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Olesen TB, Glintborg D, Jøhnk F, Olsen MH, Andersen MS. Blood pressure responses to testosterone therapy are amplified by hematocrit levels in opioid-induced androgen deficiency: a double-blind, randomized, placebo-controlled trial. J Hypertens 2024; 42:893-901. [PMID: 38088425 DOI: 10.1097/hjh.0000000000003638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2024]
Abstract
Our study aimed to examine the effect of testosterone replacement therapy (TRT) on blood pressure in opioid-treated men with relative hypogonadism, and whether the effect of TRT on blood pressure was modified by body composition, red blood cell levels, or carotid intima media thickness. Men (over 18 years old) receiving opioid treatment and total testosterone less than 12 nmol were randomly assigned to receive either TRT or placebo. Baseline and 6-month measurements included anthropometric measurements, office blood pressure (OBPM), 24-h ambulatory blood pressure, blood samples, and carotid ultrasound. The mean systolic OBPM increased by 6.2 mmHg (0.2-12.1) in the TRT group and decreased by 7.0 mmHg (1.0-15.1) in the placebo group, with a mean difference of 13.2 mmHg (3.4-23.1), P = 0.01. In the TRT group, a 10 mmHg increase in systolic OBPM was associated with an increase in hematocrit of 0.3% points (0.1-0.5) ( P = 0.01), whereas no association was observed in the placebo group ( P = 0.266). Daytime SBP showed a nonsignificant increase of 5.2 mmHg (-1.7, 12.1) ( P = 0.134) in the TRT group compared to that in the placebo group. However, the impact of TRT on the increase in daytime ambulatory blood pressure was significantly accentuated by baseline values of BMI, hematocrit, and hemoglobin. In conclusion, TRT was associated with higher OBPM compared to placebo, and the increase in blood pressure was linked to higher hematocrit during TRT. Our data suggest that men with opioid-induced androgen deficiency, particularly those with obesity or red blood cell levels in the upper normal range, are more susceptible to increased daytime SBP during TRT.
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Affiliation(s)
| | - Dorte Glintborg
- Department of Endocrinology, Odense University Hospital, Odense
| | - Frederik Jøhnk
- Department of Internal Medicine, Sygehus Lillebaelt, Kolding
| | - Michael Hecht Olsen
- Department of Internal Medicine, Cardiology Section, Holbaek Hospital, Holbaek, Denmark
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2
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Green DJ, Chasland LC, Naylor LH, Yeap BB. New Horizons: Testosterone or Exercise for Cardiometabolic Health in Older Men. J Clin Endocrinol Metab 2023; 108:2141-2153. [PMID: 36964918 PMCID: PMC10438896 DOI: 10.1210/clinem/dgad175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/14/2023] [Accepted: 03/22/2023] [Indexed: 03/27/2023]
Abstract
Middle-aged and older men have typically accumulated comorbidities, are increasingly sedentary, and have lower testosterone concentrations (T) compared to younger men. Reduced physical activity (PA) and lower T both are associated with, and may predispose to, metabolically adverse changes in body composition, which contribute to higher risks of cardiometabolic disease. Exercise improves cardiometabolic health, but sustained participation is problematic. By contrast, rates of T prescription have increased, particularly in middle-aged and older men without organic diseases of the hypothalamus, pituitary, or testes, reflecting the unproven concept of a restorative hormone that preserves health. Two recent large randomized trials of T, and meta-analyses of randomized trials, did not show a signal for adverse cardiovascular (CV) events, and T treatment on a background of lifestyle intervention reduced type 2 diabetes by 40% in men at high risk. Men with both higher endogenous T and higher PA levels have lower CV risk, but causality remains unproven. Exercise training interventions improve blood pressure and endothelial function in middle-aged and older men, without comparable benefits or additive effects of T treatment. Therefore, exercise training improves cardiometabolic health in middle-aged and older men when effectively applied as a supervised regimen incorporating aerobic and resistance modalities. Treatment with T may have indirect cardiometabolic benefits, mediated via favorable changes in body composition. Further evaluation of T as a pharmacological intervention to improve cardiometabolic health in aging men could consider longer treatment durations and combination with targeted exercise programs.
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Affiliation(s)
- Daniel J Green
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, WA, 6009, Australia
| | - Lauren C Chasland
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, WA, 6009, Australia
- Allied Health Department, Fiona Stanley Hospital, Perth, WA, 6150, Australia
| | - Louise H Naylor
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, WA, 6009, Australia
- Allied Health Department, Fiona Stanley Hospital, Perth, WA, 6150, Australia
| | - Bu B Yeap
- Medical School, The University of Western Australia, Perth, WA, 6009, Australia
- Department of Endocrinology and Diabetes, Fiona Stanley Hospital, Perth, WA, 6150, Australia
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Chasland LC, Naylor LH, Yeap BB, Maiorana AJ, Green DJ. Testosterone and Exercise in Middle-to-Older Aged Men: Combined and Independent Effects on Vascular Function. Hypertension 2021; 77:1095-1105. [PMID: 33611937 DOI: 10.1161/hypertensionaha.120.16411] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Lauren C Chasland
- School of Human Sciences (Exercise and Sport Science) (L.C.C., L.H.N., D.J.G.), The University of Western Australia, Perth
| | - Louise H Naylor
- School of Human Sciences (Exercise and Sport Science) (L.C.C., L.H.N., D.J.G.), The University of Western Australia, Perth.,Allied Health Department, Fiona Stanley Hospital, Perth (L.C.C., L.H.N., A.J.M.)
| | - Bu B Yeap
- Medical School (B.B.Y.), The University of Western Australia, Perth.,Department of Endocrinology and Diabetes, Fiona Stanley Hospital, Perth, Western Australia (B.B.Y.)
| | - Andrew J Maiorana
- Allied Health Department, Fiona Stanley Hospital, Perth (L.C.C., L.H.N., A.J.M.).,and School of Physiotherapy and Exercise Science, Curtin University, Perth, Western Australia (A.J.M.)
| | - Daniel J Green
- School of Human Sciences (Exercise and Sport Science) (L.C.C., L.H.N., D.J.G.), The University of Western Australia, Perth
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Shabbir A, Rathod KS, Khambata RS, Ahluwalia A. Sex Differences in the Inflammatory Response: Pharmacological Opportunities for Therapeutics for Coronary Artery Disease. Annu Rev Pharmacol Toxicol 2020; 61:333-359. [PMID: 33035428 DOI: 10.1146/annurev-pharmtox-010919-023229] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Coordinated molecular responses are key to effective initiation and resolution of both acute and chronic inflammation. Vascular inflammation plays an important role in initiating and perpetuating atherosclerotic disease, specifically at the site of plaque and subsequent fibrous cap rupture. Both men and women succumb to this disease process, and although management strategies have focused on revascularization and pharmacological therapies in the acute situation to reverse vessel closure and prevent thrombogenesis, data now suggest that regulation of host inflammation may improve both morbidity and mortality, thus supporting the notion that prevention is better than cure. There is a clear sex difference in the incidence of vascular disease, and data confirm biological differences in inflammatory initiation and resolution between men and women. This article reviews contemporary opinions describing the sex difference in the initiation and resolution of inflammatory responses, with a view to explore potential targets for pharmacological intervention.
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Affiliation(s)
- Asad Shabbir
- The William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, United Kingdom;
| | - Krishnaraj Sinhji Rathod
- The William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, United Kingdom;
| | - Rayomand Syrus Khambata
- The William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, United Kingdom;
| | - Amrita Ahluwalia
- The William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, United Kingdom;
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5
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Moreau KL, Babcock MC, Hildreth KL. Sex differences in vascular aging in response to testosterone. Biol Sex Differ 2020; 11:18. [PMID: 32295637 PMCID: PMC7161199 DOI: 10.1186/s13293-020-00294-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 04/01/2020] [Indexed: 12/13/2022] Open
Abstract
Large elastic arterial stiffening and endothelial dysfunction are phenotypic characteristics of vascular aging, a major risk factor for age-associated cardiovascular diseases. Compared to men, vascular aging in women appears to be slowed until menopause, whereafter vascular aging accelerates to match that seen in men. These sex differences in vascular aging have been attributed to changes in sex hormones that occur with aging. Although the role of estradiol in vascular aging in women has been highlighted in recent aging research, little is known about the impact of declining testosterone concentrations in both sexes. Importantly, while androgen concentrations generally decline with age in men, there are data that indicate reductions in androgen concentrations in women as well. Evidence suggests that low testosterone is associated with impaired endothelial function and increased arterial stiffness in men, although the effect of androgens on vascular aging in women remains unclear. Testosterone may modulate vascular aging by mitigating the effects of oxidative stress and inflammation, although there is sex specificity to this effect. The purpose of this review is to present and summarize the research regarding sex differences in vascular aging in response to androgens, specifically testosterone. Because exercise is a potent lifestyle factor for slowing and reversing vascular aging, we briefly summarize the available literature regarding the regulatory function of testosterone on vascular adaptations to exercise training.
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Affiliation(s)
- Kerrie L Moreau
- University of Colorado Anschutz Medical Campus, Bldg. L15 Rm 8111, 12631 East 17th Ave., PO Box 6511, Aurora, CO, 80045, USA. .,Denver Veterans Administration Medical Center, Geriatric Research Education and Clinical Center, Aurora, 80045, CO, USA.
| | - Matthew C Babcock
- University of Colorado Anschutz Medical Campus, Bldg. L15 Rm 8111, 12631 East 17th Ave., PO Box 6511, Aurora, CO, 80045, USA
| | - Kerry L Hildreth
- University of Colorado Anschutz Medical Campus, Bldg. L15 Rm 8111, 12631 East 17th Ave., PO Box 6511, Aurora, CO, 80045, USA
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Effect of treatment with testosterone on endothelial function in hypogonadal men: a systematic review and meta-analysis. Int J Impot Res 2019; 32:379-386. [DOI: 10.1038/s41443-019-0163-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 05/09/2019] [Accepted: 05/16/2019] [Indexed: 12/15/2022]
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Groti K, Žuran I, Antonič B, Foršnarič L, Pfeifer M. The impact of testosterone replacement therapy on glycemic control, vascular function, and components of the metabolic syndrome in obese hypogonadal men with type 2 diabetes. Aging Male 2018; 21:158-169. [PMID: 29708829 DOI: 10.1080/13685538.2018.1468429] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
OBJECTIVE This study set out to assess effects of testosterone replacement therapy (TRT) on parameters of metabolic syndrome and vascular function in obese hypogonadal males with type 2 diabetes mellitus (DM2). STUDY DESIGN Fifty-five obese hypogonadal diabetic males on oral hypoglycemic treatment were enrolled into this one-year, double-blind, randomized, placebo-controlled clinical study. Group T (n = 28) was treated with testosterone undecanoate (1000 mg i.m. every 10 weeks) while group P (n = 27) received placebo. METHODS Anthropometrical and vascular measurements - flow-mediated dilatation (FMD) and intima media thickness (IMT) - biochemical and hormonal blood sample analyses were performed at the start of the study and after one year. Derived parameters (BMI, HOMA-IR, calculated free testosterone (cFT) and bioavailable testosterone (BT)) were calculated. RESULTS TRT resulted in reduction of HOMA-IR by 4.64 ± 4.25 (p < .001), HbA1c by 0.94 ± 0.88% points (p < .001), and an increase in FMD by 2.40 ± 4.16% points (p = .005). CONCLUSION TRT normalized serum testosterone levels, improved glycemic control and endothelial function while exerting no ill effects on the study population.
