Effect of testosterone replacement on response to sildenafil citrate in men with erectile dysfunction: a parallel, randomized trial.

BACKGROUND: Erectile dysfunction and low testosterone levels frequently occur together. OBJECTIVE: To determine whether addition of testosterone to sildenafil therapy improves erectile response in men with erectile dysfunction and low testosterone levels. DESIGN: Randomized, double-blind, parallel, placebo-controlled trial. (ClinicalTrials.gov registration number: NCT00512707) SETTING: Outpatient academic research center. PARTICIPANTS: Men aged 40 to 70 years with scores of 25 or less for the erectile function domain (EFD) of the International Index of Erectile Function, total testosterone levels less than 11.45 nmol/L (<330 ng/dL), or free testosterone levels less than 173.35 pmol/L (<50 pg/mL). INTERVENTION: Sildenafil dose was optimized, and 140 participants were then randomly assigned to 14 weeks of daily transdermal gel that contained 10-g testosterone for 70 participants and placebo for the remaining 70 participants. All participants were included in the primary analysis, although 10 in the testosterone group and 12 in the placebo group did not complete the study. RESULTS: At baseline, the 2 groups had similar EFD scores. Administration of sildenafil alone was associated with a substantial increase in EFD score (mean, 7.7 [95% CI, 6.5 to 8.8]), but change in EFD score after randomization did not differ between the groups (difference, 2.2 [CI, -0.8 to 5.1]; P = 0.150). The findings were similar for other domains of sexual function in younger men, more obese men, and men with lower baseline testosterone levels or an inadequate response to sildenafil alone. Frequency of adverse events was similar for testosterone and placebo groups. LIMITATION: Whether testosterone could improve erectile function without sildenafil was not studied. CONCLUSION: Sildenafil plus testosterone was not superior to sildenafil plus placebo in improving erectile function in men with erectile dysfunction and low testosterone levels. PRIMARY FUNDING SOURCE: National Institute of Child Health and Human Development.

Effect of testosterone supplementation with and without a dual 5α-reductase inhibitor on fat-free mass in men with suppressed testosterone production: a randomized controlled trial.

CONTEXT: Steroid 5α-reductase inhibitors are used to treat benign prostatic hyperplasia and androgenic alopecia, but the role of 5α-dihydrotestosterone (DHT) in mediating testosterone's effects on muscle, sexual function, erythropoiesis, and other androgen-dependent processes remains poorly understood. OBJECTIVE: To determine whether testosterone's effects on muscle mass, strength, sexual function, hematocrit level, prostate volume, sebum production, and lipid levels are attenuated when its conversion to DHT is blocked by dutasteride (an inhibitor of 5α-reductase type 1 and 2). DESIGN, SETTING, AND PATIENTS: The 5α-Reductase Trial was a randomized controlled trial of healthy men aged 18 to 50 years comparing placebo plus testosterone enthanate with dutasteride plus testosterone enanthate from May 2005 through June 2010. INTERVENTIONS: Eight treatment groups received 50, 125, 300, or 600 mg/wk of testosterone enanthate for 20 weeks plus placebo (4 groups) or 2.5 mg/d of dutasteride (4 groups). MAIN OUTCOME MEASURES: The primary outcome was change in fat-free mass; secondary outcomes: changes in fat mass, muscle strength, sexual function, prostate volume, sebum production, and hematocrit and lipid levels. RESULTS: A total of 139 men were randomized; 102 completed the 20-week intervention. Men assigned to dutasteride were similar at baseline to those assigned to placebo. The mean fat-free mass gained by the dutasteride groups was 0.6 kg (95% CI, -0.1 to 1.2 kg) when receiving 50 mg/wk of testosterone enanthate, 2.6 kg (95% CI, 0.9 to 4.3 kg) for 125 mg/wk, 5.8 kg (95% CI, 4.8 to 6.9 kg) for 300 mg/wk, and 7.1 kg (95% CI, 6.0 to 8.2 kg) for 600 mg/wk. The mean fat-free mass gained by the placebo groups was 0.8 kg (95% CI, -0.1 to 1.7 kg) when receiving 50 mg/wk of testosterone enanthate, 3.5 kg (95% CI, 2.1 to 4.8 kg) for 125 mg/wk, 5.7 kg (95% CI, 4.8 to 6.5 kg) for 300 mg/wk, and 8.1 kg (95% CI, 6.7 to 9.5 kg) for 600 mg/wk. The dose-adjusted differences between the dutasteride and placebo groups for fat-free mass were not significant (P = .18). Changes in fat mass, muscle strength, sexual function, prostate volume, sebum production, and hematocrit and lipid levels did not differ between groups. CONCLUSION: Changes in fat-free mass in response to graded testosterone doses did not differ in men in whom DHT was suppressed by dutasteride from those treated with placebo, indicating that conversion of testosterone to DHT is not essential for mediating its anabolic effects on muscle. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00493987.

Circulating Estrogen Levels and Self-Reported Health and Mobility Limitation in Community-Dwelling Men of the Framingham Heart Study.

BACKGROUND: Self-rated health is a commonly used global indicator of health status. Few studies have examined the association of self-rated health and mobility with estrone and estradiol in men. Accordingly, we determined the cross-sectional, incident, and mediating relations between circulating estrone and estradiol levels with self-rated health, mobility limitation, and physical performance in community-dwelling men. METHODS: The cross-sectional sample included 1,148 men, who attended Framingham Offspring Study Examinations 7 and 8. Estrone and estradiol levels were measured using liquid chromatography tandem mass spectrometry at Examination 7. Self-reported mobility limitation and self-rated health were assessed at Examinations 7 and 8. Additionally, short physical performance battery, usual walking speed, and grip strength were assessed at Examination 7. RESULTS: In incident analysis, estradiol levels at Examination 7 were associated with increased odds of fair or poor self-rated health at Examination 8, after adjusting for age, body mass index, comorbidities, and testosterone levels; in an individual with 50% greater estradiol than other, the odds of reporting "fair or poor" self-rated health increased by 1.78 (95% confidence interval: 1.25-2.55; p = .001). Neither estrone nor estradiol levels were associated with any physical performance measure at baseline. CONCLUSIONS: Higher circulating levels of estradiol are associated with increased risk of incident fair/poor self-rated health in community-dwelling men. The mechanisms by which circulating levels of estradiol are related to self-rated health in men need further investigation.

