Single and multi-dose pharmacology of recombinant and urinary human chorionic gonadotrophin in men

OBJECTIVE

Human choriogonadotrophin (hCG) treatment of gonadotrophin-deficient infertile men uses hCG of urinary (uhCG) or recombinant (rhCG) origin, but these treatments have not been compared nor are there studies defining rhCG dosing in men.

DESIGN

hCG products were studied in randomized cross-over single-dose studies of standard (Study 1, 1500 IU and 62.5 µg, respectively) or high (Study 2, 5000 IU and 250 µg) dose and a multi-dose population pharmacology study of hCG use.

PARTICIPANTS

Eight (Study 1) and seven (Study 2) volunteers in cross-over and 52 gonadotrophin-deficient men in the multi-dose study MEASUREMENTS: In cross-over studies, serum testosterone (T), dihydrotestosterone (DHT) and estradiol by liquid chromatography-mass spectrometry (LCMS) and serum hCG, LH, FSH, SHBG and T (observational study) by immunoassays.

RESULTS

After standard and high-dose injection, serum hCG and testosterone responses had similar timing and peak concentrations except for a mildly lower early (<48 h) serum testosterone with uhCG. In the multi-dosing study, both hCGs had similar pharmacokinetics (pooled half-life 5.8 days, p < .001), while serum testosterone concentrations were stable after injection and did not differ between hCG products. Bench testing verified that 20% of pens from 4/10 individuals were used inappropriately.

CONCLUSIONS

Although hCG pharmacokinetics are not formally bioequivalent, the similar pharmacodynamic effects on serum testosterone indicate that at the doses tested both hCGs provide comparable clinical effects. The starting dose of rhCG for treating gonadotrophin-deficient men should be 62.5 µg (6 clicks) of the rhCG pen.

Sex steroids and androgen biomarkers in the healthy man study: within-person variability and impact of fasting

OBJECTIVE

Serum testosterone measurements in clinical practice mostly utilize "direct" (non-extraction) immunoassays which have method-specific bias due to steroid cross-reactivity and nonspecific matrix artifacts. Although more accurate, sensitive, and specific liquid chromatography-mass spectrometry (LCMS) dominates in clinical research, the within-person variability of serum testosterone in healthy men using LCMS measurement is not reported.

DESIGN

Longitudinal multi-sampling observational study of men in excellent health over 3 months.

METHODS

Elite healthy men (n = 325) over 40 years of age in excellent, asymptomatic health provided 9 blood samples over 3 months with serum testosterone, dihydrotestosterone (DHT), estradiol (E2), and estrone (E1) measured by validated LCMS with conventional biochemical and anthropometric variables.

RESULTS

Quantitative estimates of within-person variability within day and between day, week, month, and quarter were stable other than an increase due to fasting. The androgen biomarkers most sensitive to age and testosterone among widely used biochemical and anthropometric variables in middle-aged and older men were identified.

CONCLUSIONS

This study provides estimates of variability in serum testosterone and the best androgen biomarkers that may prove useful for future studies of androgen action in male ageing.

Long-term Outcomes of Testosterone Treatment in Men: A T4DM Postrandomization Observational Follow-up Study

CONTEXT

The T4DM study randomized 1007 men with impaired glucose tolerance or newly diagnosed diabetes to testosterone undecanoate (TU, 1000 mg) or matching placebo (P) injections every 12 weeks for 24 months with a lifestyle program with testosterone (T) treatment reducing diabetes diagnosis by 40%.

BACKGROUND

The long-term effects on new diagnosis of diabetes, cardiovascular and prostate disease, sleep apnea, weight maintenance trajectory and androgen dependence were not yet described.

METHODS

A follow-up email survey after a median of 5.1 years since last injection obtained 599 (59%) completed surveys (316 T, 283 P), with participants in the follow-up survey compared with nonparticipants in 23 anthropometric and demographic variables.

RESULTS

Randomization to was TU associated with stronger belief in study benefits during (64% vs 49%, P < .001) but not after the study (44% vs 40%, P = .07); there is high interest in future studies. At T4DM entry, 25% had sleep apnea with a new diagnosis more frequent on TU (3.0% vs 0.4%, P = .03) during, but not after, the study. Poststudy, resuming prescribed T treatment was more frequent among TU-treated men (6% vs 2.8%, P = .03). Five years after cessation of TU treatment there was no difference in self-reported rates of new diagnosis of diabetes, and prostate or cardiovascular disease, nor change in weight maintenance or weight loss behaviors.

CONCLUSION

We conclude that randomized T treatment for 24 months in men with impaired glucose tolerance or new diabetes but without pathological hypogonadism was associated with higher levels of self-reported benefits and diagnosis of sleep apnea during, but not after, the study as well as more frequent prescribed poststudy T treatment consistent with androgen dependence in some men receiving prolonged injectable TU.

Recovery of male reproductive endocrine function after ceasing prolonged testosterone undecanoate injections

CONTEXT

The time course of male reproductive hormone recovery after stopping injectable testosterone undecanoate (TU) treatment is not known.

OBJECTIVE

The aim of this study was to investigate the rate, extent, and determinants of reproductive hormone recovery over 12 months after stopping TU injections.

MATERIALS AND METHODS

Men (n = 303) with glucose intolerance but without pathologic hypogonadism who completed a 2-year placebo (P)-controlled randomized clinical trial of TU treatment were recruited for further 12 months while remaining blinded to treatment. Sex steroids (testosterone (T), dihydrotestosterone, oestradiol, oestrone) by liquid chromatography-mass sprectometry, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and sex hormone-binding globulin (SHBG) by immunoassays and sexual function questionnaires (Psychosexual Diary Questionnaire, International Index of Erectile Function, and short form survey (SF-12)) were measured at entry (3 months after the last injection) and 6, 12, 18, 24, 40, and 52 weeks later.

RESULTS

In the nested cohort of TU-treated men, serum T was initially higher but declined at 12 weeks remaining stable thereafter with serum T and SHBG at 11 and 13%, respectively, lower than P-treated men. Similarly, both questionnaires showed initial carry-over higher scores in T-treated men but after 18 weeks showed no difference between T- and P-treated men. Initially, fully suppressed serum LH and FSH recovered slowly towards the participant's own pre-treatment baseline over 12 months since the last injection.

CONCLUSIONS

After stopping 2 years of 1000 mg injectable TU treatment, full reproductive hormone recovery is slow and progressive over 15 months since the last testosterone injection but may take longer than 12 months to be complete. Persistent proportionate reduction in serum SHBG and T reflects lasting exogenous T effects on hepatic SHBG secretion rather than androgen deficiency.

Optimal injection interval for testosterone undecanoate treatment of hypogonadal and transgender men

OBJECTIVE

To define the optimized inter-injection interval of injectable testosterone undecanoate (TU) treatment for hypogonadal and transmen based on individual dose titration in routine clinical practice.

DESIGN AND METHODS

A prolective observational study of consecutive TU injections in men undergoing testosterone replacement therapy for pathological hypogonadism or masculinization of female-to-male transgender (transmen) subject to individual dosing titration to achieve a stable replacement regimen.

RESULTS

From 2006 to 2019, 6899 injections were given to 325 consecutive patients. After excluding the 6-week loading dose, 6300 injections were given to 297 patients who had at least three and a median of 14 injections. The optimal injection interval (mean of last three injection intervals) had a median of 12.0 weeks (interquartile range 10.4-12.7 weeks). The interval was significantly influenced by age and body size (body surface area, BSA) but not by diagnosis or trough serum LH, FSH, and SHBG. Longer (≥14 weeks; 68/297, 23%), but not shorter (≤10 weeks; 22/297, 7.4%), intervals were weakly correlated with age but not diagnosis or other covariables. Low blood hemoglobin increased with trough serum testosterone to reach plateau once testosterone was about 10 nmol/L or higher.

CONCLUSION

Optimal intervals between TU injection after individual titration resulted in the approved 12-week interval in 70% of patients with only minor influence for clinical application of BSA and not of trough serum LH, FSH, and SHBG. Individually optimized inter-injection interval did not differ between men with primary or secondary hypogonadism or transmen.

Rate and Extent of Recovery from Reproductive and Cardiac Dysfunction Due to Androgen Abuse in Men

CONTEXT

Androgen abuse impairs male reproductive and cardiac function, but the rate, extent, and determinants of recovery are not understood.

OBJECTIVE

To investigate recovery of male reproductive and cardiac function after ceasing androgen intake in current and past androgen abusers compared with healthy non-users.

METHODS

Cross-sectional, observational study recruited via social media 41 current and 31 past users (≥3 months since last use, median 300 days since last use) with 21 healthy, eugonadal non-users. Each provided a history, examination, and serum and semen sample and underwent testicular ultrasound, body composition analysis, and cardiac function evaluation.

RESULTS

Current abusers had suppressed reproductive function and impaired cardiac systolic function and lipoprotein parameters compared with non- or past users. Past users did not differ from non-users, suggesting full recovery of suppressed reproductive and cardiac functions after ceasing androgen abuse, other than residual reduced testicular volume. Mean time to recovery was faster for reproductive hormones (anti-Mullerian hormone [AMH], 7.3 months; luteinizing hormone [LH], 10.7 months) than for sperm variables (output, 14.1 months) whereas spermatogenesis (serum follicle-stimulating hormone [FSH], inhibin B, inhibin) took longer. The duration of androgen abuse was the only other variable associated with slower recovery of sperm output (but not hormones).

CONCLUSION

Suppressed testicular and cardiac function due to androgen abuse is effectively fully reversible (apart from testis volume and serum sex hormone binding globulin) with recovery taking between 6 to 18 months after ceasing androgen intake with possible cumulative effects on spermatogenesis. Suppressed serum AMH, LH, and FSH represent convenient, useful, and underutilized markers of recovery from androgen abuse.

Complications of injectable testosterone undecanoate in routine clinical practice

OBJECTIVE

Injectable testosterone undecanoate (TU) was marketed within the last decade, but its complications in routine clinical practice are not well defined.

DESIGN AND METHODS

Prospective observational study of consecutive TU injections in an Andrology Clinic to estimate the incidence of i) immediate cough/syncope due to pulmonary oil microembolisation (POME), ii) post-injection haematoma and iii) the prevalence of secondary polycythaemia.