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Affiliation(s)
- Kristina Groti
- a Department of Endocrinology, Diabetes and Metabolic Diseases , University Medical Center , Ljubljana , Slovenia
| | - Ivan Žuran
- b Department of Angiology, Endocrinology and Rheumatology , General Hospital Celje , Celje , Slovenia
| | - Blaž Antonič
- c Blaž Antonič s.p., IT Equipment Development , Ljubljana , Slovenia
| | - Lidija Foršnarič
- b Department of Angiology, Endocrinology and Rheumatology , General Hospital Celje , Celje , Slovenia
| | - Marija Pfeifer
- d Medical Faculty , University of Ljubljana , Ljubljana , Slovenia
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8
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Cheung AS, Grossmann M. Physiological basis behind ergogenic effects of anabolic androgens. Mol Cell Endocrinol 2018; 464:14-20. [PMID: 28159654 DOI: 10.1016/j.mce.2017.01.047] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 01/28/2017] [Accepted: 01/29/2017] [Indexed: 11/21/2022]
Abstract
Anabolic androgenic steroids (AAS) are widely abused by the sporting community. Demonstrating performance enhancing effects of AAS in rigorous scientific studies is fraught with difficulty. In controlled studies, AAS have consistently been reported to increase muscle mass and strength. The clinical evidence that these anabolic effects are independent of, and additive to exercise are supported by preclinical studies suggesting that AAS and exercise affect muscle by overlapping, yet distinct mechanisms. AAS may also improve performance by their actions on other organ systems, such as the vasculature, and the erythropoietic and central nervous system, although this evidence is less strong. While most of the actions of AAS are thought to be mediated via classical androgen receptor-mediated genomic signalling, AAS may also produce rapid effects via non-genomic mechanisms.
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Affiliation(s)
- Ada S Cheung
- Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, Victoria, Australia; Department of Endocrinology, Austin Health, Heidelberg, Victoria, Australia
| | - Mathis Grossmann
- Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, Victoria, Australia; Department of Endocrinology, Austin Health, Heidelberg, Victoria, Australia.
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Presence of Androgen Receptor Variant in Neuronal Lipid Rafts. eNeuro 2017; 4:eN-NWR-0109-17. [PMID: 28856243 PMCID: PMC5575139 DOI: 10.1523/eneuro.0109-17.2017] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 08/03/2017] [Accepted: 08/14/2017] [Indexed: 11/21/2022] Open
Abstract
Fast, nongenomic androgen actions have been described in various cell types, including neurons. However, the receptor mediating this cell membrane–initiated rapid signaling remains unknown. This study found a putative androgen receptor splice variant in a dopaminergic N27 cell line and in several brain regions (substantia nigra pars compacta, entorhinal cortex, and hippocampus) from gonadally intact and gonadectomized (young and middle-aged) male rats. This putative splice variant protein has a molecular weight of 45 kDa and lacks an N-terminal domain, indicating it is homologous to the human AR45 splice variant. Interestingly, AR45 was highly expressed in all brain regions examined. In dopaminergic neurons, AR45 is localized to plasma membrane lipid rafts, a microdomain involved in cellular signaling. Further, AR45 protein interacts with membrane-associated G proteins Gαq and Gαo. Neither age nor hormone levels altered AR45 expression in dopaminergic neurons. These results provide the first evidence of AR45 protein expression in the brain, specifically plasma membrane lipid rafts. AR45 presence in lipid rafts indicates that it may function as a membrane androgen receptor to mediate fast, nongenomic androgen actions.
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10
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Armeni E, Lambrinoudaki I. Androgens and cardiovascular disease in women and men. Maturitas 2017; 104:54-72. [PMID: 28923177 DOI: 10.1016/j.maturitas.2017.07.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 07/25/2017] [Indexed: 02/01/2023]
Abstract
Cardiovascular disease is the leading cause of death in both women and men. Its pathogenesis is multifactorial, with sex hormones playing an important role. Androgens have both direct and indirect effects on the vasculature. This review summarizes evidence on the association of both endogenous and exogenous androgens with subclinical and overt cardiovascular disease in women and men. Concerning women, both high and low levels of endogenous androgens have been associated with cardiovascular disease, while other studies have reported no association. Adiposity, impaired glucose metabolism, dyslipidemia and estrogen levels may mediate the observed associations. Regarding testosterone therapy in women, there have been no large prospective studies on cardiovascular outcomes. Concerning men, most studies indicate that low levels of circulating testosterone are associated with increased rates of cardiovascular disease in the general population; the causality, however, of this association remains to be proven. Testosterone replacement therapy in men with symptoms of hypogonadism and low serum testosterone merits caution with regard to cardiovascular safety, as evidence is still conflicting.
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Affiliation(s)
- Eleni Armeni
- 2nd Department of Obstetrics and Gynecology, National and Kapodistrian University of Athens, Aretaieio Hospital, Athens, Greece
| | - Irene Lambrinoudaki
- 2nd Department of Obstetrics and Gynecology, National and Kapodistrian University of Athens, Aretaieio Hospital, Athens, Greece.
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11
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Holmes S, Singh M, Su C, Cunningham RL. Effects of Oxidative Stress and Testosterone on Pro-Inflammatory Signaling in a Female Rat Dopaminergic Neuronal Cell Line. Endocrinology 2016; 157:2824-35. [PMID: 27167771 PMCID: PMC4929547 DOI: 10.1210/en.2015-1738] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Parkinson's disease, a progressive neurodegenerative disorder, is associated with oxidative stress and neuroinflammation. These pathological markers can contribute to the loss of dopamine neurons in the midbrain. Interestingly, men have a 2-fold increased incidence for Parkinson's disease than women. Although the mechanisms underlying this sex difference remain elusive, we propose that the primary male sex hormone, testosterone, is involved. Our previous studies show that testosterone, through a putative membrane androgen receptor, can increase oxidative stress-induced neurotoxicity in dopamine neurons. Based on these results, this study examines the role of nuclear factor κ B (NF-κB), cyclooxygenase-2 (COX2), and apoptosis in the deleterious effects of androgens in an oxidative stress environment. We hypothesize, under oxidative stress environment, testosterone via a putative membrane androgen receptor will exacerbate oxidative stress-induced NF-κB/COX2 signaling in N27 dopaminergic neurons, leading to apoptosis. Our data show that testosterone increased the expression of COX2 and apoptosis in dopamine neurons. Inhibiting the NF-κB and COX2 pathway with CAPE and ibuprofen, respectively, blocked testosterone's negative effects on cell viability, indicating that NF-κB/COX2 cascade plays a role in the negative interaction between testosterone and oxidative stress on neuroinflammation. These data further support the role of testosterone mediating the loss of dopamine neurons under oxidative stress conditions, which may be a key mechanism contributing to the increased incidence of Parkinson's disease in men compared with women.
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Affiliation(s)
- Shaletha Holmes
- Department of Pharmacology and Neuroscience, Institute for Aging and Alzheimer's Disease Research, University of North Texas Health Science Center, Fort Worth, Texas 76107
| | - Meharvan Singh
- Department of Pharmacology and Neuroscience, Institute for Aging and Alzheimer's Disease Research, University of North Texas Health Science Center, Fort Worth, Texas 76107
| | - Chang Su
- Department of Pharmacology and Neuroscience, Institute for Aging and Alzheimer's Disease Research, University of North Texas Health Science Center, Fort Worth, Texas 76107
| | - Rebecca L Cunningham
- Department of Pharmacology and Neuroscience, Institute for Aging and Alzheimer's Disease Research, University of North Texas Health Science Center, Fort Worth, Texas 76107
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12
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Novo S, Iacona R, Bonomo V, Evola V, Corrado E, Di Piazza M, Novo G, Pavone C. Erectile dysfunction is associated with low total serum testosterone levels and impaired flow-mediated vasodilation in intermediate risk men according to the Framingham risk score. Atherosclerosis 2014; 238:415-9. [PMID: 25562576 DOI: 10.1016/j.atherosclerosis.2014.12.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2014] [Revised: 11/26/2014] [Accepted: 12/01/2014] [Indexed: 12/15/2022]
Abstract
BACKGROUND The role erectile dysfunction (ED) coupled with low testosterone levels as early markers of atherosclerosis is not well understood. OBJECTIVES To analyze the relationship between serum testosterone levels with both ED and brachial artery flow-mediated vasodilation (FMD), in a primary prevention sample of men. METHODS We enrolled 802 asymptomatic, intermediate CV risk patients, according to the Framingham Risk Score, aged 40-80 years, who underwent the ultrasound examination of FMD, the evaluation of ED and the assessment of total serum testosterone levels. RESULTS Testosterone levels correlated both with FMD (r = 0.85; p < 0.0001) and IIEF-5 score (rs = 0.65; p < 0.0001). Multivariable logistic regression analyses revealed that lower serum testosterone levels were strongly associated (p < 0.001) with severe (OR 0.78; 95% CI: 0.62-0.86), and moderate ED (OR 0.85; 95% CI: 0.72-0.97), while impaired FMD percentages were strongly associated (p < 0.001) with severe (OR 0.68; 95% CI: 0.59-0.79), moderate (OR 0.76; 95% CI: 0.63-0.83) and mild to moderate ED (OR 0.8; 95% CI: 0.69-0.94). Mild ED resulted statistically associated with lower FMD (OR 0.94; 95% CI: 0.82 - 1.07; p = 0.03) but not with serum testosterone levels. These relations were not substantially affected by adjustments for further potential confounders including smoking status, hypertension, diabetes mellitus and body mass index. CONCLUSIONS lower total serum testosterone levels are associated with impaired FMD and ED in this sample of intermediate CV risk men according to the Framingham Risk Score.
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Affiliation(s)
- Salvatore Novo
- Chair and Division of Cardiology, University Hospital "Paolo Giaccone", via del Vespro 129, 90127 Palermo, Italy.
| | - Rosanna Iacona
- Chair and Division of Cardiology, University Hospital "Paolo Giaccone", via del Vespro 129, 90127 Palermo, Italy
| | - Vito Bonomo
- Chair and Division of Cardiology, University Hospital "Paolo Giaccone", via del Vespro 129, 90127 Palermo, Italy
| | - Vincenzo Evola
- Chair and Division of Cardiology, University Hospital "Paolo Giaccone", via del Vespro 129, 90127 Palermo, Italy
| | - Egle Corrado
- Chair and Division of Cardiology, University Hospital "Paolo Giaccone", via del Vespro 129, 90127 Palermo, Italy
| | - Mariaconcetta Di Piazza
- Chair and Division of Cardiology, University Hospital "Paolo Giaccone", via del Vespro 129, 90127 Palermo, Italy
| | - Giuseppina Novo
- Chair and Division of Cardiology, University Hospital "Paolo Giaccone", via del Vespro 129, 90127 Palermo, Italy
| | - Carlo Pavone
- Chair and Division of Urology, University Hospital "Paolo Giaccone", via del Vespro 129, 90127 Palermo, Italy.
