Testosterone replacement therapy: current trends and future directions

Directed mouse embryonic stem cells into leydig-like cells rescue testosterone-deficient male rats in vivo

The primary function of Leydig cells is to secrete testosterone, which is critical in the regulation of male reproduction and development. Low levels of testosterone will lead to male hypogonadism. Stem cell-derived Leydig cell transplantation may be a promising alternative therapy for male hypogonadism. Thus far, others have reported that Leydig-like cells can be derived from mesenchymal stem cells, embryonic stem cells (ESCs), and induced pluripotent stem cells. However, the efficiency of the differentiating Leydig cells remains low, and progress toward generating functional adult Leydig cells (ALCs) is limited. Herein, we describe a robust method of directing differentiation of mouse embryonic stem cells (mESCs) into Leydig-like cells in vitro by overexpression of the transcription factor steroidogenic factor-1 (SF-1) and treatment with a combination of 8-Bromoadenosine-3',5'-cyclic monophosphate and forskolin. These differentiated cells express mRNA encoding the steroidogenic enzymes and produce progesterone and testosterone. Importantly, when transplanted into male rats that had their original Leydig cells selectively eliminated by ethylene dimethanesulfonate, these in vitro-derived Leydig-like cells further developed into functional ALCs that rescued serum testosterone levels. These data provide evidence that mESCs can be induced to differentiate into Leydig-like cells in vitro, which can develop in the in vivo microenvironment.

Effects of three different testosterone formulations in female-to-male transsexual persons

INTRODUCTION

Gender dysphoria is characterized by a strong discomfort with the gender assigned at birth and the urge to live as a member of the opposite gender. The acquisition of phenotypic features of the desired gender requires the use of cross-sex hormones. Female-to-male (FtM) transsexual persons are treated with testosterone to induce virilization.

AIM

The aim of the study was to assess the effects of three different testosterone formulations on body weight and composition and metabolic and bone parameters.

METHODS

Forty-five FtM transsexuals were randomly assigned to receive testoviron depot (i.m.: 100 mg/10 days; n = 15), testosterone gel (50 mg/die; n = 15), and testosterone undecanoate (i.m.: 1,000 mg every 6 weeks for the first 6 weeks and then every 12 weeks, n = 15). FtM individuals were studied before, at week 30, and at week 54 of testosterone treatment.

MAIN OUTCOME MEASURES

Anthropometric, metabolic, bone, hematological, and biochemical parameters were evaluated at baseline and after 12 months of treatment.

RESULTS

Lean body mass significantly increased and fat mass decreased in all groups. No modifications were reported in fasting insulin and insulin sensitivity index. High-density plasma lipoprotein levels declined significantly and low-density lipoprotein concentrations increased significantly in the three groups. The activated partial thromboplastin time and factor I did not change while prothrombin time significantly increased in all groups. At week 54, all subjects were amenorrheic and time to amenorrhea did not differ between the three groups. Current general life satisfaction was increased in all subjects after 1 year of treatment.

CONCLUSIONS

One-year testosterone administration in FtM transsexuals appears to be very safe with no differences among the testosterone formulations used. Our study is preliminary, and the detection of subtle or long-term differences in the effects of the three formulations may require further larger and longer term studies in this and other populations.

Effect of deodorant and antiperspirant use and presence or absence of axillary hair on absorption of testosterone 2% solution applied to men's axillae

INTRODUCTION

Testosterone 2% solution is applied to axillae and is indicated for testosterone replacement therapy in males deficient in endogenous testosterone.

AIM

This open-label crossover study evaluated the effect of deodorant/antiperspirant use and presence or absence of axillary hair on absorption of testosterone solution.

METHODS

Healthy males (N = 30; ≥50 years of age with baseline testosterone <400 ng/dL) were randomized to one of four treatment sequences involving six treatments. Each treatment consisted of one 1.5-mL dose of testosterone 2% solution (30 mg of testosterone) applied to each axilla. Axillae were unshaved or shaved, and were untreated or pretreated with deodorant/antiperspirant.

MAIN OUTCOME MEASURES

Blood samples were taken over 72 hours after each dose for measuring serum testosterone concentrations.

RESULTS

Profiles of mean testosterone concentrations were similar across treatments. For all treatments, area under the concentration-time curve through 24 hours (AUC[0-24] ) and 72 hours (AUC[0-72] ), and maximum total testosterone concentration (Cmax ) were similar except for 15% lower Cmax when treatment was applied after deodorant/antiperspirant to shaved vs. unshaved axillae (least squares mean, 531 ng/dL vs. 626 ng/dL, respectively; P = 0.011). This difference is not considered clinically significant. The 95% confidence intervals for AUC(0-24) , AUC(0-72) , and Cmax fell within the traditional bioequivalence limits of 0.8 to 1.25. Incidence of treatment-emergent adverse events (TEAEs) was low (<15%) in each treatment arm, and most TEAEs were mild.

CONCLUSIONS

Absorption of testosterone 2% solution was unaffected by use of deodorant/antiperspirant or by the presence or absence of axillary hair. Testosterone solution was generally well tolerated.

Male hypogonadism and metabolic syndrome

The role of androgens in cardiovascular disease is still controversial in men. In this study, we investigated metabolic disorders in Tunisian hypogonadal men compared with healthy controls. Forty hypogonadal men and 80 control subjects were enrolled. Patients with a history of pre-existing panhypopituitarism, thyroid dysfunction or inflammatory disease were excluded. Glycaemia, glycated haemoglobin (HbA1c), high-sensitive C-reactive protein (hsCRP), lipid profile, insulin, testosterone and gonadotrophins were measured. Insulin resistance was assessed by homoeostasis model assessment of insulin resistance (Homa IR). Waist circumference, body mass index and blood pressure were significantly higher in patients compared with controls. Glycemia, HbA1c, fasting serum insulin and Homa IR were significantly increased among hypogonadal men. In univariate analysis, testosterone levels were inversely correlated with body mass index, waist circumference, blood pressure, glycaemia, HbA1C, insulin, Homa IR and hsCRP. In multivariate analysis including all significant variables, initial testosterone level was the only independent risk factor for developing dyslipidaemia. With logistic regression, male hypogonadism was an independent risk factor for MS (P < 0.001). We conclude that low testosterone level plays a central role in the development of metabolic syndrome. Further prospective data are required to establish the causative link.