RESULTS

In 3022 injections given to 347 patients over 3.5 years, POME was observed after 56 injections (66% mild, 19% severe; 40% with onset before injection completed) in 43 patients. The incidence of 19 (95% CI 14-24) per 1000 injections did not differ between three experienced nurse injectors, but recurrences were more frequent than by chance. No post-injection haematoma was reported including after 269 injections to men taking antiplatelet, anticoagulant or both drugs (upper 95% confidence limit 1%) with 56 not withholding drugs prior to TU administration (upper 95% confidence limit 5.4%). Mean haematocrit was 0.44±0.04 (s.d.) with 25 (7%) >0.50, 14 (4%) >0.52 and 3 (1%) >0.54.

CONCLUSION

TU injections produce a low incidence of POME with injections by experienced nurses, but recurrence is more frequent than by chance. Post-injection haematoma was not observed even among men using anticoagulant and/or antiplatelet drugs, and polycythaemia was a minor problem rarely requiring treatment other than optimising inter-injection interval.

Detection and effects on serum and urine steroid and LH of repeated GnRH analog (leuprolide) stimulation

Non-steroidal drugs that increase endogenous testosterone (T) may be used to exploit ergogenic effects of androgens in power sports. While superactive GnRH analog use is suspected, neither screening nor detection tests are developed. This study aimed to determine if (a) stimulation for 5 days by leuprolide (a superactive GnRH analog) of serum and urine steroids and urine LH is reproducible at a 2 week interval, (b) nandrolone decanoate (ND) co-administration masks responses to leuprolide administration, (c) performance of urine measurement of leuprolide and M1, its major metabolite, as a detection test. Healthy men were randomized into a 4 week parallel group, open label clinical study in which all men had daily sc injections of leuprolide (1mg) for 4 days in the 1st and 3rd weeks with hormone-free 2nd and 4th weeks. In the 3rd week, men were randomized to either ND injections or no extra treatment. Serum steroids were determined by liquid chromatography, tandem mass spectrometry (LC-MS), urine steroids by gas chromatography, mass spectrometry (GC-MS), urine leuprolide and M1 by high resolution LC-MS and urine LH by immunoassay. Leuprolide stimulated striking, reproducible increases in serum and urine LH and steroids (serum T, dihydroT (DHT), 3α diol; urine T, epitestosterone (E) and androsterone (A). ND suppressed basal serum T, E2, 3α diol, and urinary E but did not mask or change the magnitude of responses to leuprolide. Urine leuprolide and M1 measurement had 100% sensitivity and specificity in detecting leuprolide administration up to one day after cessation of injections with the detection window between 1 and 3 days after last dose. Screening using urine steroid and LH measurements, optimally by urinary log10(LHxT), correctly classified 82% of urine samples. It is concluded that leuprolide stimulation of endogenous testosterone is reproducible after a 10-day interval, is not masked by ND and is reliably detected by urine leuprolide or M1 measurement for at least 1 day after administration.

Dispersion of a Nanoliter Bolus in Microfluidic Co-Flow

Microfluidic systems enable reactions and assays on the scale of nanoliters. However, at this scale nonuniformities in sample delivery become significant. To determine the fundamental minimum sample volume required for a particular device, a detailed understanding of mass transport is required. Co-flowing laminar streams are widely used in many devices, but typically only in the steady-state. Because establishing the co-flow steady-state consumes excess sample volume and time, there is a benefit to operating devices in the transient state, which predominates as the volume of the co-flow reactor decreases. Analysis of the co-flow transient has been neglected thus far. In this work we describe the fabrication of a pneumatically controlled microfluidic injector constructed to inject a discrete 50nL bolus into one side of a two-stream co-flow reactor. Using dye for image analysis, injections were performed at a range of flow rates from 0.5-10μL/min, and for comparison we collected the co-flow steady-state data for this range. The results of the image analysis were also compared against theory and simulations for device validation. For evaluation, we established a metric that indicates how well the mass distribution in the bolus injection approximates steady-state co-flow. Using such analysis, transient-state injections can approximate steady-state conditions within predefined errors, allowing straight forward measurements to be performed with reduced reagent consumption.

Randomised controlled trial of whether erotic material is required for semen collection: impact of informed consent on outcome

Semen is collected to evaluate male fertility or cryostore sperm preferentially in laboratories but such collection facilities have no standard fit-out. It is widely believed but untested whether providing erotic material (EM) is required to collect semen by masturbation in the unfamiliar environment. To test this assumption, 1520 men (1046 undergoing fertility evaluation, 474 sperm cryostorage, providing 1932 semen collection episodes) consecutively attending the semen laboratory of a major metropolitan teaching hospital for semen analysis were eligible for randomization to be provided or not with printed erotic material EM (X-rated, soft-core magazines) during semen collection. Randomization was performed by providing magazines in the collection rooms (as a variation on non-standard fit-out) on alternate weeks using a schedule concealed from participants. In the pilot study, men were randomized without seeking consent. In the second part of the study, which continued on from the first without interruption, an approved informed consent procedure was added. The primary outcome, the time to collect semen defined as the time from receiving to returning the sample receptacle, was significantly longer (by ~6%, 14.9 ± 0.3 [mean ± standard error of mean] vs. 14.0 ± 0.2 minutes, p = 0.02) among men provided with EM than those randomized to not being provided. There was no significant increase in the failure to collect semen samples (2.6% overall) nor any difference in age, semen volume or sperm concentration, output or motility according to whether EM was provided or not. The significantly longer time to collect was evident in the pilot study and the study overall, but not in the main study where the informed consent procedure was used. This study provides evidence that refutes the assumption that EM needs to be provided for semen collection in a laboratory. It also provides an example of a usually unobservable participation bias influencing study outcome of a randomized controlled trials.

Serum testosterone, dihydrotestosterone and estradiol concentrations in older men self-reporting very good health: the healthy man study

OBJECTIVE

To determine serum concentrations, intra-individual variability and impact of age-related co-morbidities on serum testosterone (T), dihydrotestosterone (DHT), estradiol (E(2)) and estrone (E(1)) in older men.

DESIGN

Observational, repeated measures study.

PARTICIPANTS

Men (n = 325) with 40 years and older self-reporting very good or excellent health.

MEASUREMENTS

Standardized history, physical examination and collection of nine blood samples at fixed time intervals were measured over 3 months (three at 20 min intervals on days 1 (fasting) and 2 (non-fasting), one at days 7, 30 and 90). Serum T, DHT, E(2) and E(1) (n = 2900, > 99% of scheduled samples) measured by liquid chromatography-tandem mass spectrometry (LC-MS) were analysed by linear mixed model analysis with fasting, age and obesity as covariables.

RESULTS

Mean serum T did not vary with age (P = 0·76) but obesity (-0·35 nM per body mass index (BMI) unit, P < 0·0001) and ex-smoker status (-1·6 nM, P < 0·001) had significant effects. Serum DHT was increased with age (+0·011 nM per year, P = 0·001) but decreased with obesity (-0·05 nM per BMI unit, P < 0·0001). Serum E(2) did not vary with age (P = 0·31) or obesity (P = 0·12). Overnight fasting increased (by 9-16%, all P < 0·001) and reduced variability in morning serum T, DHT, E(2) and E(1). Non-fasting serum T and DHT were stable over time (day, week, month or 3 months; P > 0·28).

CONCLUSIONS

Serum T, DHT and E(2) displayed no decrease associated with age among men over 40 years of age who self-report very good or excellent health although obesity and ex-smoking status were associated with decreased serum androgens (T and DHT) but not E(2). These findings support the interpretation that the age-related decline in blood T accompanying non-specific symptoms in older men may be due to accumulating age-related co-morbidities rather than a symptomatic androgen deficiency state.

Long-term effects of dihydrotestosterone treatment on prostate growth in healthy, middle-aged men without prostate disease: a randomized, placebo-controlled trial

BACKGROUND

Benign prostatic hypertrophy increases with age and can result in substantially decreased quality of life for older men. Surgery is often required to control symptoms. It has been hypothesized that long-term administration of a nonamplifiable pure androgen might decrease prostate growth, thereby decreasing or delaying the need for surgical intervention.

OBJECTIVE

To test the hypothesis that dihydrotestosterone (DHT), a nonamplifiable and nonaromatizable pure androgen, reduces late-life prostate growth in middle-aged men.

DESIGN

Randomized, placebo-controlled, parallel-group trial. (Australian New Zealand Clinical Trials Registry number: ACTRN12605000358640) SETTING: Ambulatory care research center.

PARTICIPANTS

Healthy men (n = 114) older than 50 years without known prostate disease.

INTERVENTION

Transdermal DHT (70 mg) or placebo gel daily for 2 years.

MEASUREMENTS

Prostate volume was measured by ultrasonography; bone mineral density (BMD) and body composition were measured by dual-energy x-ray absorptiometry; and blood samples and questionnaires were collected every 6 months, with data analyzed by mixed-model analysis for repeated measures.

RESULTS

Over 24 months, there was an increase in total (29% [95% CI, 23% to 34%]) and central (75% [CI, 64% to 86%]; P < 0.01) prostate volume and serum prostate-specific antigen level (15% [CI, 6% to 24%]) with time on study, but DHT had no effect (P > 0.2). Dihydrotestosterone treatment decreased spinal BMD (1.4% [CI, 0.6% to 2.3%]; P < 0.001) at 24 months but not hip BMD (P > 0.2) and increased serum aminoterminal propeptide of type I procollagen in the second year of the study compared with placebo. Dihydrotestosterone increased serum DHT levels and its metabolites (5α-androstane-3α,17β-diol and 5α-androstane-3β,17β-diol) and suppressed serum testosterone, estradiol, luteinizing hormone, and follicle-stimulating hormone levels. Dihydrotestosterone increased hemoglobin levels (7% [CI, 5% to 9%]), serum creatinine levels (9% [CI, 5% to 11%]), and lean mass (2.4% [CI, 1.6% to 3.1%) but decreased fat mass (5.2% [CI, 2.6% to 7.7%]) (P <0.001 for all). Protocol-specific discontinuations due to DHT were asymptomatic increased hematocrit (n = 8), which resolved after stopping treatment, and increased prostate-specific antigen levels (n = 3; none with prostate cancer) in the DHT group. No serious adverse effects due to DHT occurred.

