Déficit Androgénique Lié à l’Age

In contrast with the abrupt cessation of ovarian function at menopause in women, alteration of testicular functions in aging males is partial and progressive. Several cross-sectional studies have demonstrated an age-related decrease of testosterone levels in men. This decrease has also been observed when only men in good health are included in such studies. This age-related decline of testosterone levels has been recently confirmed by a longitudinal study including a large number of subjects. The progressive decline begins early, from the late thirties, and continues at a constant rate throughout the subject’s lifetime. Since SHBG increases with age, free testosterone and non-SHBG-bound testosterone (referred to as bioavailable testosterone) decrease more markedly than total testosterone. As variations of SHBG levels (mainly a decrease in obese and/or insulin-resistant subjects) are often encountered in clinical practice and as it is difficult to reliably measure free testosterone, bioavailable testosterone appears to be the better index to diagnose androgen deficiency in the aging male. Elevation of basal LH levels, decrease of hCG-induced testosterone levels and reduction of Leydig cell number demonstrate the testicular origin of hypogonadism. However, gonadotropic function is also relatively altered with aging. As a result of this alteration of gonadotropic function, LH level is not a reliable index of hypogonadism in the aging male. None of the androgen-dependent functions that are altered with aging, i.e. libido, erectile function, sense of well-being, muscle mass, muscle strength, fat mass, bone mass, etc., are exclusively controlled by androgens. In clinical practice, the indication for androgen replacement therapy must therefore be based on a combination of clinical symptoms and a reduction of bioavailable testosterone below a certain cut-off value, indicating “significant” hypogonadism.     

Skeletal muscle and bone: effect of sex steroids and aging

Both estrogen and testosterone are present in males and females. Both hormones contribute to the well being of skeletal muscle and bone in men and women, and there is evidence that the loss of sex hormones is associated with the age-related decline in bone and skeletal muscle mass. Hormonal supplementation of older adults to restore estrogen and testosterone levels to those of young men and women is not without penalty.     

Déficit androgénique lié à l’âge. Que faut-il attendre de l’androgénothérapie?

With the exception of disease or drug-induced changes in Leydig cell function, aging is accompanied by specific changes of androgen status in healthy men. The level of testosterone production decreases in contrast with the rise in plasma protein testosterone binding capacity. Free testosterone, considered to be the biologically active fraction, decreases, leading to tissue androgen deficiency. The resulting clinical picture mimics hypogonadism, including physical and psychological asthenia, decreased libido and sexual behaviour, increased fat mass and decreased lean mass, gynaecomastia, osteoporosis and pro-atherogenic metabolic changes. The cut-off value for plasma testosterone below which androgen deficiency can be considered to be responsible for clinical signs is a key point which determines the therapeutic approach. In the absence of clearly validated data in healthy aging males, this cut-off value has been consensually defined as the mean plasma testosterone levels of men between 30 and 50 years of age minus two standard deviations, corresponding to the zone of hypogonadism in adult males. The association of clinical signs compatible with hypogonadism and reduced total (or preferably bioavailable) plasma testosterone level justifies initiation of hormone replacement therapy after excluding any contraindications (especially prostatic). The aim of this treatment is to reverse the consequences of age-related hypogonadism. Some benefits of this treatment have been clearly demonstrated, such as a decrease of fat mass, and an increase of lean mass and muscle strength. Similarly, bone mineral density increases, particularly in men with the lowest pretreatment plasma testosterone levels. It must be stressed that these changes are observed in truly hypogonadal aging men, but not in aging men with normal plasma testosterone levels. Testosterone replacement therapy can promote the development of gynaecomastia, while dihydrotestosterone tends to reduce gynaecomastia. Finally, androgen replacement therapy appears to improve a hypogonadism-related decrease in libido or sexual behaviour, provided other associated non-endocrine factors have been previously treated. Androgen replacement therapy improves well-being, and physical and psychological asthenia in hypogonadal men. However, this treatment has not been demonstrated to be effective in healthy aging men. Although androgen replacement therapy does not have a negative impact on lipid parameters, its possible cardiovascular protective effects have not yet been demonstrated. In conclusion, androgen replacement therapy, respecting the contraindications, is beneficial in patients of all ages with clearly demonstrated hypogonadism, but has no efficacy on symptoms in other cases.     