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Traish AM, Galoosian A. Androgens modulate endothelial function and endothelial progenitor cells in erectile physiology. Korean J Urol 2013; 54:721-31. [PMID: 24255752 PMCID: PMC3830963 DOI: 10.4111/kju.2013.54.11.721] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 09/24/2013] [Indexed: 12/21/2022] Open
Abstract
The incidence of erectile dysfunction (ED) increases with age and cardiovascular disease risk factors, such as hypertension, hyperlipidemia, insulin resistance, obesity, and diabetes. These risk factors are thought to contribute to endothelial dysfunction and atherosclerosis, thus contributing to the pathophysiology of ED. The role of the endothelium in regulating erectile physiology is well established. However, the role of androgens in modulating endothelial function and endothelial repair mechanisms subsequent to vascular injury in erectile tissue remains a subject of intensive research. The clinical and preclinical evidence discussed in this review suggests that androgens regulate endothelial function and also play an important role in the development and maturation of endothelial progenitor cells (EPCs), which are thought to play a critical role in repair of endothelial injury in vascular beds. In this review, we discuss the data available on the effects of androgens on endothelial function and EPCs in the repair of vascular injury. Indeed, more research is needed to fully understand the molecular and cellular basis of androgen action in regulating the development, differentiation, maturation, migration, and homing of EPCs to the site of injury. A better understanding of these processes will be critical to the development of new therapeutic approaches to the treatment of vascular ED.
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Affiliation(s)
- Abdulmaged M Traish
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA. ; Department of Urology, Boston University School of Medicine, Boston, MA, USA
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Holmes S, Abbassi B, Su C, Singh M, Cunningham RL. Oxidative stress defines the neuroprotective or neurotoxic properties of androgens in immortalized female rat dopaminergic neuronal cells. Endocrinology 2013; 154:4281-92. [PMID: 23959938 PMCID: PMC3800758 DOI: 10.1210/en.2013-1242] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Males have a higher risk for developing Parkinson's disease and parkinsonism after ischemic stroke than females. Although estrogens have been shown to play a neuroprotective role in Parkinson's disease, there is little information on androgens' actions on dopamine neurons. In this study, we examined the effects of androgens under conditions of oxidative stress to determine whether androgens play a neuroprotective or neurotoxic role in dopamine neuronal function. Mitochondrial function, cell viability, intracellular calcium levels, and mitochondrial calcium influx were examined in response to androgens under both nonoxidative and oxidative stress conditions. Briefly, N27 dopaminergic cells were exposed to the oxidative stressor, hydrogen peroxide, and physiologically relevant levels of testosterone or dihydrotestosterone, applied either before or after oxidative stress exposure. Androgens, alone, increased mitochondrial function via a calcium-dependent mechanism. Androgen pretreatment protected cells from oxidative stress-induced cell death. However, treatment with androgens after the oxidative insult increased cell death, and these effects were, in part, mediated by calcium influx into the mitochondria. Interestingly, the negative effects of androgens were not blocked by either androgen or estrogen receptor antagonists. Instead, a putative membrane-associated androgen receptor was implicated. Overall, our results indicate that androgens are neuroprotective when oxidative stress levels are minimal, but when oxidative stress levels are elevated, androgens exacerbate oxidative stress damage.
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Affiliation(s)
- Shaletha Holmes
- PhD, Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, 3400 Camp Bowie Boulevard, Fort Worth, Texas 76107-2699.
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Ruige JB, Ouwens DM, Kaufman JM. Beneficial and adverse effects of testosterone on the cardiovascular system in men. J Clin Endocrinol Metab 2013; 98:4300-10. [PMID: 24064693 DOI: 10.1210/jc.2013-1970] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
CONTEXT The widespread use of T therapy, particularly in aging males, necessitates knowledge of the relationship between T and the cardiovascular system. EVIDENCE ACQUISITION The review is based on a 1970 to 2013 PubMed search with terms related to androgens in combination with cardiovascular disease, including T, dihydrotestosterone, trial, mortality, cardiovascular disease, myocardial infarction, blood pressure, endothelial function, dyslipidemia, thrombosis, ventricular function, and arrhythmia. Original articles, systematic reviews and meta-analyses, and relevant citations were screened. EVIDENCE SYNTHESIS Low T has been linked to increased blood pressure, dyslipidemia, atherosclerosis, arrhythmia, thrombosis, endothelial dysfunction, as well as to impaired left ventricular function. On the one hand, a modest association is suggested between low endogenous T and incident cardiovascular disease or cardiovascular mortality, implying unrecognized beneficial T effects, residual confounding, or a relationship with health status. On the other hand, treatments with T to restore "normal concentrations" have so far not been proven to be beneficial with respect to cardiovascular disease; neither have they definitely shown specific adverse cardiovascular effects. The cardiovascular risk-benefit profile of T therapy remains largely evasive in view of a lack of well-designed and adequately powered randomized clinical trials. CONCLUSIONS The important knowledge gap as to the exact relationship between T and cardiovascular disease would support a cautious, restrained approach to T therapy in aging men, pending clarification of benefits and risks by adequately powered clinical trials of sufficient duration.
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Affiliation(s)
- Johannes B Ruige
- MD, PhD, Department of Endocrinology, Ghent University Hospital, De Pintelann 185, B9000 Gent, Belgium.
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16
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Abstract
Coronary heart disease is a leading cause of premature death in men. Epidemiological studies have shown a high prevalence of low serum testosterone levels in men with cardiovascular disease (CVD). Furthermore, a low testosterone level is associated in some but not in all observational studies with an increase in cardiovascular events and mortality. Testosterone has beneficial effects on several cardiovascular risk factors, which include cholesterol, endothelial dysfunction and inflammation: key mediators of atherosclerosis. A bidirectional relationship between low endogenous testosterone levels and concurrent illness complicates attempts to validate causality in this association and potential mechanistic actions are complex. Testosterone is a vasoactive hormone that predominantly has vasodilatory actions on several vascular beds, although some studies have reported conflicting effects. In clinical studies, acute and chronic testosterone administration increases coronary artery diameter and flow, improves cardiac ischaemia and symptoms in men with chronic stable angina and reduces peripheral vascular resistance in chronic heart failure. Although the mechanism of the action of testosterone on vascular tone in vivo is not understood, laboratory research has found that testosterone is an L-calcium channel blocker and induces potassium channel activation in vascular smooth muscle cells. Animal studies have consistently demonstrated that testosterone is atheroprotective, whereas testosterone deficiency promotes the early stages of atherogenesis. The translational effects of testosterone between in vitro animal and human studies, some of which have conflicting effects, will be discussed in this review. We review the evidence for a role of testosterone in vascular health, its therapeutic potential and safety in hypogonadal men with CVD, and some of the possible underlying mechanisms.
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Affiliation(s)
- Daniel M Kelly
- Department of Human Metabolism, Medical School, The University of Sheffield, Sheffield S10 2RX, UK
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17
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Empen K, Lorbeer R, Dörr M, Haring R, Nauck M, Gläser S, Krebs A, Reffelmann T, Ewert R, Völzke H, Wallaschofski H, Felix SB. Association of Testosterone Levels With Endothelial Function in Men. Arterioscler Thromb Vasc Biol 2012; 32:481-6. [DOI: 10.1161/atvbaha.111.232876] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objective—
Because population-based data are lacking, we assessed the cross-sectional association between serum testosterone levels and endothelial function, as measured by flow-mediated dilation (FMD) and nitroglycerin-mediated dilation (NMD) of the brachial artery, in men from the population-based Study of Health in Pomerania.
Methods and Results—
Personal characteristics, including major cardiovascular confounders, were collected in 722 men, aged 25 to 85 years. Serum total testosterone and sexual hormone-binding globulin (SHBG) levels were determined by chemiluminescence immunoassays. Free testosterone levels were calculated according to the law of mass action. FMD and NMD measurements were performed using standardized ultrasound techniques. FMD and NMD values below the 20th percentile were considered decreased. Multivariable logistic regression analyses revealed an association for each decrement of total testosterone standard deviation (6.0 nmol/L) with decreased FMD after adjustment for potential confounders (odds ratio 1.30, 95% confidence interval 1.04–1.63;
P
=0.023). Multiple adjusted findings for free testosterone were similar (odds ratio 1.37, 95% confidence interval 1.06–1.76;
P
=0.016). There was no such association of SHBG levels with decreased FMD. Neither testosterone nor SHBG levels were significantly associated with decreased NMD.
Conclusion—
Lower serum total and free testosterone levels are associated with impaired endothelial function in this population-based sample of men.
