Clinical review: Why is androgen replacement in males controversial?

Registry of Hypogonadism in Men (RHYME): design of a multi-national longitudinal, observational registry of exogenous testosterone use in hypogonadal men

OBJECTIVE

Despite the prevalence of hypogonadism (HG) and widespread use of testosterone therapy, little is known about the safety/effectiveness of long-term testosterone use. The Registry of Hypogonadism in Men (RHYME) is a multi-national patient registry assessing prostate health and other outcomes associated with testosterone treatment in men.

DESIGN

Observational patient disease registry.

METHODS

RHYME is a non-interventional disease registry with longitudinal data collection on a large sample (N = 999) of well-characterized, hypogonadal men aged 18 years or older. The Registry will prospectively evaluate male patients diagnosed with HG, who have not previously been treated with testosterone therapy. Key design features include: (1) broad inclusion/exclusion criteria, (2) standardized central laboratory hormone assays, (3) independent adjudication of prostate biopsies and mortalities, (4) standard of care treatment, (5) comprehensive medical record and questionnaire data at six months and annually post-enrollment and (6) adequate statistical power for assessing prostate endpoints at 36 months.

RESULTS

A total of 25 clinical sites in six European countries (Germany, Italy, the Netherlands, Spain, Sweden and the United Kingdom) have completed recruitment for the study. Recruitment was initiated in May 2009, and completed in December 2011. Data collection is ongoing with a minimum of two years of follow-up on all patients.

Age-associated changes in hypothalamic-pituitary-testicular function in middle-aged and older men are modified by weight change and lifestyle factors: longitudinal results from the European Male Ageing Study

OBJECTIVE

Health and lifestyle factors are associated with variations in serum testosterone levels in ageing men. However, it remains unclear how age-related changes in testosterone may be attenuated by lifestyle modifications. The objective was to investigate the longitudinal relationships between changes in health and lifestyle factors with changes in hormones of the reproductive endocrine axis in ageing men.

DESIGN

A longitudinal survey of 2736 community-dwelling men aged 40-79 years at baseline recruited from eight centres across Europe. Follow-up assessment occurred mean (±S.D.) 4.4±0.3 years later.

RESULTS

Paired testosterone results were available for 2395 men. Mean (±S.D.) annualised hormone changes were as follows: testosterone -0.1±0.95  nmol/l; free testosterone (FT) -3.83±16.8  pmol/l; sex hormone-binding globulin (SHBG) 0.56±2.5  nmol/l and LH 0.08±0.57  U/l. Weight loss was associated with a proportional increase, and weight gain a proportional decrease, in testosterone and SHBG. FT showed a curvilinear relationship to weight change; only those who gained or lost ≥15% of weight showed a significant change (in the same direction as testosterone). Smoking cessation was associated with a greater decline in testosterone than being a non-smoker, which was unrelated to weight change. Changes in number of comorbid conditions or physical activity were not associated with significant alterations in hypothalamic-pituitary-testicular (HPT) axis function.

CONCLUSIONS

Body weight and lifestyle factors influence HPT axis function in ageing. Weight loss was associated with a rise, and weight gain a fall, in testosterone, FT and SHBG. Weight management appears to be important in maintaining circulating testosterone in ageing men, and obesity-associated changes in HPT axis hormones are reversible following weight reduction.

Reference ranges and determinants of testosterone, dihydrotestosterone, and estradiol levels measured using liquid chromatography-tandem mass spectrometry in a population-based cohort of older men

CONTEXT

Testosterone (T) levels decline with increasing age. Controversy exists over the threshold for classifying T as low vs. normal in older men. The relevance of assessing dihydrotestosterone (DHT) and estradiol (E2) remains unclear.

OBJECTIVE

We assessed the associations of T, DHT, and E2 in men aged 70 yr or older and established reference ranges for these in healthy older men.

PARTICIPANTS

Community-dwelling men aged 70-89 yr residing in Perth, Western Australia, Australia, participated in the study.

MAIN OUTCOME MEASURES

Plasma T, DHT, and E2 were assayed using liquid chromatography-tandem mass spectrometry in early morning samples from 3690 men.

RESULTS

Increasing age, higher body mass index and waist to hip ratio, dyslipidemia, diabetes, and higher LH were independently associated with lower levels of T and DHT. Increasing age, diabetes, and higher LH were associated with lower E2. In a reference group of 394 men aged 76.1 ± 3.2 yr reporting excellent or very good health with no history of smoking, diabetes, cardiovascular disease, cancer, depression, or dementia, the 2.5th percentile for T was 6.4 nmol/liter (184 ng/dl); DHT, 0.49 nmol/liter; and E2, 28 pmol/liter. Applying these cutoffs to all 3690 men, those with low T or DHT had an increased odds ratio for frailty, diabetes, and cardiovascular disease. Men with both low T and DHT had a higher odds ratio for these outcomes.

