable contraceptive efficacy to female hormonal methods, but the confidence intervals around these estimates remain relatively large, reflecting the limited number of exposure years reported. Also, inconsistencies in the rapidity and depth of spermatogenic suppression, potential for secondary escape of sperm into the ejaculate and onset of fertility return not readily explainable by analysis of subject serum hormone levels, germ cell number or intratesticular steroidogenesis, are apparent. As such, a better understanding of the endocrine and genetic regulation of spermatogenesis is necessary and may allow for new treatment paradigms. The development of an effective, consumer-friendly male contraceptive remains challenging, as it requires strong translational cooperation not only between basic scientists and clinicians but also between public and private sectors. At present, a prototype MHC product using a long-acting injectable testosterone and depot progestin is well advanced.

Drug insight: Testosterone and selective androgen receptor modulators as anabolic therapies for chronic illness and aging

Several regulatory concerns have hindered development of androgens as anabolic therapies, despite unequivocal evidence that testosterone supplementation increases muscle mass and strength in men; it induces hypertrophy of type I and II muscle fibers, and increases myonuclear and satellite cell number. Androgens promote differentiation of mesenchymal multipotent cells into the myogenic lineage and inhibit their adipogenic differentiation, by facilitating association of androgen receptors with beta-catenin and activating T-cell factor 4. Meta-analyses indicate that testosterone supplementation increases fat-free mass and muscle strength in HIV-positive men with weight loss, glucocorticoid-treated men, and older men with low or low-normal testosterone levels. The effects of testosterone on physical function and outcomes important to patients have not, however, been studied. In older men, increased hematocrit and increased risk of prostate biopsy and detection of prostate events are the most frequent, testosterone-related adverse events. Concerns about long-term risks have restrained enthusiasm for testosterone use as anabolic therapy. Selective androgen-receptor modulators that are preferentially anabolic and that spare the prostate hold promise as anabolic therapies. We need more studies to determine whether testosterone or selective androgen-receptor modulators can induce meaningful improvements in physical function and patient-important outcomes in patients with physical dysfunction associated with chronic illness or aging.

Testosterone induces an intracellular calcium increase by a nongenomic mechanism in cultured rat cardiac myocytes

Androgens are associated with important effects on the heart, such as hypertrophy or apoptosis. These responses involve the intracellular androgen receptor. However, the mechanisms of how androgens activate several membrane signaling pathways are not fully elucidated. We have investigated the effect of testosterone on intracellular calcium in cultured rat cardiac myocytes. Using fluo3-AM and epifluorescence microscopy, we found that exposure to testosterone rapidly (1-7 min) led to an increase of intracellular Ca2+, an effect that persisted in the absence of external Ca2+. Immunocytochemical analysis showed that these effects occurred before translocation of the intracellular androgen receptor to the perinuclear zone. Pretreatment of the cells with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethylester and thapsigargin blocked this response, suggesting the involvement of internal Ca2+ stores. U-73122, an inhibitor of phospholipase C, and xestospongin C, an inhibitor of inositol 1,4,5-trisphosphate receptor, abolished the Ca2+ signal. The rise in intracellular Ca2+ was not inhibited by cyproterone, an antagonist of intracellular androgen receptor. Moreover, the cell impermeant testosterone-BSA complex also produced the Ca2+ signal, indicating its origin in the plasma membrane. This effect was observed in cultured neonatal and adult rat cardiac myocytes. Pertussis toxin and the adenoviral transduction of beta- adrenergic receptor kinase carboxy terminal peptide, a peptide inhibitor of betagamma-subunits of G protein, abolished the testosterone-induced Ca2+ release. In summary, this is the first study of rapid, nongenomic intracellular Ca2+ signaling of testosterone in cardiac myocytes. Using various inhibitors and testosterone-BSA complex, the mechanism for the rapid, testosterone-induced increase in intracellular Ca2+ is through activation of a plasma membrane receptor associated with a Pertussis toxin-sensitive G protein-phospholipase C/inositol 1,4,5-trisphosphate signaling pathway.

Testosterone inhibits adipogenic differentiation in 3T3-L1 cells: nuclear translocation of androgen receptor complex with beta-catenin and T-cell factor 4 may bypass canonical Wnt signaling to down-regulate adipogenic transcription factors

Testosterone supplementation in men decreases fat mass; however, the mechanisms by which it inhibits fat mass are unknown. We hypothesized that testosterone inhibits adipogenic differentiation of preadipocytes by activation of androgen receptor (AR)/beta-catenin interaction and subsequent translocation of this complex to the nucleus thereby bypassing canonical Wnt signaling. We tested this hypothesis in 3T3-L1 cells that differentiate to form fat cells in adipogenic medium. We found that these cells express AR and that testosterone and dihydrotestosterone dose-dependently inhibited adipogenic differentiation as analyzed by Oil Red O staining and down-regulation of CCAAT/enhancer binding protein-alpha and -delta and peroxisome proliferator-activated receptor-gamma2 protein and mRNA. These inhibitory effects of androgens were partially blocked by flutamide or bicalutamide. Androgen treatment was associated with nuclear translocation of beta-catenin and AR. Immunoprecipitation studies demonstrated association of beta-catenin with AR and T-cell factor 4 (TCF4) in the presence of androgens. Transfection of TCF4 cDNA inhibited adipogenic differentiation, whereas a dominant negative TCF4 cDNA construct induced adipogenesis and blocked testosterone's inhibitory effects. Our gene array analysis indicates that testosterone treatment led to activation of some Wnt target genes. Expression of constitutively activated AR fused with VP-16 did not inhibit the expression of CCAAT/enhancer binding protein-alpha in the absence of androgens. Testosterone and dihydrotestosterone inhibit adipocyte differentiation in vitro through an AR-mediated nuclear translocation of beta-catenin and activation of downstream Wnt signaling. These data provide evidence for a regulatory role for androgens in inhibiting adipogenic differentiation and a mechanistic explanation consistent with the observed reduction in fat mass in men treated with androgens.

Recent insights into androgen action on the anatomical and physiological substrate of penile erection

Erectile response is centrally and peripherally regulated by androgens. The original insights into the mechanisms of action of androgens were that androgens particularly exert effects on libido and that erections in response to erotic stimuli were relatively androgen-independent. It was shown that sexual functions in men required androgen levels at the low end of reference values of testosterone. So it seemed that testosterone was not useful treatment for men with erectile difficulties, particularly following the advent of the phosphodiesterase type 5 (PDE5) inhibitors. However, approximately 50% of those treated with PDE5 inhibitors discontinue their treatment. A number of recent developments shed new light on testosterone treatment of erectile dysfunction (ED) in aging men. (1) A recent insight is that, in contrast to younger men, elderly men might require higher levels of testosterone for normal sexual functioning. (2) Several studies have indicated that PDE5 inhibitors are not always sufficient to restore erectile potency in men, and that testosterone improves the therapeutical response to PDE5 inhibitors considerably. (3) There is growing insight that testosterone has profound effects on tissues of the penis involved in the mechanism of erection and that testosterone deficiency impairs the anatomical and physiological substrate of erectile capacity, reversible upon androgen replacement. The synthesis of PDE5 is upregulated by androgens, and the arterial inflow into the penis is improved by giving androgen. The above invites a re-examination of the merits of giving testosterone to aging men with ED. The beneficial effects of PDE5 inhibitors may only be optimally expressed in a eugonadal environment.