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Affiliation(s)
- Klaus Empen
- From the Department of Internal Medicine (K.E., M.D., S.G., T.R., R.E., S.B.F.), Institute for Community Medicine (R.L., H.V.), Institute for Clinical Chemistry and Laboratory Medicine (R.H., M.N., A.K., H.W.), Ernst Moritz Arndt University, Greifswald, Germany
| | - Roberto Lorbeer
- From the Department of Internal Medicine (K.E., M.D., S.G., T.R., R.E., S.B.F.), Institute for Community Medicine (R.L., H.V.), Institute for Clinical Chemistry and Laboratory Medicine (R.H., M.N., A.K., H.W.), Ernst Moritz Arndt University, Greifswald, Germany
| | - Marcus Dörr
- From the Department of Internal Medicine (K.E., M.D., S.G., T.R., R.E., S.B.F.), Institute for Community Medicine (R.L., H.V.), Institute for Clinical Chemistry and Laboratory Medicine (R.H., M.N., A.K., H.W.), Ernst Moritz Arndt University, Greifswald, Germany
| | - Robin Haring
- From the Department of Internal Medicine (K.E., M.D., S.G., T.R., R.E., S.B.F.), Institute for Community Medicine (R.L., H.V.), Institute for Clinical Chemistry and Laboratory Medicine (R.H., M.N., A.K., H.W.), Ernst Moritz Arndt University, Greifswald, Germany
| | - Matthias Nauck
- From the Department of Internal Medicine (K.E., M.D., S.G., T.R., R.E., S.B.F.), Institute for Community Medicine (R.L., H.V.), Institute for Clinical Chemistry and Laboratory Medicine (R.H., M.N., A.K., H.W.), Ernst Moritz Arndt University, Greifswald, Germany
| | - Sven Gläser
- From the Department of Internal Medicine (K.E., M.D., S.G., T.R., R.E., S.B.F.), Institute for Community Medicine (R.L., H.V.), Institute for Clinical Chemistry and Laboratory Medicine (R.H., M.N., A.K., H.W.), Ernst Moritz Arndt University, Greifswald, Germany
| | - Alexander Krebs
- From the Department of Internal Medicine (K.E., M.D., S.G., T.R., R.E., S.B.F.), Institute for Community Medicine (R.L., H.V.), Institute for Clinical Chemistry and Laboratory Medicine (R.H., M.N., A.K., H.W.), Ernst Moritz Arndt University, Greifswald, Germany
| | - Thorsten Reffelmann
- From the Department of Internal Medicine (K.E., M.D., S.G., T.R., R.E., S.B.F.), Institute for Community Medicine (R.L., H.V.), Institute for Clinical Chemistry and Laboratory Medicine (R.H., M.N., A.K., H.W.), Ernst Moritz Arndt University, Greifswald, Germany
| | - Ralf Ewert
- From the Department of Internal Medicine (K.E., M.D., S.G., T.R., R.E., S.B.F.), Institute for Community Medicine (R.L., H.V.), Institute for Clinical Chemistry and Laboratory Medicine (R.H., M.N., A.K., H.W.), Ernst Moritz Arndt University, Greifswald, Germany
| | - Henry Völzke
- From the Department of Internal Medicine (K.E., M.D., S.G., T.R., R.E., S.B.F.), Institute for Community Medicine (R.L., H.V.), Institute for Clinical Chemistry and Laboratory Medicine (R.H., M.N., A.K., H.W.), Ernst Moritz Arndt University, Greifswald, Germany
| | - Henri Wallaschofski
- From the Department of Internal Medicine (K.E., M.D., S.G., T.R., R.E., S.B.F.), Institute for Community Medicine (R.L., H.V.), Institute for Clinical Chemistry and Laboratory Medicine (R.H., M.N., A.K., H.W.), Ernst Moritz Arndt University, Greifswald, Germany
| | - Stephan B. Felix
- From the Department of Internal Medicine (K.E., M.D., S.G., T.R., R.E., S.B.F.), Institute for Community Medicine (R.L., H.V.), Institute for Clinical Chemistry and Laboratory Medicine (R.H., M.N., A.K., H.W.), Ernst Moritz Arndt University, Greifswald, Germany
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18
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Toot JD, Reho JJ, Ramirez RJ, Novak J, Ely DL. Alterations in vasomotor systems and mechanics of resistance-sized mesenteric arteries from SHR and WKY male rats following in vivo testosterone manipulation. Biol Sex Differ 2012; 3:1. [PMID: 22214247 PMCID: PMC3264497 DOI: 10.1186/2042-6410-3-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Accepted: 01/03/2012] [Indexed: 11/10/2022] Open
Abstract
Background Testosterone (T) and the sympathetic nervous system each contribute to the pathology of hypertension. Altered blood vessel reactivity is also associated with the pathology of high blood pressure. The purpose of this study was to examine the effects of T manipulation in the regulation of resistance-sized blood vessel reactivity. Methods Adult spontaneously hypertensive (SHR) and Wistar Kyoto (WKY) male rats at 8 weeks of age were used. The rats were divided into groups consisting of gonadally intact controls (CONT), castrate with sham implant (CAST) and castrate with T implant (CAST + T) (n = 6 to 12 per group). Following a short-term period of T treatment (approximately 4 weeks), plasma norepinephrine (NE) and plasma T were assessed by performing high-performance liquid chromatography and RIA, respectively. Resistance-sized mesenteric artery reactivity was assessed on a pressurized arteriograph for myogenic reactivity (MYO), phenylephrine (PE) responsiveness and passive structural mechanics. Results SHR and WKY males exhibited similar physiological trends in T manipulation, with castration significantly lowering plasma T and NE and T replacement significantly increasing plasma T and NE. T manipulation in general resulted in significant alterations in MYO of second-order mesenteric arteries, with T replacement decreasing MYO in SHR (P < 0.05) compared to CONT, T replacement increasing MYO, and CAST decreasing MYO in WKY rats (P < 0.001) compared to CONT rats. Additionally, PE-induced constriction was significantly altered in both strains following T treatment, with the effective concentration of PE to constrict the vessel to 50% of the total diameter significantly increased in the CAST + T SHR compared to CONT (P < 0.05). Comparisons of passive structural mechanics between SHR and WKY treatment groups indicated in SHR a significantly increased wall-to-lumen ratio and decreased circumferential wall stress compared to WKY treatment groups. Conclusions These data suggest that T and NE are involved in a complex interaction with both myogenic reactivity and structural alterations of resistance-sized blood vessels and that these factors likely contribute to the development and maintenance of hypertension.
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Affiliation(s)
- Jonathan D Toot
- Department of Biology, 303 Carroll St,,The University of Akron, Akron, OH 44325-3908.
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19
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Fahed AC, Gholmieh JM, Azar ST. Connecting the Lines between Hypogonadism and Atherosclerosis. Int J Endocrinol 2012; 2012:793953. [PMID: 22518131 PMCID: PMC3296205 DOI: 10.1155/2012/793953] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 11/09/2011] [Indexed: 11/18/2022] Open
Abstract
Epidemiological studies show that atherosclerotic cardiovascular disease is a leading cause of morbidity and mortality worldwide and point to gender differences with ageing males being at highest risk. Atherosclerosis is a complex process that has several risk factors and mediators. Hypogonadism is a commonly undiagnosed disease that has been associated with many of the events, and risk factors leading to atherosclerosis. The mechanistic relations between testosterone levels, atherosclerotic events, and risk factors are poorly understood in many instances, but the links are clear. In this paper, we summarize the research journey that explains the link between hypogonadism, each of the atherosclerotic events, and risk factors. We look into the different areas from which lessons could be learned, including epidemiological studies, animal and laboratory experiments, studies on androgen deprivation therapy patients, and studies on testosterone-treated patients. We finish by providing recommendations for the clinician and needs for future research.
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Affiliation(s)
- Akl C. Fahed
- Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Joanna M. Gholmieh
- School of Pharmacy, Lebanese American University, P.O. Box 36, Byblos, Lebanon
| | - Sami T. Azar
- Department of Internal Medicine, American University of Beirut, Bliss Street, P.O. Box 11-0236, Beirut, Lebanon
- *Sami T. Azar:
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20
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Mäkinen JI, Perheentupa A, Irjala K, Pöllänen P, Mäkinen J, Huhtaniemi I, Raitakari OT. Endogenous testosterone and brachial artery endothelial function in middle-aged men with symptoms of late-onset hypogonadism. Aging Male 2011; 14:237-42. [PMID: 21831030 DOI: 10.3109/13685538.2011.593655] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In aging men, serum endogenous testosterone is inversely associated with common carotid intima-media thickness (IMT) and directly with beneficial plasma lipid levels; however, the relationship to endothelial function is poorly characterized. We examined the association between serum testosterone and endothelium-dependent brachial artery flow-mediated dilatation (FMD) in middle-aged to elderly men. A group of 83 men aged 40?69 years (mean 55.9 ± 7.5 [SD]) with andropausal symptoms were studied. We measured their serum lipids, testosterone, luteinizing hormone, mean carotid IMT and brachial artery FMD by high resolution B-mode ultrasound. Brachial FMD correlated inversely with vessel diameter (r = -0.38, p = 0.0004), alcohol consumption (r = -0.22, p = 0.047) and serum testosterone (r = -0.27, p = 0.01), but not with luteinizing hormone. In multivariate analysis, FMD was explained by testosterone (β = -0.17, p = 0.0226), high density lipoprotein cholesterol (β = 4.17, p = 0.0312) and vessel diameter (β = -4.37, p < 0.0001) when adjusted for age, body mass index, triglycerides, blood pressure, carotid IMT, smoking, alcohol consumption, cardiovascular diseases and use of lipid lowering medication (HMG-CoA reductase inhibitors). In middle-aged to elderly men, there is an inverse correlation between serum testosterone and brachial FMD. These data suggest that testosterone may have an adverse effect on systemic endothelial function.
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Affiliation(s)
- Juuso I Mäkinen
- Department of Clinical Physiology, University of Turku, Turku, Finland.
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21
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Saad F, Aversa A, Isidori AM, Zafalon L, Zitzmann M, Gooren L. Onset of effects of testosterone treatment and time span until maximum effects are achieved. Eur J Endocrinol 2011; 165:675-85. [PMID: 21753068 PMCID: PMC3188848 DOI: 10.1530/eje-11-0221] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
OBJECTIVE Testosterone has a spectrum of effects on the male organism. This review attempts to determine, from published studies, the time-course of the effects induced by testosterone replacement therapy from their first manifestation until maximum effects are attained. DESIGN Literature data on testosterone replacement. RESULTS Effects on sexual interest appear after 3 weeks plateauing at 6 weeks, with no further increments expected beyond. Changes in erections/ejaculations may require up to 6 months. Effects on quality of life manifest within 3-4 weeks, but maximum benefits take longer. Effects on depressive mood become detectable after 3-6 weeks with a maximum after 18-30 weeks. Effects on erythropoiesis are evident at 3 months, peaking at 9-12 months. Prostate-specific antigen and volume rise, marginally, plateauing at 12 months; further increase should be related to aging rather than therapy. Effects on lipids appear after 4 weeks, maximal after 6-12 months. Insulin sensitivity may improve within few days, but effects on glycemic control become evident only after 3-12 months. Changes in fat mass, lean body mass, and muscle strength occur within 12-16 weeks, stabilize at 6-12 months, but can marginally continue over years. Effects on inflammation occur within 3-12 weeks. Effects on bone are detectable already after 6 months while continuing at least for 3 years. CONCLUSION The time-course of the spectrum of effects of testosterone shows considerable variation, probably related to pharmacodynamics of the testosterone preparation. Genomic and non-genomic effects, androgen receptor polymorphism and intracellular steroid metabolism further contribute to such diversity.
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Affiliation(s)
- Farid Saad
- Scientific Affairs Men's Healthcare, BU General Medicine/Men's Healthcare, Bayer Pharma AG, D-13342 Berlin, Germany.
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22
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Toot JD, Reho JJ, Novak J, Dunphy G, Ely DL, Ramirez RJ. Testosterone Increases Myogenic Reactivity of Second-Order Mesenteric Arteries in both Defective and Normal Androgen Receptor Adult Male Rats. ACTA ACUST UNITED AC 2011; 8:40-52. [DOI: 10.1016/j.genm.2011.01.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Revised: 01/19/2011] [Accepted: 01/26/2011] [Indexed: 10/18/2022]
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23
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Testosterone and coronary artery disease in men. Maturitas 2010; 67:15-9. [PMID: 20447781 DOI: 10.1016/j.maturitas.2010.03.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Revised: 03/29/2010] [Accepted: 03/31/2010] [Indexed: 11/20/2022]
Abstract
Coronary artery disease (CAD) is the leading cardiovascular cause of death, and in men, endogenous testosterone concentrations are inversely related to the extent and severity of CAD. Testosterone is known to affect a number of risk factors for CAD and has effects on vascular tone, vasoreactivity and blood flow of blood vessels beyond the reproductive system, indicating that testosterone may be involved in the pathogenesis of CAD. In this review we will present and discuss the actions of endogenous testosterone and testosterone treatment on risk factors for CAD, on the blood vessel wall and blood flow, and on atheroma development and progression, and discuss the potential for testosterone use in men with CAD.
