Supraphysiological Levels Of Testosterone Research Articles

(088) Impact of Testosterone Replacement Therapy on Adverse Cardiovascular Events in Hypogonadism Patients: A Comprehensive Evaluation of Physiological and Supraphysiological T Levels

Abstract Introduction Sustained treatment with elevated levels of exogenous testosterone (T) has been linked to various adverse events, particularly concerning cardiovascular risks. However, there is currently a lack of sufficient literature that comprehensively describes the overall safety profile of supraphysiologic testosterone levels. Objective To compare the safety profiles and rates of polycythemia, venous thromboembolism (VTE), major adverse cardiac events (MACE), deep vein thrombosis (DVT), myocardial infarction (MI), and stroke between hypogonadism patients treated with testosterone replacement therapy (TRT) at physiological and supraphysiological testosterone levels. Methods We identified patients with hypogonadism (<300 ng/dL) who underwent testosterone replacement therapy (TRT) at our institution through electronic medical record review. Patients lacking records of their first encounter, documented medical history, sufficient follow-up, or post-TRT adverse event data were excluded from the analysis. Supraphysiological testosterone levels were defined as >1000 ng/dL. The included patients were retrospectively analyzed using two-way nonparametric testing for continuous variables and chi-square and Fisher exact tests for categorical variables (α = 0.05). Results From a cohort of 537 men diagnosed with hypogonadism, we included 184 patients who underwent testosterone replacement therapy (TRT). Among these patients, 135 (73.4%) were treated to achieve physiological testosterone levels, with a median level of 468.0 ng/dL (interquartile range, IQR = 308.0-644.5), while 49 patients (26.6%) were treated to attain supraphysiologic testosterone levels, with a median level of 1552 ng/dL (IQR = 1279-1700). Before initiating TRT, there was no significant difference in testosterone levels between the two groups (p = 0.11). Moreover, no significant differences were found between the groups in terms of a history of diabetes mellitus (DM; p = 0.422) or prostate cancer (p = 0.29). However, significant differences were observed in the history of hypertension (HTN; p = 0.003) and hyperlipidemia (HLD; p = 0.006), with more patients in the physiologic testosterone group having a diagnosis of HTN and HLD prior to treatment. Regarding adverse events, there were more cases of polycythemia in the supraphysiologic testosterone group compared to the physiologic testosterone group (p < 0.001; 35.4% vs. 7.0%). Interestingly, there was no significant difference in the rate of other adverse events after TRT between the two groups, including venous thromboembolism (VTE; p = 0.285), major adverse cardiovascular events (MACE; p = 0.768), deep vein thrombosis (DVT; p > 0.999), myocardial infarction (MI; p = 0.562), and stroke (p > 0.999). Conclusions Despite widespread concerns, these findings suggest that although patients treated to achieve supraphysiologic testosterone levels had a higher incidence of polycythemia, there were no significant differences in the rates of other adverse events after TRT between patients treated to attain physiological versus supraphysiologic testosterone levels. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Consultant for AbbVie, Marius, Tolmar, Endo, Petros, Boston Scientific, Coloplast Investor: Sprout.

Supraphysiological testosterone levels from anabolic steroid use and reduced sensitivity to negative facial expressions in men

RationaleAnabolic-androgenic steroids (AAS) are used to improve physical performance and appearance, but have been associated with deficits in social cognitive functioning. Approximately 30% of people who use AAS develop a dependence, increasing the risk for undesired effects.ObjectivesTo assess the relationship between AAS use (current/previous), AAS dependence, and the ability to recognize emotional facial expressions, and investigate the potential mediating role of hormone levels.MethodsIn total 156 male weightlifters, including those with current (n = 45) or previous (n = 34) AAS use and never-using controls (n = 77), completed a facial Emotion Recognition Task (ERT). Participants were presented with faces expressing one out of six emotions (sadness, happiness, fear, anger, disgust, and surprise) and were instructed to indicate which of the six emotions each face displayed. ERT accuracy and response time were recorded and evaluated for association with AAS use status, AAS dependence, and serum reproductive hormone levels. Mediation models were used to evaluate the mediating role of androgens in the relationship between AAS use and ERT performance.ResultsCompared to never-using controls, men currently using AAS exhibited lower recognition accuracy for facial emotional expressions, particularly anger (Cohen’s d = −0.57, pFDR = 0.03) and disgust (d = −0.51, pFDR = 0.05). Those with AAS dependence (n = 47) demonstrated worse recognition of fear relative to men without dependence (d = 0.58, p = 0.03). Recognition of disgust was negatively correlated with serum free testosterone index (FTI); however, FTI did not significantly mediate the association between AAS use and recognition of disgust.ConclusionsOur findings demonstrate impaired facial emotion recognition among men currently using AAS compared to controls. While further studies are needed to investigate potential mechanisms, our analysis did not support a simple mediation effect of serum FTI.

