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

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

Pharmacokinetic evaluation and dosing of subcutaneous testosterone pellets

Subcutaneous testosterone (T) pellets are a viable treatment modality for hypogonadism. Optimal dosing, frequency of reimplantation, and long-term safety of T pellets remain incompletely elucidated parameters. A retrospective review of 273 patients treated for hypogonadism using subcutaneous T pellets was performed. Serum total T (TT), free T (FT), and estradiol (E2) levels were analyzed as a function of time from implantation, number of pellets implanted (6-9 or 10-12), body mass index (BMI; <25 or ≥25 kg/m(2)), number of implantations (≤4 rounds, 501 insertions), and preimplantation T levels (<300 or ≥300 ng/dL). T decay was determined using linear regression and TT levels immediately postimplantation and the time for TT levels to reach 300 ng/dL extrapolated for all variables. Mean patient age ± SD was 56 ± 12.6 years. Baseline TT level was 328 ± 202 ng/dL, FT 9.49 ± 27.8 pg/mL, and E2 25.1 ± 17.3 pg/mL. Extrapolated TT and FT peaks were lower in men receiving 6 to 9 pellets than men receiving 10 to 12, although decay rates differed insignificantly. E2 levels rose significantly in men receiving 10 to 12 but not 6 to 9 pellets. Men with BMI ≥25 kg/m(2) attained lower TT peaks with slower decay than men with BMI <25 kg/m(2) receiving 10 to 12 pellets, although 300 ng/dL TT levels were reached at approximately 100 days in both groups. No differences were seen in decay rates for men with multiple implant rounds, and no differences in T peaks or decay rates were seen in men with preimplant T level <300 or ≥300 ng/dL. One patient developed erythrocytosis, and no prostate-specific antigen recurrences were observed in men with prostate cancer treated with T pellets. Men with BMI <25 kg/m(2) should receive fewer pellets, and reimplantation for all men should occur 100 to 120 days after prior implantation. Men receiving 10 to 12 pellets have higher E2 levels, potentially reflecting increased aromatization of T. Reimplantation and preimplantation TT levels do not affect pellet decay kinetics.     

Nanomilled oral testosterone plus dutasteride effectively normalizes serum testosterone in normal men with induced hypogonadism

Oral androgen development has been hampered by the rapid metabolism of orally administered testosterone (T) and low bioavailibility. The addition of the 5alpha-reductase inhibitor dutasteride (D) to oral T in oil dramatically improves concentrations of serum T. In this study we evaluate the absorption of oral T+D, comparing nanomilled T (NmT+D) vs T dissolved in oil (Capmul; CpT+D), as nanomilling might offer a simpler, more practical means of oral T administration, given the limited solubility of T in oil. Twelve healthy men were administered leuprolide on Day -14 to suppress endogenous T biosynthesis and were pretreated with D to block 5alpha-reductase. Once hypogonadal, subjects were sequentially administered 200- and 400-mg doses of CpT+D and NmT+D in the fasted and fed states. Serum T and dihydrotestosterone (DHT) were measured: before dose and at 0.5, 1, 2, 3, 4, 6, 8, 10, 12, and 24 hours after each dose. Two weeks after leuprolide administration, T levels were below the normal range. A 400-mg dose of either formulation of oral T+D increased mean serum T above the lower limit of the normal range for 8-10 hours. Food had a minimal effect on the pharmacokinetic parameters of the NmT+D formulation but decreased the maximum observed concentration after dosing (C(max)) for CpT+D. Serum DHT remained below the normal range throughout the study period with both formulations. No significant changes in liver function tests or other adverse events were observed. A 400-mg dose of either oral T+D formulation normalized serum T for 8-10 hours and suppressed DHT. NmT allows for tablet formulation, and its pharmacokinetics were not affected by food, demonstrating the feasibility of oral nanomilled T as a promising and practical twice-daily therapy for the treatment of male hypogonadism.     