Male hormonal contraception: a safe option?

Hormonal male contraception is based on the administration of testosterone alone or more likely with a progestogen. Testosterone has been used for several decades for the treatment of male hypogonadism, with an excellent safety record. Use as part of a contraceptive regimen by healthy people for prolonged periods will necessitate careful re-examination of safety issues. Although potential male contraceptive regimens have been investigated for many years, there have been mostly small-scale studies unable to assess safety. This is now changing, with larger studies of regimens underway. This, and the increasing involvement of the pharmaceutical industry, means that much more data will shortly be forthcoming and it is hoped that this will also provide valuable information relevant to normal male health. The main areas of interest are the cardiovascular system and the prostate, but bone health and body composition are also important, as are behavioral and psychologic aspects. The development of this field also allows the investigation of potential health benefits, which may be related to the use of synthetic androgens with tissue-selective metabolism or action.

Psychiatric side effects induced by supraphysiological doses of combinations of anabolic steroids correlate to the severity of abuse

OBJECTIVE

The objective of our study was to evaluate the psychological consequences of real-world AAS use in athletes abusing such agents, in comparison with a placebo and control group of comparable athletes, while correlating the severity of abuse with the side effects observed. The hypothesis tested by the study was that the use of AAS induces a wide range of psychological side effects whose impact and emergence is dependent upon the severity of the abuse.

DESIGN

The study includes a substantial group of AAS abusing athletes and two more groups demographically similar to the first, one composed of athletes not using any substance and a placebo group. All athletes were stratified according to the severity of AAS abuse. Psychometric instruments were applied to all athletes in specific time intervals, dependent to the AAS abusers' regimens, providing us with a final psychological profile that was to be compared to the pre-study profile. All results were comparable (within and between groups) for statistically significant differences and correlated to the severity of the abuse. Homogeneity of all groups was safeguarded by random doping controls, monitoring of drug levels and analysis of all self obtained drugs by method of liquid chromatography/mass spectrometry. All athletes were provided with a common exercise and dietary regime, so common training and nutritional conditions were achieved.

METHODS

We studied a cohort of 320 body-building, amateur and recreational athletes, of whom 160 were active users of AAS (group C), 80 users administering placebo drugs (group B) and 80 not abusing any substance (Group A). Group C athletes were stratified according to AAS abuse parameters, thus providing us with three subgroups of "light, medium and heavy abuse". Athletes of groups A and B were included in a "no abuse" subgroup. The psychometric instruments used were the Symptoms Check List-90 (SCL-90) and the Hostility and Direction of Hostility Questionnaire (HDHQ). The psychometric evaluations took place within a time interval of 13 months. Statistical analysis was performed by using the Mann-Whitney/Wilcoxon two-sample non-parametric test (Kruskal-Wallis test for two groups) for data that were not normally distributed and Linear regression analysis was used to ascertain the correlation between severity of use and escalation of side effects.

RESULTS

The study showed a statistically significant increase in all psychometric subscales recorded in group C, and no statistically significant difference in group C and A. There was a significant increase in the scorings of group C for all subscales of SCL-90 and HDHQ. Correlation of abuse severity and side effects showed that there was a statistical significant increase in Delta values of all SCL-90 and HDHQ subscales that escalated from light abuse to medium and heavy abuse/consumption patterns.

CONCLUSIONS

The results of the study suggest that the wide range of psychiatric side effects induced by the use of AAS is correlated to the severity of abuse and the force of these side effects intensifies as the abuse escalates.

Male hypogonadism : an update on diagnosis and treatment

Male hypogonadism is one of the most common endocrinologic syndromes. The diagnosis is based on clinical signs and symptoms plus laboratory confirmation via the measurement of low morning testosterone levels on two different occasions. Serum luteinizing hormone and follicle-stimulating hormone levels distinguish between primary (hypergonadotropic) and secondary (hypogonadotropic) hypogonadism. Hypogonadism associated with aging (andropause) may present a mixed picture, with low testosterone levels and low to low-normal gonadotropin levels. Androgen replacement therapy in hypogonadal men has many potential benefits: improved sexual function, an enhanced sense of well-being, increased lean body mass, decreased body fat, and increased bone density. However, it also carries potential risks, including the possibility of stimulating the growth of an occult prostate cancer. The benefits of androgen therapy outweigh the risks in men with classic hypogonadism. However, for men with mild hypogonadism or andropause, the balance between benefits and risks is not always clear. Unfortunately, studies to date have included too small a number of patients and have been too short in duration to provide meaningful data on the long-term risks versus the benefits of androgen replacement therapy in these populations. Several products are currently marketed for the treatment of male hypogonadism. Weekly-to-biweekly injections of testosterone cypionate (cipionate) or testosterone enanthate (enantate) are widely used, as they are economical and generally well tolerated. However, once-daily transdermal therapies have become increasingly popular and now include both patch and gel systems. Intramuscular injection of testosterone undecanoate is an attractive new therapy that can be administered quarterly. To confirm an adequate replacement dosage, assessment of clinical responses and measurement of serum testosterone levels generally suffice. For selected men, serial measurement of bone mineral density during androgen therapy might be helpful to confirm end-organ effects. For men aged >50 years, we advocate measurement of hematocrit for detection of polycythemia and a digital rectal examination with a serum prostate-specific antigen level measurement for prostate cancer screening during the first few months of androgen therapy. Subsequently, a hematocrit should be obtained yearly or after changes in therapy, and annual prostate cancer screening can be offered to the patient after a discussion of its risks and benefits.

Endocrine causes of erectile dysfunction

Erectile dysfunction (ED) is one of the commonest disorders of male sexual function. Penile erection depends on a complex interaction of psychological, neural, vascular and endocrine factors. Testosterone has an important role in both central and peripheral domains of this process. In this article we discuss the role of testosterone in male sexual function and endocrine causes of ED.

Selective androgen receptor modulator treatment improves muscle strength and body composition and prevents bone loss in orchidectomized rats

The partial agonist activity of a selective androgen receptor modulator (SARM) in the prostate was demonstrated in orchidectomized rats. In the current study, we characterized the full agonist activity of S-3-(4-acetylamino-phenoxy)-2-hydroxy-2-methyl-N-(4-nitro-3-trifluoromethyl-phenyl)-propionamide (a structurally related SARM referred to in other publications and hereafter as S-4) in skeletal muscle, bone, and pituitary of castrated male rats. Twelve weeks after castration, animals were treated with S-4 (3 or 10 mg/kg), dihydrotestosterone (DHT) (3 mg/kg), or vehicle for 8 wk. S-4 (3 and 10 mg/kg) restored soleus muscle mass and strength and levator ani muscle mass to that seen in intact animals. Similar changes were also observed in DHT-treated (3 mg/kg) animals. Compared with the anabolic effects observed in muscle, DHT (3 mg/kg) stimulated prostate and seminal vesicle weights more than 2-fold greater than that observed in intact controls, whereas S-4 (3 mg/kg) returned these androgenic organs to only 16 and 17%, respectively, of the control levels. S-4 (3 and 10 mg/kg) and DHT (3 mg/kg) restored castration-induced loss in lean body mass. Furthermore, S-4 treatment caused a significantly larger increase in total body bone mineral density than DHT. S-4 (3 and 10 mg/kg) also demonstrated agonist activity in the pituitary and significantly decreased plasma LH and FSH levels in castrated animals in a dose-dependent manner. In summary, the strong anabolic effects of S-4 in skeletal muscle, bone, and pituitary were achieved with minimal pharmacologic effect in the prostate. The tissue-selective pharmacologic activity of SARMs provides obvious advantages over steroidal androgen therapy and demonstrates the promising therapeutic utility that this new class of drugs may hold.