Supraphysiological levels of testosterone induces endothelial injury via increasing generation of reactive oxygen species and ERK1/2 activation

Introduction: High levels of testosterone (Testo) is associated with higher cardiovascular risk by positively modulate the generation of reactive oxygen species (ROS) and inflammatory response. Excessive ROS generation by NADPH oxidases (NOX, major source of ROS in the vasculature) leads to endothelial dysfunction, apoptosis, and inflammation. However, the intracellular mechanisms whereby supraphysiological levels of Testo promote cardiovascular damage are still ill defined. We sought to determine whether supraphysiological levels of Testo induces endothelial cell dysfunction via ROS generation and ERK1/2 activation. Methods: To study whether Testo present the same effects independent on endothelial cell type, we used Primary Human Mesenteric vascular Endothelial Cells (HMEC) and Human Umbilical Vein Endothelial Cells (HUVEC). Cells were stimulated with Testo (10 −7 M, for different time points) in the presence or absence of superoxide dismutase mimetic (Tempol, 10 -4 M, for 30 min). NOX activity, gene expression, and protein expression were determined pharmacological assays and immunoblotting, respectively. Results: Testo increased superoxide anion (O 2 − ) generation in HMEC and HUVEC at short (10 min) stimulation times, which was abolished by superoxide dismutase (SOD) mimetic [(% of control) Ctrl: 100.0 ± 0.0 n=5 vs Testo: 363.2 ± 19.77 n=6 vs. Tempol+Testo: 156.7 ± 12.12 n=6, *P<0.05]. Furthermore, long-term treatment (24 h) of endothelial cells with Testo increased Nox4 expression at gene (2.44-Fold change) and protein levels [(% of control) Ctrl: 100.0 ± 0.0 n=4 vs. Testo: 157.3 ± 4.49 n=4, *P<0.05]. Testo did not affect Nox1, Nox2, and Nox5 expressions. Furthermore, Testo increased ERK1/2 phosphorylation at 10 minutes and promoted endothelial cell inflammation at 8h, characterized by increased ICAM-1(6.49-Fold changes) and VCAM-1 [(1.42-Fold changes) gene expressions. To confirm that Testo-induced ROS production is leading to endothelial injury via ERK1/2, we treated endothelial cells with Tempol prior Testo treatment. Interestingly, superoxide dismutase mimetic prevented ERK1/2 phosphorylation induced by Testo [(% of control) Testo: 161.2 ± 11.39 n=5 vs. Tempol+Testo: 91.45 ± 9.61 n=5, *P<0.05]. Conclusion: These data indicate that supraphysiological levels of testosterone induce endothelial dysfunction via ROS generation and inflammatory response. Our data helps understanding the intracellular mechanisms that justify the cardiovascular damage caused by supraphysiological doses of testosterone and places antioxidant therapy as a possible pharmacological approach to treat patients with dysregulated testosterone levels. 2022/00103-3, São Paulo Research Foundation (FAPESP). NHLBI-R00 (R00HL14013903), AHA-CDA (CDA857268), Vascular Medicine Institute, the Hemophilia Center of Western Pennsylvania Vitalant, and Children's Hospital of Pittsburgh of the UPMC Health System. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The testosterone paradox of advanced prostate cancer: mechanistic insights and clinical implications.

The discovery of the benefits of castration for prostate cancer treatment in 1941 led to androgen deprivation therapy, which remains a mainstay of the treatment of men with advanced prostate cancer. However, as early as this original publication, the inevitable development of castration-resistant prostate cancer was recognized. Resistance first manifests as a sustained rise in the androgen-responsive gene, PSA, consistent with reactivation of the androgen receptor axis. Evaluation of clinical specimens demonstrates that castration-resistant prostate cancer cells remain addicted to androgen signalling and adapt to chronic low-testosterone states. Paradoxically, results ofseveral studies have suggested that treatment with supraphysiological levels of testosterone can retard prostate cancer growth. Insights from these studies have been used toinvestigate administration of supraphysiological testosterone to patients with prostate cancer for clinical benefits, a strategy that is termed bipolar androgen therapy (BAT). BAT involves rapid cycling from supraphysiological back to near-castration testosterone levels over a 4-week cycle. Understanding how BAT works at the molecular and cellular levels might help to rationalize combining BAT with other agents to achieve increased efficacy and tumour responses.

Response to supraphysiological testosterone is predicted by a distinct androgen receptor cistrome.