A novel testosterone 2% gel for the treatment of hypogonadal males

Testosterone replacement therapy (TRT) can improve the symptoms, signs, and well being of hypogonadal men by restoring serum testosterone concentrations to physiologic levels. This multicenter, open-label noncomparative trial of men with hypogonadism evaluated the pharmacokinetic profile and safety of a novel testosterone 2% gel (Fortesta? Gel), administered once daily to the front and inner thighs at starting doses of 40 mg/d. The metered-dose delivery system allowed dose adjustments in 10-mg increments between 10 and 70 mg/d. Of the 149 patients enrolled, 138 patients (92.6%) completed the study and 129 patients (86.6%) were included in the efficacy analysis. On day 90, mean testosterone concentration (C(avg) [0-24 hours] ± SD) was 438.6 ± 162.5 ng/dL. Overall, 100 (77.5%) patients achieved serum total testosterone concentrations within the normal physiologic range (≥ 300 and ≤ 1140 ng/dL). On day 90, mean testosterone C(max) (± SD) was 827.6 ± 356.5 ng/dL. On day 90, a total of 122 patients (94.6%) had C(max) levels of 1500 ng/dL or less and 2 patients (1.6%) had values between 1800 and 2500 ng/dL. Similar results for C(avg) (0-24 hours) and C(max) were observed on day 35. All enrolled patients were included in the safety analysis. Testosterone 2% gel was generally well tolerated, with the most common adverse events (AE) being mild and moderate skin reactions. There were no serious AEs related to testosterone 2% gel. Once-daily testosterone 2% gel restored levels of testosterone in more than 75% of patients, with low risk of supraphysiologic testosterone levels. Patients may find this a suitable option for TRT because of its application site and low volume.     

The association of time of day and serum testosterone concentration in a large screening population

OBJECTIVE: To assess testosterone patterns during clinical hours in a large population of men participating in a national screening programme for prostate cancer, as the effect of time of day on serum testosterone concentration is unclear and largely reported in small studies. SUBJECTS AND METHODS: Testosterone levels were measured in 3006 men attending the national Prostate Cancer Awareness Week screening programme. Blood samples were obtained between 06.00 and 18.00 hours, whenever men presented for screening. All men completed questionnaires on age, comorbidities, height and weight. Testosterone levels were compared based on four periods, i.e. T1, 06.00-10.00 (632 men), T2, 10.00-12.00 (812), T3, 12.00-14.00 (388), and T4, 14.00-18.00 hours (1174). RESULTS: The mean (sd, range) age of the men was 60.3 (9.9, 40-94) years and the mean (sd) testosterone level was 415.2 (190.9) ng/dL. There was no change in mean (sd) testosterone levels over T1, T2 and T3, at 444.9 (206.2), 433.5 (195.8) and 434.4 (181.2) ng/dL, respectively, but levels at T4, at 380.4 (176.4) ng/dL, were lower by approximately 13% (P < 0.05). Advancing age, diabetes and obesity were associated with lower testosterone levels. The percentage of men with biochemical hypogonadism (<300 ng/dL) did not change across all four periods. CONCLUSIONS: Testosterone levels in older men are stable throughout the morning and early afternoon, declining only modestly thereafter. Further case-controlled studies are needed to confirm these findings.     

Serum dihydrotestosterone and testosterone concentrations in human immunodeficiency virus-infected men with and without weight loss.

Weight loss is an important determinant of disease outcome in human immunodeficiency virus (HIV)-infected men. Others have suggested that a defect in dihydrotestosterone (DHT) generation contributes to weight loss in HIV-infected men. To determine whether DHT levels correlate with weight loss independently of changes in testosterone levels, we prospectively measured serum total- and free-testosterone and DHT levels in 148 consecutive HIV-infected men and 42 healthy men. Thirty-one percent of HIV-infected men had serum testosterone levels less than 275 ng/dL, the lower limit of the normal male range; of these, 81% had normal or low LH and FSH levels (hypogonadotropic), and 19% had elevated LH and FSH levels (hypergonadotropic). Overall, serum testosterone, free-testosterone, and DHT levels were lower in HIV-infected men than in healthy men, but serum DHT-to-testosterone ratios were not significantly different between the two groups. Serum total- and free-testosterone levels were lower in HIV-infected men who had lost 5 lb or more of weight in the preceding 12 months than in those who had not lost any weight. Serum DHT levels and DHT-to-testosterone ratios did not differ between those who had lost weight and those who had not. Serum testosterone and free-testosterone levels, but not DHT levels, correlated with weight change and with Karnofsky performance status. We also performed a retrospective analysis of data from a previous study in which HIV-infected men with serum testosterone levels less than 400 ng/dL had been treated with placebo or testosterone patches designed to nominally release 5 mg testosterone over 24 hours. Serum testosterone-to-DHT ratios did not change after testosterone treatment. Changes in fat-free mass were correlated with changes in both serum testosterone (r = 0.42, P = 0.018) and DHT (r = 0.35, P = 0.049) levels. Serum total- testosterone and DHT levels were highly correlated with one another, and when the change in serum testosterone was taken into account, serum DHT levels no longer showed a significant correlation with change in fat-free mass. We conclude that DHT levels are lower in HIV-infected men than in healthy men but that neither DHT levels nor DHT-to-testosterone ratios correlate with weight loss. During testosterone treatment, serum DHT levels increase proportionately, but the increments in serum testosterone correlate with the change in fat-free mass. Our data do not support the hypothesis that a defect in DHT generation contributes to weight loss in HIV-infected men independently of changes in testosterone levels; it is possible that such a defect might exist in HIV-infected men with more severe weight loss.     