Testosterone replacement and bone mineral density in male pituitary tumor patients

BACKGROUND

Hypopituitarism is associated with osteoporosis and osteopenia especially when hypogonadotropic hypogonadism is present. Despite hypopituitarism being an important cause of secondary osteoporosis, osteoporosis in patients receiving surgery for pituitary tumors in Korea has not been studied. In this study, we evaluated the effects of testosterone replacement therapy (TRT) on bone mineral density (BMD) in postoperative hypogonadal patients with pituitary tumors.

METHODS

To examine the effect of TRT on BMD, we performed a retrospective observational study in 21 postoperative male patients who underwent pituitary tumor surgery between 2003 and 2012 at the Ajou University Hospital. Testosterone was replaced in postoperative hypogonadal patients by regular intramuscular injection, daily oral medication, or application of transdermal gel. BMD (g/cm(2)) measurements of central skeletal sites (lumbar spine, femoral neck, and total femur) were obtained using dual-energy X-ray absorptiometry (GE Lunar). For lumbar spine BMD, L1 to L4 values were chosen for analysis. Femur neck and total femur were also analyzed.

RESULTS

During the follow-up period (mean, 56 months; range, 12 to 99 months) serum testosterone levels increased with the administration of TRT (P=0.007). There was significant improvement (4.56%±9.81%) in the lumbar spine BMD compared to baseline BMD. There were no significant changes in the femur neck BMD or total femur BMD. We did not find any statistically significant relationships between changes in testosterone levels and BMD using Spearman correlation analysis.

CONCLUSION

Our results indicated that TRT used in the postoperative period for hypogonadal pituitary tumor surgery patients may have beneficial effects on the BMD of the spine.

Is testosterone replacement therapy in males with hypogonadism cost-effective? An analysis in Sweden

INTRODUCTION

Testosterone replacement therapy (TRT) has been recommended for the treatment of primary and secondary hypogonadism. However, long-term implications of TRT have not been investigated extensively.

AIM

The aim of this analysis was to evaluate health outcomes and costs associated with life-long TRT in patients suffering from Klinefelter syndrome and late-onset hypogonadism (LOH).

METHODS

A Markov model was developed to assess cost-effectiveness of testosterone undecanoate (TU) depot injection treatment compared with no treatment. Health outcomes and associated costs were modeled in monthly cycles per patient individually along a lifetime horizon. Modeled health outcomes included development of type 2 diabetes, depression, cardiovascular and cerebrovascular complications, and fractures. Analysis was performed for the Swedish health-care setting from health-care payer's and societal perspective. One-way sensitivity analyses evaluated the robustness of results.

MAIN OUTCOME MEASURES

The main outcome measures were quality-adjusted life-years (QALYs) and total cost in TU depot injection treatment and no treatment cohorts. In addition, outcomes were also expressed as incremental cost per QALY gained for TU depot injection therapy compared with no treatment (incremental cost-effectiveness ratio [ICER]).

RESULTS

TU depot injection compared to no-treatment yielded a gain of 1.67 QALYs at an incremental cost of 28,176 EUR (37,192 USD) in the Klinefelter population. The ICER was 16,884 EUR (22,287 USD) per QALY gained. Outcomes in LOH population estimated benefits of TRT at 19,719 EUR (26,029 USD) per QALY gained. Results showed to be considerably robust when tested in sensitivity analyses. Variation of relative risk to develop type 2 diabetes had the highest impact on long-term outcomes in both patient groups.

CONCLUSION

This analysis suggests that lifelong TU depot injection therapy of patients with hypogonadism is a cost-effective treatment in Sweden. Hence, it can support clinicians in decision making when considering appropriate treatment strategies for patients with testosterone deficiency.

Negative association between testosterone concentration and inflammatory markers in young men: a nested cross-sectional study

Objective

Low grade systemic inflammation (LGSI) as well as androgen deficiency has in older men been associated with several pathologies, including cardiovascular disease (CVD). We wanted to investigate whether low testosterone levels are linked to biomarkers of LGSI already in young age, before any concurrent manifestations of CVD or other systemic diseases.

Design

Nested cross-sectional study.

Methods

Forty subfertile biochemically hypogonadal (n = 20) or eugonadal (n = 20) men (mean age 37 years, SD = 4.3) and 20 age-matched controls were randomly selected from an ongoing study on male subfertility. Subjects comprised male partners in infertile couples in whom also subnormal sperm concentration was present. Blood sampling, interviews, and anthropometric measures were undertaken. Serum levels of testosterone, LH, estradiol, SHBG, and 21 LGSI-markers were assessed.

Results

Among 21 inflammatory markers, macrophage inflammatory protein 1-alpha (MIP1a) (ß = −0.025; p = 0.028), 1-beta (MIP1B) (ß = −0.015; p = 0.049) and tumor necrosis factor alpha (TNFa) (ß = −0.015; p = 0.040) showed negative association to total testosterone (TT) levels. MIP1a (ß = −1.95; p = 0.001) and TNFa (ß = −0.95; p = 0.014) showed negative association to calculated free testosterone (cFT) levels. Compared to men with normal TT and cFT levels, TNFa levels were higher in men with subnormal levels of TT (mean ratio 1.61; p = 0.006) and cFT (mean ratio 1.58; p = 0.007). Also, MIP1a levels were higher in men with subnormal levels of TT (mean ratio 1.84; p = 0.030).

Conclusions

Subnormal testosterone may already in young age associate to LGSI, which might be a part of the mechanism underlying adverse health outcomes of male hypogonadism.

Topical testosterone supplementation for the treatment of male hypogonadism

Age-related hormonal decline is gradual and less recognized in men than in women. Symptoms are oftentimes ignored and non-specific. Fatigue, lack of concentration, mood swings, decreased sexual desire, erectile dysfunction, infertility, hair loss, reduced muscle and bone mass, and weight gain are a few of the symptoms of male hypogonadism. This disorder is linked to reduction in quality of life, and poorer health outcomes as it may increase the risk for cardiovascular disease, diabetes mellitus, metabolic syndrome, Alzheimer's disease and premature death. Different modalities of testosterone replacement therapy have evolved over 70 years, and sales continue to grow. Each preparation is differentiated by route of delivery, ease of use, cost and pharmacokinetics. Topical/transdermal testosterone replacement therapy, including patches and gels, are the most modern formulations on the market. These are more expensive treatments, but yield more physiological concentrations of testosterone. Restoration of testosterone levels to the eugonadal range reverses signs and symptoms of hypogonadism, except for infertility, and may alleviate co-morbidities associated with hypogonadism. Patient understanding of and compliance with both treatment and monitoring are of utmost importance to achieve clinical success with maximum benefit and minimum risk. The aim of our review is to summarize the indications, contraindications, benefits and risks of testosterone replacement therapy as they relate to transdermal administration. Further, we compare the various testosterone preparations, focusing on the newest topical/transdermal routes of administration that are currently available.

