Dihydrotestosterone is elevated following sprint exercise in healthy young men

2013 ◽  
Vol 114 (10) ◽  
pp. 1435-1440 ◽  
Author(s):  
Alan A. Smith ◽  
Rebecca Toone ◽  
Oliver Peacock ◽  
Scott Drawer ◽  
Keith A. Stokes ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Venous Blood ◽  
Young Men ◽  
Free Testosterone ◽  
Total Testosterone ◽  
Cycle Exercise ◽  
Skeletal Muscle Function ◽  
Sprint Exercise ◽  
Rate Maximum ◽  
Repeat Sprint

Dihydrotestosterone (DHT) exerts both functional and signaling effects extending beyond the effects of testosterone in rodent skeletal muscle. As a primer for investigating the role of DHT in human skeletal muscle function, this study aimed to determine whether circulating DHT is acutely elevated in men following a bout of repeat sprint exercise and to establish the importance of training status and sprint performance to this response. Fourteen healthy active young men (V̇o2max61.0 ± 8.1 ml·kg body mass−1·min−1) performed a bout of repeat sprint cycle exercise at a target workload based on an incremental work-rate maximum (10 × 30 s at 150% Wmaxwith 90-s recovery). Venous blood samples were collected preexercise and 5 and 60 min after exercise. Five minutes after exercise, there were significant elevations in total testosterone (TT; P < 0.001), free testosterone (FT; P < 0.001), and DHT ( P = 0.004), which returned to baseline after 1 h. Changes in DHT with exercise (5 min postexercise − preexercise) correlated significantly with changes in TT ( r = 0.870; P < 0.001) and FT ( r = 0.914; P < 0.001). Sprinting cadence correlated with changes in FT ( r = 0.697; P = 0.006), DHT ( r = 0.625; P = 0.017), and TT ( r = 0.603; P = 0.022), and habitual training volume correlated with the change in TT ( r = 0.569, P = 0.034). In conclusion, our data demonstrate that DHT is acutely elevated following sprint cycle exercise and that this response is influenced by cycling cadence. The importance of DHT in the context of exercise training and sports performance remains to be determined.

Impaired Function and Altered Morphology in the Skeletal Muscles of Adult Men and Women with Type 1 Diabetes

2021 ◽  
Author(s):  
Athan G Dial ◽  
Cynthia M F Monaco ◽  
Grace K Grafham ◽  
Tirth P Patel ◽  
Mark A Tarnopolsky ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Type 1 Diabetes ◽  
Muscle Function ◽  
Morphological Changes ◽  
Venous Blood ◽  
Accelerated Aging ◽  
Myosin Heavy Chain Isoforms ◽  
Hybrid Fibers ◽  
Skeletal Muscle Function

Abstract Context Previous investigations on skeletal muscle health in type 1 diabetes (T1D) has generally focused on later stages of disease progression where comorbidities are present and are posited as a primary mechanism of muscle dysfunction. Objective To investigate skeletal muscle function and morphology across the adult lifespan in those with and without T1D. Design Participants underwent maximal contraction (MVC) testing, resting muscle biopsy and venous blood sampling. Setting Procedures in this study were undertaken at the McMaster University Medical Centre. Participants Sixty-five healthy adult (18-78 years old) men/males and women/females [T1D=34; control=31] matched for age/biological sex/body mass index (BMI)/self-reported physical activity levels were included. Main Outcome Measures Our primary measure in this study was MVC, with supporting histological/immunofluorescent measures. Results After 35 years of age (‘older adults’), MVC declined quicker in T1D subjects compared to controls. Loss of strength in T1D was accompanied by morphological changes associated with accelerated aging. Type 1 myofiber grouping was higher in T1D, and the groups were larger and more numerous than in controls. Older T1D females exhibited more myofibers expressing multiple myosin heavy chain isoforms (hybrid fibers) than controls, another feature of accelerated aging. Conversely, T1D males exhibited a shift towards type 2 fibers, with less evidence of myofiber grouping or hybrid fibers. Conclusions These data suggest impairments to skeletal muscle function and morphology exist in T1D. The decline in strength with T1D is accelerated after 35 years of age and may be responsible for the earlier onset of frailty which characterizes those with diabetes.

scholarly journals Acute hormonal response to sublingual androstenediol intake in young men

2002 ◽  
Vol 92 (1) ◽  
pp. 142-146 ◽  
Author(s):  
Gregory A. Brown ◽  
Emily R. Martini ◽  
B. Scott Roberts ◽  
Matthew D. Vukovich ◽  
Douglas S. King
Keyword(s):  
Peak Concentration ◽  
Young Men ◽  
Serum Testosterone ◽  
Free Testosterone ◽  
Total Testosterone ◽  
Serum Estradiol ◽  
Hormonal Response ◽  
Double Blind ◽  
First Pass ◽  
Serum Hormone

The effectiveness of orally ingested androstenediol in raising serum testosterone concentrations may be limited because of hepatic breakdown of the ingested androgens. Because androstenediol administered sublingually with cyclodextrin bypasses first-pass hepatic catabolism, we evaluated the acute hormonal response to sublingual cyclodextrin androstenediol supplement in young men. Eight men (22.9 ± 1.2 yr) experienced in strength training consumed either 20 mg androstenediol in a sublingual cyclodextrin tablet (Sl Diol) or placebo (Pl) separated by at least 1 wk in a randomized, double-blind, crossover manner. Blood samples were collected before supplementation and at 30-min intervals for 3 h after supplementation. Serum hormone concentrations did not change with Pl. Serum androstenedione concentrations were increased ( P < 0.05) above baseline (11.2 ± 1.1 nmol/l) with Sl Diol from 60 to 180 min after intake and reached a peak concentration of 25.2 ± 2.9 nmol/l at 120 min. Serum free testosterone concentrations were increased from 86.2 ± 9.1 pmol/l with Sl Diol from 30 to 180 min and reached a peak concentration of 175.4 ± 12.2 pmol/l at 60 min. Serum total testosterone concentrations increased above basal (25.6 ± 2.3 nmol/l) from 30 to 180 min with Sl Diol and reached a peak concentration of 47.9 + 2.9 nmol/l at 60 min. Serum estradiol concentrations were elevated ( P < 0.05) above baseline (0.08 ± 0.01 nmol/l) from 30 to 180 min with Sl Diol and reached 0.14 ± 0.02 nmol/l at 180 min. These data indicate that sublingual cyclodextrin androstenediol intake increases serum androstenedione, free testosterone, total testosterone, and estradiol concentrations.

