Although the link between androgens and depression is well established in adults, the effects of cofactors on this association are less clearly understood, particularly in youth. Epidemiological cohort study of adolescents in Dresden, Germany. Analyses comprised data of 985 individuals assessed at baseline and of 512 individuals at 1-year follow-up. We investigated multivariable regression models for cross-sectional and longitudinal associations of hair testosterone, dehydroepiandrosterone (DHEA), and their cortisol ratios with 12-month diagnoses of major depressive disorder (MDD) and MDD without any anxiety disorder assessed with standardized diagnostic interview (DIA-X-5), and with dimensional depression scores (PHQ-9, PROMIS), separately for males and females. The potential moderating effect of social support was determined. Cross-sectional analyses yielded inverse associations of testosterone and DHEA with MDD and MDD without any anxiety disorders in males. In cross-sectional and longitudinal analyses, baseline ratio cortisol/DHEA was significantly, inversely associated to PROMIS-depression in males. Only cross-sectional associations for ratio cortisol/DHEA and PROMIS-depression remained significant after Bonferroni-Holm correction. No robust associations were observed in female participants. Social support exerted no consistent moderating effect on the investigated association. The present observational cohort study showed no consistent association of hair androgen concentrations with depressive disorders in adolescents. However, findings provide some support for the association between the cortisol/DHEA ratio and depression in males. Longitudinal research designs in large samples are needed to understand the interplay between androgens, depression, and developmental and social factors in youth.

No description available.

Thesis (MPhil (Physiological Sciences))--University of Stellenbosch, 2006. / Background. Creatine monohydrate is widely used for its purported ergogenic and anabolic properties. The mechanism by which creatine supplementation enhances muscle growth is not understood. This study was undertaken to determine whether creatine monohydrate supplementation increases the conversion rate of testosterone to dihydrotestosterone. An increase in dihydrotestosterone could partly explain the beneficial effect of creatine monohydrate on muscle hypertrophy. Methods. Subcommittee C of the research committee of the University of Stellenbosch approved the study. Project number 2001/ C045. The study was designed as a double blind crossover with subjects (n = 20) in each leg of the study. Group 1 (n = 10) taking creatine monohydrate and group 2 (n = 10) glucose during the first leg of the study. In accordance with crossover study design the groups were reversed in the second leg of the study. Gelatin capsules were filled with 5g of either creatine monohydrate or 5g of glucose. Subjects taking creatine monohydrate also took 25g of glucose to improve absorption of creatine. Subjects took creatine monohydrate 25g plus 25g of glucose (ten capsules in all) or glucose ten capsules per day for seven days in the loading phase. In the maintenance phase they took 5g of creatine monohydrate plus 25g of glucose (six capsules in all) per day or six capsules of glucose, for 14 days. The groups were reversed after a six-week washout period and the dosages repeated as per crossover study design. Blood samples were taken on day zero of the study as baseline measurements, repeated on day 7, (after the loading phase), and again on day 21, (after the maintenance phase). These were again repeated in the second leg of the study as per crossover design. Serum was separated within one hour of collection and stored at minus 70 oC. Testosterone and dihydrotestosterone concentrations were determined using a radio-immunoassay kit by an accredited university laboratory. The percentage conversion of testosterone to dihydrotestosterone was calculated. The results were statistically analyzed: A paired t - tests at the beginning of each leg of the study and repeated measure analysis of variance, for the pooled data for each condition over the whole study. Results. The difference in blood levels of testosterone and dihydrotestosterone on both days 0, were not statistically significant. This made the pooling of the data possible. The difference in the percentage conversion of testosterone to dihydrotestosterone over the study period between the creatine monohydrate condition and the glucose condition, was however significant (p < 0.0001). In this small study highly significant statistical results were obtained. The answer to how creatine taken as a supplement exerts its effect may lie in the increased rate of conversion of testosterone to dihydrotestosterone. Conclusion. With the known greater androgenic effect of dihydrotestosterone as opposed to testosterone, the increase in testosterone conversion to dihydrotestosterone could explain how creatine supplementation exerts its anabolic effect in susceptible individuals. A larger study should be done to confirm these results and answer the questions arising from the findings.

In der Schweiz wird die Diskussion um eine Testosteron-Behandlung gerade beim älteren Mann sehr konservativ und mit vielen Vorbehalten geführt. In der schweizerischen Fachliteratur finden sich keine nationalen Guidelines zu diesem Thema. In Zeitungsartikeln in schweizerischen Fachzeitschriften wird die Testosteron-Behandlung befürwortet, aber mit vielen Einschränkungen und Vorbehalten versehen. Daraus lässt sich eine Gruppe von „offenen Fragen“ zusammenstellen, die in der Folge aufgrund der aktuellen internationalen Fachliteratur diskutiert werden. / The discussion about testosterone therapy is hold in Switzerland in a conservative way and with many objections. In the Swiss medical literature there are no national guidelines published about this object. In publications in Swiss medical papers the testosterone therapy is approved but with many restrictions and reservations. There are some "open questions" collected together and discussed comparing the actual international medical literature.