Testosterone therapy during exercise rehabilitation in male patients with chronic heart failure who have low testosterone status: a double-blind randomized controlled feasibility study

BACKGROUND

This study assessed the feasibility of a 12-week program of exercise, with and without intramuscular testosterone supplementation, in male patients with chronic heart failure (CHF) and low testosterone status and collected preliminary data for key health outcomes.

METHODS

Male patients with CHF (n = 41, age 67.2 years, range 51-84 years) with mean ± SD testosterone levels of 10.7 ± 2.6 nmol/L (309 ± 76 ng/dL) were randomly allocated to exercise with testosterone or placebo groups. Feasibility was assessed in terms of recruitment, intervention compliance, and attrition. Outcomes included an incremental shuttle walk test, peak oxygen uptake, muscular strength, echocardiographic measures, N-terminal pro-brain natriuretic peptide, inflammatory markers, depression (Beck Depression Inventory), and health-related quality of life (Minnesota Living with Heart Failure Questionnaire and Medical Outcomes Study Short-Form).

RESULTS

Attrition was 30% but with 100% compliance to exercise and injections in patients who completed the study. Similar improvements in shuttle walk test (18% vs 19%), body mass (-1.3 kg vs -1.0 kg), and hand grip strength (2.1 kg vs 2.5 kg) from baseline were observed in both groups. The exercise with testosterone group showed improvements from baseline in peak oxygen uptake (P < .01), Beck Depression Inventory (P < .05), leg strength (P < .05), and several Medical Outcomes Study Short-Form quality of life domains (P < .05), which were generally not apparent in the exercise with placebo group. Echocardiographic measures, N-terminal pro-brain natriuretic peptide, and inflammatory markers were mostly unchanged.

CONCLUSIONS

This study shows for the first time that testosterone supplementation during a program of exercise rehabilitation is feasible and can positively impact on a range of key health outcomes in elderly male patients with CHF who have a low testosterone status.

Contraceptive choices: is the future with men?

A credible, reversible male contraceptive with sufficient efficacy and convenience to rival established female methods has been eagerly awaited for some years. What are the issues surrounding its development and when is a launch likely? At present, many different approaches and targets have been identified for further development. These include spermatogenesis, unique testicular proteins, immunocontraception, the vas deferens and the potential method currently closest to fruition, hormonal contraception. This is now in Phase III studies in China and commercial studies are underway in Europe.

Andrological aspects of physical exercise and sport medicine

Appropriate physical activity is one of the bases of healthy lifestyle. In fact, physical exercise and playing sport may be associated with both improvements and injury to both general and reproductive health. A biologically normal testosterone secretion appears fundamental in males to guarantee both a physiological exercise adaptation and safe sport participation. The reproductive system is highly sensitive to the effects of exercise-related stress and the reproductive hormones may both increase and decrease after different acute or chronic exercises. Exercise and sport participation may positively or negatively influence andrological health status depending on the type, intensity and duration of performed physical activity and on individual health status. In addition, prohibited substances administration (e.g. androgenic-anabolic steroids, and so forth) in competitive and non-competitive athletes represents the main cause of iatrogenic andrological diseases. Preventing and treating andrological problems in active healthy and unhealthy individuals is as important as promoting a correct lifestyle. Physicians need to be educated on the relationships between the male reproductive system and sport participation and on the great role of the pre-participation physical examination in the prevention of andrological diseases.

Effects of Eurycoma longifolia on Testosterone Level and Bone Structure in an Aged Orchidectomised Rat Model

Testosterone replacement is the choice of treatment in androgen-deficient osteoporosis. However, long-term use of testosterone is potentially carcinogenic. Eurycoma longifolia (EL) has been reported to enhance testosterone level and prevent bone calcium loss but there is a paucity of research regarding its effect on the bone structural parameters. This study was conducted to explore the bone structural changes following EL treatment in normal and androgen-deficient osteoporosis rat model. Thirty-six male Sprague-Dawley rats aged 12 months were divided into normal control, normal rat supplemented with EL, sham-operated, orchidectomised-control, orchidectomised with testosterone replacement, and orchidectomised with EL supplementation groups. Testosterone serum was measured both before and after the completion of the treatment. After 6 weeks of the treatment, the femora were processed for bone histomorphometry. Testosterone replacement was able to raise the testosterone level and restore the bone volume of orchidectomised rats. EL supplementation failed to emulate both these testosterone actions. The inability of EL to do so may be related to the absence of testes in the androgen deficient osteoporosis model for EL to stimulate testosterone production.

Effect of long-acting testosterone undecanoate treatment on quality of life in men with testosterone deficiency syndrome: a double blind randomized controlled trial

This study aimed to investigate the effect of intramuscular injection of testosterone undecanoate on overall quality of life (QoL) in men with testosterone deficiency syndrome (TDS). A randomized controlled trial over a 12-month period was carried out in 2009. One hundred and twenty men aged 40 years and above with a diagnosis of TDS (serum total testosterone <12 nmol l(-1) and total Aging Male Symptom (AMS) scores ≥27) were invited to participate. Interventions comprised intramuscular injection of either placebo or 1000 mg testosterone undecanoate, given at weeks 0, 6, 18, 30 and 42. This paper presents the secondary analysis of QoL changes measured in the scores of Short-Form-12 (SF-12) scale at baseline, weeks 30 and 48 after the first injection. A total of 56/60 and 58/60 men from the active treatment and placebo group, respectively, completed the study. At week 48, before adjusting for baseline differences, the QoL of men in the treatment group improved significantly in five out of the eight domains on SF-12. The physical health composite scores improved 4.0 points from a baseline of 41.9±7.0 in the treatment group compared to 0.8 point from a baseline of 43.7±7.1 in the placebo group (F=3.652, P=0.027). The mental health composite scores improved 4.4 points from a baseline of 37.1±9.0 in the treatment group compared to 1.0 points from a baseline of 37.6±7.9 in the placebo group (F=4.514, P=0.018). After adjusting for baseline differences, significant improvement was observed in mental health composite scores, but not in physical health composite scores. Long-acting testosterone undecanoate significantly improved the mental health component of QoL in men with TDS.