Endogenous estradiol and testosterone levels are associated with cognitive performance in older women and men

Relatively few studies have investigated the relationship between endogenous sex steroid levels and cognition in older people and the reported results have been inconsistent. A number of experimental hormone replacement studies have suggested that estrogen replacement in older women enhances cognition, especially verbal memory. In contrast, little research has been done focusing on men. In the current study the association between endogenous sex steroids (estradiol and testosterone) and cognition was investigated in 38 healthy older women (mean age 68 years) and 30 healthy older men (mean age 69 years). Five cognitive tests measuring verbal memory, spatial memory, verbal fluency, mental rotation, and susceptibility to interference were administered. Results revealed that in women higher estradiol levels as well as testosterone levels were associated with better verbal memory (paired associates and estradiol; r =.38, P < 0.05; paired associates and testosterone; r =.33, P < 0.05;). Moreover estradiol, but not testosterone was associated with less susceptibility to interference (Stroop color word test; r = -0.34, P < 0.05). In men the only significant association was a negative correlation between testosterone and verbal fluency (r = -0.38, P < 0.05). The associations observed in this small study support the notion that estradiol is protecting verbal memory and possibly also frontal lobe mediated functions in older women. In contrast to the positive findings in women endogenous sex steroids do not appear to be closely linked to better cognition in older men.     

Andropause or Male Menopause? Rationale for Testosterone Replacement Therapy in Older Men with Low Testosterone Levels

ObjectiveTo provide rationale for testosterone replacement therapy (TRT) in older men with low testosterone levels and symptoms consistent with testosterone deficiency.MethodsThe relevant literature was reviewed using PubMedResultsCross-sectional and longitudinal population-based studies indicate that total and free testosterone levels fall with aging, and they may be accompanied by symptoms consistent with androgen deficiency. Testosterone treatment of younger men with very low testosterone levels and hypothalamic, pituitary, or testicular disease is associated with improvements in symptoms, body composition, bone density, and hematocrit/hemoglobin. Studies evaluating testosterone treatment of older men with low testosterone levels are limited, but they suggest some increase in fat free mass, some decrease in fat mass, and some increase in bone density of the lumbar spine and femoral neck.ConclusionThe Testosterone Trial should provide definitive information regarding the potential benefits of TRT in men ≥ years of age. If efficacy is confirmed, we will still need more information regarding the risks of TRT in older men. (Endocr Pract. 2013;19:847-852)     

Le déficit androgénique lié à l’âge: du diagnostic biologique au traitement substitutif