CONCLUSIONS

The 2.5th percentile in a reference group of healthy older men provides age-appropriate thresholds for defining low T, DHT, and E2. Additional studies are needed to test their potential applicability and clinical utility in older men.

Do low testosterone levels contribute to ill-health during male ageing?

Testosterone regulates male sexual development and body composition. In adult men, testosterone levels exhibit a gradual decline with increasing age. Whether it is age per se or health and behaviour related factors that are responsible for this decline, and the implications thereof for subsequent health remain controversial. Observational studies report associations of lower testosterone levels with poorer health outcomes in ageing men, including frailty, reduced sexual activity, insulin resistance and cardiovascular events and mortality. However, outcome data from randomised clinical trials of testosterone are limited, and are lacking for major endpoints such as cardiovascular events. The risks and benefits of testosterone intervention in older men require further clarification. This article will review the role of testosterone in men, discuss epidemiological and interventional data illuminating its potential role to preserve health during male ageing, consider the limitations of the evidence base and implications for clinical practice, and explore future directions for research in this topical area.

Hormones and health outcomes in aging men

Increasing age is a predictor of ill-health and mortality related to cardiovascular disease and to frailty, a syndrome characterized by deterioration of multiple organ systems leading to loss of physiological reserve, diminished capacity to cope with stressors, and increased risk of disability and death. As men grow older, their levels of testosterone decline while the prevalence of ill-health increases. Observational studies have linked lower testosterone levels with cardiovascular disease and mortality in middle-aged and older men. More recently, lower testosterone has been shown to predict reduced sexual activity and frailty in aging men. Additional studies are needed to determine whether lower testosterone is a biomarker or a potentially treatable risk factor for poorer health outcomes in older men. During aging, the response of the pituitary-thyroid axis alters to manifest higher thyrotropin levels. The presences of subclinical hypo- and hyper-thyroidism predict adverse cardiovascular outcomes. Newer results indicate that in euthyroid older men, differences in free thyroxine levels within the normal range predict specific health outcomes including frailty. Clarification of the roles of endogenous testosterone and thyroxine in the genesis of ill-health during male aging offers the prospect of future intervention to preserve health and well-being in this growing population.

Risques prostatiques de la testostérone : nouveau retour du balancier?

Depuis les années 1940, la testostérone (T) est réputée dangereuse pour la prostate, bien que sans preuve solide. Les études longitudinales ne montrent pas de corrélation entre taux de T et incidence des cancers de la prostate (CaP), dont les formes graves sont au contraire associées à des taux faibles de cette hormone. Les essais cliniques randomisés contre placebo de traitement par la T n’ont pas montré d’augmentation de l’incidence du CaP dans les groupes T. Ces données rassurantes ont conduit certains à prescrire des traitements de substitution androgénique à des hommes porteurs de néoplasies intra-épithéliales prostatiques, ou précédemment traités pour un CaP de bon pronostic, ou sous surveillance active pour un tel cancer non traité, sans qu’apparaisse un risque élevé de progression ou de récidive du CaP sous ce traitement. Il ne fait pourtant aucun doute que la prostate normale et son cancer, au moins dans ses formes évoluées, sont faits de tissus androgénodépendants. Ces apparentes contradictions pourraient s’expliquer, outre par la possibilité d’une très faible diffusion de la T circulante dans le tissu prostatique, par l’hypothèse d’une saturation des récepteurs androgéniques prostatiques dès des niveaux très bas de T circulante, proches des taux de castration, expliquant qu’une augmentation de la T au-delà de ce niveau ne puisse pas stimuler le tissu prostatique. Quelques publications récentes d’évolution de CaP sous traitement androgénique, persistant parfois à l’arrêt de ce traitement, montrent qu’on ne peut pas généraliser les résultats très favorables des études précédentes. Des données objectives suggèrent aussi que le niveau de saturation du récepteur androgénique prostatique pourrait être en réalité proche de la limite inférieure des taux physiologiques de T. Il faut donc rester prudent avant d’élargir les indications du traitement par la T chez les hommes avec antécédent de CaP. Seules des études randomisées à grande échelle, en double insu contre placebo, permettront de se faire une idée exacte des risques auxquels expose ce traitement.