The decline of androgen levels in elderly men and its clinical and therapeutic implications

Aging in men is accompanied by a progressive, but individually variable decline of serum testosterone production, more than 20% of healthy men over 60 yr of age presenting with serum levels below the range for young men. Albeit the clinical picture of aging in men is reminiscent of that of hypogonadism in young men and decreased testosterone production appears to play a role in part of these clinical changes in at least some elderly men, the clinical relevancy of the age-related decline in sex steroid levels in men has not been unequivocally established. In fact, minimal androgen requirements for elderly men remain poorly defined and are likely to vary between individuals. Consequently, borderline androgen deficiency cannot be reliably diagnosed in the elderly, and strict differentiation between "substitutive" and "pharmacological" androgen administration is not possible. To date, only a few hundred elderly men have received androgen therapy in the setting of a randomized, controlled study, and many of these men were not androgen deficient. Most consistent effects of treatment have been on body composition, but to date there is no evidence-based documentation of clinical benefits of androgen administration to elderly men with normal or moderately low serum testosterone in terms of diminished morbidity or of improved survival or quality of life. Until the long-term risk-benefit ratio for androgen administration to elderly is established in adequately powered trials of longer duration, androgen administration to elderly men should be reserved for the minority of elderly men who have both clear clinical symptoms of hypogonadism and frankly low serum testosterone levels.

The effect of 6 months of androgen deprivation therapy on muscle and fat mass in older men with localized prostate cancer

OBJECTIVE

To evaluate body composition changes, specifically skeletal muscle mass, in men receiving androgen deprivation with luteinizing-hormone releasing hormone-agonist (LHRH-A) for prostate cancer (PCa) in comparison with healthy controls.

DESIGN

Retrospective analysis of body composition changes in men with prostate cancer receiving LHRH-A therapy from 2 clinical trials compared to men without prostate cancer serving as a placebo-control in another clinical trial.

SETTING

Clinical Research Center in Connecticut.

PARTICIPANTS

Thirty men (> 60 years) receiving 6 months of LHRH-A therapy for PCa were compared to a healthy group of 25 men without PCa.

MEASUREMENTS

Appendicular skeletal muscle/height2 (ASM/ht2), lean and fat mass were assessed by dual energy x-ray absorptiometry. Total testosterone levels were assessed by enzyme immunoassay.

RESULTS

At baseline, 12/30 (40%) of the treatment group and 7/25 (28%) of the control group (p = 0.11) met criteria for sarcopenia. There were no differences between control groups in ASM/ht2 or lean mass. The LHRH-A group had a higher percent body fat than the control group, 29.8 +/- 6.3 versus 26.3 +/- 4.6 (p = 0.02). ASM/ht2 and lean mass decreased in the LHRH-A group from 7.5 +/- 0.9 kg to 7.3 +/- 0.9 kg (-2.3% +/- 0.03; p < or = 0.001) and 53.5 +/- 5.4 kg to 52.3 +/- 5.3 kg (-2.1% +/- 0.03; p < or = 0.001), respectively. There was no muscle loss in the control group. At 6 months, the LHRH-A group had increased percent body fat from 29.8 +/- 6.4 to 32.2 +/- 5.8 (9.5% +/- 0.13; p < or = 0.001), whereas the control group had decreased in percent body fat from 26.6 +/- 4.6 to 25.3 +/- 5.0 (-3.8% +/- 0.08; p = 0.02).

CONCLUSIONS

Men undergoing LHRH-A treatment for PCa decreased appendicular skeletal muscle and lean tissue and increased body fat within 6 months of initiation of therapy. Lifestyle changes or medical interventions to minimize the effects of androgen deprivation therapy for PCa deserve investigation.

Male hypogonadism. Part II: etiology, pathophysiology, and diagnosis

Male hypogonadism has a multifactorial etiology that includes genetic conditions, anatomic abnormalities, infection, tumor, and injury. Defects in the hypothalamic-pituitary-gonadal axis may also result from type II diabetes mellitus and treatment with a range of medications. Circulating testosterone levels have been associated with sexual function, cognitive function, and body composition. Apart from reduced levels of testosterone, clinical hallmarks of hypogonadism include absence or regression of secondary sex characteristics, reduced fertility (oligospermia, azoospermia), anemia, muscle wasting, reduced bone mass (and bone mineral density), and/or abdominal adiposity. Some patients, particularly those with partial androgen deficiency of the aging male, also experience sexual dysfunction, reduced sense of vitality, depressed mood, increased irritability, difficulty concentrating, and/or hot flushes in certain cases of acute onset. As many patients with male hypogonadism-like patients with erectile dysfunction-do not seek medical attention, it is important for clinicians to be acquainted with the signs and symptoms of hypogonadism, and to conduct appropriate laboratory testing and other assessments to determine the causes and inform the treatment of this condition.

Advances in male hormone substitution therapy

Increased awareness of the clinical diagnosis of male hypogonadism has resulted in the wider use of androgen substitution therapy. Clinical signs and symptoms together with a low serum testosterone level confirm the diagnosis of male hypogonadism. Androgen replacement results in improved sexual function, mood, muscle mass and bone density in most hypogonadal men. Such benefits must be assessed against potential risks. In older men, the potential risks of androgen treatment of hypogonadism are not known. Many delivery systems for androgen substitution are now available; the preparation chosen depends on the choice of the patient and his physician. Selective androgen receptor modulators offer tissue selective biological effects and the possibility of attaining maximum efficacy and minimum adverse effects.

Correlates of circulating androgens in mid-life women: the study of women's health across the nation

CONTEXT

Androgens influence sexual differentiation and behavior, body composition, and physical functioning in men, but their role in women is less well understood. Because circulating androgens decline with age, the use of androgen supplementation for women to improve health and well-being has been increasing.

OBJECTIVE

The aim of this study was to assess the association between androgens and a variety of end points thought to be affected by androgens.

DESIGN

In a community-based baseline cohort of women aged 42-52 yr from the Study of Women's Health Across the Nation, we measured circulating testosterone (T), dehydroepiandrosterone sulfate, and SHBG, and calculated a free androgen index (FAI) in 2961 women.

MAIN OUTCOME MEASURES

Correlations of androgen measures with each other and with body mass index, waist circumference, and waist-hip ratio were computed, and odds ratios (OR) were estimated for the categorical outcomes of functional limitations, functional status, self-reported health, scores indicative of depressed mood, quality of life, sexual desire and arousal, and the presence of the metabolic syndrome.