Pharmacokinetics and pharmacodynamics of oral testosterone enanthate plus dutasteride for 4 weeks in normal men: implications for male hormonal contraception

Oral administration of testosterone enanthate (TE) and dutasteride increases serum testosterone and might be useful for male hormonal contraception. To ascertain the contraceptive potential of oral TE and dutasteride by determining the degree of gonadotropin suppression mediated by 4 weeks of oral TE plus dutasteride, 20 healthy young men were randomly assigned to 4 weeks of either 400 mg oral TE twice daily or 800 mg oral TE once daily in a double-blinded, controlled fashion at a single site. All men received 0.5 mg dutasteride daily. Blood for measurement of serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, dihydrotesterone (DHT), and estradiol was obtained prior to treatment, weekly during treatment, and 1, 2, 4, 8, 12, 13, 14, 16, 20, and 24 hours after the morning dose on the last day of treatment. FSH was significantly suppressed throughout treatment with 800 mg TE once daily and after 4 weeks of treatment with 400 mg TE twice daily. LH was significantly suppressed after 2 weeks of treatment with 800 mg TE, but not with 400 mg TE. Serum DHT was suppressed and serum estradiol increased during treatment in both groups. High-density lipoprotein cholesterol was suppresed during treatment, but liver function tests, hematocrit, creatinine, mood, and sexual function were unaffected. The administration of 800 mg oral TE daily combined with dutasteride for 28 days significantly suppresses gonadotropins without untoward side effects and might have utility as part of a male hormonal contraceptive regimen.     

Trends in sex hormone concentrations in US males: 1988-1991 to 1999-2004

Previous studies suggest that male testosterone concentrations have declined over time. To explore this in a large US population, we examined testosterone and free testosterone concentrations in National Health and Nutrition Examination Surveys (NHANES) from 1988-1991 and 1999-2004. We also examined sex hormone-binding globulin (SHBG), estradiol, and androstanediol glucuronide (3α-diol-G) over the same period. Non-Hispanic white, non-Hispanic black, and Mexican-American men from 1988-1991 and 1999-2004 NHANES surveys who were ≥20 years old and had serum from morning blood draws were included in this analysis (1988-1991: N = 1,413; 1999-2004: N = 902). Testosterone, estradiol and SHBG were measured by competitive electrochemiluminescence immunoassays and 3α-diol-G was measured by enzyme immunoassay. Free testosterone was calculated using testosterone and SHBG values. Adjusted mean hormone concentrations were estimated using linear regression, accounting for NHANES sampling weights and design, age, race/ethnicity, body mass index, waist circumference, alcohol use and smoking. Differences in adjusted mean concentrations (Δ) and two-sided p-values were calculated; p < 0.05 was statistically significant. Overall, 3α-diol-G and estradiol declined between 1988-1991 and 1999-2004, but there was little change in testosterone, free testosterone, or SHBG (Δ: 3α-diol-G = -1.83 ng/mL, p < 0.01; estradiol = -6.07 pg/mL, p < 0.01; testosterone = -0.03 ng/mL, p = 0.75; free testosterone = -0.001 ng/mL, p = 0.67; SHBG = -1.17 nmol/L, p = 0.19). Stratification by age and race revealed that SHBG and 3α-diol-G declined among whites 20-44 years old (Δ: SHBG = -5.14 nmol/L, p < 0.01; 3α-diol-G = -2.89 ng/mL, p < 0.01) and free testosterone increased among blacks 20-44 years old (Δ: 0.014 ng/mL, p = 0.03). Estradiol declined among all ages of whites and Mexican-Americans. In conclusion, there was no evidence for testosterone decline between 1988-1991 and 1999-2004 in the US general population. Subgroup analyses suggest that SHBG and 3α-diol-G declined in young white men, estradiol declined in white and Mexican-American men, and free testosterone increased in young black men. These changes may be related to the increasing prevalence of reproductive disorders in young men.     