Approach to the male patient with congenital hypogonadotropic hypogonadism

The term "congenital hypogonadotropic hypogonadism" (CHH) refers to a group of disorders featuring complete or partial pubertal failure due to insufficient secretion of the pituitary gonadotropins LH and FSH. Many boys (or their parents) will seek medical consultation because of partial or absent virilization after 14 yr of age. Small testes are very frequent, but height is generally normal. Laboratory diagnosis of hypogonadotropic hypogonadism is relatively simple, with very low circulating total testosterone and low to low-normal gonadotropin and inhibin B levels. This hormone profile rules out a primary testicular disorder. Before diagnosing CHH, however, it is necessary to rule out a pituitary tumor or pituitary infiltration by imaging studies, juvenile hemochromatosis, and a systemic disorder that, by undermining nutritional status, could affect gonadotropin secretion and pubertal development. Anterior pituitary function must be thoroughly investigated to rule out a more complex endocrine disorder with multiple hormone deficiencies and thus to conclude that the hypogonadotropic hypogonadism is isolated. The most likely differential diagnosis before age 18 yr is constitutional delay of puberty. Apart from non-Kallmann syndromic forms, which are often diagnosed during childhood, the two main forms of CHH seen by endocrinologists are Kallmann syndrome, in which CHH is associated with impaired sense of smell, and isolated CHH with normal olfaction. Anosmia can be easily diagnosed by questioning the patient, whereas olfactometry is necessary to determine reliably whether olfaction is normal or partially defective. This step is important before embarking on a search for genetic mutations, which will also be useful for genetic counseling. The choice of a particular hormone replacement therapy protocol aimed at virilizing the patient will depend on age at diagnosis and local practices.

Concerns about serum androgens monitoring during testosterone replacement treatments in hypogonadal male athletes: a pilot study

INTRODUCTION

A well-tailored testosterone replacement treatment (TRT) in male hypogonadal athletes plays a pivotal role to restore physiological performances, to reduce health risks, and to guarantee the ethic of competition. Few studies evaluated individual androgens profiles during TRT in trained individuals.

AIM

The aim of this article was to verify the efficacy in restoring eugonadal serum and urinary androgens profiles after testosterone enanthate (TE) and gel (TG) administration.

METHODS

Ten male Caucasian-trained volunteers affected by severe hypotestosteronemia (<8 nmol/L) were included. Serum androgens and urinary testosterone metabolites were evaluated, in the same subjects, before and weekly for 5 weeks after both a single intramuscular TE injection (250 mg) and during a daily administration of TG (50 mg/die of testosterone), respectively.

MAIN OUTCOME MEASURES

The main outcome measures of this article were serum total testosterone (TT), dihydrotestosterone (DHT), calculated free and bioavailable testosterone (cFT, cBioT), 17-β-estradiol, and urinary glucuronide testosterone metabolites.

RESULTS

Supraphysiological TT concentrations were observed in 50% of our volunteers until 7 days after TE and in the 4% of total samples after TG. Serum DHT was high both after TE (all volunteers on day 7 and 50% on day 14) and during TG (32% of total samples). A relatively low number of samples showed normal cFT and cBioT both after TE and TG (20-44%, respectively). Urinary metabolites were related to the type of treatment and to serum androgens profile and resulted in the normal ranges from 15% to 60% of total samples.

CONCLUSION

Besides well-known variations of mean serum TT, we showed a high percentage of serum and urinary samples with abnormal androgens, being TG safer than TE. We conclude that monitoring TRT with TT only may be inaccurate because of abnormal fluctuations of other circulating androgens. Further studies to identify the appropriate markers of eugonadism during TRT are highly warranted both in athletes and in non-athletes.

Association of Testosterone Levels With Endothelial Function in Men

Objective—

Because population-based data are lacking, we assessed the cross-sectional association between serum testosterone levels and endothelial function, as measured by flow-mediated dilation (FMD) and nitroglycerin-mediated dilation (NMD) of the brachial artery, in men from the population-based Study of Health in Pomerania.

Methods and Results—

Personal characteristics, including major cardiovascular confounders, were collected in 722 men, aged 25 to 85 years. Serum total testosterone and sexual hormone-binding globulin (SHBG) levels were determined by chemiluminescence immunoassays. Free testosterone levels were calculated according to the law of mass action. FMD and NMD measurements were performed using standardized ultrasound techniques. FMD and NMD values below the 20th percentile were considered decreased. Multivariable logistic regression analyses revealed an association for each decrement of total testosterone standard deviation (6.0 nmol/L) with decreased FMD after adjustment for potential confounders (odds ratio 1.30, 95% confidence interval 1.04–1.63; P =0.023). Multiple adjusted findings for free testosterone were similar (odds ratio 1.37, 95% confidence interval 1.06–1.76; P =0.016). There was no such association of SHBG levels with decreased FMD. Neither testosterone nor SHBG levels were significantly associated with decreased NMD.

Conclusion—

Lower serum total and free testosterone levels are associated with impaired endothelial function in this population-based sample of men.