RESULTS

Androgens, and particularly SHBG, were associated most strongly with body mass index, waist circumference, and waist-hip ratio. SHBG was associated prominently inversely with the metabolic syndrome (OR = 0.32; 95% confidence interval = 0.26-0.39), which was present in 17% of women at baseline. Dehydroepiandrosterone sulfate was associated modestly with functional status and self-reported health. T was associated minimally with increased sexual desire (OR = 1.09; 95% confidence interval = 1.00-1.18). The association of FAI with self-reported health and depressive symptomatology based on the Center for Epidemiologic Studies Depression Scale score was explained more by T than by SHBG, whereas the association of FAI with sexual arousal and metabolic syndrome was due more to SHBG than to T.

CONCLUSIONS

Circulating SHBG and androgens are most strongly associated with physical characteristics and the metabolic syndrome in women in this community-based cohort. Androgens are related weakly to physical functioning and other symptoms to which they commonly are attributed, such as sexual desire, sexual arousal, and well-being.

A randomized, placebo-controlled trial of nandrolone decanoate in human immunodeficiency virus-infected men with mild to moderate weight loss with recombinant human growth hormone as active reference treatment

OBJECTIVE

We compared the effectiveness of a biweekly regimen of 150 mg nandrolone with placebo in HIV-infected men with mild to moderate weight loss and contrasted its effects against a Food and Drug Administration-approved regimen of recombinant human (rh)GH.

METHODS

In this placebo-controlled, randomized, 12-wk trial, placebo and nandrolone (150 mg im biweekly) were administered double blind, and rhGH (6 mg sc daily) was administered in an open-label manner. Participants were HIV-infected men with 5-15% weight loss over 6 months and on stable antiretroviral therapy for more than 12 wk. Lean body mass (LBM), muscle performance, physical function, endurance, hormone levels, insulin sensitivity, sexual function, quality of life, and appetite were assessed at baseline and after 12 wk.

RESULTS

Nandrolone administration was associated with a greater increase in LBM (+1.6 +/- 0.3 kg) by dual-energy x-ray absorptiometry scan than placebo (+0.4 +/- 0.3 kg; P < 0.05); however, the change in LBMs with nandrolone was not significantly different from rhGH (+2.5 +/- 0.3 kg). Nandrolone administration was also associated with significantly greater gains in fat-free mass (+1.6 +/- 0.3 kg), body cell mass (+1.0 +/- 0.2 kg), and intracellular water (+0.9 +/- 0.2 kg) than placebo; these changes in the nandrolone group were not significantly different from the rhGH group. rhGH administration was associated with greater loss of whole body fat mass and higher frequency of drug-related adverse effects and treatment discontinuations than nandrolone and placebo and a greater increase in extracellular water than nandrolone. Nandrolone treatment was associated with greater improvements in perception of health than rhGH and sexual function than placebo. The cachexia/anorexia scores, health care resource use, and insulin sensitivity did not significantly change.

CONCLUSION

We conclude that nandrolone is superior to placebo and not significantly different from a Food and Drug Administration-approved regimen of rhGH in improving lean body mass in HIV-infected men with mild to moderate weight loss.

ISA, ISSAM and EAU recommendations for the investigation, treatment and monitoring of late-onset hypogonadism in males: scientific background and rationale

Prescription sales for testosterone products have substantially increased over the last several years reflecting the growing awareness of physicians for the potential benefits of testosterone replacement therapy in men with hypogonadism. Indiscriminate administration of testosterone poses a risk and has to be deprecated. Testosterone supplementation to treat late-onset hypogonadism (LOH), a term for androgen deficiency in elderly men, is still controversially discussed mainly due to a lack of large, controlled clinical trials on efficacy and safety. To provide guidance for physicians primarily dealing with aging men, ISSAM is periodically updating and publishing its recommendations as new data become available [Morales A, Lunenfeld B. International Society for the Study of the Aging Male. Investigation, treatment and monitoring of late-onset hypogonadism in males. Official recommendations of ISSAM. International Society for the Study of the Aging Male. Aging Male 2002;5:74-86 and Morales A, Lunenfeld B. Androgen replacement therapy in aging men with secondary hypogonadism. Draft recommendations for endorsement by ISSAM. Aging Male 2001;4:1]. Following a panel discussion at the 4th ISSAM Congress in Prague in February 2004, the International Society of Andrology (ISA), the International Society for the Study of the Aging Male (ISSAM) and the European Association of Urology (EAU) revised existing recommendations on the definition, diagnosis and management of LOH. The recommendations are based on the currently available scientific data on androgen supplementation therapy and should be regarded as provisional until larger-scale, long-term studies are available. While certainly not intending to be exhaustive, this review will highlight some relevant background information and provide the underlying scientific rationale for the ISA, ISSAM and EAU recommendations on LOH published in this issue.

Effects of androgenic-anabolic steroids on apolipoproteins and lipoprotein (a)

OBJECTIVES

To investigate the effects of two different regimens of androgenic-anabolic steroid (AAS) administration on serum lipid and lipoproteins, and recovery of these variables after drug cessation, as indicators of the risk for cardiovascular disease in healthy male strength athletes.

METHODS

In a non-blinded study (study 1) serum lipoproteins and lipids were assessed in 19 subjects who self administered AASs for eight or 14 weeks, and in 16 non-using volunteers. In a randomised double blind, placebo controlled design, the effects of intramuscular administration of nandrolone decanoate (200 mg/week) for eight weeks on the same variables in 16 bodybuilders were studied (study 2). Fasting serum concentrations of total cholesterol, triglycerides, HDL-cholesterol (HDL-C), HDL2-cholesterol (HDL2-C), HDL3-cholesterol (HDL3-C), apolipoprotein A1 (Apo-A1), apolipoprotein B (Apo-B), and lipoprotein (a) (Lp(a)) were determined.

RESULTS

In study 1 AAS administration led to decreases in serum concentrations of HDL-C (from 1.08 (0.30) to 0.43 (0.22) mmol/l), HDL2-C (from 0.21 (0.18) to 0.05 (0.03) mmol/l), HDL3-C (from 0.87 (0.24) to 0.40 (0.20) mmol/l, and Apo-A1 (from 1.41 (0.27) to 0.71 (0.34) g/l), whereas Apo-B increased from 0.96 (0.13) to 1.32 (0.28) g/l. Serum Lp(a) declined from 189 (315) to 32 (63) U/l. Total cholesterol and triglycerides did not change significantly. Alterations after eight and 14 weeks of AAS administration were comparable. No changes occurred in the controls. Six weeks after AAS cessation, serum HDL-C, HDL2-C, Apo-A1, Apo-B, and Lp(a) had still not returned to baseline concentrations. Administration of AAS for 14 weeks was associated with slower recovery to pretreatment concentrations than administration for eight weeks. In study 2, nandrolone decanoate did not influence serum triglycerides, total cholesterol, HDL-C, HDL2-C, HDL3-C, Apo-A1, and Apo-B concentrations after four and eight weeks of intervention, nor six weeks after withdrawal. However, Lp(a) concentrations decreased significantly from 103 (68) to 65 (44) U/l in the nandrolone decanoate group, and in the placebo group a smaller reduction from 245 (245) to 201 (194) U/l was observed. Six weeks after the intervention period, Lp(a) concentrations had returned to baseline values in both groups.