The direct and indirect costs among U.S. privately insured employees with hypogonadism

INTRODUCTION

While previous studies have noted that hypogonadism (HG) may pose a significant economic and quality-of-life burden, no studies have evaluated the impact of HG on healthcare utilization and costs in the United States.

AIM

Compare direct (health care) and indirect (disability leave or medical absence) costs between privately insured U.S. employees with HG and controls without HG.

METHODS

The study sample included 4,269 male employees, ages 35-64, with ≥ 2 HG diagnoses (International Classification of Diseases, Ninth Revision, Clinical Modification: 257.2x) or ≥ 1 HG diagnosis and ≥ 1 claim for testosterone therapy, 1/1/2005-3/31/2009, identified from a large, private insurance administrative database that includes medical, prescription drug, and disability claims data. The index date was the most recent HG diagnosis that had continuous eligibility for at least 1 year before (baseline period) and 1 year after (study period). Employees with HG were matched 1:1 on age, region, salaried vs. nonsalaried employment status, and index year to controls without HG.

MAIN OUTCOME MEASURES

Descriptive analyses compared demographic characteristics, comorbidities, resource utilization, direct and indirect costs inflated to USD 2009. Multivariate analyses adjusting for baseline characteristics were used to estimate risk-adjusted costs.

RESULTS

HG employees and controls had a mean age of 51 years. HG employees compared with controls had higher baseline comorbidity rates, including hyperlipidemia (50.2% vs. 25.3%), hypertension (37.7% vs. 21.1%), back/neck pain (32.0% vs. 15.7%), and human immunodeficiency virus/acquired immunodeficiency syndrome (7.1% vs. 0.3%) (all P < 0.0001). HG employees had higher mean study period direct ($10,914 vs. $3,823) and indirect costs ($3,204 vs. $1,450); HG-related direct costs were $832 (all P < 0.0001). Risk-adjusted direct ($9,291 vs. $5,248) and indirect ($2,729 vs. $1,840) costs were also higher for HG employees (all P < 0.0001).

CONCLUSIONS

Employees with HG had higher comorbidity rates and costs compared with controls. Given the low HG-related costs, a primary driver of costs among HG patients appears to be their comorbidity burden.

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.

Hypogonadism in the aging male diagnosis, potential benefits, and risks of testosterone replacement therapy

Hypogonadism in older men is a syndrome characterized by low serum testosterone levels and clinical symptoms often seen in hypogonadal men of younger age. These symptoms include decreased libido, erectile dysfunction, decreased vitality, decreased muscle mass, increased adiposity, depressed mood, osteopenia, and osteoporosis. Hypogonadism is a common disorder in aging men with a significant percentage of men over 60 years of age having serum testosterone levels below the lower limits of young male adults. There are a variety of testosterone formulations available for treatment of hypogonadism. Data from many small studies indicate that testosterone therapy offers several potential benefits to older hypogonadal men. A large multicenter NIH supported double blind, placebo controlled study is ongoing, and this study should greatly enhance the information available on efficacy and side effects of treatment. While safety data is available across many age groups, there are still unresolved concerns associated with testosterone therapy. We have reviewed the diagnostic methods as well as benefits and risks of testosterone replacement therapy for hypogonadism in aging men.

Pharmacology and clinical use of sex steroid hormone receptor modulators

Sex steroid receptors are ligand-triggered transcription factors. Oestrogen, progesterone and androgen receptors form, together with the glucocorticoid and mineralocorticoid receptors, a subgroup of the superfamily of nuclear receptors. They share a common mode of action, namely translating a hormone-i.e. a small-molecule signal-from outside to changes in gene expression and cell fate, and thereby represent "natural" pharmacological targets.For pharmacological therapy, these receptors have originally been addressed by hormones and synthetic hormone analogues in order to overcome pathologies related to deficiencies in the natural ligands. Another major use for female sex hormone receptor modulators is oral contraception, i.e. birth control.On the other side, blocking the activity of sex steroid receptors has become an established way to treat hormone-dependent malignancies, such as breast and prostate cancer.In this review, we will discuss how the experience gained from the classical pharmacology of these receptors and their molecular similarities led to new options for the treatment of gender-specific diseases and highlight recent progress in medicinal chemistry of sex hormone-modulating drugs.

Efficacy and safety of the 2% formulation of testosterone topical solution applied to the axillae in androgen-deficient men

OBJECTIVES

Testosterone replacement therapy in hypogonadal men relieves symptoms and restores serum testosterone levels to the physiological range. In this study, we assessed the safety, pharmacokinetics, and efficacy of the 2% formulation of testosterone topical solution applied daily to the axillae.

DESIGN AND PATIENTS

An open-label trial was conducted in testosterone-deficient men who started on a daily dose of 60 mg of testosterone. Dose was adjusted on Days 45 and 90 when necessary to maintain serum testosterone levels within the physiological range (10·41-36·44 nmol/l) based on average serum testosterone levels on Days 15 and 60, respectively. Sexual function and mood changes were assessed by the Psychosexual Daily Questionnaire (PDQ) for the 7 days preceding visits at Days 1, 15, 60, and 120; and quality of life by SF-36 questionnaire on Days 1, 60, and 120. Safety parameters, laboratory tests, and adverse events were collected at each visit.

RESULTS

Among the Completer Set (135 study completers and 3 patients who discontinued due to adverse events), 76·1% (Days 15/16), 84·8% (Days 60/61), and 84·1% (Days 120/121) had an average total testosterone level between 10·41-36·44 nmol/l. PDQ scores increased significantly from baseline to 120 days of treatment (p < 0·0001). Significant improvement was observed in the physical (p < 0·05) and mental (p < 0·0001) components of the SF-36 after 120 days of treatment. Adverse events reported in >2% of the 155 subjects who received ≥ 1 dose were application site irritation (7·1%), application site erythema (5·2%), headache (5·2%), increased hematocrit (3.9%), nasopharyngitis (3·9%), diarrhea (2·6%), and vomiting (2·6%).

CONCLUSIONS

These results indicate that once-daily application of the testosterone topical solution 2% to the axillae is a safe and effective treatment for androgen replacement in hypogonadal men.

Testosterone and phosphodiesterase type-5 inhibitors: new strategy for preventing endothelial damage in internal and sexual medicine?