LIMITATION

Negative findings on prostate growth cannot exclude adverse effects on the natural history of prostate cancer.

CONCLUSION

Dihydrotestosterone treatment for 24 months has no beneficial or adverse effect on prostate growth but causes a decrease in spinal but not hip BMD. These findings have important implications for the wider use of nonsteroidal pure androgens in older men.

PRIMARY FUNDING SOURCE

BHR Pharma.

Randomized cross-over clinical trial of injectable vs. implantable depot testosterone for maintenance of testosterone replacement therapy in androgen deficient men

BACKGROUND

Life-long testosterone replacement therapy (TRT) for younger men with organic androgen deficiency is best provided by depot testosterone (T) products. This study compared directly the two long-acting depot T products, subdermal T implants (TI) and injectable T undecanoate (TU) for maintenance of TRT.

DESIGN, SETTING AND PARTICIPANTS

Men with organic androgen deficiency (n = 38) undergoing regular TRT at an academic Andrology centre were recruited for a two period, randomized sequence, cross-over clinical trial without intervening wash-out period of TRT maintenance.

OUTCOMES

For both depot T products, their pharmacokinetics and pharmacodynamics were evaluated using a range of androgen sensitive clinical, laboratory and quality of life measures as well as preference for ongoing treatment after experience of both products.

RESULTS

The two depot T products had distinct pharmacokinetics and were not bioequivalent. However, there were no consistent clinical differences in a comprehensive range of pharmacodynamic measures reflecting androgen effects on biochemistry and haematology, muscle mass and strength, and quality of life, mood and sexual function. The majority (91%) of participants chose TU over TI at study completion.

CONCLUSION

Despite significant pharmacokinetic differences, the two depot T products are clinically interchangeable allowing for choice dependent on patient and physician delivery preference in practice but most patients preferred the injectable over the implantable form.

Induction of spermatogenesis and fertility during gonadotropin treatment of gonadotropin-deficient infertile men: predictors of fertility outcome

BACKGROUND

The induction of spermatogenesis and fertility with gonadotropin therapy in gonadotropin-deficient men varies in rate and extent. Understanding the predictors of response would inform clinical practice but requires multivariate analyses in sufficiently large clinical cohorts that are suitably detailed and frequently assessed.

DESIGN, SETTING, AND PARTICIPANTS

A total of 75 men, with 72 desiring fertility, was treated at two academic andrology centers for a total of 116 courses of therapy from 1981-2008.

OUTCOMES

Semen analysis and testicular examination were performed every 3 months.

RESULTS

A total of 38 men became fathers, including five through assisted reproduction. The median time to achieve first sperm was 7.1 months [95% confidence interval (CI) 6.3-10.1]) and for conception was 28.2 months (95% CI 21.6-38.5). The median sperm concentration at conception for unassisted pregnancies was 8.0 m/ml (95% CI 0.2-59.5). Multivariate correlated time-to-event analyses show that larger testis volume, previous treatment with gonadotropins, and no previous androgen use each independently predicts faster induction of spermatogenesis and unassisted pregnancy.

CONCLUSIONS

Larger testis volume is a useful prognostic indicator of response. The association of slower responses after prior androgen therapy suggests that faster pregnancy rates might be achieved by substituting gonadotropin for androgen therapy for pubertal induction, although a prospective randomized trial will be required to prove this.

Effects of testosterone and nandrolone on cardiac function: a randomized, placebo-controlled study

BACKGROUND

Androgens have striking effects on skeletal muscle, but the effects on human cardiac muscle function are not well defined, neither has the role of metabolic activation (aromatization, 5alpha reduction) of testosterone on cardiac muscle been directly studied.

OBJECTIVE

To assess the effects of testosterone and nandrolone, a non-amplifiable and non-aromatizable pure androgen, on cardiac muscle function in healthy young men.

DESIGN

Double-blind, randomized, placebo-controlled, three-arm parallel group clinical trial.

SETTING

Ambulatory care research centre.

PARTICIPANTS

Healthy young men randomized into three groups of 10 men.

INTERVENTION

Weekly intramuscular injections of testosterone (200 mg mixed esters), nandrolone (200 mg nandrolone decanoate) or matching (2 ml arachis oil vehicle) placebo for 4 weeks.

MAIN OUTCOME MEASURES

Comprehensive measures of cardiac muscle function involving transthoracic cardiac echocardiography measuring myocardial tissue velocity, peak systolic strain and strain rates, and bioimpedance measurement of cardiac output and systematic vascular resistance.

RESULTS

Left ventricular (LV) function (LV ejection fraction, LV modified TEI index), right ventricular (RV) function (ejection area, tricuspid annular systolic planar motion, RV modified TEI index) as well as cardiac afterload (mean arterial pressure, systemic vascular resistance) and overall cardiac contractility (stroke volume, cardiac output) were within age- and gender-specific reference ranges and were not significantly (P < 0.05) altered by either androgen or placebo over 4 weeks of treatment. Minor changes remaining within normal range were observed solely within the testosterone group for: increased LV end-systolic diameter (30 +/- 7 vs. 33 +/- 5 mm, P = 0.04) and RV end-systolic area (12.8 +/- 1.3 vs. 14.6 +/- 3.3 cm(2), P = 0.04), reduced LV diastolic septal velocity (Em, 9.5 +/- 2.6 vs. 8.7 +/- 2.0 cm/s, P = 0.006), increased LV filling pressure (E/Em ratio, 7.1 +/- 1.6 vs. 8.3 +/- 1.8, P = 0.02) and shortened PR interval on the electrocardiogram (167 +/- 13 vs. 154 +/- 12, P = 0.03).

CONCLUSION

Four weeks of treatment with testosterone or nandrolone had no beneficial or adverse effects compared with placebo on cardiac function in healthy young men.

Adequacy of androgen replacement influences bone density response to testosterone in androgen-deficient men

OBJECTIVE

Androgen deficiency (AD) leads to bone loss and contributes to osteoporotic fractures in men. Although low bone mineral density (BMD) in AD men is improved by testosterone replacement, the responses vary between individuals but the determinants of this variability are not well defined.

DESIGN AND METHODS

Retrospective review of dual energy X-ray absorptiometry (DEXA) of the lumbar spine and proximal femur in men with established AD requiring regular androgen replacement therapy (ART). After a DEXA scan all men were treated with testosterone implants (800 mg, approximately 6 month intervals). Patients were classified as having a congenital, childhood, or post-pubertal onset, as well as according to the adequacy of treatment prior to their first DEXA scan as untreated, partially treated or well treated.

RESULTS

Men with AD requiring regular ART (n = 169, aged 46.3+/-1.1 years, range 22-84 years) underwent a DEXA scan prior to being treated with testosterone implants (800 mg, approximately 6 month intervals). In cross-sectional analysis at the time of the first DEXA scan untreated men (n = 24) had significantly reduced age-adjusted BMD at all four sites (L1-L4, femoral neck, Ward's triangle and trochanter). Well-treated men (n = 77) had significantly better age-adjusted BMD at all four sites compared with those who were partially treated (n = 66) or untreated (n = 24) with their age-adjusted BMD being normalized. In a longitudinal assessment of men (n = 60) who had two or more serial DEXA scans, at the second DEXA scan after a median of 3 years, men who were previously partially treated (n = 19) or untreated (n = 11) had proportionately greater improvements in BMD, significantly for Ward's triangle (P = 0.025) and the trochanter (P = 0.044) compared with men (n = 30) previously well treated.

CONCLUSIONS

The present study demonstrates a positive relationship between adequacy of testosterone replacement and BMD in men with overt organic AD. Additionally, the BMD of well-treated AD men approximates that of age-matched non-AD controls. The greatest BMD gains are made by those who have been either untreated or partially treated, and optimal treatment over time (median 3 years) normalizes BMD to the level expected for healthy men of the same age.

Blood testosterone threshold for androgen deficiency symptoms

There are few systematic studies of the relationship between blood testosterone concentrations and the symptoms of overt androgen deficiency. Because most testosterone preparations are relatively short-term, the rapid changes in blood testosterone concentrations they cause make it difficult to define any testosterone threshold. By contrast, subdermal testosterone implants provide stable blood testosterone concentrations over days to weeks, while gradually declining to baseline over 5-7 months. Hence, this provides an opportunity to define a blood testosterone threshold for androgen deficiency symptoms by observing androgen-deficient men as their familiar androgen deficiency symptoms return as testosterone pellets slowly dissolve. Among 52 androgen-deficient men who underwent 260 implantations over 5 yr, at the time of return of androgen deficiency symptoms the blood total and free testosterone concentrations were highly reproducible within individuals (F = 0.8, P = 0.49 and F = 1.4, 0.24, respectively) but varied markedly between men (F = 167 and F = 138, both P < 0.001), indicating that each person had a consistent testosterone threshold for androgen deficiency symptoms that differed markedly between individuals. The most reported symptoms of androgen deficiency were lack of energy, lack of motivation, and reduced libido. The symptomatic threshold was significantly lower in men with secondary hypogonadism compared with men with primary or mixed hypogonadism (total, 9.7 +/- 0.5 nmol/liter vs. 11.7 +/- 0.4 nmol/liter and 10.2 +/- 0.3 nmol/liter, P = 0.006; free, 146 +/- 10 pmol/liter vs. 165 +/- 6 pmol/liter and 211 +/- 18 pmol/liter, P = 0.002) but was not affected by the underlying cause of hypogonadism or by specific symptoms of any severity. Despite a wide range in individual thresholds for androgen deficiency symptoms, the mean blood testosterone threshold corresponded to the lower end of the eugonadal reference range for young men. The implications of these observations for the development of more specific quality-of-life measures, as well as for other potential androgen deficiency states such as chronic diseases and aging, remain to be determined.

Testosterone release rate and duration of action of testosterone pellet implants

OBJECTIVE

Testosterone pellets are a highly effective subdermal depot administered at regular intervals with the timing individualized depending upon return of the patient's characteristic androgen deficiency symptoms. Yet the in vivo testosterone release rate and effective duration of action of these pellets has been little studied systematically.