CONCLUSIONS

Self administration of several AASs simultaneously for eight or 14 weeks produces comparable profound unfavourable effects on lipids and lipoproteins, leading to an increased atherogenic lipid profile, despite a beneficial effect on Lp(a) concentration. The changes persist after AAS withdrawal, and normalisation depends on the duration of the drug abuse. Eight weeks of administration of nandrolone decanoate does not affect lipid and lipoprotein concentrations, although it may selectively reduce Lp(a) concentrations. The effect of this on atherogenesis remains to be established.

Modulation of high-density lipoprotein cholesterol metabolism and reverse cholesterol transport

Low high-density lipoprotein (HDL)-cholesterol (C) is an important risk factor for coronary heart disease. In vitro, HDL exerts several potentially anti-atherogenic effects including reverse cholesterol transport (RCT) from peripheral cells to the liver. Hence, raising HDL-C has become an interesting target for anti-atherosclerotic drug therapy. Levels of HDL-C and the composition of HDL subclasses in plasma are regulated by apolipoproteins, lipolytic enzymes, lipid transfer proteins, receptors, and cellular transporters. The interplay of these factors leads to RCT and determines the composition and thereby the anti-atherogenic properties of HDL. Recent findings suggest that the mechanism of HDL modification rather than a sole increase in HDL-C determines the efficacy of anti-atherosclerotic drug therapy. In several controlled and prospective intervention studies, patients with low HDL-C and additional risk factors benefited from treatment with fibrates or statins. However, in only some of the fibrate trials was prevention of coronary events in patients with low HDL-C and hypertriglyceridaemia related to an increase in HDL-C. This may be because currently available drugs increase HDL-C levels only moderately and because HDL levels per se do not necessarily correlate with the functionality of HDL. However, several novel targets to modify RCT have emerged from the recent understanding of HDL synthesis, maturation and catabolism. The four major targets for an anti-atherogenic strategy in HDL metabolism include stimulation of apoA-I synthesis and secretion, the stimulation of ABCA1 expression, the inhibition of cholesterol ester transfer protein, and the up-regulation of scavenger receptor BI. These and other modulations of HDL metabolism are thought to result in improved RCT making them attractive targets for the development of new regimens of anti-atherogenic drug therapy.

Phosphorylation of p70s6 kinase is implicated in androgen-induced levator ani muscle anabolism in castrated rats

Androgens are known to increase muscle mass, strength and muscle protein synthesis. However, the molecular mechanisms by which androgens regulate skeletal muscle development remain poorly understood. The ribosomal protein kinase p70(s6k) is a regulator of ribosome biogenesis and plays an important role in the regulation of growth-related protein synthesis. The phosphorylation of p70(s6k) has been implicated in load-induced skeletal muscle hypertrophy. In the current study, we determined the effect of DHT on the phosphorylation of p70(s6k) in the androgen-sensitive levator ani muscle of castrated rats. DHT induced a rapid increase in the phosphorylation of p70(s6k), which was detectable within 6 h after a single injection. Interestingly, DHT-induced phosphorylation of p70(s6k) occurred only in androgen-sensitive muscles, but not prostate and seminal vesicle. Co-administration of flutamide, an AR antagonist, inhibited DHT-induced p70(s6k) phosphorylation. While serum IGF-I levels were not changed by DHT treatment, IGF-I gene expression levels increased and the mRNA levels of IGFBP3 and IGFBP5 were suppressed in the LA muscle after DHT replacement in castrated rats. These results suggest that the phosphorylation of p70(s6k), likely via the IGF-I pathway, may play an important role in androgen-induced skeletal muscle hypertrophy.

IGF-I mRNA levels in bovine satellite cell cultures: effects of fusion and anabolic steroid treatment

Androgenic and estrogenic steroids enhance muscle growth in a number of species; however, the mechanism by which anabolic steroids enhance muscle growth is not known. Castrated male cattle (steers) provide a particularly good model system in which to study the effects of anabolic steroids on muscle growth because they respond dramatically to treatment with both estrogens and androgens. The goal of this study was to determine if treatment of bovine satellite cell (BSC) cultures with 17beta-estradiol (E(2)) or trenbolone (a synthetic androgen) directly affects proliferation rate or level of mRNA for estrogen receptor (ER)-alpha, androgen receptor, and growth factors that have been shown to affect muscle growth (insulin-like growth factor (IGF)-I, IGF binding protein (IGFBP)-3, and myostatin). BSC cultures were established from the semimembranosus muscles of steers and then treated for 48 h with various concentrations of E(2) or trenbolone ranging from 0.001 to 10 nM. IGF-I mRNA levels in proliferating BSC cultures were significantly increased at 0.01 (1.9-times control values, P < 0.02) and at 0.1, 1, and 10 nM E(2) (2.9-, 3.5-, and 3.5-times control values, respectively, P < 0.0001). Additionally both 1 and 10 nM trenbolone increased IGF-I mRNA levels to 1.7-times control values (P < 0.02). ER-alpha mRNA was detectable in BSC cultures, and levels were increased (2.3-times control levels, P < 0.001) in cultures treated with 0.001 nM E(2) but not in cultures treated with higher concentrations of E(2). Androgen receptor mRNA levels also were increased (1.5-times control levels, P < 0.02) in cultures treated with 0.001 nM trenbolone but not by treatment with higher concentrations of trenbolone. Levels of IGFBP-3 were increased (1.4-times control values, P < 0.02) by treatment with 0.001 nM E(2) but not by treatment with high concentrations of E(2). Myostatin mRNA levels were not affected by any concentration of either of the steroids. Although, levels of IGF-I mRNA were 10-times greater (P < 0.02) in fused BSC cultures than in proliferating cultures, treatment of fused cultures for 48 h with 10 nM E(2) increased IGF-I mRNA levels (2.5-times control levels, P < 0.02). Both E(2) and trenbolone increased (3)H-thymidine incorporation rate (1.5-times control levels, P < 0.001) in BSC cultures in media containing serum from which IGFBP-3 had been removed by anti-IGFBP-3 affinity chromatography. In summary, treatment of BSC cultures with either E(2) or trenbolone increased IGF-I mRNA level and proliferation rate, thus, establishing that these steroids have direct anabolic effects on cells present in the BSC culture.