Immunity and reproduction are important and costly life-history traits and a large part of eco-immunology focuses on trade-offs between investing in reproduction versus immunity. Male Cape ground squirrels (Xerus inauris) are a good organism to test these trade-offs as they invest heavily in sperm competition, evidenced by their large testes, and exhibit alternative reproductive tactics. My research objective was to determine 1) if testosterone suppresses immunity, or if immunity suppresses testosterone, and 2) if alternative reproductive tactics differ in their investments in immunity and reproduction. I found evidence that testosterone was suppressed after an immune challenge, and that manipulatively increased testosterone had no effect on immunity, body condition or parasites. The dispersing tactic males were in worse condition, had higher parasite abundances, but showed no difference in their innate immune ability to non-dispersing males. Males incur increased costs with dispersal and may focus their energy into reproduction instead of immunity. / October 2015

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Bakgrund: Minskade testosteronnivåer hos äldre överviktiga män är ett fenomen som varit omtalat i många år. Allvarliga sjukdomar som kan leda till för tidig bortgång kan förekomma vid för låga testosteronnivåer hos män. I många år har äldre överviktiga män använt sig av medicinska ingrepp för att öka sina hormonnivåer med syftet att återfå sin ungdomliga hälsa och undvika sjukdomar. Syftet med denna studie är att göra en sammanfattning av sökt och hittad litteratur om träningseffekter på testosteronnivåer hos äldre överviktiga män med 29+ i BMI. Metoden som författaren valt är en systematisk litteraturstudie. Resultat utgår från hittade studier från databaserna PubMed och Discovery. Med hjälp av sökord och andra begränsningar hittades relevanta vetenskapliga artiklar som analyserades, evidensvärderades och diskuterades av författaren. Resultaten framfördes från sju hittade artiklar där fyra av de visade att testosteronnivåerna kan ökas genom träning för äldre överviktiga män. Träningsformen som visade bäst resultat var aerob träning och denna träningsform användes i fem av samtliga artiklar. Testosteronnivåökning och andra förbättrade hälsotillstånd resulterades av aerob träning i olika former och tidsperioder. Slutsats: Vid utövandet av aerob träning av olika former under olika tidsperioder kan testosteronnivåer öka hos äldre överviktiga män med 29+ i BMI. Kostmodifiering i kombination med aerob träning visar sig öka chansen för att öka testosteronnivåerna hos drabbade.

Aggression is a phenomenon which acquired a substantial share on attention of biological literature, especially since the beginning of 20th century. In this thesis, various approaches to the problem from the field of biology are summarized. Intensified attention is dedicated to the theoretical concepts of aggression, especially the concepts consulting the problem of aggression from the evolutionary point of view and to the research on the field of hormonal regulation of aggression, stressing out the role of the hormone testosterone, and to particular hypothesis, which take account on its mutual relationship with behavior. The empirical part of the thesis is dedicated to verification of premises of the challenge hypothesis according to the relationship between testosterone and aggressive behavior. Significant findings of the empirical part refer to the existence of a link between basal level of testosterone and aggressive tendencies and to the existence of a negative link between basal level of testosterone and its increase in reaction to a competitive situation.

La mort subite d’origine cardiaque est fréquemment rencontrée chez les sportifs de haut niveau ayant recours à des produits illicites afin d’accroitre leur performances physiques. Parmi les substances consommées, les stéroïdes anabolisants occupent une place importante. L’objectif de notre travail était : 1) de préciser la nature exacte des lésions cardiaques consécutives à l’usage des stéroïdes anabolisants chez les sportifs décédés de morts subites et chez les lapins traités par la noréthandrolone (NED) et la testostérone (TST); 2) d’en élucider le(s) mécanisme(s) responsable(s) et enfin ; 3) de vérifier si des substances à effets antiischémiques (trimétazidine : TMZ) ou cardioprotecteurs (dexrazoxane : DEX) pouvaient protéger le cœur « agressé » par un stéroïde anabolisant et prévenir le développement de telles lésions / Sudden death of cardiac origin is frequently observed in athletes with a history of illicit products abuse to increase physical performance. Anabolic steroids play a significant role amongst these substances. The aim of this work was: 1) to precisely describe the nature of heart lesions resulting from anabolic steroid abuse in athletes who suddenly died, and in rabbits treated with norethandrolone (NED) or testosterone (TST); 2) to elucidate the underlying mechanism(s) and finally; 3) to test whether anti-ischemia (trimetazidine: TMZ) or cardioprotective (dexrazoxane: DEX) drugs could protect the heart from anabolic steroids and prevent the development of lesions

Title: Hormonal changes in strength training Objectives: Perform a systematic review of literature dealing with hormonal changes in strength training. Based on the informations from aforementioned literature, describe wheather acute hormonal response after a bout of strength training significantly influence the proces of hypertrophy or not. Hormone testosterone and changes of its concentrations is for this thesis the most important. Methods: Method of traditional review was used in this thesis. Results: The presence of acute hormonal changes occurred in strength training was confirmed in numerous studies. Role of this hormonal response is because of variability in results not very clear yet. Chronicle changes of resting hormonal levels in strength training are not observed according to results of studies. For better understanding of hormonal strength in strength training, another studies have to be executed. Keywords: endocrinal system, strength training, hormonal response, testosterone, hypertrophy.