The androgen receptor (AR) is a master transcription factor that regulates prostate cancer (PC) development and progression. Inhibition of AR signaling by androgen deprivation is the first-line therapy with initial efficacy for advanced and recurrent PC. Paradoxically, supraphysiological levels of testosterone (SPT) also inhibit PC progression. However, as with any therapy, not all patients show a therapeutic benefit, and responses differ widely in magnitude and duration. In this study, we evaluated whether differences in the AR cistrome before treatment can distinguish between SPT-responding (R) and -nonresponding (NR) tumors. We provide the first preclinical evidence to our knowledge that SPT-R tumors exhibit a distinct AR cistrome when compared with SPT-NR tumors, indicating a differential biological role of the AR. We applied an integrated analysis of ChIP-Seq and RNA-Seq to the pretreatment tumors and identified an SPT-R signature that distinguishes R and NR tumors. Because transcriptomes of SPT-treated clinical specimens are not available, we interrogated available castration-resistant PC (CRPC) transcriptomes and showed that the SPT-R signature is associated with improved survival and has the potential to identify patients who would respond to SPT. These findings provide an opportunity to identify the subset of patients with CRPC who would benefit from SPT therapy.

Testosterone increases bradykinin-induced relaxation in the coronary bed of hypertensive rats.

Physiological or supraphysiological levels of testosterone appear to be associated with the development of risk factors for cardiovascular diseases such as hypertension, as this hormone modulates the release of endothelial factors. However, its actions are still controversial, especially in the coronary circulation of hypertensive animals. This study was designed to assess the effects of testosterone treatment (T) on endothelium-dependent coronary vascular reactivity in orchiectomized SHR. The animals were divided into SHAM, orchiectomized (ORX), ORX+T and ORX+T+aromatase inhibitor (AI). All treatments lasted 15 days. Blood pressure (BP) was measured. Dose-response curves to bradykinin (BK) were constructed using the Langendorff technique, followed by inhibition of endothelium mediators (NO, prostanoids, EETs) and potassium channels. The intensity of eNOS, COX-1, COX-2, Akt, and gp91phox protein expression was quantified by Western blotting. BP was elevated in SHAM, ORX+T, and ORX+T+AI groups. However, we did not observe differences in the ORX group. Baseline coronary perfusion pressure (CPP) remained unaffected. Orchiectomy did not change the BK-induced relaxation compared to the SHAM group, whereas testosterone treatment increased it. This response was diminished in the absence of NO, prostanoids, and EETs in the SHAM and ORX groups, while in ORX+T group the relaxation was diminished only in the absence of NO and EETs. There was no difference in eNOS, COX-1, COX-2, and gp91phox protein expression, though Akt expression was increased in ORX and ORX+T groups. These results show that testosterone treatment can modulate endothelial function, especially in the coronary circulation under hypertension conditions, via NO and EETs pathways.

Supraphysiological Levels of Testosterone Induce Vascular Dysfunction via Activation of the NLRP3 Inflammasome.

Background: Both supraphysiological and subphysiological testosterone levels are associated with increased cardiovascular risk. Testosterone consumption at supraphysiological doses has been linked to increased blood pressure, left ventricular hypertrophy, vascular dysfunction, and increased levels of inflammatory markers. Activation of the NLRP3 inflammasome contributes to the production of proinflammatory cytokines, leading to cardiovascular dysfunction. We hypothesized that supraphysiological levels of testosterone, via generation of mitochondrial reactive oxygen species (mROS), activates the NLRP3 inflammasome and promotes vascular dysfunction.Methods: Male, 12 week-old C57Bl/6J (WT) and NLRP3 knockout (NLRP3−/−) mice were used. Mice were treated with testosterone propionate [TP (10 mg/kg) in vivo] or vehicle for 30 days. In addition, vessels were incubated with testosterone [Testo (10−6 M, 2 h) in vitro]. Testosterone levels, blood pressure, vascular function (thoracic aortic rings), pro-caspase-1/caspase-1 and interleukin-1β (IL-1β) expression, and generation of reactive oxygen species were determined.Results: Testosterone increased contractile responses and reduced endothelium-dependent vasodilation, both in vivo and in vitro. These effects were not observed in arteries from NLRP3−/− mice. Aortas of TP-treated WT mice (in vivo), as well as aortas from WT mice incubated with testo (in vitro), exhibited increased mROS levels and increased caspase-1 and IL-1β expression. These effects were not observed in arteries from NLRP3−/− mice. Flutamide [Flu, 10−5 M, androgen receptor (AR) antagonist], carbonyl cyanide m-chlorophenyl hydrazone (CCCP, 10−6 M, mitochondrial uncoupler) and MCC950 (MCC950, 10−6 M, a NLRP3 receptor inhibitor) prevented testosterone-induced mROS generation.Conclusion: Supraphysiological levels of testosterone induce vascular dysfunction via mROS generation and NLRP3 inflammasome activation. These events may contribute to increased cardiovascular risk.