Twenty-five milligrams of clomiphene citrate presents positive effect on treatment of male testosterone deficiency - a prospective study

Introduction: Male testosterone deficiency is associated with bad sexual function and quality of life (QoL). The aim of this study was to determine whether a daily dose of 25 mg clomiphene citrate (CC) is effective in stimulating the endogenous testosterone production pathway and to address the applicability of this medication as a therapeutic option for symptomatic hypogonadism. Materials and Methods: This was a prospective study. Men with low sexual desire and testosterone levels (T) below 400 ng/dL were selected to receive CC. Blood samples were obtained to determine baseline measurements of serum T, estradiol, LH, lipid profile and fasting plasma glucose. Each patient was treated with a daily dose of 25 mg CC for at least 3 months. Patients were asked if they experienced any side effects related to the use of CC and if they experienced any improvement in their sexual profile. Paired samples T-test was utilized to analyze responses to therapy. Results: Our cohort consisted of 125 men with hypogonadism and low libido. Mean age was 62 years (± 11.1 years). Serum T levels ranged from 309 ng/dL (baseline, mean value) to 642 ng/dL (3 months after CC initiation, mean value) (p < 0.001). Serum cholesterol levels ranged from 197 to 186 mg/dL (p = 0.003). There were no statistically significant differences when comparing pre and post-treatment HDL-Cholesterol, triglycerides, fasting plasma glucose and prolactin. All men reported improvements in the post-treatment QoL scores. No serious adverse events were recorded. Conclusions: The CC was effective in stimulating the endogenous production of testosterone. A lower level of total cholesterol was verified after three months of treatment. This medication should be considered as a therapeutic option for some patients with symptomatic male testosterone deficiency.     

Clomiphene citrate treatment outcomes in Taiwanese hypogonadal men: A single-center preliminary report

ObjectiveWe evaluated the treatment efficacy of clomiphene citrate (CC) in hypogonadal men.MethodsWe retrospectively reviewed our patients with a diagnosis of hypogonadism who received CC treatment, and compared the pretreatment and post-treatment serum testosterone levels. Subjective patient improvements were recorded using the Androgen Deficiency in Aging Males questionnaire.ResultsA total of 10 patients were included in our analysis. Mean serum testosterone level increase from 246 ± 76 ng/dL to 548 ± 281 ng/dL was noted after treatment (p < 0.01). Eight (80%) patients successfully reached a target serum testosterone level of > 400 ng/dL after treatment.ConclusionCC is an effective alternative treatment for patients with hypogonadism.     

Oral testosterone in oil: pharmacokinetic effects of 5alpha reduction by finasteride or dutasteride and food intake in men

Oral administration of 400 mg of testosterone (T) in oil, when combined with the 5alpha reductase inhibitor dutasteride (D), elevates serum T in medically castrated men to the normal range. In this study, we sought to determine the impact of 1) finasteride (F) and 2) food intake on the serum T and dihydrotestosterone (DHT) levels observed after the oral administration of T in oil. Therefore, we conducted a pharmacokinetic study of oral T in oil, alone or with D or F, in the fasting and fed states in normal men whose endogenous T production was suppressed by the GnRH antagonist acyline. After acyline administration, 7 healthy men (mean age 31 +/- 8 years) were sequentially administered five 400-mg doses of oral T in sesame oil once daily. The first dose of oral T (T-alone) in oil was given while fasting without F or D. The second (fasting) and third (fed) doses were administered after pretreatment with F (T + F). Four days later, the fourth (fasting) and fifth (fed) doses were administered after pretreatment with D (T + D). Blood samples for measurement of serum T and DHT were obtained before T dosing and 0.5, 1, 2, 3, 4, 6, 8, 10, 12, and 24 hours after each administration. In the fasting state, 24-hour area-under-the-curve of serum T after oral T administration was significantly greater with coadministration of either D or F compared with T-alone (126 +/- 36 nmol-h/L [T-alone] vs 287 +/- 98 nmol-h/L [T + F] vs 236 +/- 82 nmol-h/L [T + D]; P < .05 for T + F and T + D vs T-alone). Administration of the T with food nonsignificantly decreased serum T levels compared with fasting administration. The administration of oral T in oil combined with either F or D results in serum T levels adequate to treat men with testicular failure. Additional studies of the combination of oral T in oil with 5alpha-reductase inhibitors as a novel form of oral T therapy are warranted.     