Normal vascular endothelium is essential for the synthesis and release of substances affecting vascular tone (e.g. nitric oxide; NO), cell adhesion (e.g. endothelins, interleukins), and the homeostasis of clotting and fibrinolysis (e.g. plasminogen inhibitors, von Willebrand factor). The degeneration of endothelial integrity promotes adverse events (AEs) leading to increased atherogenesis and to the development of vascular systemic and penile end-organ disease. Testosterone (T) is an important player in the regulation of vascular tone through non-genomic actions exerted via blockade of extracellular-calcium entry or activation of potassium channels; also, adequate T concentrations are paramount for the regulation of phosphodiesterase type-5 (PDE5) expression and finally, for the actions exerted by hydrogen sulphide, a gas involved in the alternative pathway controlling vasodilator responses in penile tissue. It is known that an age-related decline of serum T is reported in approximately 20 to 30% of men whereas T deficiency is reported in up to 50% of men with metabolic syndrome or diabetes. A number of laboratory and human studies have shown the combination of T and other treatments for erectile dysfunction (ED), such as PDE5 inhibitors, to be more beneficial in patients with ED and hypogonadism, who fail monotherapy for sexual disturbances.The aim of this review is to show evidence on the role of T and PDE5 inhibitors, alone or in combination, as potential boosters of endothelial function in internal medicine diseases associated with reduced T or NO bioavailability, i.e. metabolic syndrome, obesity, diabetes, coronary artery disease, hyperhomocysteinemia, that share common risk factors with ED. Furthermore, the possibility of such a strategy to prevent endothelial dysfunction in men at increased cardiovascular risk is discussed.

Reexamination of pharmacokinetics of oral testosterone undecanoate in hypogonadal men with a new self-emulsifying formulation

Many hypogonadal men prefer oral testosterone (T) treatment. Oral T undecanoate (TU) is available in many countries, but not in the United States. We aimed to assess the pharmacokinetics of oral TU in a new self-emulsifying drug delivery system formulation. Pharmacokinetics studies were conducted in 3 parts: 12 hypogonadal men were enrolled in 2 centers for a 1-day dosing study; 29 participants were enrolled from 3 centers for a 7-day dosing study; and 15 participants were enrolled from 1 center for a 28-day dosing study. Serial blood samples for serum sex hormone measurements by liquid chromatography-tandem mass spectrometry were drawn for up to 36 hours after oral TU administration. Mean serum T levels (C(avg)) after oral dosing of T 200 mg as TU twice daily with food were within the adult male range in most participants in the 1-, 7-, and 28-day dosing studies but were much lower in the fasting state. The dose-proportional increase in C(avg) of serum T after oral T 300 mg twice daily resulted in more participants with supraphysiologic serum T levels. In the 28-day study, trough serum T reached a steady state at day 7. Serum dihydrotestosterone and estradiol levels tracked serum T concentration. Dihydrotestosterone-testosterone ratios increased 3-fold after oral TU administration. Oral T 200 mg twice daily as TU in a new SEDDS formulation may be a viable therapy for hypogonadal men.

Intranasal administration of testosterone increased immobile-sniffing, exploratory behavior, motor behavior and grooming behavior in rats

Currently, testosterone (T) replacement therapy is typically provided by oral medication, injectable T esters, surgically implanted T pellets, transdermal patches and gels. However, most of these methods of administration are still not ideal for targeting the central nervous system. Recently, therapeutic intranasal T administration (InT) has been considered as another option for delivering T to the brain. In the present study, the effects of 21-day InT treatment were assessed on open field behavior in gonadectomized (GDX) rats and intact rats. Subcutaneous injections of T at same dose were also tested in GDX rats. A total of 12 behavioral events were examined in GDX groups with or without T and in intact groups with or without InT. Significant decreases in open field activity were observed in rats after GDX without InT compared to sham-operated rats. The open field activity scores for most tests significantly increased with InT treatment in GDX rats and in intact rats compared with the corresponding GDX rats and intact rats. Intranasal administration of T improved the reduced behaviors resulted from T deficiency better than subcutaneous injection of T, demonstrating that T can be delivered to the brain by intranasal administration. Our results suggest that intranasal T delivery is an effective option for targeting the central nervous system.

Are there symptom-specific testosterone thresholds in aging men?

OBJECTIVE

• To study the association between specific clinical symptoms (e.g. low libido and erectile dysfunction) and testosterone levels and age in order to define symptom-specific testosterone thresholds.

MATERIALS AND METHODS

• Serum samples for testosterone determination were obtained from 675 healthy men. • Participants underwent urological examination and completed the Aging Males Symptoms scale, the Beck Depression Index and the International Index of Erectile Function. Overall scores and those from individual questions from the questionnaires were evaluated. • Testosterone levels in men with symptoms were compared with those in men without symptoms. • The risks of clinical symptoms were evaluated using univariate, multiple multinomial regression analyses and Bonferroni correction.

RESULTS

• Significant associations between testosterone levels and a number of androgen deficiency symptoms were seen at testosterone levels of 13.5-14.4 nmol/L, but multiple logistic regression analysis revealed confounding effects with age. • Symptoms such as loss of libido, lack of vigour and sexual dysfunction were associated with age rather than with testosterone. • Erectile dysfunction was reported at testosterone levels between 14.65 nmol/L and 14.8 nmol/L, but was again significantly associated with age rather than testosterone levels. • The severity of symptoms significantly increased with decreasing testosterone levels using univariate analysis, but only the relationship with psychological symptoms remained significant after Bonferroni correction.

CONCLUSION

• In aging males, androgen deficiency symptoms were reported at normal levels of testosterone, but age was an important confounder. Symptom-specific testosterone thresholds could not be defined.

The rational use of pituitary stimulation tests

BACKGROUND

Diseases of the pituitary gland can lead to the dysfunction of individual hormonal axes and to the corresponding clinical manifestations. The diagnostic assessment of pituitary function has not yet been standardized.

METHODS

The members of the Neuroendocrinology Section and the Pituitary Study Group of the German Society for Endocrinology (Deutsche Gesellschaft für Endokrinologie) prepared outlines of diagnostic methods for the evaluation of each of the pituitary hormonal axes. These outlines were discussed in open session in recent annual meetings of the Section and the Study Group.

RESULTS

For the evaluation of the thyrotropic axis, basal TSH and free T4 usually suffice. For the evaluation of the gonadotropic axis in men, the testosterone level should be measured; if the overall testosterone level is near normal, then calculating the free testosterone level may be additionally useful. In women, an intact menstrual cycle is sufficient proof of normal function. In the absence of regular menstruation, measurement of the basal estradiol and gonadotropin levels aids in the diagnosis of the disturbance. For the evaluation of the adrenocorticotropic axis, the basal cortisol level may be helpful; provocative testing is in many cases necessary for precise characterization. The evaluation of the somato-tropic axis requires provocative testing. Aside from the insulin tolerance test, the GHRH-arginine test has become well established. Reference ranges normed to the body mass index (BMI) are available.