DESIGN

Analysis of prospectively collected data from three randomized controlled clinical trials. Collection of extruded pellets.

PATIENTS

Androgen-deficient men (n = 136) undergoing long-term androgen replacement therapy with a standard dose (800 mg) of testosterone pellets implanted subdermally at intervals from 5 to 7 months.

MEASUREMENTS

Testosterone release rate of pellets, consisting of pure crystalline testosterone without excipients, is estimated by measuring the dry weight lost by pellets (n = 179) over their time in situ. The effective duration of the standard regimen, and the influence of extrusion and patient or procedural characteristics on it, was estimated by timing of return for re-implantation due to recurrence of the patient's familiar androgen deficiency symptoms.

RESULTS

The loss of dry weight of intact (n = 112) pellets was strongly correlated with time in situ (r2 = 0.969) providing an estimate of daily testosterone release rate per 200 mg pellet of 1.34 +/- 0.02 mg/pellet/day (95% CI 1.30-1.37 mg/day) for the first 3 months. After 756 implantations of the standard dose, men return for re-implantation at 5.8 calendar months following no or only a single pellet extrusion, but the time to return was significantly shorter after multiple extrusions. No patient or procedural features influenced the timing of return. Among men with primary hypogonadism, increases in plasma LH and FSH were more sensitive than plasma total or free testosterone to changes in testosterone delivery following an extrusion.

CONCLUSION

Testosterone pellet implants release testosterone at a steady rate of 1.3 mg/200 mg implant/day (95% CI). The duration of action is about 6 months in an uncomplicated cycle with timing of return shortened by extrusions only in the 3.6% of procedures followed by multiple extrusions. No other patient or procedural features influenced duration of action. Among men with an intact hypothalamo-pituitary unit, plasma gonadotropins are more sensitive than blood total or free testosterone to reduced testosterone delivery following an extrusion.

Contraceptive efficacy of a depot progestin and androgen combination in men

WHO studies provided proof of concept for hormonal male contraception using a prototype androgen-alone regimen. Combined testosterone plus progestin regimens offer more practical promise, but no contraceptive efficacy studies have been completed. The objective of this study was to establish the proof of principle for depot hormonal androgen/progestin combination as a male contraceptive. We performed a contraceptive efficacy study of 55 healthy men in stable fertile relationships seeking a change in contraceptive method. Testosterone (four 200-mg implants, every 4 or 6 months) and 300 mg depot medroxyprogesterone acetate, im, every 3 months were administered. Once sperm output was suppressed (<1 million/ml for 2 consecutive months), men entered a 12-month contraceptive efficacy period, ceasing other contraception. The main outcome measure was contraceptive failure (pregnancy) rate. No pregnancies occurred in 426 person-months (35.5 person-years; 95% confidence limits for contraceptive failure rate, 0-8%/annum), superior to the first year failure rate of condoms, the only reversible male method. Sperm density fell rapidly, so 94% of men entered the efficacy phase by 3 months, with only 2 of 55 (3.6%) men not sufficiently suppressed to enter efficacy. A few men treated with testosterone implants at 6-month intervals demonstrated androgen deficiency symptoms and/or escape of gonadotropin and spermatogenic suppression between months 5 and 6; after a protocol amendment, all men receiving testosterone implants at 4-month intervals avoided androgen deficiency or loss of gonadotropin and sperm output suppression. Recovery was complete (median, 3.6 months to sperm reappearance and 5.0 months to 20 million sperm/ml) in all but one man with an incidental testicular disorder. Discontinuations were for protocol-related reasons (n = 15) or altered personal circumstances (n = 12), but there were no serious adverse effects related to drug exposure. The first male contraceptive efficacy study using a prototype depot androgen/progestin combination demonstrates high contraceptive efficacy with satisfactory short-term safety and recovery of spermatogenesis. Further studies of purpose-developed products are required to extend the overall safety and efficacy experience with depot androgen/progestin combinations, the most promising approach to hormonal male contraception.

Induction of spermatogenesis by recombinant follicle-stimulating hormone (puregon) in hypogonadotropic azoospermic men who failed to respond to human chorionic gonadotropin alone

A multicenter, open-label, randomized efficacy and safety study was performed with combined human chorionic gonadotropin (hCG) and recombinant follicle-stimulating hormone (recFSH) (Puregon(R)) treatment to induce spermatogenesis in hypogonadotropic hypogonadal male patients. Patients were pretreated for 16 weeks with hCG to normalize testosterone levels. A total of 30 of 49 (61%) subjects had normalized testosterone levels but were still azoospermic after the hCG-alone phase. These patients were randomized into 2 treatment schemes with recFSH (2 x 225 IU recFSH per week [group A] or 3 x 150 IU recFSH per week [group B]), in combination with hCG for a period of 48 weeks. Total testosterone increased during the hCG-alone period from 1.08 and 1.22 ng/mL to 6.26 and 4.52 ng/mL for groups A and B, respectively. Combined gonadotropin treatment was effective in inducing spermatogenesis (sperm count >/=1 x 10(6)/mL) in 14 of 30 subjects (47%) and this was achieved after a median duration of treatment of approximately 5.5 months. Treatment time necessary for first sperm cells to appear in the ejaculate was related to the initial testicular volume. Subjects with a history of maldescended testes (11 of 30 subjects, 37%) showed a lower mean response to treatment as indicated by the relatively lower number of subjects reaching levels of at least 1 x 10(6) sperm cells per milliliter. Combined testicular volume increased during combined gonadotropin treatment from 11.4 to 24.0 mL. Although subjects with a history of maldescended testes had a lower starting testicular volume, subjects with and without a history of maldescended testes showed approximately the same relative increase in testicular volume. Total testosterone levels showed only a minor further increase during the combined gonadotropin treatment period. In conclusion, a weekly dose of 450 IU (3 x 150 IU or 2 x 225 IU) recFSH, in addition to hCG, was able to induce spermatogenesis in many hypogonadotropic azoospermic men who failed to respond to treatment with hCG alone.

Do reproductive hormones modify insulin sensitivity and metabolism in older men? A randomized, placebo-controlled clinical trial of recombinant human chorionic gonadotropin

OBJECTIVE

In order to assess the hormonal determinants of insulin sensitivity and related components of the metabolic syndrome, we evaluated the effect of subcutaneous recombinant human chorionic gonadotropin (r-hCG; Ovidrel) on insulin sensitivity, vascular reactivity, leptin, insulin-like growth factor-I (IGF-I) and lipids in ambulant, community dwelling men >60 Years of age with serum testosterone <or= 15 nmol/l on two occasions.

DESIGN

Forty eligible men were randomized to receive 250 microg (5000 IU) r-hCG subcutaneously twice each week (n=20) or placebo (n=20) injections for 3 Months, and all subjects (mean age 67 (range 60-85) Years) completed the study.

METHODS AND RESULTS

Groups were well matched for height, weight, anthropometry and insulin sensitivity. Insulin sensitivity was assessed by homeostasis model (HOMA) and euglycemic hyperinsulinemic clamp at baseline and at the end of the treatment period in the first 30 men who did not have diabetes mellitus. Insulin sensitivity (HOMA and euglycemic clamp) or beta cell function (HOMA) were not significantly changed by r-hCG despite a significant increase in lean body mass (approximately 2 kg, P<0.001) and reduced fat mass (approximately 1 kg, P<0.05). Subcutaneous fat (skinfold measurements), abdominal girth and serum leptin all decreased and IGF-I tended to increase, but these changes were not significant. Recombinant hCG significantly reduced total and low density lipoprotein cholesterol, and triglycerides, but did not significantly alter high density lipoprotein cholesterol. Endothelial function (vascular reactivity) was not significantly worsened. We conclude that three-Months of treatment with r-hCG demonstrates expected hormonal effects, improved lipids and did not worsen vascular endothelial function. Insulin sensitivity was not altered despite suggestive changes in body composition.

CONCLUSIONS

These findings suggest short-term metabolic and cardiovascular safety and argue against an important role for androgens in the hormonal control of insulin sensitivity in older men.

A randomised controlled clinical trial of antibiotic impregnation of testosterone pellet implants to reduce extrusion rate

OBJECTIVE

Testosterone pellet implantation is a safe, effective and convenient form of depot androgen replacement, with extrusion of pellets following about 10% of procedures the most frequent adverse effect. This study aimed to determine whether extrusion rate could be reduced by antibiotic impregnation of pellets immediately prior to implantation.

DESIGN

Prospective, randomised, parallel-group, open-label study design in a single centre. One hundred and eighty-six androgen-deficient men (400 implantation procedures) were randomised into either a group who had their pellets soaked for approximately 2 min in gentamicin solution prior to implantation, or a control group who had the standard implantation procedure.

METHODS

Extrusion, infection and/or bruising were evaluated prospectively by self-report from the participants, and retrospectively at subsequent implantation. Other variables (site, shaving, skin preparation, operator, pellet batch, bruising) were collected at implantation time.

RESULTS

The extrusion rate was 20% lower (odds ratio=0.80, 95% confidence interval (CI) 0.40-1.62) but not statistically different between the two groups (extrusion rate 23/205 (11.2%) for the control group vs 18/195 (9.2%) for the antibiotic-soak group, P=0.42). One operator experienced more total (P=0.0002) and infection-related (P=0.0008) extrusions and marginally more bruising (P=0.06) than other operators. The operator effect did not appear to be explained by differences in experience or implantation style. There was a 4.6-fold excess (95% CI 1.6-18.6) of multiple (19 vs 4 expected) over single (22 vs 10 expected) and no (359 vs 386 expected) extrusions. Extrusion was not related to batch number (P=0.15), location (P=0.15), shaving (P=0.32), old or new site (P=0.59), or the presence of suppuration or not (P=0.42); however, povidone-iodine skin disinfectant had statistically fewer extrusions than mixed alcohol solution.

CONCLUSIONS

Antibiotic impregnation prior to implantation does not significantly decrease testosterone pellet extrusion rate. An operator effect, not due to experience or procedural style, an excess of multiple extrusions and disinfectant effects were confirmed. Neither location, nor preparation of the site, nor pellet batch, influences extrusion rate.