Effect of aromatase inhibition on bone metabolism in elderly hypogonadal men

Both estrogens and androgens play important roles in skeletal development and maintenance in men. The relative importance of estrogens and androgens in male bone metabolism, however, remains undefined. Anastrozole is an oral aromatase inhibitor that decreases estrogen production and increases androgen production in men. Currently, anastrozole is being investigated as a potential agent for the treatment of hypogonadism in aging men. Because anastrozole lowers estrogen levels and raises androgen levels, its effect on bone metabolism is difficult to predict. To assess the effects of anastrozole on bone turnover, we randomized 37 elderly (ages 62–74) mildly hypogonadal men (serum testosterone <350 ng/dl) to receive either anastrozole 1 mg daily ( n =12), anastrozole 1 mg twice weekly ( n =11), or daily placebo ( n =14) for 12 weeks. Serum gonadal steroid levels, serum and urine biochemical markers of bone turnover, serum osteoprotegerin, and total body bone mineral density were measured at baseline and week 12. Mean serum levels of total and bioavailable testosterone increased substantially in both treated groups. Specifically, mean ± SD bioavailable testosterone levels increased from 99±31 ng/dl to 207±65 ng/dl in the group receiving 1 mg of anastrozole daily and from 115±37 ng/dl to 178±55 ng/dl in the subjects receiving 1 mg of anastrozole twice weekly ( p <0.001 vs placebo for both groups). Serum estradiol levels decreased modestly in both treated groups (from 26±8 pg/ml to 17±6 pg/ml in the daily treatment group and from 27±8 pg/ml to 17±5 pg/ml in the twice-weekly treatment group, p <0.001 vs placebo for both groups). Despite these hormonal changes, no increases in biochemical markers of bone resorption were observed. Specifically, mean serum N-telopeptide and urinary deoxypyridinoline concentrations remained stable in both treated groups over the 12-week treatment period. Similarly, serum biochemical markers of bone formation (osteocalcin and amino-terminal propeptide of type 1 collagen), serum osteoprotegerin, and total body bone mineral density did not change. These data demonstrate that although short-term administration of anastrozole decreases serum estradiol levels in elderly men with mild hypogonadism, this intervention does not adversely affect bone metabolism over a 12-week period. This lack of an effect may be due to the concomitant increase in testosterone production, the relative modest effect on estradiol production, or a combination of both factors. These results suggest that anastrozole therapy is unlikely to have an adverse effect on bone metabolism when taken over extended periods and may prove to be a valuable method of normalizing testosterone production in older men.     

The effect of dutasteride on intraprostatic dihydrotestosterone concentrations in men with benign prostatic hyperplasia

The dual 5alpha-reductase inhibitor, dutasteride has been shown to suppress serum dihydrotestosterone (DHT) by >90%. In the present study, the effect of dutasteride 0.5 mg/day on intraprostatic DHT levels was investigated. In this multicenter, double-blind trial, 43 men with benign prostatic hyperplasia (BPH) scheduled to undergo transurethral resection of the prostate (TURP) were randomized to receive dutasteride, 0.5 mg/day or placebo for 3 months before surgery. Intraprostatic DHT, testosterone and dutasteride levels were determined at the time of TURP. Changes in serum DHT and testosterone from baseline, and both serum and intraprostatic dutasteride levels at the time of TURP were also assessed. Dutasteride reduced intraprostatic DHT by 94% relative to placebo (P<0.001); the adjusted mean intraprostatic DHT concentration was 3.23 and 0.209 ng/g in the placebo and dutasteride groups, respectively. In the dutasteride group, serum DHT was reduced from baseline by 93% at month 3, a significantly greater reduction (P<0.001) than the 15% decrease observed in the placebo group. There was a reciprocal increase in intraprostatic testosterone but the level of intraprostatic testosterone in the dutasteride group tended to be lower than the intraprostatic DHT level in the placebo group (P=0.06). Significant intraprostatic DHT suppression was achieved in all subjects who received dutasteride, regardless of the level of intraprostatic dutasteride. There was a strong positive correlation between serum and intraprostatic dutasteride concentrations (R(2)=0.73). After 3 months of treatment, dutasteride 0.5 mg/day provided near-complete suppression of both intraprostatic and serum DHT in men with BPH.     