Restorative increases in serum testosterone levels are significantly correlated to improvements in sexual functioning

It is recognized that testosterone (T) levels decrease in men with age, as does sexual function. We hypothesize that T supplementation in hypogonadal men with sexual dysfunction will restore certain elements of sexual function. Hypogonadal male subjects (total T < or = 300 ng/dL, n = 406, mean age 58 years) reporting one or more symptoms of low testosterone were randomized to T gel (50 mg/d and 100 mg/d), T patch, or placebo. Twenty-four-hour pharmacokinetic profiles for T were obtained. The 3 primary end points evaluated at 30 and 90 days posttreatment included a significant change in the frequency of intercourse and nighttime erections per 7-day week as well as a change in sexual desire measured on a Likert-type scale and calculated as a mean daily score. At day 30, a significant increase from baseline in sexual desire was noted for those on 100 mg/d T gel compared with those on 50 mg/d T gel, T patch, or placebo (1.2 vs 0.4, 0.7, and 0.4, respectively). A significant increase from baseline in the frequency of nighttime erections was also noted for those on 100 mg/d T gel compared with those on 50 mg/d T gel or placebo (51% of subjects in the 100 mg/d T gel group had an increase in frequency vs 30% for the 50 mg/d T gel group and 26% in the placebo group). Finally, a significant increase from baseline in the frequency of intercourse was evidenced for those on 100 mg/d T gel compared with those on T patch or placebo (39% of subjects in the 100 mg/d T gel group had an increase in frequency vs 21% for the T patch group and 24% in the placebo group). Similar results were seen for 100 mg/d T gel at day 90 for sexual desire and nighttime erections vs placebo. These data demonstrate a clear relationship between restoring serum T concentrations and improvement in certain parameters of sexual function. We propose that threshold T levels are needed in order to significantly affect improvements in sexual functioning.

Effects of Testosterone and Resistance Training in Men with Chronic Obstructive Pulmonary Disease

Dysfunction of the muscles of ambulation contributes to exercise intolerance in chronic obstructive pulmonary disease (COPD). Men with COPD have high prevalence of low testosterone levels, which may contribute to muscle weakness. We determined effects of testosterone supplementation (100 mg of testosterone enanthate injected weekly) with or without resistance training (45 minutes three times weekly) on body composition and muscle function in 47 men with COPD (mean FEV(1) = 40% predicted) and low testosterone levels (mean = 320 ng/dl). Subjects were randomized to 10 weeks of placebo injections + no training, testosterone injections + no training, placebo injections + resistance training, or testosterone injections + resistance training. Testosterone injections yielded a mean increase of 271 ng/dl in the nadir serum testosterone concentration (to the middle of the normal range for young men). The lean body mass (by dual-energy X-ray absorptiometry) increase averaged 2.3 kg with testosterone alone and 3.3 kg with combined testosterone and resistance training (p < 0.001). Increase in one-repetition maximum leg press strength averaged 17.2% with testosterone alone, 17.4% with resistance training alone, and 26.8% with testosterone + resistance training (p < 0.001). Interventions were well tolerated with no abnormalities in safety measures. Further studies are required to determine long-term benefits of adding testosterone supplementation and resistance training to rehabilitative programs for carefully screened men with COPD and low testosterone levels.

Testosterone replacement therapy: current trends and future directions

Male hypogonadism is characterized by abnormally low serum testosterone levels associated with typical symptoms, including mood disturbance, sexual dysfunction, decreased muscle mass and strength, and decreased bone mineral density. By restoring serum testosterone levels to the normal range using testosterone replacement therapy, many of these symptoms can be relieved. For many years, injectable testosterone esters or surgically implanted testosterone pellets have been the preferred treatment for male hypogonadism. Recently, newer treatment modalities have been introduced, including transdermal patches and gels. The development of a mucoadhesive sustained-release buccal tablet is the latest innovation, which will provide patients with an additional option. The availability of new treatment modalities has helped to renew interest in the management of male hypogonadism, highlighting the need to address a number of important but previously neglected questions in testosterone replacement therapy. These include the risks and benefits of treatment in different patient populations (e.g. the elderly) and the need for evidence-based diagnosis and treatment monitoring guidelines. While some recommendations have been developed in individual countries, up-to-date, internationally accepted evidence-based guidelines that take into account national differences in clinical practice and healthcare delivery would optimize patient care universally.

Social variables predict between-subject but not day-to-day variation in the testosterone of US men

Previous research has shown lower testosterone (T) levels associated with involvement in committed, romantic relationships ("paired" men) and paternal care in eight studies of North American men. An unanswered question is whether differences in male T levels associated with relationship status better reflect state (e.g., a man has lower T levels because he is involved in a relationship) or trait (e.g., low T men are more inclined toward such relationships) effects. Toward addressing this question, this paper presents data on male salivary T levels among a sample of 65 men varying in marital and parental status. Subjects collected saliva samples (at approximately waking, 17:00 and 21:00 h) and filled out questionnaires concerning their activities on four days. Each subject collected samples in two settings that varied in social interactions: for unmarried men, two working and two non-working days; for married non-fathers, two days spent mostly with their wives and two days spent mostly away from their wives; and for married fathers, two days spent mostly with their young children and two days spent mostly away from their children. Analyses revealed no significant within-subject T differences between these different conditions. However, between-group analyses revealed that married men had lower evening T levels than unmarried men, corroborating existing North American studies of male T and relationship status. These results suggest that day-to-day differences in social interactions may not be associated with differences in T levels, and lend further support to the growing body of evidence that hormone-behavior effect sizes may be greater in the afternoon and evening than in the morning.

Testosterone metabolism and replacement therapy in patients with end-stage renal disease

Hypogonadism is common among men with end-stage renal disease (ESRD), beginning before the need for dialysis and not improved with the initiation of dialysis. Many of the manifestations of hypogonadism, such as bone disease and muscle wasting, are also frequently seen among dialysis patients. There have been few studies of testosterone replacement therapy in this patient population, but available data suggest that testosterone can be administered without adjustment of the doses used in hypogonadal men with normal renal function. Extrapolation from results of treatment of hypogonadal older men with normal renal function suggests that testosterone replacement could improve libido and could have salutary effects on muscle mass and bone mineral density in patients with kidney disease. However, caution is warranted because of the potential side effects of testosterone therapy, and further research is needed to more precisely define the balance of risk and benefit in patients with chronic kidney disease. Specifically it will be important to determine the prevalence and clinical significance of hypogonadism in ESRD patients in the modern era and to measure the effects of replacement therapy on various symptoms of hypogonadism as well as on overall quality of life, physical functioning, and survival.

Macronutrient considerations for the sport of bodybuilding

Participants in the sport of bodybuilding are judged by appearance rather than performance. In this respect, increased muscle size and definition are critical elements of success. The purpose of this review is to evaluate the literature and provide recommendations regarding macronutrient intake during both 'off-season' and 'pre-contest' phases. Body builders attempt to increase muscle mass during the off-season (no competitive events), which may be the great majority of the year. During the off-season, it is advantageous for the bodybuilder to be in positive energy balance so that extra energy is available for muscle anabolism. Additionally, during the off-season, adequate protein must be available to provide amino acids for protein synthesis. For 6-12 weeks prior to competition, body builders attempt to retain muscle mass and reduce body fat to very low levels. During the pre-contest phase, the bodybuilder should be in negative energy balance so that body fat can be oxidised. Furthermore, during the pre-contest phase, protein intake must be adequate to maintain muscle mass. There is evidence that a relatively high protein intake (approximately 30% of energy intake) will reduce lean mass loss relative to a lower protein intake (approximately 15% of energy intake) during energy restriction. The higher protein intake will also provide a relatively large thermic effect that may aid in reducing body fat. In both the off-season and pre-contest phases, adequate dietary carbohydrate should be ingested (55-60% of total energy intake) so that training intensity can be maintained. Excess dietary saturated fat can exacerbate coronary artery disease; however, low-fat diets result in a reduction in circulating testosterone. Thus, we suggest dietary fats comprise 15-20% of the body builders' off-season and pre-contest diets. Consumption of protein/amino acids and carbohydrate immediately before and after training sessions may augment protein synthesis, muscle glycogen resynthesis and reduce protein degradation. The optimal rate of carbohydrate ingested immediately after a training session should be 1.2 g/kg/hour at 30-minute intervals for 4 hours and the carbohydrate should be of high glycaemic index. In summary, the composition of diets for body builders should be 55-60% carbohydrate, 25-30% protein and 15-20% of fat, for both the off-season and pre-contest phases. During the off-season the diet should be slightly hyperenergetic (approximately 15% increase in energy intake) and during the pre-contest phase the diet should be hypoenergetic (approximately 15% decrease in energy intake).