New testosterone 2% gel using Ferring Advanced Skin Technology (FAST), for the treatment of testosterone deficiency in men, with a novel applicator

ABSTRACT Introduction Testosterone deficiency (TD) is an increasing problem that can affect a man’s physical and psychological health, and quality of life. Testosterone replacement therapy (TRT), combined with weight reduction, lifestyle advice, and the treatment of co-morbidities, is the treatment of choice in men who are not concerned about fertility. However, there remains an unmet need in this therapeutic area, relating to factors such as inconvenient or painful administration, fluctuations in testosterone levels, supra-physiologic testosterone levels, poor tolerability, and secondary safety issues, which may be associated with the current TRT options. Advances in transdermal delivery systems have resulted in the development of a new 2% transdermal testosterone gel, that may offer some additional features over the other currently available TRTs. Areas covered We performed a comprehensive review of the published and gray literature to identify randomized studies and non-randomized studies (NRS) involving adult men receiving treatment for low testosterone levels. Expert opinion Topical gels are often the most convenient first-line treatment for testosterone deficiency, but options are important as patient preference is more important than virtually any other clinical area of medicine. The chosen therapy must be convenient to use and reach reliable therapeutic levels to effectively and consistently relieve symptoms. Testavan, a new 2% testosterone gel, goes some way to achieving these goals.

Bipolar androgen therapy in prostate cancer: Current evidences and future perspectives.

Testosterone suppression by androgen deprivation therapy is the cornerstone of prostate cancer treatment. New-generation hormone therapies improved overall survival in castration-resistant prostate cancer. More recent trials showed a further increase in overall survival when enzalutamide or abiraterone are associated with androgen deprivation therapy in hormone-sensitive disease. However, a higher clonal pressure may lead to the upregulation of alternative pathways for cancer progression and to dedifferentiated diseases that would probably respond poorly to subsequent treatments. In this contest, new strategies that could be able to delay or even revert resistance are needed. The bipolar androgen therapy is an under-investigation treatment that consists in periodical oscillation between castration levels and supraphysiological levels of testosterone in order to prevent the adaptation of prostate cancer cells to a low-androgen environment. This review aims to underline the biological rationale of bipolar androgen therapy and gather evidences from the most recent clinical trials.

The effects of supraphysiological levels of testosterone on neural networks upstream of gonadotropin-releasing hormone neurons.

Objective(s):Several pathological conditions are associated with hyper-production of testosterone; however, its impacts are not well understood. Hence, we evaluated the effects of supraphysiological levels of testosterone on gonadotropin-releasing hormone (GnRH) system in the hypothalamus of male rats. Also, we assessed the expression of two excitatory (kisspeptin and neurokinin-B) and two inhibitory (dynorphin and RFamide-related-peptide) neuropeptides upstream of GnRH neurons as possible routes to relay androgen information. Materials and Methods:Gonadectomized (GDX) male rats received single injection of 100, 250 or 500 mg/kg testosterone undecanoate and three weeks later, posterior (PH) and anterior (AH) hypothalamus was dissected for evaluation of target genes using quantitative RT-PCR.Results:We found that GnRH mRNA in the PH was high in GDX rats and 500 mg/kg testosterone reduced GnRH level expression. Finding revealed extremely high level of Kiss1 mRNA in the PH of GDX rats. However, in GDX rats treated with different levels of testosterone, Kiss1 expression was not significantly different than control. We also found that testosterone replacement increased the Kiss1 mRNA level in the AH. Moreover, neurokinin-B mRNA level in PH of GDX rats was similar to control. However, excess testosterone levels were effective in significantly inducing the down-regulation of neurokinin-B expression. The basal level of dynorphin mRNA was increased following testosterone treatments in the AH, where we found no significant difference in the level of RFamide-related-peptide mRNA between the experimental groups. Conclusion:Excess levels of testosterone could act differently from its physiological concentration to regulate hypothalamic androgen sensitive neurons to control GnRH cell.