Osteoporosis in men: a potential role for the sex hormone binding globulin

The exact mechanism of bone loss remains unknown in primary male osteoporosis. It has been suggested that estrogen and sex hormone binding globulin (SHBG) play a role in regulating bone turnover and bone mass in healthy men > 65 years of age. In the present study, 80 men (mean age 49.7 years) with bone mineral density >2.5 SD below the young adult value and 40 age-matched controls were recruited to evaluate the relationships between sex hormone levels, bone biochemical markers levels, and bone mineral density. Fasting serum samples were assayed for total and free testosterone total estradiol, and SHBG. The free androgen index, was calculated as: [total testosterone/SHBG * 100]. Bone remodeling was evaluated by measurement of urinary levels of the C-telopeptide of type I collagen (CTx) and free deoxypyridinoline (D-Pyr), serum osteocalcin, and bone-specific alkaline phosphatase (bSAP). There was no significant difference between controls and osteoporotic men according to age, body mass index (BMI), total testosterone, and estradiol. In contrast, serum SHBG level was significantly higher (+42.2%), whereas free androgen index was lower (-24.8%) in patients with primary or secondary osteoporosis. Testosterone and estradiol levels did not correlate with any bone resorption or bone formation markers. In contrast, stepwise linear regression analysis showed that SHBG was significantly correlated with D-Pyr (r = 0.45, p < 0.05) and CTx (r = 0.34, p < 0.05) in primary osteoporosis. In secondary osteoporosis, SHBG was correlated with D-Pyr (r = 0.48, p < 0.05) and bSAP (r = 0.55, p < 0.01). After adjustment for age and BMI, hip bone mineral density (BMD) was not associated with testosterone or estradiol but only with serum SHBG (r = -0.33, p < 0.01) in primary osteoporosis. The same relationship was observed in men with secondary osteoporosis (r = -0.34, p < 0.01). Among osteoporotic patients, spinal radiography showed at least one vertebral crush fracture in 36 men and none in 44. Serum SHBG concentration was significantly associated with the presence of vertebral fracture: the odds ratio was 2.0 (95% confidence interval [CI] 1.2-3.5) for an increase of one standard deviation of SHBG. In conclusion, the present study showed that serum SHBG concentration is increased in middle-aged men with primary or secondary osteoporosis and is correlated with bone remodeling markers, hip bone mineral density, and vertebral fracture risk.     

Testosterone release from a subcutaneous, biodegradable microcapsule formulation (Viatrel) in hypogonadal men.

Men with hypogonadism require testosterone replacement for optimal health. In the United States, testosterone is currently administered by daily transdermal patches, topical gels or intramuscular injections every 1-3 weeks. Biodegradable polylactide-co-glycolide microcapsules are currently used for long-term drug delivery in humans. Such microcapsules that contain testosterone could provide a better means of long-term testosterone therapy. We therefore studied the pharmacokinetics and pharmacodynamics of testosterone release from testosterone microcapsules in men with hypogonadism. Fourteen men who had been treated previously with testosterone were enrolled in an open-label, prospective study of testosterone microcapsule administration. Subjects were enrolled if 2 consecutive serum total testosterone levels were lower than 8.7 nmol/L after a 4-week washout from testosterone therapy. Subjects were injected with a single dose of either 267 mg (n = 7) or 534 mg (n = 7) of (Viatrel) testosterone microcapsule, and serum total testosterone, dihydrotestosterone, estradiol, sex-hormone binding globulin, luteinizing hormone, and follicle-stimulating hormone levels were determined at days -14, -7, and 0 before the injection; at days 1, 2, and 7 after the injection; and then weekly thereafter for 8-12 weeks. Mean serum total testosterone levels peaked immediately following injection on day 1 at 25.2 +/- 2.6 nmol/L in the 267 mg group and 34.7 +/- 2.4 nmol/L in the 534 mg group. Total serum testosterone levels declined gradually and fell below 8.7 nmol/L at 42 days after injection in the 267 mg group, and 70 days after injection in the 534 mg group. Estradiol and dihydrotestosterone levels followed a similar pattern. Mean serum free testosterone also peaked immediately following injection on day 1 at 0.51 +/- 0.05 nmol/L in the 267 mg group and 0.97 +/- 0.08 nmol/L in the 534 mg group. No significant adverse reactions were seen, although 2 subjects complained of transient tenderness and fullness at their injection sites. We conclude that a single injection of 534 mg of testosterone microcapsules to men with hypogonadism normalizes serum hormone levels for up to 10-11 weeks, albeit with a pronounced early peak and a relatively long period of low-normal serum total testosterone. Subcutaneously administered testosterone microcapsules may provide a safe and convenient method for the long-term treatment of male hypogonadism or testosterone replacement in male contraceptive regimens.     