CONCLUSION

The diagnostic evaluation of pituitary insufficiency should proceed in stepwise fashion, depending on the patient's clinical manifestations and underlying disease. For some pituitary axes, measurement of basal hormone levels suffices; for others, stimulation tests are required. In general, the performance of combined pituitary tests should be viewed with caution.

Hormones and antioxidant systems: role of pituitary and pituitary-dependent axes

Oxidative stress, a condition defined as unbalancing between production of free radicals and antioxidant defenses, is an important pathogenetic mechanism in different diseases. Despite the abundant literature, many aspects of hormone role in regulating antioxidant synthesis and activity still remain obscure. Therefore, we reviewed experimental data, in vivo and in vitro, about the effects of the different pituitary- dependent axes on antioxidant levels, trying to give a broad view from hormones which also have antioxidant properties to the classic antioxidants, from the lipophilic antioxidant Coenzyme Q10, strictly related to thyroid function, to total antioxidant capacity, a measure of non-protein non-enzymatic antioxidants in serum and other biological fluids. Taken together, these data underline the importance of oxidative stress in various pituitary-dependent disorders, suggesting a possible clinical usefulness of antioxidant molecules.

Emotional disorders in testicular cancer survivors in relation to hypogonadism, androgen receptor polymorphism and treatment modality

PURPOSE

It has been documented that testicular germ cell cancer (TGCC) patients may be at increased risk of developing emotional distress (EMD). Hence, the aim of the present study was to investigate whether EMD is related to the presence of hypogonadism, androgen receptor (AR) polymorphism and/or treatment intensity.

PATIENTS AND METHODS

Three to five years after treatment, testosterone and luteinizing hormone (LH) levels were measured in 165 TGCC patients. These patients also completed a questionnaire concerning mental health. EMD was measured by the Hospital Anxiety and Depression Scale (HADS). The androgen receptor (AR) gene has two polymorphic regions in exon I; glutamine encoding CAG and glycine encoding GGN repeats. Association between emotional disorders and AR polymorphisms as well as type of treatment was assessed.

RESULTS

Neither anxiety (OR 1.0; 95% CI 0.40-2.4) nor depression (OR 1.1; 95% CI 0.20-6.4) were overrepresented in biochemically hypogonadal TGCC patients and no association between AR polymorphisms and EMD was found. Patients treated with >or=5 cycles of cisplatinum based chemotherapy due to refractory or relapsed disease were more prone to experiencing symptoms of anxiety (p=0.006), but not depression (p=0.38).

CONCLUSIONS

Biochemical hypogonadism and AR polymorphism do not seem to be risk factors for EMD in TGCC patients. Patients with refractory or relapsed disease receiving >or=5 cycles of cisplatinum based chemotherapy may, to a higher degree than patients receiving less intense therapy, suffer from anxiety.

Androgens and male aging: Current evidence of safety and efficacy

Many signs of aging, such as sexual dysfunction, visceral obesity, impaired bone and muscle strength, bear a close resemblance to features of hypogonadism in younger men. The statistical decline of serum testosterone in aging men is solidly documented. It has been presumed that the above features of aging are related to the concurrent decline of androgens, and that correction of the lower-than-normal circulating levels of testosterone will lead to improvement of symptoms of aging. But in essence, the pivotal question whether the age-related decline of testosterone must be viewed as hypogonadism, in the best case reversed by testosterone treatment, has not been definitively resolved. Studies in elderly men with lower-than-normal testosterone report improvement of features of the metabolic syndrome, bone mineral density, of mood and of sexual functioning. But as yet there is no definitive proof of the beneficial effects of restoring testosterone levels to normal in elderly men on clinical parameters. Few of these studies meet as yet rigorous standards of scientific enquiry: double-blind, placebo-controlled design of the study. The above applies also to the assessment of safety of testosterone administration to elderly men. There is so far no convincing evidence that testosterone is a main factor in the development of prostate cancer in elderly men and guidelines for monitoring the development of prostate disease have been developed. It is of note that there are presently no long-term safety data with regard to the prostate. Polycythemia is another potential complication of testosterone treatment. It is dose dependent and can be managed with dose adjustment.

Position stand on androgen and human growth hormone use

Hoffman, JR, Kraemer, WJ, Bhasin, S, Storer, T, Ratamess, NA, Haff, GG, Willoughby, DS, and Rogol, AD. Position stand on Androgen and human growth hormone use. J Strength Cond Res 23(5): S1-S59, 2009-Perceived yet often misunderstood demands of a sport, overt benefits of anabolic drugs, and the inability to be offered any effective alternatives has fueled anabolic drug abuse despite any consequences. Motivational interactions with many situational demands including the desire for improved body image, sport performance, physical function, and body size influence and fuel such negative decisions. Positive countermeasures to deter the abuse of anabolic drugs are complex and yet unclear. Furthermore, anabolic drugs work and the optimized training and nutritional programs needed to cut into the magnitude of improvement mediated by drug abuse require more work, dedication, and preparation on the part of both athletes and coaches alike. Few shortcuts are available to the athlete who desires to train naturally. Historically, the NSCA has placed an emphasis on education to help athletes, coaches, and strength and conditioning professionals become more knowledgeable, highly skilled, and technically trained in their approach to exercise program design and implementation. Optimizing nutritional strategies are a vital interface to help cope with exercise and sport demands (). In addition, research-based supplements will also have to be acknowledged as a strategic set of tools (e.g., protein supplements before and after resistance exercise workout) that can be used in conjunction with optimized nutrition to allow more effective adaptation and recovery from exercise. Resistance exercise is the most effective anabolic form of exercise, and over the past 20 years, the research base for resistance exercise has just started to develop to a significant volume of work to help in the decision-making process in program design (). The interface with nutritional strategies has been less studied, yet may yield even greater benefits to the individual athlete in their attempt to train naturally. Nevertheless, these are the 2 domains that require the most attention when trying to optimize the physical adaptations to exercise training without drug use.Recent surveys indicate that the prevalence of androgen use among adolescents has decreased over the past 10-15 years (). The decrease in androgen use among these students may be attributed to several factors related to education and viable alternatives (i.e., sport supplements) to substitute for illegal drug use. Although success has been achieved in using peer pressure to educate high school athletes on behaviors designed to reduce the intent to use androgens (), it has not had the far-reaching effect desired. It would appear that using the people who have the greatest influence on adolescents (coaches and teachers) be the primary focus of the educational program. It becomes imperative that coaches provide realistic training goals for their athletes and understand the difference between normal physiological adaptation to training or that is pharmaceutically enhanced. Only through a stringent coaching certification program will academic institutions be ensured that coaches that they hire will have the minimal knowledge to provide support to their athletes in helping them make the correct choices regarding sport supplements and performance-enhancing drugs.The NSCA rejects the use of androgens and hGH or any performance-enhancing drugs on the basis of ethics, the ideals of fair play in competition, and concerns for the athlete's health. The NSCA has based this position stand on a critical analysis of the scientific literature evaluating the effects of androgens and human growth hormone on human physiology and performance. The use of anabolic drugs to enhance athletic performance has become a major concern for professional sport organizations, sport governing bodies, and the federal government. It is the belief of the NSCA that through education and research we can mitigate the abuse of androgens and hGH by athletes. Due to the diversity of testosterone-related drugs and molecules, the term androgens is believed to be a more appropriate term for anabolic steroids.