Abstract 379: Supraphysiological testosterone inhibits tumor growth and is associated with inhibition of ARV7 signaling and DNA damage response in preclinical models of enzalutamide-resistant prostate cancer

Abstract Background: Anti-androgen therapies suppress castration-resistant prostate cancer (CRPC) but CRPC cells develop resistance. One of the mechanisms of resistance is through overexpression of androgen receptor (AR) and AR splice variants. In contrast to AR pathway inhibition therapies, recent clinical studies using bipolar androgen therapy demonstrated CRPC inhibition using supraphysiological levels of testosterone (SPT). The objective of this study was to investigate the mechanisms driving SPT-mediated tumor growth inhibition using CRPC patient-derived xenografts (PDX). Methods: PDXs were implanted in castrated SCID mice and randomized to control or SPT arms. For enzalutamide-resistant (ENZR) PDX studies, mice with established tumors were treated with enzalutamide and randomized to control or SPT upon development of resistance. Tumors were monitored for growth and collected for analyses. Results: In a SPT preclinical trial using thirteen LuCaP CRPC PDX models, four PDXs responded to SPT treatment while nine demonstrated de novo resistance. Our analysis revealed that responding PDXs had intrinsically higher AR and ARV7 expression compared to non-responding PDXs. Moreover, ARV7 expression was negatively correlated with E2F signaling and proliferation only in responding PDXs, suggesting that the ARV7 program functions differently in responder and non-responder phenotypes. Another PDX trial using ENZR PDXs determined that SPT inhibited the growth of LuCaP 35CR ENZR and LuCaP 96CR ENZR (responders), but not LuCaP 77CR ENZR (non-responder). Serum and intratumoral T were increased in both responders and the non-responder, suggesting that differential T delivery and tumoral retention were not the cause of differential tumor responses. Tumor analyses determined that SPT decreased AR transcript levels, however, nuclear AR protein levels and canonical AR signaling remained high in both responders and the non-responder. Conversely, ARV7 transcript was consistently decreased but the ARV7 program was downregulated only in responders. Additionally, an unbiased pathway analysis of RNASeq revealed that SPT drastically decreased genes associated with E2F-mediated cell cycle progression and proliferation and the DNA damage response (DDR) exclusively in responders. Further support for these pathways driving SPT-mediated tumor inhibition was demonstrated through the resolution of the suppressed ARV7/E2F1/DDR pathways in LuCaP 35CR ENZR upon acquiring SPT resistance, whereas the pathways remained suppressed in LuCaP 96CR ENZR, which exhibited a durable response to SPT. Conclusion: Our data indicates that SPT therapy inhibits progression of a unique subset of ENZR CRPC and highlights critical roles for ARV7 signaling, DDR and E2F1-mediated proliferation in tumor inhibition. Citation Format: Hung-Ming Lam, Mark P. Labrecque, Holly M. Nguyen, Lisha G. Brown, Ilsa M. Coleman, Roman Gulati, Bryce Lakely, Daniel Sondheim, Brett Marck, Alvin M. Matsumoto, Elahe A. Mostaghel, Michael T. Schweizer, Peter S. Nelson, Eva Corey. Supraphysiological testosterone inhibits tumor growth and is associated with inhibition of ARV7 signaling and DNA damage response in preclinical models of enzalutamide-resistant prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 379.

Role of HPA and the HPG Axis Interaction in Testosterone-Mediated Learned Helpless Behavior.

Affective disorders show sex-specific differences in prevalence, symptoms, and complications. One hypothesis for this discrepancy is the interaction between the hypothalamic-pituitary-adrenal (HPA) axis and hypothalamic-pituitary-gonadal (HPG) axis. The present study investigates the influence of androgen on the behavioral phenotype and explores how it interacts with HPA axis genes. Gonadectomized (GDX) and GDX rats treated with testosterone propionate (T) were tested for learned helplessness (LH) behavior and compared with tested controls (TC). Prefrontal cortex was used for analyses of HPG- axis-related genes (androgen receptor, (Ar); estrogen receptor-β (Er-β)) and HPA axis-related genes (corticotropin-releasing hormone, (Crh); glucocorticoid receptor, (Nr3c1); corticotropin-releasing hormone receptor 1, (Crhr1); corticotropin-releasing hormone receptor 2, (Crhr2); FK506 binding protein 5, (Fkbp5)). Promoter-specific CpG methylation in the Crh gene was determined by bisulfite sequencing. Chromatin immunoprecipitation (ChIP) assay was used for determining ER-β binding on the proximal promoter region of Crh gene. Serum testosterone levels confirmed a testosterone-depleted GDX group, a group with supraphysiological levels of testosterone (T) and another group with physiological levels of testosterone (control (C)). Unlike GDX rats, T group exhibited significantly higher LH score when compared with any other group. Crh and Fkbp5 genes were significantly upregulated in GDX group compared with controls, whereas Er-β showed a significant downregulation in the same group. Methylation analysis showed no significant differences in-between groups. ChIP assay was unable to determine a significant change in ER-β binding but revealed a notable contrast in Crh promoter occupancy between T and GDX groups. Altogether, the present study reveals an increased susceptibility to depression-like behavior due to chronic supraphysiological level of androgen via HPA axis inhibition.