Low testosterone bioavailability is related to prostate cancer diagnose in patients submitted to prostate biopsy

Introduction

Relationship between prostate cancer (PCa) and testosterone (T) is controversial. Conflicting evidence has been published about T levels and development of PCa.

Aim

(1) To determine the relationship between hormone levels and the diagnosis of PCa. (2) To specifically focus on the relationship between PCa and T in men classified as biochemically hypogonadal.

Materials and methods

Prospective analysis of 1,000 transrectal ultrasound guided prostate biopsies (5?+?5 cores biopsies) between September 2007 and January 2010 in one center. Indication for prostate biopsy was suspicion of PCa on the basis of elevated prostate-specific antigen (PSA) and/or digital rectal examination (DRE). Serum testosterone and sex hormones binding globulin (SHBG) were determined in these patients. Of 557 men, the data were sufficient for further analysis. Age, body mass index (BMI), smoking/drinking habits, PSA, free PSA, PSA density, prostate volume, number of previous biopsies, DRE, and hormone levels were prospectively recorded.

Results

No relationship was found between T and PCa (449?±?167?ng/dL in PCa versus 437?±?169?ng/dL in non-PCa). SHBG was significantly higher in patients with PCa (51?±?27?ng/dL in PCa vs. 44?±?18?ng/dL in non-PCa). In hypogonadal men, T levels correlated with the PCa (235?±?95?ng/dL in men with PCa versus 270?±?58?ng/dL in men without PCa, P?=?0.004).

Conclusions

T levels were comparable in men with and without PCa, but SHBG levels were significantly higher in men with PCa. In men with low T, the men with PCa had a lower serum T levels and a lower prostate volume than the men without PCa.     

Low testosterone and non-alcoholic fatty liver disease: Evidence for their independent association in men with chronic spinal cord injury

Objective: Non-alcoholic fatty liver disease (NAFLD) has been claimed as a liver phenotype of metabolic syndrome, which in turn is associated with male hypogonadism. We assessed whether an independent association between NAFLD and androgen deficiency could be revealed in men with chronic spinal cord injury (SCI), who exhibit a high prevalence of biochemical androgen deficiency and a combination of risk factors for metabolic syndrome.

Design: Fifty-five consecutive men with chronic SCI admitted to a rehabilitation program underwent clinical/biochemical evaluations and liver ultrasonography.

Results: NAFLD was diagnosed in 27 patients (49.1%). Men with NAFLD were older and exhibited significantly higher body mass index, Homeostatic model assessment of insulin resistance, triglycerides and gamma-glutamyl transpeptidase values, lower total and free testosterone levels and they were engaged in a significantly poorer weekly leisure time physical activity (LTPA). At the multiple logistic regression analysis, only total and free testosterone levels exhibited a significant independent association with NAFLD. The risk of having NAFLD increased indeed of 1% for each decrement of 1 ng/dL of total testosterone and of 3% for each decrement of 1 pg/mL of free testosterone, after adjustment for confounders. In men with total testosterone < 300 ng/dL (36.4%) the prevalence of NAFLD reached 85%: they had a risk of having NAFLD significantly higher (～12-fold) than those with total testosterone ≥ 300 ng/dL, after adjustment for confounders.

Conclusion: The evidence of an independent association between NAFLD and low testosterone is strongly reinforced by its demonstration in men with chronic SCI, in spite of the many confounders peculiar to this population.     

The Limited Clinical Utility of Testosterone,Estradiol, and Sex Hormone Binding Globulin Measurements in the Prediction of Fracture Risk and Bone Loss in Older Men