There is increasing interest in the assessment of testicular function in aging men, probably because of an increasing number of males above 60 years and because of the emerging gap in the medical management of aging between men and women. In the last three decades, the endocrinological problems of menopause have been thoroughly taken into consideration, while the decline in testis activity in the so called andropause was only recently recognized to deserve a similar interest. In fact, testis endocrine function is not so easy to evaluate in elderly men: total testosterone (tT) level declines very slowly and it is a fallacious index of testis function because of the increase in testosterone/estradiol binding globulin (TeBG) levels in aging males. Free testosterone level is an accurate index when measured by reference techniques, while routine direct assays using testosterone analogues have been proven to be unreliable diagnostic tools. The measurement of bioavailable testosterone (bT) after ammonium sulfate precipitation of TeBG-bound testosterone is currently considered as the method of choice for diagnosing ADAM syndrome. Indeed, in aging males, bT levels are more closely correlated than tT with bone mineral density, muscle strength and muscle mass. Bioavailable estradiol is also a reliable index of testis aging in elderly males and is strongly correlated with bone mineral density. Unfortunately a serious expertise is needed for accurate measurement of bioavailable estradiol levels. Another difficulty in the diagnosis of ADAM syndrome in the uncertainty in the bT threshold to be taken into account. The 5th percentile of bT levels in young adult men can be arbitrarily choosen; however, there is no definite proof that such a threshold is totally appropriate, since no data are available regarding the evolution with years of androgen receptor sensitivity. Nevertheless, identifying androgen deficiency by means of bT measurement may lead to hormone replacement therapy, at least as a therapeutic test. Several formulations of testosterone are currently available using oral, intra-muscular and transdermal routes. Testosterone undecanoate (Pantestone®) is given orally and is supposed to reach the blood stream via the lymph thoracic channel. Intra-muscular testosterone in oil (Androtardyl® and Testosterone Heptylate®) can maintain high testosterone levels for two to three weeks, but can also induce supra-physiological levels of testosterone and dihydrotestosterone (DHT) within the first week after injection. Transdermal formulations have been recently proposed as non-invasive ways to administer testosterone while by-passing liver metabolism. Permeation enhanced transdermal system (Androderm®) can mimic the testosterone circadian rythm, but testosterone levels may be supra-physiological for several hours. DHT levels however are generally maintained whithin physiological values. Testosterone gel (Androgel®) can induce stable and physiological levels of testosterone, DHT and estradiol. Care should be taken to avoid contamination of the familial environment by testosterone after its application. The choice between these formulations depends obviously on the patient’s needs, the patient’s requests, and the patient’s compliance with a particular formulation.     

The evolution of sexually selected traits and antagonistic androgen expression in actinopterygiian fishes

Many sexually selected traits in male fishes are controlled by testosterone. Directional selection for male ornaments could theoretically increase male testosterone levels over evolutionary timescales, and when genetically correlated, female testosterone levels as well. Because of the negative fitness consequences of high testosterone, it is plausible that female choice for sexually selected traits in males results in decreased female reproductive fitness. I used comparative analysis to examine the association between male peak testosterone expression and sexually selected ornaments. I also tested for genetic correlation between male and female androgen levels. The presence of sexually selected traits in males was significantly correlated with increased peak androgen levels in males as well as females, and female testosterone levels were significantly correlated with male peak testosterone titers, although the slope was only marginally <1. This suggests that selection to decouple high male and female testosterone levels is either weak or otherwise ineffective.     

Identification of serum biomarkers for aging and anabolic response

Objective

With the progressive aging of the human population, there is an inexorable decline in muscle mass, strength and function. Anabolic supplementation with testosterone has been shown to effectively restore muscle mass in both young and elderly men. In this study, we were interested in identifying serum factors that change with age in two distinct age groups of healthy men, and whether these factors were affected by testosterone supplementation.

Methods

We measured the protein levels of a number of serum biomarkers using a combination of banked serum samples from older men (60 to 75 years) and younger men (ages 18 to 35), as well as new serum specimens obtained through collaboration. We compared baseline levels of all biomarkers between young and older men. In addition, we evaluated potential changes in these biomarker levels in association with testosterone dose (low dose defined as 125 mg per week or below compared to high dose defined as 300 mg per week or above) in our banked specimens.

Results

We identified nine serum biomarkers that differed between the young and older subjects. These age-associated biomarkers included: insulin-like growth factor (IGF1), N-terminal propeptide of type III collagen (PIIINP), monokine induced by gamma interferon (MIG), epithelial-derived neutrophil-activating peptide 78 (ENA78), interleukin 7 (IL-7), p40 subunit of interleukin 12 (IL-12p40), macrophage inflammatory protein 1β (MIP-1β), platelet derived growth factor β (PDGFβ) and interferon-inducible protein 10 (IP-10). We further observed testosterone dose-associated changes in some but not all age related markers: IGF1, PIIINP, leptin, MIG and ENA78. Gains in lean mass were confirmed by dual energy X-ray absorptiometry (DEXA).