MP47-18 LOW TESTOSTERONE ELEVATES PRO-INFLAMMATORY INTERLEUKIN FAMILY CYTOKINES: A POSSIBLE MECHANISM FOR THE POTENTIATION OF VASCULAR DISEASE IN ANDROGEN DEFICIENT MALES

You have accessJournal of UrologySexual Function/Dysfunction/Andrology: Basic Research II1 Apr 2014MP47-18 LOW TESTOSTERONE ELEVATES PRO-INFLAMMATORY INTERLEUKIN FAMILY CYTOKINES: A POSSIBLE MECHANISM FOR THE POTENTIATION OF VASCULAR DISEASE IN ANDROGEN DEFICIENT MALES Brian Freeman, Deidra Mountain, Timothy Brock, Jason Chapman, Stacy Kirkpatrick, Joshua Arnold, Scott Stevens, Mitchell Goldman, Frederick Klein, Michael Freeman, and Oscar Grandas Brian FreemanBrian Freeman More articles by this author , Deidra MountainDeidra Mountain More articles by this author , Timothy BrockTimothy Brock More articles by this author , Jason ChapmanJason Chapman More articles by this author , Stacy KirkpatrickStacy Kirkpatrick More articles by this author , Joshua ArnoldJoshua Arnold More articles by this author , Scott StevensScott Stevens More articles by this author , Mitchell GoldmanMitchell Goldman More articles by this author , Frederick KleinFrederick Klein More articles by this author , Michael FreemanMichael Freeman More articles by this author , and Oscar GrandasOscar Grandas More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.1471AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail Introduction and Objectives Androgen deficiency (AD) is associated with increased risk of atherosclerosis, cardiovascular and peripheral arterial disease. Molecular mechanisms underlying this risk remain unclear. Matrix metalloproteinases (MMP) are enzymes largely responsible for vascular remodeling. We hypothesize that AD is a pro-inflammatory modulator, contributing to dysfunctional vascular remodeling. Here we investigated the role of testosterone in the modulation of inflammatory and MMP regulatory mechanisms. Methods Aged orchiectomized male rats underwent testosterone (TST) supplementation per controlled release pellet implantation (0-150mg). Young and aged intact groups served as controls. Serum was collected 0-28d post-implantation and analyzed by ELISAs, qualitative cytokine screening arrays, and quantitative multiplex analyses. Results When compared with TST levels in young, aged intact (AI), and placebo controls (2.72±0.35, 2.31±0.66, 0.15±0.07ng/ml, respectively), sub-physiological, physiological, and supra-physiological TST levels were achieved with 0.5, 2.5, and 35mg pellet implants (0.37±0.09, 2.89±0.44, 13.45±0.65ng/ml, respectively) per ELISA. Qualitative inflammatory cytokine screening arrays indicated interleukin family cytokines were elevated in the absence of TST. Quantitative multiplex analysis confirmed interleukin family regulation, with significant elevation of IL-2, IL-6, IL-10, IL-12, and IL-13 at sub-physiological TST levels (P<0.05; n=6), while increasing TST supplementation decreased interleukins in a dose-dependent manner approaching basal young and AI levels. G-CSF, TNFá, and INFã were also significantly elevated at sub-physiological levels (P<0.05; n=6). ELISA indicated MMP-9 was significantly decreased in AI vs. young (25.2±2.4, 53.1±8.6ng/ml; P<0.05; n=6), while supra-physiological levels significantly elevated MMP-9 (72.0±17.9ng/ml). MMP inhibitor TIMP-1 was decreased in AI and placebo vs. young, while supra-physiological TST increased TIMP-1. Conclusions Interleukin family cytokines, G-CSF, TNFá and INFã were elevated in groups with low testosterone, and MMP levels were differentially regulated by testosterone. These results suggest a correlation between AD and a pro-inflammatory environment. AD may play a role in vascular pathogenesis via regulation of inflammatory cascades. Future studies will examine the role of AD in inflammatory cytokine and MMP-modulated hyperplasia development in animal models. © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e525 Peer Review Report Advertisement Copyright & Permissions© 2014MetricsAuthor Information Brian Freeman More articles by this author Deidra Mountain More articles by this author Timothy Brock More articles by this author Jason Chapman More articles by this author Stacy Kirkpatrick More articles by this author Joshua Arnold More articles by this author Scott Stevens More articles by this author Mitchell Goldman More articles by this author Frederick Klein More articles by this author Michael Freeman More articles by this author Oscar Grandas More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Low testosterone elevates interleukin family cytokines in a rodent model: a possible mechanism for the potentiation of vascular disease in androgen-deficient males

