Evaluation of sex hormone levels and some metabolic factors in men with coronary atherosclerosis

Women’s lifetime reproductive profiles and frailty among aging individuals in the USA and the Philippines

Frailty, particularly traits which are related to sex steroid hormone production, results from the age-associated decline in function considered to be part of the typical aging process. This process may vary with influences including environmental, biological, or lifestyle factors. An area of concern that has received relatively little attention is the impact of cumulative lifetime changes in sex steroid hormones related to the traits we see that typify the human aging process. Women’s lifetime reproductive profiles include menstrual/ovulatory cycles, gestation, and lactation, all of which respond to changes in sex steroid hormone levels. Here, we review data on reproductive profiles and risks of frailty among post-menopausal women. In the current study, our team collected reproductive histories of women to determine the estimated number of lifetime reproductive cycles (ELC). We interviewed 44 women in the USA and 67 women in the Philippines aged 65 years plus to obtain data on reproductive cycles, pregnancy, and breastfeeding. Participants completed several frailty tasks including grip strength, a sit-to-stand test, and gait speed. While ELC was not associated with frailty in the US population, higher ELC was associated with lower frailty among the Philippine population. The current study should be considered as an exploratory project investigating field-friendly methods to use when considering lifetime reproductive histories and the influence on the aging process.

Testosterone to oestradiol ratio reflects systemic and plaque inflammation and predicts future cardiovascular events in men with severe atherosclerosis

Aims

The effects of testosterone on cardiovascular disease (CVD) as reported in literature have been ambiguous. Recently, the interplay between testosterone and oestradiol as assessed by testosterone/oestradiol (T/E2) ratio was suggested to be better informative on the normal physiological balance. Considering the role in CVD, we hypothesized that a low T/E2 ratio in men with CVD is associated with increased inflammation, a more unstable plaque and a worse cardiovascular outcome.

Methods and results

Testosterone and oestradiol concentrations were determined in blood samples of 611 male carotid endarterectomy patients included in the Athero-Express Biobank Study. T/E2 ratio was associated with baseline characteristics, atherosclerotic plaque specimens, inflammatory biomarkers, and 3 year follow-up information. Patients with low T/E2 ratio had more unfavourable inflammatory profiles compared with patients with high T/E2 as observed by higher levels of C-reactive protein [2.81 μg/mL vs. 1.22 μg/mL (P < 0.001)] and higher leucocyte counts [8.98*109/L vs. 7.75*109/L (P = 0.001)] in blood. In atherosclerotic plaques, a negative association between T/E2 ratio and number of neutrophils [B = -0.366 (P = 0.012)], plaque calcifications [OR: 0.816 (P = 0.044)], interleukin-6 (IL-6) [B = -0.15 (P = 0.009)], and IL-6 receptor [B = -0.13 (P = 0.024)] was found. Furthermore, in multivariate Cox regression analysis, low T/E2 ratio was independently associated with an increased risk for major cardiovascular events (MACE) during 3 year follow-up [hazard ratio 1.67 (95% confidence interval 1.02-2.76), P = 0.043]. In men with elevated body mass index (BMI), these effects were strongest.

Conclusion

In male patients with manifest atherosclerotic disease, low T/E2 ratio was associated with increased systemic inflammation, increased inflammatory plaque proteins, and an increased risk of future MACE as compared to men with normal T/E2 ratio. These effects are strongest in men with elevated BMI and are expected to be affected by aromatase activity in white fat tissues. Normalization of T/E2 ratio may be considered as target for the secondary prevention of CVD in men.

Androgen receptor (AR) in cardiovascular diseases

Cardiovascular diseases (CVDs) are still the highest leading cause of death worldwide. Several risk factors have been linked to CVDs, including smoking, diabetes, hyperlipidemia, and gender among others. Sex hormones, especially the androgen and its receptor, androgen receptor (AR), have been linked to many diseases with a clear gender difference. Here, we summarize the effects of androgen/AR on CVDs, including hypertension, stroke, atherosclerosis, abdominal aortic aneurysm (AAA), myocardial hypertrophy, and heart failure, as well as the metabolic syndrome/diabetes and their impacts on CVDs. Androgen/AR signaling exacerbates hypertension, and anti-androgens may suppress hypertension. Androgen/AR signaling plays dual roles in strokes, depending on different kinds of factors; however, generally males have a higher incidence of strokes than females. Androgen and AR differentially modulate atherosclerosis. Androgen deficiency causes elevated lipid accumulation to enhance atherosclerosis; however, targeting AR in selective cells without altering serum androgen levels would suppress atherosclerosis progression. Androgen/AR signaling is crucial in AAA development and progression, and targeting androgen/AR profoundly restricts AAA progression. Men have increased cardiac hypertrophy compared with age-matched women that may be due to androgens. Finally, androgen/AR plays important roles in contributing to obesity and insulin/leptin resistance to increase the metabolic syndrome.

Relationship between androgenetic alopecia and cardiovascular risk factors according to BASP classification in Koreans

There have been many studies on the relationship between androgenetic alopecia (AGA) and cardiovascular risk factors, but the study results were inconsistent and research on AGA in Asians remains insufficient. This study investigated the relationship between Korean AGA and various cardiovascular risk factors, considering life habits, type of hair loss and sex. We investigated subjects who visited a hospital for public or industrial health medical examinations between October 2012 and December 2014. A questionnaire as well as anthropometric measurements and a blood test were performed. Among the 1884 total subjects, 52.6% had AGA. AGA patients displayed a significantly higher prevalence rate of cardiovascular diseases, smoking rate, fasting glucose and triglyceride, and a significantly lower high-density lipoprotein cholesterol level than did the non-AGA group. The results of the subgroup analysis showed higher prevalence rates of hypertension, stroke, metabolic syndrome and smoking in male AGA patients. The more severe the AGA, the higher the incidences of hypertension, diabetes and smoking were observed. According to the analysis results by BASP classification, the F-type AGA patients displayed a higher body mass index, waist circumference and diastolic blood pressure, and had a significantly higher prevalence rate of hypertension. As a result of the large population-based study, modifications in lifestyle and early screening for cardiovascular disease, as well as hypertension and diabetes, are suggested.