Conclusions

Results from this study suggest that there are potential phenotypic biomarkers in serum that can be associated with healthy aging and that some but not all of these biomarkers reflect gains in muscle mass upon testosterone administration.     

L'andropause

In men, aging is associated with progressive impairment of testicular function. Decrease in total testosterone levels with aging has been reported in many studies in normal healthy men. This decrease has a primarily testicular origin, as shown by decreased number of Leydig cells in histological studies, increased basal gonadotropin levels and decreased response to hCG. A greater decrease in bioavailable testosterone rather in than total testosterone concentrations is explained by the age-dependent increase in the SHBG concentration. Although immunoreactive gonadotropin levels are higher than in young men, a relative alteration of bioactive gonadotropin secretion by the pituitatry occurs in ederly men. Althought the definitive demonstration of an alteration of GnRH secretion by the hypothalamus cannot be established in healthy ederly men, such an alteration might be responsible for a decompensation of the testicular function in case of intercurrent illness. Increased FSH and decreased inhibin plasma levels are indicating a similar alteration in seminiferous tubules as directly demonstrated by histological data showing a decrease of Sertoli cell number and daily sperm production with aging. Although the incidence of sexual dysfunction increases with aging, the relationship between sexual behaviour and testicular endocrine function remained a mater of controversy. A threshold of testosterone action on sexual behavior might be responsible for the difficulty in establishing this relationship. Although some controled studies are available, the risk-to-benefit balance of androgen substitution in older male remained a controversial issue. A positive effect on sense of well-being and/or libido has been and the lack of adverse effect on lipid and carbohydrate metabolism had been demonstrated in short term studies, however, the role of androgens in the benign hypertrophy of the prostate and in stimulating the growth of latent prostate adenocarcinoma remained to be more clearly established by longterm controlled studies.     

Increased adiposity in DNA binding-dependent androgen receptor knockout male mice associated with decreased voluntary activity and not insulin resistance

In men, as testosterone levels decrease, fat mass increases and muscle mass decreases. Increased fat mass in men, in particular central obesity, is a major risk factor for type 2 diabetes, cardiovascular disease, and all-cause mortality. Testosterone treatment has been shown to decrease fat mass and increase fat-free mass. We hypothesize that androgens act directly via the DNA binding-dependent actions of the androgen receptor (AR) to regulate genes controlling fat mass and metabolism. The aim of this study was to determine the effect of a global DNA binding-dependent (DBD) AR knockout (DBD-ARKO) on the metabolic phenotype in male mice by measuring body mass, fat mass, food intake, voluntary physical activity, resting energy expenditure, substrate oxidation rates, serum glucose, insulin, lipid, and hormone levels, and metabolic gene expression levels and second messenger protein levels. DBD-ARKO males have increased adiposity despite a decreased total body mass compared with wild-type (WT) males. DBD-ARKO males showed reduced voluntary activity, decreased food intake, increased serum leptin and adiponectin levels, an altered lipid metabolism gene profile, and increased phosphorylated CREB levels compared with WT males. This study demonstrates that androgens acting via the DNA binding-dependent actions of the AR regulate fat mass and metabolism in males and that the increased adiposity in DBD-ARKO male mice is associated with decreased voluntary activity, hyperleptinemia and hyperadiponectinemia and not with insulin resistance, increased food intake, or decreased resting energy expenditure.     