Endocrinological and pathological effects of anabolic-androgenic steroid in male rats

Many athletes use drugs, especially anabolic androgenic steroids (AAS), but there are few reports on the endocrinological and pathological changes in AAS abusers. In this study we reported the results of endocrinological examinations in rats administered AAS and also physical changes. We separated 37 male Wistar rats (7 weeks old) into 3 groups: Group A was medicated with nandrolone decanoate, metenolone acetate, and dromostanolone; Group B with nandrolone decanoate and saline; and Group C was given only saline. They were given subcutaneous injections of the medications or the control vehicle once a week for 6 weeks. Medications were stopped for 4 weeks, and then resumed for another 6 weeks. After that, rats were sacrificed. Serum testosterone level in Group A was significantly higher than that in Group C. Serum dihydrotestosterone in Group A was significantly higher than that in both Groups B and C. Serum estradiol-17beta levels in Groups A and B were significantly higher than that in Group C. In pathological evaluation, heart, testis, and adrenal gland were severely damaged. These findings indicate that there is a high degree of risk related to the use of AAS.

Bicalutamide 150 mg maintains bone mineral density during monotherapy for localized or locally advanced prostate cancer

PURPOSE

We evaluated changes in bone mineral density (BMD), fat-free mass (FFM) and serum lipid levels during bicalutamide 150 mg monotherapy compared with medical castration for 2 years.

MATERIALS AND METHODS

A total of 103 men with localized or locally advanced prostate cancer (T1-T4, Nx, M0) for whom immediate androgen deprivation was indicated were enrolled in this prospective, multicenter, open-label, parallel group study. Patients were randomized to bicalutamide 150 mg once daily (51) or medical castration with a luteinizing hormone releasing hormone analogue (52) for 96 weeks. Primary end points were mean percent change from baseline in lumbar spine BMD, hip BMD and FFM at 96 weeks. Mean changes in lipid parameters with time were also evaluated.

RESULTS

BMD was maintained during bicalutamide 150 mg monotherapy (+2.42% for lumbar spine BMD and +1.13% for hip BMD at week 96), while castration was associated with a progressive loss in BMD (-5.40% and -4.39% at week 96, respectively, both p <0.0001 at week 96). There was no significant difference between bicalutamide 150 mg and castration in mean percent change from baseline in FFM (-1.56% and -3.86%, respectively, at week 96, p = 0.31), although there was a trend for greater progressive loss over time with castration. Mean changes in lipid parameters were small and similar in the 2 groups.

CONCLUSIONS

Bicalutamide 150 mg monotherapy may offer an important advantage compared to castration in terms of bone loss and body composition for patients who require long-term androgen deprivation for localized or locally advanced prostate cancer.

Prevalence of anemia in persons 65 years and older in the United States: evidence for a high rate of unexplained anemia

Clinicians frequently identify anemia in their older patients, but national data on the prevalence and causes of anemia in this population in the United States have been unavailable. Data presented here are from the noninstitutionalized US population assessed in the third National Health and Nutrition Examination Survey (1988-1994). Anemia was defined by World Health Organization criteria; causes of anemia included iron, folate, and B(12) deficiencies, renal insufficiency, anemia of chronic inflammation (ACI), formerly termed anemia of chronic disease, and unexplained anemia (UA). ACI by definition required normal iron stores with low circulating iron (less than 60 microg/dL). After age 50 years, anemia prevalence rates rose rapidly, to a rate greater than 20% at age 85 and older. Overall, 11.0% of men and 10.2% of women 65 years and older were anemic. Of older persons with anemia, evidence of nutrient deficiency was present in one third, ACI or chronic renal disease or both was present in one third, and UA was present in one third. Most occurrences of anemia were mild; 2.8% of women and 1.6% of men had hemoglobin levels lower than 110 g/L (11 g/dL). Therefore, anemia is common, albeit not severe, in the older population, and a substantial proportion of anemia is of indeterminate cause. The impact of anemia on quality of life, recovery from illness, and functional abilities must be further investigated in older persons.

Effects of testosterone on mood, aggression, and sexual behavior in young men: a double-blind, placebo-controlled, cross-over study

The prospects of wider application of testosterone (T) in novel indications such as male contraception have prompted renewed interest in the investigation of nonreproductive actions and safety of androgens. This study investigated potential changes in mood and behavior in response to elevations in circulating T concentrations produced by the new long-acting preparation, T undecanoate (TU). Twenty-eight eugonadal men were randomized into one of two treatment groups: A1) active, receiving 1000 mg TU i.m. followed by A2) washout, followed by A3) placebo, receiving 4 ml castor oil i.m.; B1) placebo, 4 ml castor oil i.m.; B2) washout followed by B3) active, receiving 1000 mg TU i.m.. Mood, self- and partner-reported physical and verbal aggression, anger, hostility, irritability, assertiveness, self-esteem, and sexual function were assessed. A single injection of 1000 mg TU i.m. increased plasma T concentrations from 20.7 +/- 1.5 to 37.5 +/- 2.2 nmol/liter at wk 1 and 31.6 +/- 1.5 nmol/liter at wk 2, and estradiol from 74.0 +/- 4.9 to 120.4 +/- 10.7 pmol/liter at wk 1, and 100.0 +/- 6.3 pmol/liter at wk 2. The T increment was associated with detectable but minor mood changes. Increased circulating T was associated with significant increases in anger-hostility from baseline (mean score = 7.48) to wk 2 (mean score = 10.71) accompanied by an overall reduction in fatigue-inertia (treatment = 6.21 vs. placebo = 7.84). TU treatment did not increase aggressive behavior or induce any changes in nonaggressive or sexual behavior. Changes in estradiol were not associated with any behavioral alterations. Our results suggest that exogenous TU-induced elevation of circulating T, to the range likely to be used in hormonal male contraception, has limited psychological effects. Future research should investigate the implications of these minor mood changes.