BackgroundAndrogen deficiency (AD) is associated with increased risk of atherosclerosis, cardiovascular, and peripheral arterial disease. Although the biochemical and molecular mechanisms underlying this risk remain unclear, higher testosterone (TST) levels correlate to significant immunoprotective molecular and cellular responses. Our group has previously demonstrated that female sex hormones influence vascular pathogenesis via inflammatory-modulated matrix metalloproteinase (MMP) regulation. Here we investigated the role of AD and androgen replacement therapy in the modulation of these hormonally responsive pathways that could be playing a role in the development of vascular pathogenesis. MethodsAged orchiectomized male rats underwent TST supplementation per controlled release pellet implantation (0–150 mg). Young and aged intact groups served as controls. Serum was collected at 0–4 wk and analyzed by enzyme-linked immunosorbent assays, qualitative cytokine screening, and quantitative multiplex analyses. Human aortic smooth muscle cells were treated with 4,5α-dihydrotestosterone (DHT; 0–3000 nM) before or after interleukin 1β (IL-1β; 5 ng/mL) stimulation. Quantitative polymerase chain reaction and in-gel zymography was used to assay the effect on MMP expression and activity. ResultsSubphysiological, physiological, and supraphysiological levels of TST were achieved with 0.5, 2.5, and 35 mg TST pellet implants in vivo, respectively. Inflammatory arrays indicated that interleukin cytokines, specifically IL-2, IL-6, IL-10, IL-12, and IL-13, were elevated at subphysiological level of TST, whereas TST supplementation decreased interleukins. Supraphysiological TST resulted in a significant increase in MMP-9 and tissue inhibitor of metalloproteinase-1 (TIMP-1) in vivo. Pretreatment with IL-1β slightly increased membrane type 1-MMP (MT1-MMP) and MMP-2 expression at low to mid-level DHT exposure in vitro, although these trends were not statistically significant. ConclusionsHere we demonstrate AD is a proinflammatory modulator and indicate that MMP-independent mechanisms may play a role downstream of AD-induced inflammatory signaling in dysfunctional vascular remodeling. Future in vivo studies will examine AD and TST supplementation in acute inflammatory response to vascular injury and in MMP-modulated vascular disease.

Low systemic testosterone levels induce androgen maintenance in benign rat prostate tissue

Prostate cancer (PC) is both an age- and an androgen-dependent disease. Paradoxically, systemic levels of androgens decline with age as the risk of PC rises. While there is no correlation between systemic androgen levels and the risk of PC, systemic androgen levels do not reflect the levels of androgens in prostate tissue. In metastatic PC, changes in the androgen biosynthesis pathway during hormone therapy result in increased levels of androgens in cancer tissue and contribute to continued androgen receptor (AR) signaling. It is possible that similar changes occur in normal prostate tissue as androgen levels decline with age and that this contributes to tumorigenesis. In the present study, we sought to determine whether the rat prostate is able to maintain functional levels of androgens despite low serum testosterone levels. Rats were castrated and implanted with capsules to achieve castrate, normal, sub-physiological, and supra-physiological levels of testosterone. After 6 weeks of treatment, LC-MS/MS was used to quantify the levels of testosterone and dihydrotestosterone (DHT) in the serum and prostate tissue. Quantitative RT-PCR was used to quantify the expression of genes involved in the androgen/AR signaling axis. Despite significantly different levels of testosterone and DHT being present in the serum, testosterone and DHT concentrations in prostate tissue from different testosterone-treatment groups were very similar. Furthermore, the expression of androgen-regulated genes in the prostate was similar among all the testosterone-treatment groups, demonstrating that the rat prostate can maintain a functional level of androgens despite low serum testosterone levels. Low-testosterone treatment resulted in significant alterations in the expression of androgen biosynthesis genes, which may be related to maintaining functional androgen levels.

The Effect of Supra‐ and Subphysiologic Testosterone Levels on Ligature‐Induced Bone Loss in Rats — A Radiographic and Histologic Pilot Study