Effects of age on testosterone responses to resistance exercise and musculoskeletal variables in men

This study compared serum total testosterone (TT) and free testosterone (FT) responses of young (20-26 years, n = 8), middle-aged (38-53 years, n = 7), and older (59-72 years, n = 9) men to resistance exercise. We also examined the relationships between testosterone (T) levels and strength, bone mineral density (BMD), and body composition variables for each age group. Subjects were tested for isotonic muscular strength (1 repetition maximum [1RM]), BMD (dual-energy x-ray absorptiometry [DXA]) and body composition (DXA). Each group performed an acute exercise protocol (3 sets, 10 repetitions, 80% of 1RM, 6 exercises). Blood samples were obtained at baseline, immediately postexercise, and 15 minutes postexercise for the TT and FT assays. The older age group had significantly (p < 0.05) lower T levels than the young group, but each group exhibited an increase (p < 0.05) in TT and FT immediately postexercise. Total T and FT were significantly correlated (p < 0.05) with strength in middle-aged and older men and with bone-free lean tissue mass in older men. In conclusion, middle-aged and older men showed similar relative T responses to those of younger men to a single bout of high-intensity resistance exercise. However, T levels were related to strength and muscle mass only in middle-aged or older men. On a practical application level, older men can complete a high-intensity resistance exercise program resulting in spikes in T that may attenuate age-related muscle and BMD loss.     

Fundamental aspects of hypogonadism in the aging male

With aging in men, serum testosterone levels decline progressively and the prevalence of hypogonadism increases; these changes are associated with alterations in androgen-regulated physiological functions. In young hypogonadal men, similar alterations improve with testosterone replacement. In older men, short-term testosterone treatment trials suggest benefits (eg, on body composition and bone mineral density), without significant adverse effects. Therefore, androgen deficiency may contribute to physiological decline with aging, and testosterone therapy is reasonable for older men with clinical manifestations of androgen deficiency and low testosterone levels. However, the long-term benefits and potential risks (eg, for prostate disease) of testosterone treatment in older men are unknown.     

Effects of testosterone and corticosterone on immunocompetence in the zebra finch

The original immunocompetence handicap hypothesis (ICHH) suggested that testosterone has a handicapping effect in males by both promoting the development of sexual signals and suppressing immune function. A modified version, the stress-linked ICHH, has recently proposed that testosterone is immunosuppressive indirectly by increasing production of corticosterone. To test both the original and stress-mediated versions of the ICHH, we implanted male zebra finches taken from lines selected for divergent maximum stress-induced levels of corticosterone (high, low and control) with either empty or testosterone-filled implants. Their humoral and cell-mediated immune responses were then assessed by challenge with diphtheria:tetanus vaccine and phytohemagglutinin respectively. We found no effect of the hormone manipulations on either PHA or tetanus antibody responses, but found a significant interaction between titers of both testosterone and corticosterone on diphtheria secondary antibody response; antibody response was greatest in individuals with high levels of both hormones. There was also a significant interactive effect between testosterone treatment group and corticosterone titer on body mass; the body mass of males in the elevated testosterone treatment group decreased with increasing corticosterone titer. These results suggest that, contrary to the assumption of the stress-mediated version of the ICHH, high plasma levels of corticosterone are not immunosuppressive, but are in fact immuno-enhancing in the presence of high levels of plasma testosterone. Equally, the central assumption of the ICHH that testosterone is obligately immunosuppressive is also not supported. The same individuals with the highest levels of both hormones and consequently the most robust antibody response also possessed the lowest body mass.     