Androgen receptor immunoreactivity in skeletal muscle: enrichment at the neuromuscular junction

Potential cellular targets of androgen action within skeletal muscle of the rat were determined by comparing the cellular distribution of androgen receptor (AR)-positive nuclei in the highly androgen-responsive levator ani (LA) muscle with that of the relatively androgen-unresponsive extensor digitorum longus (EDL) muscle. We found that androgen responsiveness correlates with AR expression in muscle fibers and not in fibroblasts. Results indicate that a much higher percentage of myonuclei in the LA are AR(+) than in the EDL (74% vs. 7%), correlating with differences in androgen responsiveness. Both muscles contain an equivalent proportion of AR(+) fibroblasts (approximately 62%). AR(+) nuclei were not observed in terminal Schwann cells in either muscle. These results suggest that ARs within LA muscle fibers mediate the androgen-dependent survival and growth of the LA muscle and its motoneurons. We also observed an unexpected enrichment of AR(+) myonuclei and fibroblasts proximate to neuromuscular junctions, suggesting that ARs at muscle synapses may selectively regulate synapse-specific genes important for the survival and growth of motoneurons. Although castration reduced the proportion of AR(+) fibroblasts in both muscles, the proportion of AR(+) myonuclei was reduced only in the LA. As expected, testosterone treatment prevented these effects of castration but, unexpectedly, increased the proportion of AR(+) myonuclei in the EDL to above normal. These results suggest that how AR expression in skeletal muscle is influenced by androgens depends not only on the particular muscle but on the particular cell type within that muscle.

Association of bioavailable, free, and total testosterone with insulin resistance: influence of sex hormone-binding globulin and body fat

OBJECTIVE

Previous reports of an association between low testosterone levels and diabetes risk were often confounded by covariation of sex hormone-binding globulin (SHBG) and testosterone measurements. Measurements of bioavailable and free testosterone, more reliable indexes of biologically active testosterone, were examined for their associations with markers of insulin resistance and body fat measures in 221 middle-aged nondiabetic men.

RESEARCH DESIGN AND METHODS

Bioavailable and free testosterone were calculated from the concentrations of total testosterone, SHBG, and albumin, and they were not significantly correlated with SHBG (r = 0.07-0.1). In contrast, total testosterone correlated significantly with SHBG (r = 0.63). We evaluated the relationship between these measures of circulating testosterone and markers for insulin resistance (i.e., fasting insulin, C-peptide, and homeostasis model assessment for insulin resistance [HOMA-IR]) as well as total body fat (assessed by dual-energy X-ray absorptiometry [DEXA]) and abdominal fat distribution (assessed by single-slice computed tomography [CT]).

RESULTS

Bioavailable, free, and total testosterone and SHBG all correlated significantly with fasting insulin (age-adjusted r = -0.15 [P = 0.03], -0.14 [P = 0.03], -0.32 [P < 0.0001], and -0.38 [P < 0.0001], respectively), fasting C-peptide (r = -0.18 [P = 0.009] to -0.41 [P < 0.0001]), HOMA-IR (r = -0.15 [P = 0.03] to - 0.39 [P < 0.0001]), and body fat measures (r = -0.17 [P = 0.008] to -0.44 [P < 0.0001]). Only SHBG and total testosterone were significantly associated with fasting glucose (r = -0.20 [P = 0.003] to -0.21 [P = 0.002]). In multivariate analysis, bioavailable or free testosterone was significantly and inversely associated with insulin, C-peptide, and HOMA-IR, but this was not independent of total body or abdominal fat. SHBG was a significant determinant of insulin, C-peptide, and HOMA-IR, independent of body fat. The associations between total testosterone and insulin resistance were confounded by SHBG.

CONCLUSIONS

The inverse association between testosterone and insulin resistance, independent of SHBG, was mediated through body fat.

Male hormonal contraception

Male hormonal contraception, based on the suppression of both gonadotropins, follicle-stimulating hormone and luteinizing hormone, resulting in marked decrease in sperm production, is designed for couples in stable relationships where the male partner desires to assume family planning responsibilities using reversible methods. Two large scale, multicenter studies that used testosterone injections as the prototype male hormonal contraceptive demonstrated when azoospermia and/or very severe oligozoospermia were attained, contraceptive efficacy was equivalent to female hormonal methods. Current studies aim to find the androgen alone or androgen plus progestin preparations that are most efficacious, user friendly, and with least potential adverse effects. It is likely that injections or implants of androgens either alone or with progestins will become the first male hormonal contraceptive available within this decade. Further research and development include the use of selective androgen and/or progestin receptor modulators, nonpeptide GnRH antagonists, and agents with local actions on the testis for male contraception.

Current concepts in anabolic-androgenic steroids

Anabolic-androgenic steroids (AAS) are synthetic derivatives of testosterone. According to surveys and media reports, the legal and illegal use of these drugs is gaining popularity. Testosterone restores sex drive and boosts muscle mass, making it central to 2 of society's rising preoccupations: perfecting the male body and sustaining the male libido. The anabolic effects of AAS have been questioned for decades, but recent scientific investigation of supraphysiologic doses supports the efficacy of these regimens. Testosterone has potent anabolic effects on the musculoskeletal system, including an increase in lean body mass, a dose-related hypertrophy of muscle fibers, and an increase in muscle strength. For athletes requiring speed and strength and men desiring a cosmetic muscle makeover, illegal steroids are a powerful lure, despite the risk of subjective side effects. Recent clinical studies have discovered novel therapeutic uses for physiologic doses of AAS, without any significant adverse effects in the short term. In the wake of important scientific advances during the past decade, the positive and negative effects of AAS warrant reevaluation. Guidelines for the clinical evaluation of AAS users will be presented for sports medicine practitioners.

Low high-density lipoprotein cholesterol: physiological background, clinical importance and drug treatment

Low high-density lipoprotein (HDL) cholesterol is an important risk factor for coronary heart disease (CHD). In vitro, HDL exerts several potentially anti-atherogenic activities. HDLs mediate the reverse cholesterol transport (RCT) from peripheral cells to the liver, inhibit oxidation of low-density lipoprotein (LDL), adhesion of monocytes to the endothelium, apoptosis of vascular endothelial and smooth muscle cells and platelet activation, and stimulate the endothelial secretion of vasoactive substances as well as smooth muscle cell proliferation. Hence, raising HDL-cholesterol levels has become an interesting target for anti-atherosclerotic drug therapy. Levels of HDL cholesterol and the composition of HDL subclasses in plasma are regulated by apolipoproteins, lipolytic enzymes, lipid transfer proteins, receptors and cellular transporters. The interplay of these factors leads to RCT and determines the composition and, thereby, the anti-atherogenic properties of HDL. Several inborn errors of metabolism, as well as genetic animal models, are characterised by both elevated HDL cholesterol and increased rather than decreased cardiovascular risk. These findings suggest that the mechanism of HDL modification rather than simply increasing HDL cholesterol determine the efficacy of anti-atherosclerotic drug therapy. In several controlled and prospective intervention studies, patients with low HDL cholesterol and additional risk factors benefited from treatment with fibric acid derivatives (fibrates) or HMG-CoA reductase inhibitors (statins). However, only in some trials was prevention of coronary events in patients with low HDL cholesterol and hypertriglyceridaemia related to an increase in HDL cholesterol. We discuss the clinical and metabolic effects of fibrates, statins, nicotinic acid and sex steroids, and present novel therapeutic strategies that show promise in modifying HDL metabolism. In conclusion, HDL-cholesterol levels increase only moderately after treatment with currently available drugs and do not necessarily correlate with the functionality of HDL. Therefore, the anti-atherosclerotic therapy of high-risk cardiovascular patients should currently be focused on the correction of other risk factors present besides low HDL cholesterol. However, modification of HDL metabolism and improvement of RCT remain an attractive target for the development of new regimens of anti-atherogenic drug therapy.