Measurement of serum testosterone (T) levels is recommended in the evaluation of osteoporosis in older men and estradiol (E2) and sex hormone binding globulin (SHBG) levels are associated with the rate of bone loss and fractures, but the clinical utility of sex steroid and SHBG measurements for the evaluation of osteoporosis in men has not been examined. To evaluate whether measurements of T, E2, and/or SHBG are useful for the prediction of fracture risk or the rate of bone loss in older men, we analyzed longitudinal data from 5487 community‐based men participating in the Osteoporotic Fractures in Men (MrOS) study in the United States, Sweden, and Hong Kong. Serum T, E2, and SHBG levels were assessed at baseline; incident fractures were self‐reported at 4‐month intervals with radiographic verification (US), or ascertained via national health records (Sweden, Hong Kong). Rate of bone loss was assessed by serial measures of hip bone mineral density (BMD). We used receiver operating characteristic (ROC) curves, net reclassification improvement (NRI), and integrated discrimination improvement (IDI) to assess improvement in prediction. Mean age at baseline was 72 to 75 years and the prevalence of low T levels (<300 ng/dL) was 7.6% to 21.3% in the three cohorts. There were 619 incident major osteoporotic and 266 hip fractures during follow‐up of approximately 10 years. Based on ROC curves, there were no improvements in fracture risk discrimination for any biochemical measure when added to models, including the Fracture Risk Assessment Tool (FRAX) with BMD. Although minor improvements in NRI were observed for the dichotomous parameters low bioavailable E2 (BioE2) (<11.4 pg/mL) and high SHBG (>59.1 nM), neither sex steroids nor SHBG provided clinically useful improvement in fracture risk discrimination. Similarly, they did not contribute to the prediction of BMD change. In conclusion, there is limited clinical utility of serum E2, T, and SHBG measures for the evaluation of osteoporosis risk in elderly men. © 2016 American Society for Bone and Mineral Research.     

Transdermal testosterone gel increases serum testosterone levels in hypogonadal men in Taiwan with improvements in sexual function

A randomized, double-blind, placebo-controlled trial was conducted to (1) evaluate efficacy and safety of transdermal testosterone gel (AndroGel) for hypogonadal men in Taiwan, and (2) observe improvements in sexual function through international index of erectile function (IIEF) scores. Eligible hypogonadal men were randomized to receive 50 mg/day transdermal testosterone gel (TTG) or placebo for 3 months. Primary end point was change from baseline in total testosterone (TT) and free testosterone (FT). Secondary end points were change from baseline in serum hormone levels (such as dihydrotestosterone (DHT), estradiol (E2), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and sex-hormone-binding globulin (SHBG)) and changes in IIEF scores. Safety evaluations included adverse events (AEs) and skin irritation assessment. Compared with baseline, the TTG group (n=20) had statistically significant increases in mean TT levels at month 1 (P=0.024) and month 2 (P=0.025), but no significant changes at month 3. TT levels in the placebo group (n=18) showed no statistically significant change at any visit. Changes in FT levels paralleled changes in TT levels in both groups. TTG group IIEF scores were significantly increased at month 3 (P=0.01), compared with a decline in placebo scores. No drug-related AEs occurred in the TTG group; the placebo group had 2 AEs (mild skin rash). In conclusion, TTG effectively restores serum TT and FT levels to a normal physiological range for hypogonadal men in Taiwan and improves sexual function.     

Predicting hypogonadism in men based upon age, presence of erectile dysfunction, and depression

Hypogonadism, a disorder associated with aging, can cause significant morbidity. As clinical manifestations of hypogonadism can be subtle, the challenge and the burden of diagnosis remain the responsibility of the clinician. Four different analytic methods were used to predict hypogonadism in men based upon age, the presence of erectile dysfunction (ED) and depression. 218 men were classified by age, serum testosterone level, the presence of ED and depression. Depression was determined by the Center for Epidemiologic Studies Depression Scale (CES-D). ED was assessed by the Sexual Health Inventory for Men (SHIM). Hypogonadism was defined as a serum testosterone level <300 ng/dl. An artificial neural network (ANN) was programmed and trained to predict hypogonadism based upon age, SHIM, and CES-D scores. Subject data was randomly partitioned into a training set of 148 (67.9%) and a test set of 70 (32.1%). The ANN processed the test set only after the training was complete. The discrete predicted binary output was set to (0) if testosterone level was <300 ng/dl or (1) if >300 ng/dl. The data was also analyzed by standard logistic regression (LR), linear and quadratic discriminant function analysis (LDFA and QDFA, respectively). Reverse regression (RR) analysis evaluated the statistical significance of each risk factor. The ANN can accurately predict hypogonadism in men based upon age, the presence of ED, and depression (receiver-operating characteristic=0.725). A four hidden node network was found to have the highest accuracy. RR revealed the depression index score to be most significant variable (P=0.0019), followed by SHIM score (P=0.00602), and then by age (P=0.015). Hypogonadism can be predicated by an ANN using the input factors of age, ED, and depression. This model can help clinicians assess the need for endocrinologic evaluation in men.