Predicting pregnancy and spermatogenesis by survival analysis during gonadotrophin treatment of gonadotrophin-deficient infertile men

BACKGROUND

Predictors of fertility or spermatogenesis during gonadotrophin therapy of gonadotrophin-deficient men remain poorly defined.

METHODS AND RESULTS

In order to evaluate potential predictors, this study evaluated 29 consecutive gonadotrophin-deficient men all desiring paternity who received 43 courses of therapy in one centre between 1982 and 1998. The Kaplan-Meier survival analysis estimates of median (SE) time to a sperm concentration of >0, >5 and >20 x 10(6)/ml were 5.5 (1.1), 12.4 (2.3) and 29.1 (1.9) months respectively. Conception occurred in 22/43 cycles (with eight men achieving two pregnancies) with a median (SE) Kaplan-Meier estimate of 20.5 (4.7) months. The median sperm concentration at conception was 5.0 (SE 2.0; range 0.0-59.5) x 10(6)/ml. Multivariate correlated Cox proportional hazards models predicting these same sperm thresholds and conception were developed by forward stepwise variable selection with verification of the model by backward stepping. Larger testicular volume, prior gonadotrophin therapy, completion of puberty, older age, the absence of adverse fertility factors and the absence of multiple pituitary hormone deficiency predicted a favourable response. Multivariate modelling suggests that the two most important predictors of sperm output are testicular volume and pubertal status. The most important potentially modifiable predictor was prior gonadotrophin therapy. The efficacy of recombinant and urinary FSH were similar. Prior androgen therapy and partner's age did not appear to be significant.

CONCLUSIONS

Since prolonged treatment may be required to induce spermatogenesis, attention to these predictors may allow appropriate early use of advanced reproductive technologies.

Long-term outcomes of elective human sperm cryostorage

BACKGROUND

Sperm cryopreservation allows men with threatened fertility to preserve their progenitive potential, but there is little data on long-term outcomes of elective sperm cryostorage programmes.

METHODS AND RESULTS

Over 22 years, 930 men sought semen cryostorage in a single academic hospital, of which 833 (90%) had spermatozoa cryostored. Among 692 (74%) men surviving their illness, sperm samples were discarded for 193 (21% of all applicants, 28% of survivors) and cryostored spermatozoa were used for 64 men (7% of all applicants, 9% of survivors) in 85 treatment cycles commencing at a median of 36 months post-storage (range 12-180 months) with nearly 90% of usage started within 10 years of storage and none after 15 years. Pregnancy was most efficiently produced by intracytoplasmic sperm injection (median three cycles) compared with conventional IVF (median eight cycles) or artificial insemination (median more than six cycles; P < 0.05). A total of 141 (15%) of men had died and of these, 120 (85% of those dying) had their spermatozoa discarded; requests to prolong cryostorage were received from relatives of 21 men (2% of all applicants, 15% of deceased) of which three cases had spermatozoa transferred for use with no pregnancies reported. Sperm concentration was lower for all cryostorage groups compared with healthy sperm donor controls (P < 0.05). Following orchidectomy, men with testicular cancer had sperm density approximately half that of all other groups of men seeking cryostorage (P < 0.05), the lowering attributable to removal of one testis rather than in defects in spermatogenesis.

CONCLUSION

Elective sperm cryopreservation is an effective, if sparsely used, form of fertility insurance for men whose fertility is threatened by medical treatment and is an essential part of any comprehensive cancer care programme.

Influence of implantation site and track geometry on the extrusion rate and pharmacology of testosterone implants

BACKGROUND

Implantation of testosterone pellets under the lateral abdominal wall skin is an old but popular and effective form of androgen replacement therapy. Extrusion of one or more pellets remains the most frequent adverse event.

OBJECTIVE

To determine whether an alternative implantation site (hip) and/or track geometry (two vs. four tracks) would reduce extrusion rates compared with the standard of a four-track abdominal site. Additionally, the study aimed to evaluate the effects of site and track geometry on other adverse effects (bruising, infection) and the pharmacology of testosterone release from the implants.

DESIGN

A prospective, parallel-group unmasked study design in a single centre. The primary objective was to evaluate sites, with evaluation of track geometry a subordinate objective made necessary by anatomical differences. Accordingly, androgen deficient men requiring testosterone implantation with the standard dose (four 200 mg pellets) were randomized into one of three groups (ratio 1 : 1 : 2): a four-track abdomen site (standard), a two-track abdomen site or a two-track hip site. The pharmacological substudy was to evaluate the impact of site and track geometry on testosterone implant pharmacology by monthly hormone assays following implantation.

PATIENTS

Two hundred and forty-six implantation procedures involving 96 androgen deficient men.

MEASUREMENTS

The primary end-point, extrusion rate per procedure, and secondary end-points (bruising or infection post procedure) were evaluated prospectively by self-report from the participants, and verified when they returned next for implantation. The pharmacology substudy involved monthly blood sampling for hormone (total and free testosterone, LH, FSH) measurements.

RESULTS

The extrusion rate was significantly higher [odds ratio (OR) = 2.6, 95% confidence interval (CI) 1.1-7.1] for the hip site (15/125, 12%) compared with the abdominal site (6/121, 5%). Track geometry made no significant difference (OR = 1.05, 95% CI 0.2-5.4) to the extrusion rate. No secondary end-points (bruising, infection) were significantly different according to either site or track geometry. One operator who performed the implant procedures had significantly less primary and secondary adverse events than the other operators (P = 0.006). Neither implantation site, nor track geometry influenced pharmacokinetics [peak plasma total and free testosterone concentrations and net hormone release (area-under-curve, AUC)] or pharmacodynamics [nadir plasma LH and FSH and net suppression (AUC) in men with hypergonadotrophic hypogonadism].

CONCLUSIONS

We conclude that the hip site has a higher extrusion rate than the standard abdominal wall site but that track geometry does not increase the risk of extrusion. Neither implantation site, nor track geometry influenced either other adverse effects or the pharmacokinetics or pharmacodynamics of testosterone pellet implants.

A double-blind, placebo-controlled, randomized clinical trial of transdermal dihydrotestosterone gel on muscular strength, mobility, and quality of life in older men with partial androgen deficiency

The efficacy and safety of androgen supplementation in older men remains controversial. Despite biochemical evidence of partial androgen deficiency in older men, controlled studies using T demonstrate equivocal benefits. Furthermore, the importance of aromatization and 5alpha reduction in androgen actions among older men remains unclear. Dihydrotestosterone is the highest potency natural androgen with the additional features that it is neither aromatizable nor susceptible to potency amplification by 5alpha reduction. Therefore, the effects of dihydrotestosterone may differ from those of T in older men. This study evaluated the efficacy and safety of 3 months treatment with transdermal dihydrotestosterone gel on muscle strength, mobility, and quality of life in ambulant, community-dwelling men aged 60 yr or older. Eligible men (plasma T < or =15 nmol/liter) were randomized to undergo daily dermal application of 70 mg dihydrotestosterone gel (n = 18) or vehicle (n = 19) and were studied before, monthly during, and 1 month after treatment. Among 33 (17 dihydrotestosterone, 16 placebo) men completing the study with a high degree of compliance, dihydrotestosterone had significant effects on circulating hormones (increased dihydrotestosterone; decreased total and free testosterone, LH, and FSH; unchanged SHBG and estradiol), lipid profiles (decreased total and low-density lipoprotein cholesterols; unchanged high-density lipoprotein cholesterol and triglycerides), hematopoiesis (increased hemoglobin, hematocrit, and red cell counts), and body composition (decreased skinfold thickness and fat mass; unchanged lean mass and waist to hip ratio). Muscle strength measured by isokinetic peak torque was increased in flexion of the dominant knee but not in knee extension or shoulder contraction, nor was there any significant change in gait, balance, or mobility tests, in cognitive function, or in quality of life scales. Dihydrotestosterone treatment had no adverse effects on prostate (unchanged prostate volumes and prostate-specific antigen) and cardiovascular (no adverse change in vascular reactivity or lipids) safety markers. We conclude that 3 months treatment with transdermal dihydrotestosterone gel demonstrates expected androgenic effects, short-term safety, and limited improvement in lower limb muscle strength but no change in physical functioning or cognitive function.

Effects of androgen deficiency and replacement on prostate zonal volumes

BACKGROUND AND OBJECTIVES

Androgens play a key role in prostate development and disease. However the effects of androgen deficiency and replacement on the prostate during mid-life are not well understood, and there is no information on their effects on prostate zonal volumes. This study aimed to define the effects of androgen deficiency and androgen replacement therapy on prostate zonal volumes (central, peripheral & total) using planimetric prostate ultrasound with particular emphasis on the central zone of the prostate, the most hormonally sensitive and fastest growing region of the prostate and the zone where nodular benign prostate hyperplasia originates.

PATIENTS AND MEASUREMENTS

Central and total prostate volume were measured directly, and peripheral prostate volume calculated, by a single observer using transrectal ultrasound in 71 hypogonadal men (aged 40 +/- 2, range 18-78 years) who were compared with individually age-matched health controls without prostate or gonadal disease. Among the men with androgen deficiency, 17 men had untreated androgen deficiency (never treated or no treatment for at least 6 months) and 54 men were receiving long-term androgen replacement therapy (median 32 months, 93% > or = 6 months) with testosterone implants (n = 27), testosterone ester injections (n = 24) or other testosterone treatment (n = 3).

RESULTS

Compared with individually age-matched controls, untreated androgen deficient men (n = 17) had reduced central (4.0 +/- 0.5 vs. 6.2 +/- 0.5 ml, P < 0.001) and total (23.4 +/- 2.6 vs. 29.2 +/- 1.6 ml, P < 0.001) prostate volumes whereas the reduction in peripheral prostate volume (19.4 +/- 2.1 vs. 23.0 +/- 1.3 ml, P = 0.15) was not statistically significant. Men with treated androgen deficiency (n = 54) also still had significantly reduced central (4.8 +/- 0.4 vs. 6.8 +/- 0.4, P < 0.001), peripheral prostate volume (19.6 +/- 0.8 vs. 21.6 +/- 0.7 ml, P = 0.06) and total (24.4 +/- 1.1 vs. 28.4 +/- 1.0 ml, P = 0.008) despite prolonged restoration of physiological testosterone concentrations. Neither modality of testosterone treatment nor type of hypogonadism influenced prostate zonal volumes before or after treatment. In contrast, central, peripheral and total prostate volume increased with age among healthy controls and men with androgen deficiency regardless of androgen replacement therapy. Plasma PSA concentrations were reduced in men with untreated androgen deficiency and were similar to age-matched controls in men with treated androgen deficiency.