Hypogonadism risk in men treated for childhood cancer

CONTEXT

Pediatric cancer treatment may imply an increased risk of hypogonadism, leading to metabolic disorders and osteoporosis. Such complications are potentially preventable.

OBJECTIVE

The aim of this study was to assess diagnosis- and treatment-dependent risk of hypogonadism in male childhood cancer survivors (CCS).

DESIGN

Male CCS who were treated during the period 1970-2002 and who in 2004 were 18-45 yr of age were eligible.

SETTING

The study was conducted in a university hospital clinic.

PATIENTS

A consecutive group of CCS treated at Lund University Hospital was selected for the study, of whom 151 (38%) agreed to participate. Furthermore, 141 healthy fertile men served as controls.

INTERVENTIONS

We measured serum levels of free and total testosterone, SHBG, and LH.

MAIN OUTCOME MEASURES

Odds ratios (OR) for biochemical hypogonadism, defined as total testosterone less than 10 nmol/liter and/or LH above 10 IU/liter, were calculated and related to type of cancer, treatment received, as well as testicular volume.

RESULTS

Hypogonadism was more commonly detected in CCS than in controls (OR, 6.7; 95% CI, 2.7, 17). The increased presence of hypogonadism was noted in the following treatment groups: brain surgery, chemotherapy (with and without radiotherapy), and testicular irradiation. Low total testicular volume (<or=24 ml) was associated with a high risk of hypogonadism (OR, 31; 95% CI, 11, 92).

CONCLUSION

Adult male survivors of childhood cancer are at risk of hypogonadism, which should be acknowledged in the long-term follow-up of these men.

Synergic enhancing-effect of DEET and dodecylamine on the skin permeation of testosterone from a matrix-type transdermal delivery system

The synergic in vitro skin permeation enhancing-effect of N,N-diethyl-m-toluamide (DEET) and dodecylamine was investigated in order to develop a novel non-scrotal matrix-type transdermal delivery system of testosterone (TS). When DEET was loaded in DuroTak 87-2510 together with 2% TS and 3% dodecylamine, the in vitro rat skin permeation rate of TS synergistically increased as DEET concentration increased up to 0.5%. No further increase in permeation was observed thereafter and a plateau was observed up to 3.8% DEET. Moreover, compared to 0.5% DEET concentration, the addition of 3.8% of DEET in combination with 3% dodecylamine and 6% TS further increased the permeation rate of TS, and the maximum permeation rate of 11.21 microg/cm(2)/h was achieved. The in vitro skin permeation rates of TS from a transdermal delivery system of DuroTak 87-2510 containing 6% TS, 3% dodecyamine, and 3.8% DEET were in the following order: hairless mouse skin > rat skin > human cadaver skin. Assuming that a system with a surface area of 60 cm(2) is applied, the human cadaver skin permeation rate of 5.74 microg/cm(2)/h achieved in this study can be interpreted as being equivalent to delivering approximately 8. 27 mg of TS per day. Considering that the commercially available product (Testoderm TTS) for non-scrotal skin of the same surface area is designed to administer 5 mg of TS per day, the new formulation could maintain therapeutic plasma concentration of TS at a smaller surface area of 40 cm(2).

Comparison of long-acting testosterone undecanoate formulation versus testosterone enanthate on sexual function and mood in hypogonadal men

OBJECTIVE

To compare the effects of two treatment modalities of testosterone on sexual functioning and mood. Design Forty men were randomized to receive either parenteral testosterone enanthate (TE) or long-acting parenteral testosterone undecanoate (TU) over a period of 30 weeks. Thereafter, 20 men who had received TU and 16 men who had received TE continued with TU and completed another 65 weeks to study longer-term effects of TU.

METHODS

The following variables of sexual functioning were studied: sexual thoughts and fantasy, sexual interest and desire, satisfaction with sex life, number of erections and ejaculations per week, and number of spontaneous morning erections per week. Also variables related to mood were analyzed.

RESULTS

Improvements in these variables were significant and were of a similar magnitude in the group treated with TU and TE for 30 weeks. Improvements were maintained at the same levels over a period of another 65 weeks when all men received TU. Effects on mood were recorded for 30 weeks, but were more difficult to establish in the study population. There were significant differences in baseline values between the two groups and scores showed wide s.d.

CONCLUSIONS

Both TE and TU were effective in improving sexual functions in hypogonadal men. An advantage of TU over TE is its lower frequency of administration and its better tolerability and safety profile.

Sexual function in men treated for testicular cancer

INTRODUCTION

Testicular germ cell cancer (TGCC) patients may be at risk of developing sexual dysfunction after treatment.

AIM

The aim of this study was to assess the prevalence of sexual dysfunctions in TGCC patients 3 to 5 years after treatment, and relate findings to biochemical hypogonadism, treatment intensity, and the expected prevalence in the Swedish male population.

METHODS

A questionnaire study on 129 consecutive TGCC patients 3 to 5 years post-treatment was performed. Comparators were an age-matched nationally representative group of men (N = 916) included in a study on sexual life in Sweden.

MAIN OUTCOME MEASURES

Sexual functions (including erectile dysfunctional distress), time since last intercourse, sexual satisfaction, and experience of sexological treatment seeking were assessed using the same questions used in the epidemiological study on sexual life in Sweden. The findings in TGCC patients were correlated to biochemical signs of hypogonadism and type of oncological treatment: Surveillance, adjuvant chemotherapy, adjuvant radiotherapy, or standard doses of chemotherapy.