Testosterone is the primary male sexual hormone, and varying concentrations of the hormone mediated by physiologic, pathologic, or pharmacologic mechanisms may induce large variations in the body. Data regarding the general role of testosterone in mediating inflammation are still inconclusive. Therefore, the purpose of this study is to assess the consequences of supra- and subphysiologic levels of testosterone on ligature-induced bone loss in rats. Three male adult Holtzman rats were used to observe the course of serum testosterone concentration following orchiectomy (Ocx) and testosterone injections. Another 60 rats were randomly assigned to the following groups: (1) sham-operation controls (n = 10); (2) sham-operation and ligature-induced bone loss (n = 10); (3) orchiectomy without ligature (Ocx; n = 10); (4) Ocx and ligature (n = 10); (5) Ocx plus 250 mg/kg body weight intramuscular testosterone esters injection without ligature (Ocx+T; n = 10); and (6) Ocx, T, and ligature (n = 10). The ligatures were placed 30 days postorchiectomy (or sham-operation) and maintained for 15 days. Thereafter, the rats were sacrificed, and their hemimandibles were used for radiographic evaluation of bone loss along with histologic and histometric analyses of gingival tissue. The results indicated a significant increase in bone loss in the Ocx and Ocx+T groups in the presence and absence of inflammation, respectively. In addition, the Ocx and Ocx+T groups presented increased gingival area accompanying ligature-induced bone loss. Both sub- and supraphysiologic testosterone levels may influence bone metabolism, but only subphysiologic levels significantly increase ligature-induced bone loss. Moreover, testosterone has a regulatory effect on the gingival area.

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.

Testosteron und das metabolische Syndrom

Abdominal obesity as a key cardiovascular risk factor as well as metabolic syndrome and type 2 diabetes mellitus are associated with low testosterone levels. In line with these facts, investigations of patients undergoing androgen ablation therapy for prostate cancer have shown a negative effect of this treatment approach on insulin sensitivity and body fat mass. The effects of physiological doses of testosterone seem to have less impact on the parameters of lipid metabolism. However, supraphysiological levels of testosterone can lower HDL levels. At present data on glycemic control in patients with type 2 diabetes are not yet uniform, but negative effects on glycemic control in type 2 diabetics have not been reported. In fact two studies were able to demonstrate a positive effect of testosterone on glycemic control in patients with type 2 diabetes. It is currently not yet possible to conclusively evaluate the significance of testosterone treatment in patients with metabolic syndrome and type 2 diabetes mellitus. Only larger, randomized prospective trials will show whether testosterone therapy is helpful in metabolic syndrome or type 2 diabetes. However, administration of testosterone in hypogonadal men with metabolic syndrome appears to be a promising treatment option to improve metabolic control.

Testosterone treatment of hypogonadal men participating in competitive sports

Testosterone has a steeply dose-dependent effect on muscle mass and strength irrespective of gonadal status. So, for reasons of fairness, people who engage in competitive sports should not administer exogenous testosterone raising their blood testosterone levels beyond the range of normal. There is a ban on exogenous androgens for men and women in sports, but an exception has been made for men with androgen deficiency due to pituitary or testicular disease. Men who receive testosterone administration for the indication hypogonadism have an interest in the use of testosterone preparations generating blood testosterone levels within the normal range of healthy, eugonadal men. On the grounds of a positive correlation between blood testosterone concentrations muscle and volume/strength, they are best served with a parenteral testosterone preparation, rather than transdermal testosterone, but they should not run the risk of being excluded from competition because of supraphysiological testosterone levels. The latter is a realistic risk with the traditional parenteral testosterone esters. The new parenteral testosterone undecanoate preparation offers much better perspectives. Its pharmacokinetics have been investigated in detail and there is a fair degree of predictability of resulting blood testosterone levels with use of this preparation.

Controversies Regarding Transdermal Androgen Therapy in Postmenopausal Women

Recently, the field of androgen therapy in postmenopausal women has received much attention and press. Although the ovary ceases to produce follicles and estrogen at menopause, it continues to produce androgens. Hence, many oophorectomized women complain of sexual dysfunction (despite adequate estrogenization). Previous studies of nontransdermal testosterone replacement have shown an improvement in libido and sexual frequency, although at the cost of supraphysiological testosterone levels. Transdermal testosterone patch (Intrinsa) was developed to deliver a physiological amount of testosterone. In 2004, the Food and Drug Administration voted not to approve Intrinsa until long-term safety data are available. Recent trials of Intrinsa in postmenopausal women were included. A MEDLINE search was conducted for articles published over the last 40 yr based on the key words androgen therapy/replacement and postmenopausal women. Relevant placebo-controlled trials of nontransdermal androgen therapy in postmenopausal women were also reviewed. Early results from industry-funded trials show that transdermal testosterone therapy results in only moderate (although statistically significant) improvement in libido in surgically menopausal women (on estrogen). However, the published data are of short duration (24 wk). Hence, long-term safety in these women remains unclear. We recommend a short-term trial (not to exceed 24 wk) of transdermal testosterone therapy (once approved) in surgically menopausal (estrogenized) women with distressful sexual dysfunction. Until the patch gets approval, a short trial of oral methyltestosterone in deserving estrogenized women may be justified.