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24
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Saltiki K, Papageorgiou G, Voidonikola P, Mantzou E, Xiromeritis K, Papamichael C, Alevizaki M, Stamatelopoulos K. Endogenous estrogen levels are associated with endothelial function in males independently of lipid levels. Endocrine 2010; 37:329-35. [PMID: 20960271 DOI: 10.1007/s12020-010-9307-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2009] [Accepted: 12/23/2009] [Indexed: 10/20/2022]
Abstract
Estrogens and androgens may play an important role in vascular health in both sexes. The aim of this study was to examine the relation of endogenous sex hormone levels with early markers of atherosclerosis in a cohort of apparently healthy males. 124 males (age 46.25 ± 9.56) attending a preventive medicine program were examined for unrecognised features of the metabolic syndrome. Flow-mediated dilatation (FMD) and intima-media thickness (IMT) of the common carotid artery were evaluated. Obesity parameters were recorded; estradiol, testosterone, SHBG, free testosterone, insulin, as well as glucose and lipid levels were measured. FMD was positively correlated with estradiol (r = 0.201, P = 0.041) and negatively with total cholesterol (r = -0.205, P = 0.022), low density lipoproteins (r = -0.232, P = 0.009), and triglyceride levels (r = -0.179, P = 0.046). In multivariate analysis, the association of FMD with estrogen was independent of BMI and lipid levels. No significant association between FMD and testosterone levels was found. Subjects with an increased mean IMT (> 0.73 mm, i.e., > 3rd tertile) had lower levels of free (P = 0.021) and bioavailable (P = 0.016) testosterone. In multivariate logistic regression analysis, this association was no longer significant when age or cholesterol levels were considered. Endogenous estrogen levels are associated with FMD, independently of age and lipid levels, showing a protective effect in middle-age male subjects. Circulating androgens are associated, although not independently, with structural changes such as the IMT of carotid artery; this effect is possibly influenced by lipid levels and age.
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Affiliation(s)
- Katerina Saltiki
- Endocrine Unit, Evgenidion Hospital, Athens University School of Medicine, Athens, Greece.
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25
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Abstract
Abuse of anabolic androgenic steroids (AAS) has been linked to a variety of different cardiovascular side effects. In case reports, acute myocardial infarction is the most common event presented, but other adverse cardiovascular effects such as left ventricular hypertrophy, reduced left ventricular function, arterial thrombosis, pulmonary embolism and several cases of sudden cardiac death have also been reported. However, to date there are no prospective, randomized, interventional studies on the long-term cardiovascular effects of abuse of AAS. In this review we have studied the relevant literature regarding several risk factors for cardiovascular disease where the effects of AAS have been scrutinized:(1) Echocardiographic studies show that supraphysiologic doses of AAS lead to both morphologic and functional changes of the heart. These include a tendency to produce myocardial hypertrophy (Fig. 3), a possible increase of heart chamber diameters, unequivocal alterations of diastolic function and ventricular relaxation, and most likely a subclinically compromised left ventricular contractile function. (2) AAS induce a mild, but transient increase of blood pressure. However, the clinical significance of this effect remains modest. (3) Furthermore, AAS confer an enhanced pro-thrombotic state, most prominently through an activation of platelet aggregability. The concomitant effects on the humoral coagulation cascade are more complex and include activation of both pro-coagulatory and fibrinolytic pathways. (4) Users of AAS often demonstrate unfavorable measurements of vascular reactivity involving endothelial-dependent or endothelial-independent vasodilatation. A degree of reversibility seems to be consistent, though. (5) There is a comprehensive body of evidence documenting that AAS induce various alterations of lipid metabolism. The most prominent changes are concomitant elevations of LDL and decreases of HDL, effects that increase the risk of coronary artery disease. And finally, (6) the use of AAS appears to confer an increased risk of life-threatening arrhythmia leading to sudden death, although the underlying mechanisms are still far from being elucidated. Taken together, various lines of evidence involving a variety of pathophysiologic mechanisms suggest an increased risk for cardiovascular disease in users of anabolic androgenic steroids.
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Affiliation(s)
- Paul Vanberg
- Chief Physician/Senior Cardiologist, Oslo University Hospital - Aker, Trondheimsveien 235, 0514-Oslo University Hospital, Oslo, Norway.
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26
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Manuck SB, Marsland AL, Flory JD, Gorka A, Ferrell RE, Hariri AR. Salivary testosterone and a trinucleotide (CAG) length polymorphism in the androgen receptor gene predict amygdala reactivity in men. Psychoneuroendocrinology 2010; 35:94-104. [PMID: 19493626 PMCID: PMC2825741 DOI: 10.1016/j.psyneuen.2009.04.013] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Revised: 03/05/2009] [Accepted: 04/22/2009] [Indexed: 01/21/2023]
Abstract
In studies employing functional magnetic resonance imaging (fMRI), reactivity of the amygdala to threat-related sensory cues (viz., facial displays of negative emotion) has been found to correlate positively with interindividual variability in testosterone levels of women and young men and to increase on acute administration of exogenous testosterone. Many of the biological actions of testosterone are mediated by intracellular androgen receptors (ARs), which exert transcriptional control of androgen-dependent genes and are expressed in various regions of the brain, including the amygdala. Transactivation potential of the AR decreases (yielding relative androgen insensitivity) with expansion a polyglutamine stretch in the N-terminal domain of the AR protein, as encoded by a trinucleotide (CAG) repeat polymorphism in exon 1 of the X-chromosome AR gene. Here we examined whether amygdala reactivity to threat-related facial expressions (fear, anger) differs as a function of AR CAG length variation and endogenous (salivary) testosterone in a mid-life sample of 41 healthy men (mean age=45.6 years, range: 34-54 years; CAG repeats, range: 19-29). Testosterone correlated inversely with participant age (r=-0.39, p=0.012) and positively with number of CAG repeats (r=0.45, p=0.003). In partial correlations adjusted for testosterone level, reactivity in the ventral amygdala was lowest among men with largest number of CAG repeats. This inverse association was seen in both the right (r(p)=-0.34, p<0.05) and left (r(p)=-0.32, p<0.05) hemisphere. Activation of dorsal amygdala, correlated positively with individual differences in salivary testosterone, also in right (r=0.40, p<0.02) and left (r=0.32, p<0.05) hemisphere, but was not affected by number of CAG repeats. Hence, androgenic influences on threat-related reactivity in the ventral amygdala may be moderated partially by CAG length variation in the AR gene. Because individual differences in salivary testosterone also predicted dorsal amygdala reactivity and did so independently of CAG repeats, it is suggested that androgenic influences within this anatomically distinct region may be mediated, in part, by non-genomic or AR-independent mechanisms.
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Affiliation(s)
- Stephen B Manuck
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA 15260, United States.
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27
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The effects of testosterone on risk factors for, and the mediators of, the atherosclerotic process. Atherosclerosis 2009; 207:318-27. [DOI: 10.1016/j.atherosclerosis.2009.04.016] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2009] [Revised: 04/05/2009] [Accepted: 04/14/2009] [Indexed: 01/08/2023]
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28
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Cunningham RL, Giuffrida A, Roberts JL. Androgens induce dopaminergic neurotoxicity via caspase-3-dependent activation of protein kinase Cdelta. Endocrinology 2009; 150:5539-48. [PMID: 19837873 PMCID: PMC2795716 DOI: 10.1210/en.2009-0640] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Aged men have a greater incidence of Parkinson's disease (PD) than women. PD is a neurodegenerative condition associated with the loss of dopamine neurons in the nigrostriatal pathway. This study examined the neurotoxic effects of androgens in a dopaminergic cell line (N27 cells) and the downstream signaling pathways activated by androgens. Treatment of N27 cells with testosterone- and dihydrotestosterone-induced mitochondrial dysfunction, protein kinase C (PKC)-delta cleavage, and apoptosis in dopaminergic neuronal cells. Inhibition of caspase-3 prevented the cleavage of PKCdelta from the full-length element to the catalytic fragment and apoptosis in N27 cells, suggesting that androgen-induced apoptosis is mediated by caspase-3-dependent activation of PKCdelta. Androgen-induced apoptosis may be specific to dopamine neurons as evidenced by a lack of testosterone-induced apoptosis in GnRH neurons. These results support a neurotoxic consequence of testosterone on dopaminergic neurons and may provide insight into the gender bias found in PD.
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Affiliation(s)
- Rebecca L Cunningham
- Department of Pharmacology and the Sam and Ann Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center, San Antonio, Texas 78229, USA.
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29
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Kaushik M, Sontineni SP, Hunter C. Cardiovascular disease and androgens: a review. Int J Cardiol 2009; 142:8-14. [PMID: 19923015 DOI: 10.1016/j.ijcard.2009.10.033] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Accepted: 10/18/2009] [Indexed: 11/18/2022]
Abstract
Globally, cardiovascular disease is the single largest cause of mortality. The differences in pattern of cardiovascular disease between the two genders have not been explained properly. The spotlight has largely been focused on estrogens but no conclusive evidence has proven its role in reducing the incidence of cardiovascular disease. Consequently, androgens have attracted significant interest in explaining the gender difference in cardiovascular disease. More studies in last two decades have increased our knowledge about the effects of androgens on cardiovascular disease progression. Evidence for age related fall in testosterone levels in males and increasing cardiovascular events with age had lead to the postulation of idea of 'andropause or male menopause'. Unfortunately, for the last few decades the androgens have been highlighted as agents of abuse among athletes all over the world. There have been multiple reports of their association with sudden cardiac death and adverse cardiovascular outcomes when abused. Contrastingly, there has been an increasing prescription use of testosterone supplementation in various conditions related to androgen deficiency state and for many other off-label indications. Human observational studies have mostly concluded that men with lower testosterone levels tend to have higher incidence of coronary artery disease. Emerging evidence supports that lower androgen levels predict poor cardiovascular risk profile. Role with supplementation of testosterone for cardiovascular disease is being studied in both primary and secondary prevention stages and its safety being evaluated. This is an appropriate time to review the role of androgens specifically from a cardiovascular standpoint.
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Affiliation(s)
- Manu Kaushik
- Department of Medicine, Creighton University Medical Center, Omaha, NE 68131, USA.
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de Souza Rossignoli P, Pereira OCM, Chies AB. Orchidectomy enhances the effects of phenylephrine in rat isolated portal vein. Clin Exp Pharmacol Physiol 2009; 37:368-74. [PMID: 19843099 DOI: 10.1111/j.1440-1681.2009.05313.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
1. Orchidectomy results in long-term testosterone deprivation similar to that observed in male clinical pathologies, such as hypogonadism and age-related reductions in plasma testosterone concentrations. Although the vascular effects of these sorts of hormone deprivations are known in arteries, they have not been studied to the same extent in veins. 2. The aim of the present study was to determine the effect of orchidectomy, with or without subsequent testosterone replacement (started 23 days after orchidectomy; 10 mg/kg, i.m., testosterone propionate once every 5 days for 3 weeks), on responses of rat isolated portal veins and vena cavae to exogenous phenylephrine (PE). Isolated vessels were mounted in an organ bath and concentration-response curves constructed to PE (10(-10)-10(-4) mol/L), endothelin (ET; 10(-10)-10(-5) mol/L) and KCl (10(-2)-1.2 x 10(-1) mol/L; as a control). 3. Orchidectomy had no effect on contractile responses of either the portal vein or vena cava to KCl. However, orchidectomy enhanced the maximum response (R(max)) of the portal vein, but not the vena cava, to PE. Testosterone replacement had no effect on these responses. The effects of orchidectomy on the R(max) to PE in portal veins were not altered by the nitric oxide synthase inhibitor N(G)-nitro-l-arginine methyl ester (10(-4) mol/L) alone or combined with 10(-5) mol/L indomethacin (a non-selective cyclo-oxygenase inhibitor), but they were abolished following treatment of isolated vessels with the ET(A) and ET(B) receptor antagonists BQ-123 and BQ-788 (both at 10(-6) mol/L). Orchidectomy did not alter portal vein responses to the application of exogenous ET. 4. The results of the present study indicate that orchidectomy-induced decreases in plasma testosterone can increase the venoconstrictor effects of PE on the portal vein and that this effect involves activation of both ET(A) and ET(B) receptors by locally produced ET.