Long-term effects of testim(r) 1% testosterone gel in hypogonadal men

A new transdermal preparation, Testim(R) 1% testosterone gel, has recently become available for normalization of serum testosterone in hypogonadal men. In short-term studies, it has been shown to reverse the clinical signs and symptoms of low testosterone and to be well tolerated with less applicationsite irritation than with testosterone patches. In 2 long-term studies with Testim, the predose early morning serum testosterone (T), dihydrotestosterone (DHT), and free testosterone (FT) levels were assessed. Serum T, DHT, and FT were all maintained in the normal range for up to 12 months. In these studies, involving a total of 371 hypogonadal men, evaluation by means of dual-energy x-ray absorptiometry revealed a significant increase from baseline in bone mineral density. A significant improvement was also observed in body composition (increased lean body mass, decreased fat mass, and decreased percentage fat). In addition, significant improvements in mood and sexual function were maintained for up to 12 months of treatment. The parameters measured included sexual performance, sexual motivation, sexual desire, and occurrence of spontaneous erections. These data from the 2 long-term studies support the results of the 90-day studies with Testim showing that the gel significantly improves the signs and symptoms associated with low testosterone compared with placebo. The data also support the conclusion that these improvements are maintained for up to 1 year of additional treatment.     

Monthly patterns of testosterone and behavior in prospective fathers

The individual time patterns of salivary testosterone of adult healthy men, self-reported sexual behavior and their co-occurrence with regular weekly or monthly intervals were studied. Twenty-seven volunteer males (mean age 33 +/- 1 years) collected daily morning saliva over a period of 90 days. Evening questionnaires provided daily information on sexual activity. From the saliva, testosterone immunoreactive substances were determined using enzyme immunoassay. To detect events in which increases of testosterone were associated with sexual activity and at the same time controlling for regular internal patterns in men, data were analyzed using Theme software. First results indicated a varying number of complex nonrandom interaction patterns of testosterone with sexual activity, but also with weekly (i.e., Saturdays) and monthly intervals (i.e., 28-day full-moon intervals). The social context of the occurrence of specific pattern combinations was elaborated using parameters from the men's self-reported general life history profiles. Peak hormone levels occurred around weekends in the majority of the males. The 28-day monthly interval coincided with testosterone peaks only in those of the paired men who reported a current wish for children ("prospective fathers"), but not in unpaired men or in those who did not wish to have children with their current partner. Rather than representing a direct regular pattern of the male testosterone per se, the observed patterns suggest that men have the facultative potential to adjust their testosterone responses to their female partner's cycle. In line with the interactions between behavior and androgens observed in vertebrates in general, this study adds an example of the mutual character of hormone-behavior interactions and, thus, for the social context of testosterone patterns in human males.     

Testosterone levels among Aché hunter-gatherer men

Salivary testosterone levels were measured in a population of New World indigenous adult hunter-gatherer males in order to compare circulating levels of free unbound bioactive steroid with those previously reported among Boston and nonwestern males. The study population consisted of adult Aché hunter-gatherer males (n=45) living in eastern Paraguay. Morning and evening salivary testosterone levels (TsalA.M.; TsalP.M.) among the Aché were considerably lower than western values (Boston) and even lower than other previously reported nonwestern populations (Efe, Lese, Nepalese). No association was observed between height, weight, or age and salivary testosterone levels within the Aché group, although older men (ages>40) were poorly represented in the study sample. Nevertheless, a mild correlation was observed between Aché TsalA.M. levels and BMI (r=0.133,p=0.0725). Comparison of Aché values with those for other populations confirms the prevalence of significant interpopulational variation in testosterone levels among adult males. Interpopulational variation in male testosterone is not as great, however, as has been documented for ovarian steroids among females, nor is it likely that such variation reflects differences in male fecundity. Nevertheless, such interpopulational variation in salivary testosterone levels may have a functional significance in the regulation of protein anabolism in skeletal muscle, thereby affecting the overall energy budget of the organism. It is suggested that relative suppression of average testosterone may be adaptive under conditions of chronic energy shortage. This research was funded by the National Science Foundation, the Mellon Foundation, Sigma Xi, and Harvard University. The author is a doctoral candidate in biological anthropology at Harvard University. He received his B.A. in anthropology and psychology from UCLA in 1988 and his M.A. in anthropology from Harvard in 1994. His research interests include male reproductive ecology, male hormone function, foraging societies, evolutionary biology, and behavioral evolution.     