Testosterone induces erythrocytosis via increased erythropoietin and suppressed hepcidin: evidence for a new erythropoietin/hemoglobin set point.

BACKGROUND: The mechanisms by which testosterone increases hemoglobin and hematocrit remain unclear. METHODS: We assessed the hormonal and hematologic responses to testosterone administration in a clinical trial in which older men with mobility limitation were randomized to either placebo or testosterone gel daily for 6 months. RESULTS: The 7%-10% increase in hemoglobin and hematocrit, respectively, with testosterone administration was associated with significantly increased erythropoietin (EPO) levels and decreased ferritin and hepcidin levels at 1 and 3 months. At 6 months, EPO and hepcidin levels returned toward baseline in spite of continued testosterone administration, but EPO levels remained nonsuppressed even though elevated hemoglobin and hematocrit higher than at baseline, suggesting a new set point. Consistent with increased iron utilization, soluble transferrin receptor (sTR) levels and ratio of sTR/log ferritin increased significantly in testosterone-treated men. Hormonal and hematologic responses were similar in anemic participants. The majority of testosterone-treated anemic participants increased their hemoglobin into normal range. CONCLUSIONS: Testosterone-induced increase in hemoglobin and hematocrit is associated with stimulation of EPO and reduced ferritin and hepcidin concentrations. We propose that testosterone stimulates erythropoiesis by stimulating EPO and recalibrating the set point of EPO in relation to hemoglobin and by increasing iron utilization for erythropoiesis.

Risk factors associated with cardiovascular events during testosterone administration in older men with mobility limitation.

BACKGROUND: Testosterone in Older Men with Mobility Limitations Trial found an increased incidence of cardiovascular events in men randomized to testosterone, resulting in enrollment cessation by trial's Data and Safety Monitoring Board. We evaluated changes in gonadal hormones and markers of inflammation and coagulation to elucidate risk factors associated with cardiovascular events. METHODS: Men aged 65 years or more, with mobility limitation, total testosterone 100-350 ng/dL, or free testosterone less than 50 pg/mL, were randomized to placebo or 10 g testosterone gel daily for 6 months. Changes in total and free testosterone, estradiol and estrone, C-reactive protein, interleukin 6, fibrinogen, plasminogen activator inhibitor-1, and pro-brain naturetic peptide were compared between groups and within the testosterone group between subjects who experienced cardiovascular events and those who did not. RESULTS: Of 209 men randomized (mean age 74 years), gonadal hormones and biomarkers were available in 179 men. Baseline body mass index, gonadal hormones, lipids, Framingham risk scores, and other biomarkers were similar in the two treatment groups. Within the testosterone group, the 6-month increase in free testosterone was significantly greater in men who experienced cardiovascular events than in those who did not [mean (95% confidence interval), 10.6 (4.6-16.7) vs 5.2 (3.0-7.5) ng/dL, p = .05]. In multivariable logistic regression analysis, the change in the serum levels of free testosterone was associated with cardiovascular events. CONCLUSION: Mobility-limited older men who experienced cardiovascular events had greater increases in serum free testosterone levels than those who did not.

Relation between sex hormone concentrations, peripheral arterial disease, and change in ankle-brachial index: findings from the Framingham Heart Study.

OBJECTIVE: Our objective was to investigate cross-sectional and longitudinal associations of sex hormone concentrations with ankle-brachial index (ABI) and peripheral arterial disease (PAD). METHODS AND RESULTS: We used data from 3034 (1612 women) participants of the Framingham Heart Study. ABI was measured and PAD defined as ABI below 0.90, intermittent claudication, or lower extremity revascularization. Sex hormone concentrations were measured by liquid chromatography-tandem mass spectrometry [total testosterone (T), total estradiol, and estrone], immunofluorometric assay (SHBG), or calculated (free T). Sex-specific multivariable linear and logistic regression models were conducted for each sex hormone separately. Cross-sectional multivariable analyses revealed that men with lower free T and higher estrone (E1) concentrations had a significantly lower ABI [for free T, lowest vs. higher quartiles, ß = -0.02, with 95% confidence interval (CI) = -0.04 to -0.001; and for E1, highest vs. lower quartiles, ß = -0.02, with 95% CI = -0.04 to -0.002, respectively). Lower total T and SHBG concentrations were also associated with prevalent PAD in age-adjusted [odds ratio (OR) = 2.24, 95% CI = 1.17-4.32; and OR = 2.06; 95% CI = 1.07-3.96, lowest vs. highest quartile, respectively), but not in multivariable logistic regression models. Longitudinal multivariable analyses showed an association of lower SHBG with ABI change (decline ≥ 0.15; n = 69) in men [OR for SHBG quartiles 1, 2, and 3 as compared with quartile 4 were 2.56 (95% CI = 1.01-6.45), 2.28 (95% CI = 0.98-5.32), and 2.93 (95% CI = 1.31-6.52), respectively]. In women, none of the investigated associations yielded statistically significant estimates. CONCLUSION: Our investigation of a middle-aged community-based sample suggests that sex hormone concentrations in men but not in women may be associated with PAD and ABI change.