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Evaluation of vascular reactivity of young male hypogonadotrophic hypogonadism patients. Int J Cardiovasc Imaging 2009; 26:35-40. [DOI: 10.1007/s10554-009-9505-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2009] [Accepted: 08/28/2009] [Indexed: 11/25/2022]
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Magkos F, Mittendorfer B. Gender differences in lipid metabolism and the effect of obesity. Obstet Gynecol Clin North Am 2009; 36:245-65, vii. [PMID: 19501312 DOI: 10.1016/j.ogc.2009.03.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
There are many differences between men and women, and between lean and obese subjects, in fatty acid and very low-density lipoprotein triglyceride and apolipoprotein B-100 metabolism. Currently, observations in this area are predominantly descriptive. The mechanisms responsible for sexual dimorphism in lipid metabolism are largely unknown.
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Affiliation(s)
- Faidon Magkos
- Center for Human Nutrition, Division of Geriatrics & Nutritional Science, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
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Signorelli SS, Barresi V, Musso N, Anzaldi M, Croce E, Fiore V, Condorelli DF. Polymorphisms of steroid 5-alpha-reductase type I (SRD5A1) gene are associated to peripheral arterial disease. J Endocrinol Invest 2008; 31:1092-7. [PMID: 19246976 DOI: 10.1007/bf03345658] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Although animal studies support the hypothesis that androgenic biological actions may affect experimental atherosclerosis progression, evidence for a relationship between androgen effects and peripheral arterial disease (PAD), a common clinical form of atherosclerosis, is weak or contradictory. Testosterone, the main androgen hormone, is converted in a 5alpha-reduced form by enzymatic activities in the target cells and some specific actions are mediated by such metabolites. Steroid 5-alpha reductase isoenzymes (SRD5A1 and SRD5A2) catalyze the conversion to the bioactive potent androgen dihydrotestosterone and other reduced metabolites and represent relevant regulators of local hormonal actions. In the present study we tested for the association of selected single nucleotide polymorphisms (SNP) of SRD5A1 and SRD5A2 with symptomatic PAD patients. Two different SNP in the SRD5A1 were significantly associated which the PAD phenotype (p<0.03, odds ratio 1.73), while no association was found between PAD phenotypes and SRD5A2. Since the examined SRDA1 gene variant was previously associated with a low enzymatic activity, we suggest that a decreased local enzymatic conversion of testosterone may contribute to PAD genetic susceptibility.
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Affiliation(s)
- S S Signorelli
- Department of Internal Medicine and Systemic Disease, Medical Angiology Section, Faculty of Medicine, University of Catania, Catania, Italy.
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Gooren LJ, Giltay EJ. Review of Studies of Androgen Treatment of Female-to-Male Transsexuals: Effects and Risks of Administration of Androgens to Females. J Sex Med 2008; 5:765-776. [DOI: 10.1111/j.1743-6109.2007.00646.x] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Allan CA, Strauss BJG, McLachlan RI. Body composition, metabolic syndrome and testosterone in ageing men. Int J Impot Res 2007; 19:448-57. [PMID: 17554396 DOI: 10.1038/sj.ijir.3901552] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The ageing process in men is marked by changes in body composition (loss of fat-free mass (FFM) and skeletal muscle, and gain in fat mass (FM)) and is associated with a decline in serum testosterone. Correlations between these aspects of ageing and the acknowledged role of exogenous testosterone in reversing the loss of FFM and gain in FM seen in adult men with congenital or acquired hypoandrogenism have led to the hypothesis that testosterone therapy in ageing men will result in favourable changes in body composition and may improve metabolic status and/or cardiovascular risk. Data from randomized controlled trials of testosterone therapy in ageing men addressing the endpoints of body composition and components of the metabolic syndrome and cardiovascular risk factors are reviewed, and the impact of the increasing prevalence of obesity on these relationships is considered.
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Affiliation(s)
- C A Allan
- Prince Henry's Institute, Clayton, Victoria, Australia
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Torres IP, Hafidi ME, Zamora-González J, Infante O, Chavira R, Baños G. Modulation of aortic vascular reactivity by sex hormones in a male rat model of metabolic syndrome. Life Sci 2007; 80:2170-2180. [PMID: 17499811 DOI: 10.1016/j.lfs.2007.04.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2006] [Revised: 04/11/2007] [Accepted: 04/12/2007] [Indexed: 11/26/2022]
Abstract
Modulation by sex hormones of aortic reactivity in rats with the metabolic syndrome (MS) was investigated. The following groups of weanling male Wistar rats were used: control rats (C) received regular tap water while MS rats received 30% sucrose in their drinking water; both had rodent chow for 24 weeks. These two groups were further subdivided into the following four groups: intact (Int), castrated (Cas), castrated plus testosterone (T) and castrated plus estradiol (E). Vascular response of thoracic aortic rings to norepinephrine (NE), acetylcholine (ACh), indomethacin (Indo) and nitro-l-arginine-methyl ester (L-NAME) was investigated. Blood pressure (BP) and serum nitrates and nitrites were measured. BP and serum nitrates and nitrites were modified by castration and treatments with either T or E. Vasoconstriction in Int MS and Cas MS+T aortas was larger than in C and Cas C+T, respectively. Vasodilation in Int MS and Cas MS+T was reduced in comparison with C and Cas C+T, Cas MS and Cas MS+E. Indomethacin decreased vasoconstriction in all groups (P<0.002) but Int C and Cas C+T remained significantly smaller than Int MS and Cas MS+T. l-NAME in NE-contracted vessels induced a significant increase in vasoconstriction, except in Cas C+E rats; the responses of Int MS and Cas MS+T were significantly larger than in Int C and Cas C+T. The results suggest endothelial dysfunction in Int MS and Cas MS+T and a protective effect resulting from castration and castration plus E in MS animals, indicating a sex hormone influence.
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Affiliation(s)
- Israel Pérez Torres
- Department of Pathology, Instituto Nacional of Cardiología "Ignacio Chávez." Juan Badiano 1, Sección XVI, Tlalpan, 14080 México DF, México
| | - Mohammed El Hafidi
- Biochemistry, Instituto Nacional of Cardiología "Ignacio Chávez." Juan Badiano 1, Sección XVI, Tlalpan, 14080 México DF, México
| | - José Zamora-González
- Endocrinology, Instituto Nacional of Cardiología "Ignacio Chávez." Juan Badiano 1, Sección XVI, Tlalpan, 14080 México DF, México
| | - Oscar Infante
- Instrumentation, Instituto Nacional of Cardiología "Ignacio Chávez." Juan Badiano 1, Sección XVI, Tlalpan, 14080 México DF, México
| | - Roberto Chavira
- Department of Reproduction Biology, Instituto Nacional de la Nutrición "Salvador Zubirán". Vasco de Quiroga 15. Sección XVI, Tlalpan, 14080 México DF, México
| | - Guadalupe Baños
- Biochemistry, Instituto Nacional of Cardiología "Ignacio Chávez." Juan Badiano 1, Sección XVI, Tlalpan, 14080 México DF, México.
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Montalcini T, Gorgone G, Gazzaruso C, Sesti G, Perticone F, Pujia A. Endogenous testosterone and endothelial function in postmenopausal women. Coron Artery Dis 2007; 18:9-13. [PMID: 17172924 DOI: 10.1097/01.mca.0000236290.79306.d1] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE It is well known that coronary heart disease incidence increases in women after menopause. This phenomenon was related to reduced levels of female sex hormones. Estrogen decline, however, is not the only hormonal change during the postmenopausal period and estrogen administration did not protect women from cardiovascular disease. Therefore, it is justified to explore other hormonal changes. The role of androgens is still controversial. The aim of the present study was to investigate the relationship between endogenous sex hormones and endothelial function, measuring the brachial artery flow-mediated dilation. METHODS AND RESULTS Sixty postmenopausal women were consecutively enrolled and underwent a clinical and biochemical examination. Brachial artery flow-mediated dilation was also evaluated by ultrasound. After correction for confounding variables, testosterone was positively correlated to flow-mediated dilation (beta=0.277, P=0.03). Indeed, women in the lowest testosterone tertile had a flow-mediated dilation smaller than that in the highest tertile (P=0.02). CONCLUSIONS This result could suggest that the development of cardiovascular disease after menopause is due not only to estrogen decline but also to androgen decline. More studies are needed to evaluate the role of androgen replacement therapy on postmenopausal women with low level of this hormone.
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Affiliation(s)
- Tiziana Montalcini
- Department of Medicina Sperimentale e Clinica G. Salvatore, University of Catanzaro Magna Graecia, Catanzaro, Italy
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Greco EA, Spera G, Aversa A. Combining Testosterone and PDE5 Inhibitors in Erectile Dysfunction: Basic Rationale and Clinical Evidences. Eur Urol 2006; 50:940-7. [PMID: 16979814 DOI: 10.1016/j.eururo.2006.06.049] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2006] [Accepted: 06/29/2006] [Indexed: 01/29/2023]
Abstract
INTRODUCTION Erectile dysfunction (ED) and decline of testosterone levels are frequently observed with age and also in illnesses with a common basis of endothelial damage. OBJECTIVES To review molecular mechanisms underlying androgen action upon its receptor and phosphodiesterase type 5 (PDE5) expression and regulation by testosterone in cavernous tissue and their clinical implication in the treatment of ED refractory to PDE5 inhibitors (PDE5-Is). METHODS From January 2003 to May 2006 [corrected] we performed an extensive, unsystematic MEDLINE literature search reviewing relevant data on basic and clinical studies regarding the efficacy of combination therapies. RESULTS Most trials using testosterone alone for treatment of ED in hypogonadal men suffer from methodologic problems and report inconsistent results, but overall the trials suggest that testosterone is superior to placebo. Orally effective PDE5-Is, such as sildenafil, tadalafil, or vardenafil, may be ineffective depending on the demonstration of testosterone regulation of PDE5 expression in human corpus cavernous, and their efficacy may be enhanced by testosterone adjunction whenever necessary. CONCLUSIONS Screening for hypogonadism in all men with ED is necessary to identify men with severe hypogonadism and some cases of mild to moderate hypogonadism, who may benefit from testosterone treatment. Identification of threshold values for testosterone supplementation to appropriately benefit from PDE5-Is failure may improve clinical management of unresponsive patients with minimization of unwanted effects.