Fathers have lower salivary testosterone levels than unmarried men and married non-fathers in Beijing, China

A growing body of evidence, almost entirely from North America, has found that male testosterone levels are positively associated with mating effort (male-male competition and mate-seeking behaviour), while lower testosterone levels have been associated with affiliative pair bonding and paternal care. To expand the cross-cultural scope of this research, here we investigate variation in salivary testosterone levels among Chinese men in relation to marital and parenting variables. One hundred and twenty-six men drawn from a Beijing university setting between the ages of 21 and 38 completed a questionnaire and provided both morning and late afternoon saliva samples from which testosterone levels were measured. The 66 unmarried men had slightly higher levels of testosterone than the 30 married non-fathers, but this difference was not statistically significant. However, the 30 fathers exhibited significantly lower testosterone levels than both unmarried men and married non-fathers. Among married non-fathers, marital relationship quality was not significantly related to testosterone levels. Among married fathers, men with children aged less than 4 years of age did not have lower testosterone levels than men with older children. These data are the first outside of North America to show lower testosterone levels among fathers, and lend support to the theoretical view that male testosterone levels differ according to mating and parenting effort.     

Androgen supplementation and prostate cancer risk: strategies for pretherapy assessment and monitoring

Since in men androgen levels decrease with age and result in symptoms of hypogonadism, the use of testosterone supplementation to treat symptoms resulting from hypogonadism is increasing. One potential complication of this treatment is the possibility of an increased risk of prostate cancer. Although most authorities agree that androgen is involved in the exacerbation of existing carcinoma of the prostate, the action of androgens on the carcinogenic process is not well understood. Attempts to demonstrate a correlation between hormone levels and prostate cancer have yielded inconsistent results. No clear evidence exists that androgen supplementation to restore physiologic levels produces any deleterious effects on the prostate. It is highly doubtful that when testosterone therapy is administered to middle-aged or older men, any potential prostate cancer promotion effect will be clinically manifested in the absence of already established cancer. It is, however, imperative that existing or developing prostate cancer be ruled out before initiation and during androgen replacement therapy. As with any therapeutic regimen, careful monitoring of the patient receiving treatment is recommended and constitutes good medical care.     

Androgens in women

The role of androgen treatment in women remains controversial. The proposed “Female Androgen Insufficiency Syndrome” (Fertility and Sterility, April 2002) describes a number of non-specific symptoms including unexplained fatigue, decreased well being/dysphoric mood and/or blunted motivation and diminished sexual function. An estimated 40% of women experience sexual dysfunction, highlighting the need for ongoing research into this field in order to fully define the possible contribution of androgen insufficiency. The increasing availability of products, such as dehydroepiandrosterone (DHEA) supplements also points to the need for controlled studies to assess the safety of these and other preparations.

Measurement of androgens in women requires sensitive assays with the ability to detect low levels and a narrow range with precision. Normal ranges of androgens for women of reproductive and post-reproductive age remain poorly defined. Debate exists as per importance of measurement of free versus total testosterone, with the ‘free androgen index’ offering an alternative method of assessment of testosterone availability.

Testosterone treatment is being developed for women in the form of transdermal patches, gels or cream, with percutaneous implants in common usage in some countries. Recent research has highlighted alternative means of administration, such as oral inhalation or buccal lozenge. DHEA is widely available in some countries. Research to date has demonstrated improvements in libido and sexual function, mood and well being. Evidence points to other potential benefits of androgen treatment, including preservation of bone mass, a possible protective role in breast cancer and beneficial effects on cognition.

Adverse effects of androgen treatment in women are dose-dependent and include virilisation, mood disturbance and acne. These are uncommon if appropriate doses are administered and highlight the need for treatment to be closely monitored clinically and biochemically. Beneficial effects of testosterone treatment in post-menopausal women with lowered androgen levels have been well documented, and preliminary evidence suggests a role for treatment in pre-menopausal women with symptoms and lowered testosterone levels.