Free testosterone correlated with erectile dysfunction severity among young men with normal total testosterone

2018 ◽  
Vol 31 (2) ◽  
pp. 132-138 ◽  
Author(s):  
Yan-Ping Huang ◽  
Wei Liu ◽  
Sheng-Fu Chen ◽  
Yi-Dong Liu ◽  
Bin Chen ◽  
...  
Keyword(s):  
Erectile Dysfunction ◽  
Young Men ◽  
Free Testosterone ◽  
Total Testosterone

scholarly journals The Impulse of Force as an Effective Indicator of Exercise Capacity in Competitive Rowers and Canoeists

2021 ◽  
Vol 79 (1) ◽  
pp. 87-99
Author(s):  
Katarzyna Domaszewska ◽  
Jakub Kryściak ◽  
Tomasz Podgórski ◽  
Alicja Nowak ◽  
Małgorzata Barbara Ogurkowska
Keyword(s):  
Exercise Capacity ◽  
Aerobic Capacity ◽  
Ventilatory Threshold ◽  
Venous Blood ◽  
Maximum Load ◽  
Free Testosterone ◽  
Training Intervention ◽  
Total Testosterone ◽  
Testing Session ◽  
Maximal Aerobic Capacity

Abstract The aim of the research was to present the importance of measuring the impulse of force in assessing exercise capacity in professional rowers and canoeists rather than conducting traditional physiological and biochemical analyses. A group of 20 athletes (12 rowers and 8 canoeists) underwent progressive intensity exercise tests in two testing sessions (before and after a training period). During the tests, maximal aerobic capacity, impulse of strength, metabolic indices, and markers of skeletal muscle damage were assessed. Total testosterone, free testosterone, cortisol, interleukin 1,6, and creatine kinase were evaluated in venous blood. The impulse of force at the ventilatory threshold and at the maximum load was correlated with free testosterone and a total testosterone/cortisol ratio during exercise (p ≤ 0.05) and was negatively correlated with cortisol concentration (p ≤ 0.05) in the first testing session (before training intervention). Values were positively correlated with concentration of total testosterone, free testosterone and total testosterone/cortisol, and free testosterone/cortisol ratios during exercise (p ≤ 0.05) in the second testing session (after training intervention). Biochemical indices of overtraining were correlated with maximum oxygen uptake in each session and with the impulse of force at the ventilatory threshold and the maximum load of exercise. Thus, there is an indirect relationship between maximal aerobic capacity and the impulse of force. The measurement of the impulse of force can become a simple and effective method for evaluating the overall exercise capacity of rowers because of its relationship with indices of the load and changes in hormonal indices of anabolic and catabolic processes during exercise. Therefore, it may constitute a replacement for the traditional laboratory measurement of VO2max in highly qualified rowers and canoeists.

Prevalence of and Risk Factors for Low Free Testosterone Levels in Japanese Men with Well-controlled Human Immunodeficiency Virus Infection

2020 ◽  
Vol 18 (5) ◽  
pp. 381-386
Author(s):  
Yusuke Yoshino ◽  
Ichiro Koga ◽  
Yoshitaka Wakabayashi ◽  
Takatoshi Kitazawa ◽  
Yasuo Ota
Keyword(s):  
Risk Factors ◽  
Human Immunodeficiency Virus ◽  
Standard Deviation ◽  
Hiv Infection ◽  
Free Testosterone ◽  
Serum Levels ◽  
University Hospital ◽  
Rapid Decline ◽  
Total Testosterone ◽  
Immunodeficiency Virus

Background: The change in the prevalence of hypogonadism with age in men with human immunodeficiency virus (HIV) infection is subject to debate. Objective: To address this issue, we diagnosed hypogonadism based on serum levels of free testosterone (fTST) rather than total testosterone which is thought to be an inaccurate indicator. We also determined the relationship between age and fTST levels and identified risk factors for hypogonadism in men with HIV infection. Method: We retrospectively reviewed fTST levels and associated clinical factors in 71 wellcontrolled HIV-infected men who were treated at Teikyo University Hospital between April 2015 and March 2016 and who had data available on serum fTST levels, measured >6 months after starting antiretroviral therapy. fTST was measured using radioimmunoassay on blood samples collected in the morning. Risk factors for hypogonadism were identified using Welch’s t-test and multiple regression analysis. Results: The men had a mean (± standard deviation) age of 47.4 ± 13.6 years, and mean (± standard deviation) serum fTST level of 13.0 ± 6.1 pg/mL. Fifteen (21.1%) men had hypogonadism based on a fTST <8.5 pg/mL. Serum fTST levels significantly decreased with age (−0.216 pg/mL/year). Older age and low hemoglobin levels were identified as risk factors for hypogonadism. Conclusion: The men in the study experienced a more rapid decline in fTST levels with age than men in the general population (−0.161 pg/mL/year). Serum fTST levels in men with HIV infection should be monitored, especially in older men and those with low hemoglobin levels.

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