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Affiliation(s)
- Emanuela A Greco
- Department of Medical Pathophysiology, University of Rome La Sapienza, 00161 Rome, Italy
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Malkin CJ, Jones RD, Jones TH, Channer KS. Effect of testosterone on ex vivo vascular reactivity in man. Clin Sci (Lond) 2006; 111:265-74. [PMID: 16722820 DOI: 10.1042/cs20050354] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Testosterone is reported to have an acute vasodilating action in vitro, an effect that may impart a favourable haemodynamic response in patients with chronic heart failure. However, the effect of chronic testosterone exposure on general vascular reactivity is poorly described. In the present study, fresh subcutaneous resistance arteries were obtained from patients with heart failure (n=10), healthy controls (n=9) and men with androgen-deficiency (n=17). All arteries were studied using a wire myograph to examine the effect of cumulative additions of testosterone (1 nmol/l–100 μmol/l) compared with vehicle control following maximal pre-constriction with KCl (1–100 μmol/l). The vascular reactivity of arteries from androgen-deficient patients was examined further by recording tension concentration curves to cumulative additions of noradrenaline (1 nmol/l–100 μmol/l) and U46619 (1–300 nmol/l), followed by relaxation concentration curves to additions of ACh (acetylcholine; 10 nmol/l–30 μmol/l) and SNP (sodium nitroprusside; 10 nmol–30 μmol/l) respectively. In all cases, statistical analysis was performed by ANOVA. Patients with proven androgen-deficiency were treated according to clinical recommendations for a minimum of 3 months and further arteries (n=19) were taken for experimentation using the same protocol. In all groups, testosterone was confirmed to be an acute concentration-dependent vasodilator at concentrations ≥1 μmol/l (P=0.0001). The dilating effect of testosterone was augmented in patients with androgen-deficiency prior to treatment, and this effect was abrogated following appropriate testosterone replacement. Testosterone therapy significantly reduced the normal vascular dilating response to ACh and SNP (P<0.01) and significantly increased the contractile response to noradrenaline (P<0.01), but not U46619. Testosterone is an acute dose-dependent vasodilator of resistance arteries. Physiological testosterone replacement attenuates general vascular reactivity in androgen-deficient subjects. The numerous perceived benefits of testosterone replacement may be offset by a decline in vascular reactivity and, therefore, further studies and careful monitoring of patients is recommended.
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Affiliation(s)
- Christopher J Malkin
- Department of Cardiology Research, Royal Hallamshire Hospital Sheffield, Sheffield S10 2JF, UK
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Villar IC, Francis S, Webb A, Hobbs AJ, Ahluwalia A. Novel aspects of endothelium-dependent regulation of vascular tone. Kidney Int 2006; 70:840-53. [PMID: 16837917 DOI: 10.1038/sj.ki.5001680] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The vascular endothelium plays a crucial role in the regulation of vascular homeostasis and in preventing the initiation and progress of cardiovascular disease by controlling mechanical functions of the underlying vascular smooth muscle. Three vasodilators: nitric oxide (NO), prostacyclin, and endothelium-derived hyperpolarizing factor, produced by the endothelium, underlie this activity. These substances act in a co-ordinated interactive manner to maintain normal endothelial function and operate as support mechanisms when one pathway malfunctions. In this review, we discuss recent advances in our understanding of how gender influences the interaction of these factors resulting in the vascular protective effects seen in pre-menopausal women. We also discuss how endothelial NO synthase (NOS) can act in both a pro- and anti-inflammatory action and therefore is likely to be pivotal in the initiation and time course of an inflammatory response, particularly with respect to inflammatory cardiovascular disorders. Finally, we review recent evidence demonstrating that it is not solely NOS-derived NO that mediates many of the beneficial effects of the endothelium, in particular, nitrite acts as a store of NO released during pathological episodes associated with NOS inactivity (ischemia/hypoxia). Each of these more recent findings has emphasized new pathways involved in endothelial biology, and following further research and understanding of the significance and mechanisms of these systems, it is likely that new and improved treatments for cardiovascular disease will result.
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Affiliation(s)
- I C Villar
- Clinical Pharmacology, William Harvey Research Institute, Barts & The London Medical School, Charterhouse Square, London, UK
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Jones RD, Nettleship JE, Kapoor D, Jones HT, Channer KS. Testosterone and atherosclerosis in aging men: purported association and clinical implications. Am J Cardiovasc Drugs 2006; 5:141-54. [PMID: 15901202 DOI: 10.2165/00129784-200505030-00001] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Two of the strongest independent risk factors for coronary heart disease (CHD) are increasing age and male sex. Despite a wide variance in CHD mortality between countries, men are consistently twice as likely to die from CHD than their female counterparts. This sex difference has been attributed to a protective effect of female sex hormones, and a deleterious effect of male sex hormones, upon the cardiovascular system. However, little evidence suggests that testosterone exerts cardiovascular harm. In fact, serum levels of testosterone decline with age, and low testosterone is positively associated with other cardiovascular risk factors. Furthermore, testosterone exhibits a number of potential cardioprotective actions. For example, testosterone treatment is reported to reduce serum levels of the pro-inflammatory cytokines interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha, and to increase levels of the anti-inflammatory cytokine IL-10; to reduce vascular cell adhesion molecule (VCAM)-1 expression in aortic endothelial cells; to promote vascular smooth muscle and endothelial cell proliferation; to induce vasodilatation and to improve vascular reactivity, to reduce serum levels of the pro-thrombotic factors plasminogen activator inhibitor (PAI)-1 and fibrinogen; to reduce low-density lipoprotein-cholesterol (LDL-C); to improve insulin sensitivity; and to reduce body mass index and visceral fat mass. These actions of testosterone may confer cardiovascular benefit since testosterone therapy reduces atheroma formation in cholesterol-fed animal models, and reduces myocardial ischemia in men with CHD. Consequently, an alternative hypothesis is that an age-related decline in testosterone contributes to the atherosclerotic process. This is supported by recent findings, which suggest that as many as one in four men with CHD have serum levels of testosterone within the clinically hypogonadal range. Consequently, restoration of serum levels of testosterone via testosterone replacement therapy could offer cardiovascular, as well as other, clinical advantages to these individuals.
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Affiliation(s)
- Richard D Jones
- Academic Unit of Endocrinology, Division of Genomic Medicine, Hormone & Vascular Biology Group, The University of Sheffield, Sheffield, UK.
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Lane HA, Grace F, Smith JC, Morris K, Cockcroft J, Scanlon MF, Davies JS. Impaired vasoreactivity in bodybuilders using androgenic anabolic steroids. Eur J Clin Invest 2006; 36:483-8. [PMID: 16796605 DOI: 10.1111/j.1365-2362.2006.01667.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
BACKGROUND Anabolic androgenic steroids are used by some bodybuilders to enhance performance. While the cardiovascular implications of supraphysiological androgen levels requires further clarification, use is associated with sudden death, left ventricular hypertrophy, thrombo-embolism and cerebro-vascular events. MATERIALS AND METHODS To further understand the effect of androgenic anabolic steroid abuse on vascular function, this study assessed vascular stiffness (pulse-wave analysis) and cardiovascular risk factors in 28 male, bodybuilding subjects, of whom ten were actively receiving anabolic agents (group A; 26.4 +/- 7.2 years) and eight had undergone a 3-month "wash-out" period (group B; 32.1 +/- 7.1 years). The remaining ten bodybuilding subjects (group C; 24.4 +/- 4.4 years) denied any past use of anabolic steroids or other performance enhancing drugs. Comparisons were made with ten sedentary male controls (group D, 29.3 +/- 4.7 years). RESULTS Endothelial independent dilatation in response to glycerol trinitrate was significantly impaired in the group currently using anabolic steroids (group A) compared with the other three groups [A (5.63 +/- 3.24%) versus; B (11.10 +/- 4.91%), C (17.88 +/- 9.2%) and D (14.46 +/- 3.9%), P < 0.0005, respectively], whereas no significant differences in endothelial-dependent dilatation were detected between the groups [A (5.0 +/- 3.0%), B (7.4 +/- 3.4%), C (9.6 +/- 4.5%) and D (8.2 +/- 3.3%), P < 0.059, respectively]. CONCLUSIONS Previous studies described a decline in vascular reactivity occurring in bodybuilding subjects which is independent of anabolic steroid use and may result from smooth muscle hypertrophy with increased vascular stiffness. This study revealed impaired vascular reactivity associated with anabolic agents and that improvement in vascular function may occur following their discontinuation.
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Affiliation(s)
- H A Lane
- Department of Endocrinology, University Hospital of Wales, Heath Park, Cardiff CF14 4XW, Wales, UK.
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Bernini G, Versari D, Moretti A, Virdis A, Ghiadoni L, Bardini M, Taurino C, Canale D, Taddei S, Salvetti A. Vascular reactivity in congenital hypogonadal men before and after testosterone replacement therapy. J Clin Endocrinol Metab 2006; 91:1691-7. [PMID: 16492703 DOI: 10.1210/jc.2005-1398] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT The contribution of endogenous testosterone (TS) in the functional integrity of peripheral circulation in men was studied. OBJECTIVE The objective of this study was to observe vascular reactivity in male congenital hypogonadal patients before and after prolonged exposure to normal TS levels. DESIGN This was a longitudinal study in which, basically and after 6-month (range, 6-8 months) androgen treatment, we investigated forearm blood flow (strain-gauge plethysmography) changes induced by intraarterial acetylcholine (Ach), alone or in the presence of N(G)-monomethyl-l-arginine infusion, and by sodium nitroprusside. We also evaluated, by Doppler ultrasound, flow-mediated dilation of the brachial artery (BA) in response to reactive hyperemia (RH) and glyceryl trinitrate (GTN). SETTING The studies were conducted at university referral centers for andrologic and blood pressure diseases. PATIENTS Eight adult male Caucasian hypogonadal patients and nine healthy matched control subjects were studied. INTERVENTION Intervention was TS enanthate (250 mg in 1 ml oily solution) by im injection every 3 wk. RESULTS At baseline, BA diameter and RH, flow-mediated dilation, and GTN responses showed no difference between the two groups. TS therapy increased plasma total TS (P < 0.02) and reduced high-density lipoprotein (P < 0.01) and total cholesterol (P < 0.04). It did not affect vasodilation to sodium nitroprusside (355 +/- 47%), but it further reduced the vascular response to Ach (187 +/- 29%, P < 0.01 vs. baseline) and abolished the inhibition by N(G)-monomethyl-l-arginine on Ach (inhibition, 3.2%). Moreover, TS therapy decreased (P < 0.01) flow-mediated dilation, whereas it did not modify BA diameter and responses to RH and GTN. CONCLUSIONS Hypogonadal patients show impaired vascular reactivity, including endothelial-dependent vasodilation due to reduced nitric oxide availability. TS administration further impairs nitric oxide availability in these patients.