CONCLUSIONS

We conclude that, during mid-life, chronic androgen deficiency due to hypogonadism is associated with reduced central, peripheral and total prostate volumes. Reduced prostate volumes persist even during long-term maintenance of effective androgen replacement therapy with physiological testosterone concentrations until the fourth decade of life. After that, prostate volumes increase with age regardless of androgen deficiency or replacement. These findings suggest that, during mid-life, age is a more important determinant of prostate growth than ambient testosterone concentrations maintained in the physiological range. The persistently subnormal prostate volumes despite adequate androgen replacement therapy may explain the apparent paucity of cases of overt prostate disease among testosterone-treated androgen deficient men who retain protection against prostate disease despite physiological androgen replacement therapy.

Use, misuse and abuse of androgens. The Endocrine Society of Australia consensus guidelines for androgen prescribing

Androgen replacement therapy (ART) is usually life-long, and should only be started after androgen deficiency has been proven by hormone assays. The therapeutic goal is to maintain physiological testosterone levels. Testosterone rather than synthetic androgens should be used. Oral 17 alpha-alkylated androgens are hepatotoxic and should not be used for ART. There is no indication for androgen therapy in male infertility. Although androgen deficiency is an uncommon cause of erectile dysfunction, all men presenting with erectile dysfunction should be evaluated for androgen deficiency. If androgen deficiency is confirmed, investigation for the underlying pathological cause is required. Contraindications to androgen therapy are prostate and breast cancer. Precautions include using lower starting doses for older men and induction of puberty. Intramuscular injections should be avoided in men with bleeding disorders. Androgen-sensitive epilepsy, migraine, sleep apnoea, polycythaemia or fluid overload need to be considered. Competitive athletes should be warned about the risks of disqualification. ART should be initiated with intramuscular injections of testosterone esters, 250 mg every two weeks [corrected]. Maintenance requires tailoring treatment modality to the patient's convenience. Modalities currently available include testosterone injections, implants, or capsules. Choice depends on convenience, cost, availability and familiarity. There is no convincing evidence that, in the absence of proven androgen deficiency, androgen therapy is effective and safe for older men per se, in men with chronic non-gonadal disease, or for treatment of non-specific symptoms. Until further evidence is available, such treatment cannot be recommended.

Oestradiol enhances testosterone-induced suppression of human spermatogenesis

The aim of this study was to determine for the first time in humans, the efficacy of adding a low dose oestradiol to a suboptimally suppressive testosterone dose in a depot hormonal regimen to suppress spermatogenesis in healthy eugonadal men. Twenty-six healthy men were randomized into groups that were treated by a single subdermal implantation of either 600 mg testosterone alone (T; n = 11) or together with 10 mg (TE10, n = 7) or 20 mg (TE20, n = 8) oestradiol. Administration of oestradiol produced a dose-dependent increase in peak plasma oestradiol at 1 month and prolonged suppression of plasma LH and FSH leading to significantly enhanced suppression of sperm output. Despite the augmented spermatogenic suppression, there was no significant difference in the proportions achieving azoospermia (6/26, 23%) or severe oligozoospermia (<1 or <3 x 10(6) spermatozoa per ml, 7/26, 27%) and overall these proportions were inadequate to provide reliable contraception according to the standards identified in World Health Organization male contraceptive efficacy studies. Total and free testosterone remained within the eugonadal reference range for young men throughout the study. While the lower oestradiol dosage had minimal spermatogenic suppression effects, the higher dose produced dose-limiting adverse effects of androgen deficiency and/or oestrogen excess between the fourth and sixth month of the study. This appeared to be due to the unexpectedly prolonged, low concentration of oestradiol release from the oestradiol implants. There were no significant treatment-related changes in body composition, lipids, prostate-specific antigen, haematological or biochemical variables. Thus oestradiol has a low therapeutic window and dose-limiting side-effects at dosages that fail to achieve the uniform azoospermia required of an effective male hormonal contraceptive regimen.

Extrusion of testosterone pellets: a randomized controlled clinical study

BACKGROUND

It has previously been shown that testosterone implantation is an effective and well accepted form of androgen replacement therapy, but that pellet extrusion was the most frequent side-effect. The present study aimed to reduce the extrusion rate.

OBJECTIVE

To determine whether the washing of testosterone pellets to remove potentially surface-adherent particles decreased the rate of extrusion of pellet implants.

DESIGN

Prospective, randomized parallel group design in a single centre with consecutive procedures to be randomized (1 : 1) into a wash or control group.

PATIENTS

The study included 251 testosterone implantation procedures in men with known androgen deficiency.

MEASUREMENTS

The primary endpoint, extrusion rate per procedure, was evaluated prospectively by telephone contact at 1 week and then 3 and 6 month intervals. Secondary end-points included peri-procedure adverse events (bleeding, skin reaction, excessive discomfort) noted at the time of implant. Bruising, bleeding and infection were also evaluated as later adverse events by telephone and personal follow-up. Explanatory variables recorded as possible covariables included the number of implants used, production batch number of the implants, the operator, as well as other demographic and medical factors.

RESULTS

In the wash group, the extrusion rate was 12% per procedure (19 pellets from 15 subjects) whereas in the control group, the extrusion rate was 11.1% per procedure (18 pellets from 14 subjects), indicating no evidence of any benefit of the wash procedure (OR = 1. 09 [95% CI 0.47-2.6] per procedure). There was no evidence of benefit in secondary endpoints including total adverse events (7.1%, OR 1.28 [0.44-3.9], bleeding/bruising (8.8%, 1.23 [0.47-3.3]) and infection (4.0%, 1.54 [0.35-7.6]) per procedure. Among men reporting an infection requiring antibiotic treatment according to their own general practitioners, six/ten (60%) subsequently experienced an extrusion. There were no significant differences in extrusion rate between four different operators (P = 0.24) nor among 12 different batches of pellets used during the course of the study (P = 0.77).

CONCLUSIONS

The pellet washing procedure used during implantation does not reduce the subsequent extrusion rate. The higher rate of both primary and secondary adverse events in this prospective study compared with the previous retrospective survey may reflect either more rigorous follow-up or a secular trend.

Efficacy and safety of recombinant human follicle stimulating hormone (Gonal-F) with urinary human chorionic gonadotrophin for induction of spermatogenesis and fertility in gonadotrophin-deficient men

In order to evaluate the efficacy and safety of recombinant human follicle stimulating hormone (r-hFSH) in combination with urinary human chorionic gonadotrophin (HCG) to induce spermatogenesis and fertility in gonadotrophin-deficient men, we conducted a prospective, open, non-comparative multicentre study in two Australian academic medical centres. Ten men with gonadotrophin deficiency requiring induction of spermatogenesis and fertility were treated with HCG for 3-6 months followed by the s.c. self-administration of injections of r-hFSH in combination with HCG for 18 months. Among the eight men who commenced r-hFSH treatment, seven demonstrated sperm output at a median of 6 months and five achieved the target sperm output of 1. 5x10(6) per ml at a median of 9 months of FSH treatment. Mean testicular volume increased by 4.2 ml during FSH treatment. Three men produced pregnancies in their partners, two of which resulted in the birth of healthy babies and a third patient's partner had a miscarriage. We conclude that r-hFSH is well tolerated and effective in inducing testis growth, spermatogenesis and fertility in gonadotrophin-deficient men. The efficacy of r-hFSH seems comparable with urinary FSH at restoring normal fertility in gonadotrophin-deficient men.

An analysis of testosterone implants for androgen replacement therapy

OBJECTIVE

To review 13 years of experience using fused crystalline testosterone implants for androgen replacement therapy in order to identify pattern of usage (including continuation rates) and adverse events emerging during therapy and factors associated with adverse events including implant extrusions.

DESIGN

Retrospective review of prospectively collected data on characteristics of patients and implant procedures performed as well as adverse events reported during routine follow-up.

PATIENTS

Over 13 years 973 implant procedures using fused crystalline testosterone implants were performed in 221 men.

MEASUREMENTS

Continuation rates and adverse events such as extrusions, bleeding, infection or others were recorded and analysed in relationship to characteristics of the patient and the implant procedure performed.

RESULTS

Overall rate of adverse events (108/73, 11.1%) was significantly related to increased numbers of implants (4.2 +/- 0.1 vs 4.0 +/- 0.03, P = 0.031) and higher levels of physical activity at work (P = 0.030). The most common adverse effect was extrusion (83/973, 8.5%) which was related to occupational classification (P = 0.033) and increasing work activity (P = 0.044) and occurred more frequently than by chance in multiple (16 vs 3.3 expected) rather than single (65 vs 76.1 expected) episodes. Bleeding (22/973, 2.3%) was significantly associated with an increased number of implants (4.5 +/- 0.2 vs 4.0 +/- 0.03, P = 0.020) but even in the worst cases (3/22) it was of minor clinical importance. Infection was rare (6/973, 0.6%) but occurred more among thinner men. The overall continuation rate was 92.7% increasing from 86% after the first implantation to > 99% after the tenth implant.

CONCLUSIONS

This study demonstrates the very satisfactory clinical acceptability of testosterone pellet implants for androgen replacement therapy within a single unit with experienced operators. The only regular adverse effect is extrusion, which may be related to mechanical factors such as habitual work activity but also possibly procedural factors. Other adverse effects such as bleeding, infection and fibrosis were rare. An improved method of implant delivery would enhance this old but durable technology.