Diagnosis and treatment of sexual dysfunctions in late-onset hypogonadism

Testosterone is the principal androgen in the human male. The decline of testosterone with aging was recognized to be associated with a number of symptoms and signs that reduce the quality of life and that may even have severe, debilitating consequences. Clinically, late-onset hypogonadism (LOH) is diagnosed by use of biochemical and clinical measures. Despite published guidelines and recommendations, however, uncertainty surrounds the profile of clinical symptoms as well as the biochemical threshold of diagnosis. Clinicians should be aware of these shortcomings while adhering to the guidelines. Current treatment methods are centered on restoring testosterone to mid to lower levels of young men with natural testosterone replacements. Although recent studies have highlighted possible additional benefits involving improvement of systemic disorders, the goal of treatment is to improve sexual function, while observing for adverse effects in the prostate. Overall, the problem of LOH in debilitating the quality of life and well-being is real, and by following proper guidelines with attentiveness to the results of treatment trials, testosterone replacement therapy presents a safe and effective treatment option.

Onset of effects of testosterone treatment and time span until maximum effects are achieved

OBJECTIVE

Testosterone has a spectrum of effects on the male organism. This review attempts to determine, from published studies, the time-course of the effects induced by testosterone replacement therapy from their first manifestation until maximum effects are attained.

DESIGN

Literature data on testosterone replacement.

RESULTS

Effects on sexual interest appear after 3 weeks plateauing at 6 weeks, with no further increments expected beyond. Changes in erections/ejaculations may require up to 6 months. Effects on quality of life manifest within 3-4 weeks, but maximum benefits take longer. Effects on depressive mood become detectable after 3-6 weeks with a maximum after 18-30 weeks. Effects on erythropoiesis are evident at 3 months, peaking at 9-12 months. Prostate-specific antigen and volume rise, marginally, plateauing at 12 months; further increase should be related to aging rather than therapy. Effects on lipids appear after 4 weeks, maximal after 6-12 months. Insulin sensitivity may improve within few days, but effects on glycemic control become evident only after 3-12 months. Changes in fat mass, lean body mass, and muscle strength occur within 12-16 weeks, stabilize at 6-12 months, but can marginally continue over years. Effects on inflammation occur within 3-12 weeks. Effects on bone are detectable already after 6 months while continuing at least for 3 years.

CONCLUSION

The time-course of the spectrum of effects of testosterone shows considerable variation, probably related to pharmacodynamics of the testosterone preparation. Genomic and non-genomic effects, androgen receptor polymorphism and intracellular steroid metabolism further contribute to such diversity.

Neonatal gonadotropin therapy in male congenital hypogonadotropic hypogonadism

Congenital hypogonadotropic hypogonadism (CHH) causes pubertal failure and infertility in both women and men due to partial or total secretory failure of the two pituitary gonadotropins lutropin (LH) and follitropin (FSH) during periods of physiological activation of the gonadotropic axis. Men and women with CHH frequently seek treatment for infertility after hypogonadism therapy. Some etiologies, such as autosomal dominant or X-linked Kallmann syndrome, raise the question of hereditary transmission, leading to increasing demands for genetic counseling and monitoring of medically assisted pregnancies. Diagnosis and treatment of newborn boys is, therefore, becoming an increasingly important issue. In male individuals with complete forms of CHH, the antenatal and neonatal gonadotropin deficit leads to formation of a micropenis and cryptorchidism, which could undermine future sexual and reproductive functions. Standard treatments, usually started after the age of puberty, often only partially correct the genital abnormalities and spermatogenesis. The aim of this Review is to examine the possible additional benefits of neonatal gonadotropin therapy in male patients with CHH. Encouraging results of neonatal therapy, together with a few reports of prepubertal treatment, support the use of this novel therapeutic strategy aimed at improving sexual and reproductive functions in adulthood.

Male late-onset hypogonadism: pathogenesis, diagnosis and treatment

Some aging men develop a condition of suppressed serum testosterone levels, which is associated with diffuse sexual, physical and psychological symptoms. Several terms are used for this syndrome, but late-onset hypogonadism (LOH) is preferred. The diagnosis of LOH is often uncertain because symptoms (occurring in 20-40% of men) and low circulating testosterone (found in 20% of men >70 years of age) seldom occur together. The strict diagnostic criteria for LOH include reproducibly low serum testosterone levels and sexual symptoms, including erectile dysfunction and reduced frequency of sexual thoughts and morning erections. Using these diagnostic criteria, only 2% of 40-80-year-old men have LOH. Obesity and impaired general health (including diabetes mellitus, cardiovascular and chronic obstructive pulmonary disease, and frailty) are more common reasons for low testosterone than advanced age per se. It seems logical, therefore, to begin by treating these conditions before testosterone replacement therapy is initiated. Even then, testosterone should only be used if there are no contraindications, such as unstable cardiac disease, serious prostate symptoms and high hemoglobin level. The long-term benefit of testosterone replacement therapy is uncertain, and the experimental nature of the treatment, and its associated risks, must be fully explained to the patient before treatment begins.