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Razmara A, Krause DN, Duckles SP. Testosterone augments endotoxin-mediated cerebrovascular inflammation in male rats. Am J Physiol Heart Circ Physiol 2005; 289:H1843-50. [PMID: 16006544 DOI: 10.1152/ajpheart.00465.2005] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Activation of inflammatory mechanisms contributes to cerebrovascular pathophysiology. Male gender is associated with increased stroke risk, yet little is known about the effects of testosterone in the cerebral circulation. Therefore, we explored the impact of testosterone treatment on cerebrovascular inflammation with both in vivo and in vitro models of inflammation. We hypothesized that testosterone would augment the expression of two vascular markers of cellular inflammation, cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Using four groups of male rats [intact, orchiectomized (ORX), and ORX treated with either testosterone (ORXT) or the testosterone metabolite 17β-estradiol (ORXE)], we determined effects of the sex hormones on cerebrovascular inflammation after intraperitoneal LPS injection. Western blot analysis showed that induction of inflammatory markers was increased in cerebral blood vessels from ORXT rats compared with intact or ORX rats. In contrast, in cerebral blood vessels from ORXE rats, there was a significant decrease in endotoxin-induced COX-2 and iNOS protein levels. Confocal microscopy of cerebral blood vessels from ORXT rats showed increased COX-2 and iNOS immunoreactivity in both endothelial and smooth muscle cells after LPS treatment. In vitro incubation with LPS also induced COX-2 in pial vessels isolated from the four animal treatment groups, with the greatest induction observed in ORXT vessels compared with the ORX and ORXE groups. Production of PGE2, a principal COX-2-derived prostaglandin end product, was also greatest in cerebral vessels isolated from ORXT rats. In conclusion, testosterone increases cerebrovascular inflammation; this effect may contribute to stroke differences between men and women.
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Affiliation(s)
- Ali Razmara
- Dept. of Pharmacology, School of Medicine, Univ. of California-Irvine, Irvine, CA 92697-4625, USA
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Kaufman JM, Vermeulen A. The decline of androgen levels in elderly men and its clinical and therapeutic implications. Endocr Rev 2005; 26:833-76. [PMID: 15901667 DOI: 10.1210/er.2004-0013] [Citation(s) in RCA: 698] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Aging in men is accompanied by a progressive, but individually variable decline of serum testosterone production, more than 20% of healthy men over 60 yr of age presenting with serum levels below the range for young men. Albeit the clinical picture of aging in men is reminiscent of that of hypogonadism in young men and decreased testosterone production appears to play a role in part of these clinical changes in at least some elderly men, the clinical relevancy of the age-related decline in sex steroid levels in men has not been unequivocally established. In fact, minimal androgen requirements for elderly men remain poorly defined and are likely to vary between individuals. Consequently, borderline androgen deficiency cannot be reliably diagnosed in the elderly, and strict differentiation between "substitutive" and "pharmacological" androgen administration is not possible. To date, only a few hundred elderly men have received androgen therapy in the setting of a randomized, controlled study, and many of these men were not androgen deficient. Most consistent effects of treatment have been on body composition, but to date there is no evidence-based documentation of clinical benefits of androgen administration to elderly men with normal or moderately low serum testosterone in terms of diminished morbidity or of improved survival or quality of life. Until the long-term risk-benefit ratio for androgen administration to elderly is established in adequately powered trials of longer duration, androgen administration to elderly men should be reserved for the minority of elderly men who have both clear clinical symptoms of hypogonadism and frankly low serum testosterone levels.
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Affiliation(s)
- Jean M Kaufman
- Department of Endocrinology, Ghent University Hospital, Ghent B-9000, Belgium.
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Cakir E, Ozcan O, Yaman H, Akgul EO, Bilgi C, Erbil MK, Yesilova Z. Elevated plasma concentration of asymmetric dimethylarginine that is reduced by single dose testosterone administration in idiopathic hypogonadotropic hypogonadism patients. J Clin Endocrinol Metab 2005; 90:1651-4. [PMID: 15613405 DOI: 10.1210/jc.2004-2045] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Our aim was to investigate whether plasma l-arginine and asymmetric dimethylarginine (ADMA) concentrations and nitric oxide (NO) production are altered in male idiopathic hypogonadotropic hypogonadism (IHH) patients in the hypogonadal state and after single dose testosterone administration compared with those in control subjects. Eighteen newly diagnosed male patients with IHH and 20 healthy volunteer controls matched by age and body mass index were enrolled in the study. Single dose testosterone was administrated im. Initially, pretreatment blood samples were collected after overnight fasting. Posttreatment blood samples were drawn 10 d after the injection. ADMA, l-arginine, and NO were measured in pre- and posttreatment blood samples. The pretreatment ADMA and l-arginine levels were significantly higher, and plasma nitrite plus nitrate (NOx) levels were lower than those in the control group. After 10 d of treatment, ADMA and l-arginine levels were significantly reduced, and NOx levels were significantly increased. There was a significant positive correlation (P < 0.01) between ADMA and l-arginine and a negative correlation between ADMA and NOx levels in patients and controls. In conclusion, the patients with IHH showed elevated plasma ADMA levels associated with a reduction in NO production. Single dose parenteral T administration lowered ADMA concentrations and increased NO production to the control group values.
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Affiliation(s)
- Erdinc Cakir
- Department of Emergency Medicine, Gulhane Military Medical School, 06010, Etlik, Ankara, Turkey.
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Abstract
Klinefelter's syndrome is the most common genetic cause of human male infertility, but many cases remain undiagnosed because of substantial variation in clinical presentation and insufficient professional awareness of the syndrome itself. Early recognition and hormonal treatment of the disorder can substantially improve quality of life and prevent serious consequences. Testosterone replacement corrects symptoms of androgen deficiency but has no positive effect on infertility. However, nowadays patients with Klinefelter's syndrome, including the non-mosaic type, need no longer be considered irrevocably infertile, because intracytoplasmic sperm injection offers an opportunity for procreation even when there are no spermatozoa in the ejaculate. In a substantial number of azoospermic patients, spermatozoa can be extracted from testicular biopsy samples, and pregnancies and livebirths have been achieved. The frequency of sex chromosomal hyperploidy and autosomal aneuploidies is higher in spermatozoa from patients with Klinefelter's syndrome than in those from normal men. Thus, chromosomal errors might in some cases be transmitted to the offspring of men with this syndrome. The genetic implications of the fertilisation procedures, including pretransfer or prenatal genetic assessment, must be explained to patients and their partners.
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Affiliation(s)
- Fabio Lanfranco
- Institute of Reproductive Medicine of the University of Münster, Domagkstrasse 11, D-48129 Münster, Germany
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Allan CA, McLachlan RI. Age-related changes in testosterone and the role of replacement therapy in older men. Clin Endocrinol (Oxf) 2004; 60:653-70. [PMID: 15163327 DOI: 10.1111/j.1365-2265.2004.02002.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Carolyn A Allan
- Prince Henry's Institute of Medical Research, Monash Medical Centre and Department O & G, Monash University, Clayton, Australia
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Lanfranco F, Zitzmann M, Simoni M, Nieschlag E. Serum adiponectin levels in hypogonadal males: influence of testosterone replacement therapy. Clin Endocrinol (Oxf) 2004; 60:500-7. [PMID: 15049966 DOI: 10.1111/j.1365-2265.2004.02007.x] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
OBJECTIVE Adiponectin is an adipocyte-specific secretory protein which exhibits antiatherogenic, anti-inflammatory and antidiabetic properties. We hypothesized that testosterone plays an important role in the regulation of its secretion in humans, as adiponectin concentrations are higher in women than in men and as testosterone administration is accompanied by a reduction in serum adiponectin in animals and by reduced protein secretion in cultured adipocytes. This study aimed to evaluate adiponectin levels in hypogonadal men prior to and during testosterone replacement therapy. SUBJECTS AND METHODS In a retrospective study, adiponectin, total and free testosterone, oestradiol, SHBG, total cholesterol and triglyceride levels were evaluated in 31 hypogonadal men [HM; age, mean +/- SEM: 36.5 +/- 2.4 years; body mass index (BMI) 24.6 +/- 0.8 kg/m2] and 29 weight-matched eugonadal men (EM; age 30.8 +/- 1.5 years; BMI 23.4 +/- 0.6 kg/m2). In 13 HM (age 33.9 +/- 3.2 years; BMI 24.2 +/- 0.9 kg/m2) the same parameters were also evaluated after 6 months of testosterone replacement therapy. Correlation analysis between adiponectin and hormonal, biochemical and anthropometric parameters was performed in all subjects. RESULTS Testosterone, free testosterone and oestradiol concentrations were significantly lower in HM than in EM (4.4 +/- 0.4 nmol/l, 78.4 +/- 10.9 pmol/l and 36.1 +/- 3.0 pmol/l, respectively, in HM vs. 21.9 +/- 0.7 nmol/l, 507.9 +/- 13.8 pmol/l and 65.2 +/- 1.8 pmol/l, respectively, in EM, P < 0.0001), while SHBG levels in HM were higher than in EM (54.4 +/- 7.5 vs. 30.9 +/- 2.2 nmol/l, P < 0.005). Serum adiponectin levels in HM were significantly higher than in EM (9.53 +/- 0.73 vs. 6.80 +/- 0.55 microg/ml, P < 0.01). Calculation of the Pearson coefficient showed that adiponectin levels in HM were not correlated with any of the anthropometric and hormonal parameters examined, but showed a significant negative correlation with serum triglycerides (r = -0.38, P < 0.05). Serum adiponectin levels were negatively correlated with body weight (r = -0.41, P < 0.05) in EM but not with other anthropometric, hormonal or biochemical parameters. Six months after initiation of testosterone replacement therapy, which increased testosterone and free testosterone levels to the normal range, adiponectin levels were significantly reduced in HM (6.37 +/- 0.93 vs. 9.26 +/- 1.01 microg/ml, P < 0.01) and similar to those recorded in EM. CONCLUSIONS Compared to eugonadal subjects, hypogonadal men show higher adiponectin levels which are reduced by testosterone replacement therapy. This study indicates that testosterone exerts a regulatory role on adiponectin secretion in humans.
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Affiliation(s)
- Fabio Lanfranco
- Institute of Reproductive Medicine of the University, D-48129 Münster, Germany
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Oettel M. Testosterone metabolism, dose-response relationships and receptor polymorphisms: selected pharmacological/toxicological considerations on benefits versus risks of testosterone therapy in men. Aging Male 2003; 6:230-56. [PMID: 15006261 DOI: 10.1080/13685530312331309772] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
In this review selected toxicological problems related to testosterone therapy in hypogonadal men are discussed. Applying "classical" pharmacological/toxicological findings (e.g. animal studies on short- and long-term toxicity) to clinical situations is not very helpful. Molecular biological knowledge and especially evaluation of epidemiological studies, as well as intervention studies, on testosterone therapy in hypogonadal men are more useful. Potential risks include overdosage for lifestyle reasons, e.g. excessive muscle building and reduction of visceral obesity, when erythrocytosis occurs concomitantly. Modern galenic formulations of testosterone administration (e.g. transdermal gel, suitable testosterone esters for intramuscular application and newer oral preparations) avoid supraphysiological serum concentrations, therefore significantly reducing the toxicological risk. A hypothetical model of the toxicological risks of testosterone therapy is given that is based on the influence of testosterone metabolism (aromatization vs. reduction) of the respective parameter/target chosen. Finally, the great influence of polymorphisms of the androgen receptor on the assessment of toxicological risk and on the individualization of androgen therapy is shown. Already existing national, continental and international guidelines or recommendations for the testosterone therapy should be harmonized.
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Affiliation(s)
- M Oettel
- Jenapharm GmbH & Co. KG, Otto-Schott-Strasse 15, 07745 Jena, Germany
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