Pharmacokinetics and pharmacodynamics of nandrolone esters in oil vehicle: effects of ester, injection site and injection volume

We studied healthy men who underwent blood sampling for plasma nandrolone, testosterone and inhibin measurements before and for 32 days after a single i.m. injection of 100 mg of nandrolone ester in arachis oil. Twenty-three men were randomized into groups receiving nandrolone phenylpropionate (group 1, n = 7) or nandrolone decanoate (group 2, n = 6) injected into the gluteal muscle in 4 ml of arachis oil vehicle or nandrolone decanoate in 1 ml of arachis oil vehicle injected into either the gluteal (group 3, n = 5) or deltoid (group 4, n = 5) muscles. Plasma nandrolone, testosterone and inhibin concentrations were analyzed by a mixed-effects indirect response model. Plasma nandrolone concentrations were influenced (P < .001) by different esters and injection sites, with higher and earlier peaks with the phenylpropionate ester, compared with the decanoate ester. After nandrolone decanoate injection, the highest bioavailability and peak nandrolone levels were observed with the 1-ml gluteal injection. Plasma testosterone concentrations were also influenced (P < .001) by the ester and injection site, with the most rapid, but briefest, suppression being due to the phenylpropionate ester, whereas the most sustained suppression was achieved with the 1-ml gluteal injection. Plasma inhibin concentrations were also significantly influenced by injection volume and site, with the lowest nadir occurring after the nandrolone decanoate 1-ml gluteal injection. Thus, the bioavailability and physiological effects of a nandrolone ester in an oil vehicle are greatest when the ester is injected in a small (1 ml vs. 4 ml) volume and into the gluteal vs. deltoid muscle. We conclude that the side-chain ester and the injection site and volume influence the pharmacokinetics and pharmacodynamics of nandrolone esters in an oil vehicle in men.

Establishing the minimum effective dose and additive effects of depot progestin in suppression of human spermatogenesis by a testosterone depot

Hormonally induced azoospermia induced by weekly im injections of testosterone enanthate provides effective and reversible male contraception, but more practical regimens are needed. Given our previous findings that six 200-mg pellets implanted subdermally produced more stable, physiological T levels and reduced the delivered T dose by more than 50% while maintaining equally effective suppression of sperm output with fewer metabolic side-effects than weekly 200-mg testosterone enanthate injections, we sought in this study to determine 1) whether further dose-sparing could be achieved by lower testosterone doses while maintaining efficacy and 2) the efficacy of adding a depot progestin to a suboptimally suppressive depot testosterone dose as a model depot progestin/androgen combination male contraceptive. Healthy volunteers were randomized into groups (n = 10) who received either of two lower T doses (two or four 200-mg T pellets) or four 200-mg T pellets plus a single im injection of 300 mg depot medroxyprogesterone acetate (DMPA). Two T pellets (400 mg, 3 mg/day) had a negligible effect on sperm output. Four T pellets (800 mg, 6 mg/day) suppressed sperm output between the second to fourth postimplant months; output returned to normal by the seventh postimplant month, although only 4 of 10 men became azoospermic or severely oligozoospermic (< 3 mol/L/mL). The addition of a depot progestin markedly increased the extent, but not the rate, of sperm output suppression, with 9 of 10 becoming azoospermic and 10 of 10 becoming severely oligozoospermic. There were no serious adverse effects during the study. Plasma total and free testosterone levels remained within the eugonadal range at all times with each treatment. Plasma epitestosterone was suppressed by all 3 regimens, consistent with a dose-dependent inhibition of endogenous Leydig cell steroidogenesis. Plasma LH and FSH measured by a two-site immunoassay were suppressed in a dose-dependent fashion by T and further suppressed by the addition of DMPA. Sex hormone-binding globulin levels were decreased by DMPA, but not by either T dose. Prostate-specific antigen and lipids (total, low or high density lipoprotein cholesterol, and triglycerides) were not significantly changed in any group. Thus, a depot testosterone preparation with zero order release must be delivered at between 6-9 mg/day to provide optimal (but not uniform) efficacy at inducing azoospermia. The addition of a single depot dose of a progestin to a suboptimal testosterone dose (6 mg/day) markedly enhances the extent, but not the rate, of spermatogenic suppression, with negligible biochemical androgenic side-effects. These findings provide a basis for the use of a progestin/androgen combination depot for hormonal male contraception.

Hypothalamic-pituitary-testicular function in end-stage non-alcoholic liver disease before and after liver transplantation

OBJECTIVE

Gonadal dysfunction is common in chronic liver disease, but most of the previous studies have been restricted to men with alcohol-induced liver disease. We have evaluated hypothalamic-pituitary-testicular function in patients with end-stage non-alcoholic liver disease before and at 6 and 12 months after hepatic transplantation.

DESIGN

A prospective study of hypothalamic-pituitary-testicular endocrine function before and after cadaveric hepatic transplantation.

PATIENTS

Fifty four consecutive patients with end-stage, non-alcoholic liver disease were evaluated before and after liver transplantation.

MEASUREMENTS

Hypothalamic-pituitary-testicular (HPT) axis function was evaluated under basal conditions by single morning measurements of plasma total and free testosterone, sex hormone-binding globulin and by plasma LH and FSH responses to 100 micrograms i.v. GnRH.

RESULTS

Men with chronic non-alcoholic liver disease had reduced levels of total and free testosterone and increased levels of SHBG compared with controls with normal liver function. Total and free testosterone were positively correlated with basal and stimulated LH (but not FSH) concentrations. Gonadotrophin responses to GnRH were preserved but delayed compared with healthy controls consistent with a predominantly hypothalamic defect in regulation of pituitary-testicular function. Increasing severity of underlying liver disease was associated with declining total and free testosterone as well as peak GnRH-stimulated LH concentrations. Spironolactone treatment was associated with decreased circulating testosterone levels only in men with liver disease of intermediate severity (Child-Pugh class B). Following hepatic transplantation, total and free testosterone and SHBG concentrations returned progressively towards eugonadal control levels over the first 12 months but total and free testosterone levels remained subnormal.

CONCLUSIONS

Hypothalamic-pituitary regulation of testicular function is impaired in end-stage non-alcoholic liver disease in proportion to the severity of underlying liver disease. Spironolactone reduces circulating testosterone but only among men with Child-Pugh B liver cirrhosis. Gonadal function improves, but is not normalized, over the first year following successful liver transplantation.

Pharmacokinetics of human follicle-stimulating hormone in gonadotropin-deficient men

Gonadotropin treatment of hypogonadotropic infertile men usually requires regular im administration of human urinary FSH (uFSH); however, testicular function is rarely normalized despite years of treatment. As the pharmacokinetics of standard FSH doses (75 IU, two or three times weekly) in gonadotropin-deficient men are poorly characterized, we studied 10 gonadotropin-deficient men by measuring plasma FSH levels with an ultrasensitive fluoroimmunoassay (Delfia, Pharmacia) in single dose and multidose studies. The single dose studies involved blood samples taken 15 min before and 0, 1, 2, 4, 6, 8, 10, 12, 15, 18, 21, 24, 48, 72, and 96 h after the injection of 75 IU uFSH in 1 mL diluent, either sc under the abdominal wall skin or im into the deltoid muscle, in a random sequence, cross-over design (n = 7 men) and after the injection of 150 IU, sc, with additional blood sampling at 120 and 168 h (n = 7 men). The multidose studies used a fixed ascending dose sequence, with blood sampled at 24-h intervals posttreatment after at least 1 month of regular administration of either 75 or 150 IU uFSH, sc, at injection intervals of 72, 48, and 24 h (n = 6 men). From the single dose studies, pharmacokinetic variables were estimated from a one-compartment open model fitted by a weighted polyexponential curve fit of plasma FSH over time. The bioavailability of uFSH via the sc route was high (mean area under the curve, 90% for 75 IU and 143% for 150 IU vs. 75 IU, im). Peak plasma FSH levels were later (21.1 vs. 7.1 h; P < 0.001) and lower (2.0 vs. 2.7 IU/L; P < 0.001) after sc compared with im administration of 75 IU due to a slower absorption half-time (6.1 h vs. 1.4 h; P < 0.001), whereas mean residence times and clearance half-times were similar. The pharmacokinetic features of the 150- and 75-IU doses sc were essentially identical, apart from expected dose-dependent increases in peak plasma FSH level (2.8 vs. 2.0 IU/L; P < 0.001) and area under the curve (206 vs. 129 IU.h/L; P < 0.05). Multidose simulations based on the single dose pharmacokinetic models predicted that during chronic sc administration of standard FSH doses, plasma FSH levels would be in the lower half of the eugonadal range and fluctuate less than with im administration. The multidose study confirmed empirically these predictions. These studies form a pharmacological basis for a more flexible, cost-effective, and convenient self-administered sc regimen.(ABSTRACT TRUNCATED AT 400 WORDS)

Tolerability of intramuscular injections of testosterone ester in oil vehicle

We undertook a prospective survey of the tolerability of deep i.m. injections of testosterone enanthate in a castor oil vehicle, the most widely used form of androgen replacement therapy. Over a period of 8 months, 26 men received 551 weekly injections into the gluteal, deltoid or thigh muscle and side-effects were recorded immediately and 1 week after each injection by the same nurse using a standardized questionnaire. Most injections caused no complaints [389/551, 70.6% (95% confidence interval 66.6-74.4%)] but minor local side-effects, mostly pain and bleeding, were common [162/551, 29.4% (25.6-33.4%)]; no serious side-effects were observed. Considering all side-effects, the gluteal site had fewer complaints and was less prone to bleeding but was painful more often than deltoid or thigh injection sites. The laterality of injection at any site had no significant effect on side-effects. The only systemic side-effect was episodes of sudden-onset, non-productive cough associated with faintness following eight injections [1.5% (0.6-2.9%)] which we speculate may have been due to pulmonary oil microembolism. We conclude that, when administered by an experienced nurse, deep i.m. injection of testosterone enanthate in a castor oil vehicle is generally safe and well tolerated but causes relatively frequent minor side-effects, including pain and bleeding. An improved depot form of testosterone would be highly desirable for androgen replacement therapy and hormonal male contraception.