RESULTS

A higher proportion of TGCC patients than comparators were likely to report low sexual desire (odds ratio [OR] 6.7 [95% confidence interval {CI} 2.1-21]) as well as erectile dysfunction (OR 3.8 [95% CI 1.4-10]). No significant differences were observed regarding erectile dysfunctional distress, change of desire over time, interest in sex, premature or delayed ejaculation, time since last intercourse, need for or receiving sexual advice, or sexual satisfaction. Hypogonadism did not predict erectile dysfunction (OR 1.1 [95% CI 0.26-4.5]) or low sexual desire (OR 1.2 [95% CI 0.11-14]). Treatment modality had no obvious impact on sexual function.

CONCLUSION

Men treated for testicular cancer had higher risk of having low sexual desire and erectile dysfunction 3 to 5 years after completion of therapy than comparators. These sexual dysfunctions were not significantly associated with treatment intensity or hypogonadism.

Regulation of the steroidogenic acute regulatory protein gene expression: present and future perspectives

Steroid hormones are synthesized in the adrenal gland, gonads, placenta and brain and are critical for normal reproductive function and bodily homeostasis. The steroidogenic acute regulatory (StAR) protein regulates the rate-limiting step in steroid biosynthesis, i.e. the delivery of cholesterol from the outer to the inner mitochondrial membrane. The expression of the StAR protein is predominantly regulated by cAMP-dependent mechanisms in the adrenal and gonads. Whereas StAR plays an indispensable role in the regulation of steroid biosynthesis, a complete understanding of the regulation of its expression and function in steroidogenesis is not available. It has become clear that the regulation of StAR gene expression is a complex process that involves the interaction of a diversity of hormones and multiple signaling pathways that coordinate the cooperation and interaction of transcriptional machinery, as well as a number of post-transcriptional mechanisms that govern mRNA and protein expression. However, information is lacking on how the StAR gene is regulated in vivo such that it is expressed at appropriate times during development and is confined to the steroidogenic cells. Thus, it is not surprising that the precise mechanism involved in the regulation of StAR gene has not yet been established, which is the key to understanding the regulation of steroidogenesis in the context of both male and female development and function.

Prevalence of low male testosterone levels in primary care in Germany: cross-sectional results from the DETECT study

OBJECTIVE

Low testosterone levels in men occur with increasing age and are associated with increased morbidity, particularly metabolic syndrome, and mortality. As the prevalence of hypogonadal testosterone levels has not been assessed in the primary care setting in Europe, we aimed to investigate the prevalence of low testosterone levels in this setting, and the patient characteristics and comorbidities associated with this finding.

DESIGN

A cross-sectional, epidemiological study (the Diabetes Cardiovascular Risk-Evaluation: Targets and Essential Data for Commitment of Treatment (DETECT) study).

PATIENTS

A total of 2719 male primary care patients (age 58.7 +/- 13.4 years) were included.

MEASUREMENTS

Testosterone was measured in all patients. Information on diseases, risk conditions and treatments was documented by the primary care physicians. A large set of laboratory parameters was measured in a central laboratory. We calculated univariate and multivariate logistic regression models to assess the associations of low testosterone levels with different health and life style factors.

RESULTS

A total of 19.3% of all men had hypogonadism as defined by testosterone levels < 3.0 ng/ml. Stepwise logistic regression analysis revealed that obesity, metabolic syndrome, cancer, intake of six or more drugs, acute inflammation and nonsmoking were associated with hypogonadal testosterone levels. Higher age, liver diseases, and cancer were associated with very low testosterone levels (< 1.0 ng/ml).

CONCLUSIONS

Hypogonadal testosterone levels are common in primary care, particularly in patients with the above conditions.

Dopaminergic and serotonergic activity in neostriatum and nucleus accumbens enhanced by intranasal administration of testosterone

Testosterone was administered intranasally in anesthetized male rats, and its effects on the activity of dopaminergic and serotonergic neurons in the neostriatum and nucleus accumbens were assessed by means of microdialysis and HPLC. The treatment (0.5, 1.0 or 2.0 mg/kg of testosterone or vehicle, 10 microl volume) was applied in both nostrils, half (5 microl) into each. Subcutaneous injections of testosterone (2.0, 4.0 or 8.0 mg/kg) or vehicle were tested in other subjects. Samples were collected for 5 h. In the neostriatum, an increase of dopamine occurred after 2.0 mg/kg. Serotonin levels increased after 1.0 mg/kg dose. In the nucleus accumbens, dopamine and serotonin increased after 1.0 mg/kg and 2.0 mg/kg doses. Subcutaneous administration of 8.0 mg/kg testosterone increased dopamine and serotonin in the neostriatum only. We conclude that intranasal administration of testosterone is a more efficacious way for targeting the brain than the subcutaneous route, and may be considered as a means to activate central dopaminergic and serotonergic systems.

Simultaneous measurement of serum testosterone and dihydrotestosterone by liquid chromatography-tandem mass spectrometry

BACKGROUND

Recent reports have described inherent problems with androgen immunoassays compared with mass spectrometry analyses.

METHODS

We developed a method for measuring serum testosterone (T) and 5alpha-dihydrotestosterone (DHT) simultaneously via liquid-liquid extraction followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) with positive-mode electrospray ionization.

RESULTS

The DHT and T calibrators showed a linear response from 0.069 nmol/L to 34.4 nmol/L and 69.3 nmol/L, respectively. T interference in the DHT assay and vice versa were negligible. Within- and between-run imprecision values were <5% for both analytes. Percent recoveries of T and DHT spiked into samples at concentrations spanning the calibration curve were 100%-113% and 98%-107%, respectively. The lower limit of quantification was 0.069 nmol/L for both steroids. Serum T concentrations measured by LC-MS/MS were different from those obtained by RIA, especially at lower T concentrations. Serum DHT concentrations measured by LC-MS/MS were markedly lower than those generated by RIA because of the nonselectivity of the RIA without chromatography. The reference intervals (mean +/- 2 SDs) determined for T and DHT were 9.2-33.7 nmol/L and 0.47-2.65 nmol/L, respectively, for 113 healthy adult men and 0.33-2.02 nmol/L and 0.09-0.91 nmol/L, respectively, for 133 healthy premenopausal women.

CONCLUSIONS

We have developed and validated a selective and precise method for simultaneous measurements of serum T and DHT that can be adopted for routine measurements of these androgens in health and disease in men and women.