Activity of a nitrofurazone matrix urinary catheter against catheter-associated uropathogens

Nitrofurazone-coated urinary catheter segments inhibited 51 (75%) of 70 urinary bacterial isolates from patients with indwelling catheters. Inhibition zones correlated significantly with the nitrofurazone MIC (r2 = 0.79, P = 0.0001). All strains except the Pseudomonas spp. were inhibited by < or = 64 micrograms of nitrofurazone per ml. MICs of nitrofurazone and nitrofurantoin correlated significantly (r2 = 0.93, P = 0.0001).

Hypothalamic-pituitary adrenal function in end-stage non-alcoholic liver disease

Patients with end-stage liver disease have significant mortality often associated with intercurrent episodes of bleeding or sepsis. Intact adrenal function is essential in such situations. In order to test the hypothesis that adrenal insufficiency might be present in severe liver disease, hypothalamic-pituitary adrenal function was evaluated in patients with end-stage liver disease awaiting transplantation. The study had a prospective, open comparative design with patients restricted to those having non-alcoholic liver disease in order to avoid the confounding direct effects of alcohol on adrenocortical function. Fifty-one consecutive patients with end-stage, non-alcoholic liver disease undergoing evaluation for liver transplantation and 40 healthy controls were studied. Patients who had used corticosteroids (n = 8) or who were unable to complete the investigations (n = 5) were excluded leaving 38 patients eligible for analysis. Adrenal function was evaluated under basal conditions by single morning measurements of plasma total and free cortisol, corticosteroid-binding globulin, dehydroepiandrosterone sulfate and by adrenal stimulation indirectly using insulin-induced (0.1 U/kg, i.v.) hypoglycaemia and/or directly by adrenocorticotrophic hormone (ACTH); 250 micrograms tetracosactrin, i.v.) stimulation. Compared with healthy controls, patients with liver disease had a 64% reduction in maximal increments of plasma cortisol to indirect adrenal stimulation via insulin-induced hypoglycaemia and a 39% reduction to direct adrenal stimulation by ACTH (all P < 0.001). There was a significant negative correlation between the severity of underlying liver disease as assessed by Child-Pugh scores and peak control responses to ACTH (r = -0.647, P < 0.0001) and insulin-induced hypoglycaemia (r = -0.597, P < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Suppression of human spermatogenesis by testosterone implants

Hormonally induced azoospermia is an effective, reversible form of male contraception; however, some men treated with weekly im testosterone enanthate (TE) injections fail to become azoospermic. As weekly injections cause widely fluctuating and supraphysiological testosterone levels, we tested the hypothesis that more stable, physiological testosterone levels would consistently produce azoospermia. Using a depot testosterone formulation which provides stable, physiological range testosterone levels for up to 6 months, we studied nine men before and after insertion of six 200 mg testosterone implants under the abdominal wall skin and compared the results with 38 men treated in a previous study with weekly im injections of 200 mg TE. Testosterone implants suppressed sperm output to near-azoospermia between the second to fourth postimplant months returning to normal by the sixth postimplant month. The fall in sperm output at the first month was greater after testosterone implants than TE injections (58% vs. 17%, P = 0.011) but similar proportions of men became azoospermic (5/9 vs. 25/38) or severely oligozoospermic (< 1 million/ml; 9/9 vs. 37/38). Plasma testosterone and estradiol levels remained mostly within the eugonadal range after implants but were markedly supraphysiological during TE injections. Both treatments suppressed immunoreactive LH and FSH to undetectable levels by ultrasensitive fluoroimmunoassay. Sex hormone-binding globulin levels were decreased and PRL levels increased by TE injections but neither was changed by testosterone implants. Prostate-specific antigen demonstrated a small rise of marginal significance (P = 0.065) after testosterone implants. Fewer men experienced acne after implants (0/9 vs. 25/38, p = 0.0004). Therefore a depot testosterone preparation with quasi-zero-order release demonstrates higher dose efficiency with similar (but not uniform) efficacy at inducing azoospermia but may cause fewer androgenic side-effects than weekly TE injections.

Pharmacokinetics and pharmacodynamics of testosterone pellets in man

We studied the pharmacokinetics and pharmacodynamics of sc implanted pellets of fused crystalline testosterone. Three different regimens (6 x 100 mg, 6 x 200 mg; and 3 x 200 mg) were compared in a prospective, cross-over clinical trial in which androgen deficient men were administered the three-dose combinations in a randomized starting order at intervals of at least 6 months. Plasma free and total testosterone, sex hormone-binding globulin, LH, and FSH were measured before and at monthly intervals for at least 6 months after 111 pellet implantation in 43 men with hypergonadotropic (n = 22) or hypogonadotropic (n = 21) hypogonadism. Total and free testosterone levels peaked at the first month and were maintained at physiological levels for 4 to 5 (600 mg doses) or 6 (1200 mg dose) months after a single implantation. Absorption of testosterone from 100 mg and 200 mg pellets closely approximated zero-order throughout the effective life of the pellets and exhibited a half-duration of 2.5 months. The estimated rate of release of testosterone was 1.5 (95% confidence limits 1.3-1.6) mg/day.200 mg pellet as determined from direct measurement of residue in pellets recovered after extrusion and confirmed independently from percent absorbed-time plots. The bioavailability of testosterone was virtually complete and the time course was predictable from the total implant dose and, to a lesser extent, total initial surface areas of pellets. Despite wide fluctuations in testosterone, SHBG levels were not changed during 6 months. In men with hypergonadotropic hypogonadism, both LH and FSH levels were uniformly and markedly suppressed by increased testosterone after pellet implants. LH and FSH were highly correlated with each other (r = 0.87) and inversely with total (r = 0.47 and 0.45, respectively) and free (r = 0.46 and 0.47) testosterone levels. Nadir LH levels occurred at 1-3 months (600 mg) and 1-4 months (1200 mg) reaching levels comparable with eugonadal controls. In contrast nadir FSH levels occurred at similar times but remained elevated compared with eugonadal controls. We conclude that fused pellets of crystalline testosterone provides very satisfactory depot androgen replacement exhibiting many desirable features for androgen replacement.

Randomized clinical trial of testosterone replacement therapy in hypogonadal men

We have compared the pharmacokinetics and pharmacodynamics of the three commonly used testosterone formulations in a prospective, randomized cross-over clinical trial. Plasma free and total testosterone and their ratio (proportion of unbound testosterone), sex hormone-binding globulin (SHBG), oestradiol, LH and FSH were measured in 15 hypogonadal men (nine hyper- and six hypogonadotrophic) who underwent, in a randomized sequence, three treatment periods each separated by an intervening washout period. The treatments were: (i) intramuscular injection of 250 mg mixed testosterone esters at 2-weekly intervals, (ii) oral testosterone undecanoate 120 mg bd, and (iii) subcutaneous testosterone pellets (6 x 100 mg). Pellet implantation gave the most prolonged effect with free and total testosterone levels being elevated for up to 4 months. This was accompanied by prompt and sustained suppression of plasma LH and FSH, an increase in plasma levels of oestradiol but no change in SHBG levels. In contrast, intramuscular injections induced marked but reproducible week-to-week fluctuations in free and total testosterone, which resulted in a small decrease in plasma SHBG levels, less marked suppression of LH and FSH and a smaller increase in plasma levels of oestradiol. Oral testosterone undecanoate produced the most variable plasma levels of free and total testosterone with a peak in the first treatment week and a fall thereafter and, despite maintenance of testosterone levels within the physiological range, there was no significant suppression of plasma levels of LH and FSH, and oestradiol levels were unchanged but levels of SHBG and total cholesterol were decreased. Free testosterone levels were increased disproportionately during testosterone treatment as the proportion of unbound testosterone was increased by all three treatments. All three testosterone preparations lowered plasma levels of urea and all were without biochemical or haematological toxicity. Reported sexual function was better maintained and side-effects were fewer with parenteral compared with oral treatments. The marked decrease in SHBG and cholesterol levels during oral testosterone undecanoate, when compared with parenteral treatments, occurred despite lesser androgenic effects (suppression of gonadotrophin levels and reported sexual function), which suggests that the liver is exposed to excessive androgenic load via the portal vein during oral treatment with testosterone esters. It is concluded that testosterone pellets give the closest approximation to zero-order (steady-state) delivery conditions for up to 4 months after a single insertion.(ABSTRACT TRUNCATED AT 400 WORDS)

Testicular function and fertility in men with homozygous alpha-1 antitrypsin deficiency

Fertility and testicular function were studied in eight men with severe homozygous (Pi ZZ variant genotype) alpha-1 antitrypsin (AAT) deficiency. Age- and marital duration standardized fertility, clinical androgenic features, mean testicular volume, plasma luteinizing hormone (LH) and follicle-stimulating hormone (FSH) and semen analysis were all normal apart from a reduction in semen volume. Mean plasma total and free testosterone were elevated and the percentage free testosterone reduced compared with age-matched, healthy fertile controls indicative of increased sex-hormone binding globulin (SHBG) levels representing an early marker for subclinical hepatic dysfunction associated with AAT-deficiency. In view of the preservation of normal fertility and testicular function despite chronic respiratory disease and premature death with deleterious AAT gene variants, it is proposed that the high prevalence of genetic polymorphism in the AAT protein may be maintained by the chronological asynchrony of the periods of maximal male reproductive activity (40 years) and the late onset (greater than 40 years) of symptoms in severe AAT deficiency rather than by any balance between reduced reproductive fitness of homozygotes and heterozygote advantage.

Testicular function and glycemic control in diabetic men. A controlled study

We have investigated testicular function in 28 insulin-dependent diabetic men under the age of 50 years and 119 age-matched controls. Diabetics had reduced testicular volume, semen volume, total and total motile sperm output while plasma LH and FSH levels were elevated. Reduction in semen volume and impotence were more common in long-standing complicated diabetes. Glycosylated hemoglobin (GHb) levels were positively correlated with plasma LH levels (r = 0.46, p less than 0.02) but there was no direct correlation of glycemic control and spermatogenesis. The differences in testicular function were due to decreased spermatogenesis and could not be explained by other forms of testicular pathology or the presence of diabetic neurovascular complications. We conclude that the function of the hypothalamic pituitary testicular axis is impaired in diabetic men, that this impairment is at least partly related to the degree of preceding glycemic control and that multiple levels of the axis may be dysfunctional.