Roles of Testosterone Replacement in Cardiac Ischemia-Reperfusion Injury

Testosterone is an anabolic steroid hormone, which is the major circulating androgen hormone in males. Testosterone levels decreasing below the normal physiological levels lead to a status known as androgen deficiency. Androgen deficiency has been shown to be a major risk factor in the development of several disorders, including obesity, metabolic syndrome, and ischemic heart disease. In the past decades, although several studies from animal models as well as clinical studies demonstrated that testosterone exerted cardioprotection, particularly during ischemia-reperfusion (I/R) injury, other preclinical and clinical studies have shown an inverse relationship between testosterone levels and cardioprotective effects. As a result, the effects of testosterone replacement on the heart remain controversial. In this review, reports regarding the roles of testosterone replacement in the heart following I/R injury are comprehensively summarized and discussed. At present, it may be concluded that chronic testosterone replacement at a physiological dose demonstrated cardioprotective effects, whereas acute testosterone replacement can cause adverse effects in the I/R heart.

Alopecia and its association with coronary heart disease and cardiovascular risk factors: a meta-analysis

BACKGROUND

Alopecia has been associated with an increased risk of coronary heart disease as well as the following risk factors for cardiovascular disease: hyperinsulinaemia, insulin resistance, metabolic syndrome, dyslipidaemia, and hypertension. We performed a meta-analysis to quantitatively determine the level of risk of coronary heart disease and risk factors in individuals with alopecia.

METHODS

A systematic literature search was conducted using several databases. We calculated pooled odds ratios and 95% confidence intervals using a random effects model.

RESULTS

In total, 31 studies comprising 29,254 participants with alopecia were eligible for the meta-analysis and showed that alopecia is associated with an increased risk of coronary heart disease (OR 1.22, 95% CI: 1.07-1.39), hyperinsulinaemia (OR 1.97, 95% CI: 1.20-3.21), insulin resistance (OR 4.88, 95% CI: 2.05-11.64), and metabolic syndrome (OR 4.49, 95% CI: 2.36-8.53). Individuals with alopecia were also shown to be more likely compared to those without alopecia to have higher serum cholesterol levels (OR 1.60, 95% CI: 1.17-2.21), higher serum triglyceride levels (OR 2.07, 95% CI: 1.32-3.25), higher systolic blood pressures (OR 1.73, 95% CI: 1.29-2.33), and higher diastolic blood pressures (OR 1.59, 95% CI: 1.16-2.18).

CONCLUSIONS

Alopecia is associated with an increased risk of coronary heart disease, and there appears to be a dose-response relationship with degree of baldness whereby the greater the severity of alopecia, the greater the risk of coronary heart disease. Alopecia is also associated with an increased risk of hypertension, hyperinsulinaemia, insulin resistance, metabolic syndrome, and having elevated serum total cholesterol and triglyceride levels.

Testosterone and high-sensitive C-reactive protein in coronary artery disease patients awaiting coronary artery bypass graft

Natural androgens inhibit atherosclerosis in men. This study aimed to examine whether testosterone and high-sensitive C-reactive protein differ between patients with coronary artery disease and those without coronary artery disease and to determine the association with the severity of coronary artery disease. Two hundred and six male subjects were recruited. Serum total testosterone and high-sensitive C-reactive protein were estimated. Severity of coronary artery disease was assessed by angiographic scores. Total testosterone level in patients was significantly different from controls (11.4 ± 2.7 vs. 18.1 ± 7.2 nmP = 0.001) and high-sensitive protein level in cases was significantly higher compared to controls (3.37 ± 1.62 mg l(-1) vs. 1.71 ± 0.60 mg l(-1) , P = 0.001). Testosterone levels were not significantly different with vessel (P = 0.592), Leaman (P = 0.694) and Gensini (P = 0.329) score groups, but high-sensitive C-reactive protein showed significant positive correlation among the respective groups (P = 0.005, P = 0.028, P = 0.015). Testosterone was lower, while high-sensitive C-reactive protein was higher in patients compared to controls. Testosterone showed no correlation with the severity of atherosclerosis, but high-sensitive C-reactive protein showed significant positive correlation.

High-normal Glucose Levels in Non-diabetic and Pre-diabetic Men Are Associated with Decreased Testosterone Levels

Background

Testosterone levels are decreased in diabetic patients and recent studies have suggested that high-normal fasting glucose is a risk factor for cardiovascular disease. To further elucidate the relationship between plasma glucose and testosterone, we investigated the association between fasting plasma glucose (FPG) and endogenous sex hormones (serum total testosterone, sex hormone binding globulin, estradiol, and the ratio of testosterone to estradiol) in non-diabetic and pre-diabetic men.

Methods

This study included 388 men (age ≥ 40 years) who visited the health promotion center of a university hospital from May 2007 to August 2008. The subjects were divided into quartiles based on their FPG levels and correlation and multiple linear regression analyses were performed. Q1 (65 mg/dL ≤ FPG < 88 mg/dL), Q2 (88 mg/dL ≤ FPG < 94 mg/dL), Q3 (94 mg/dL ≤ FPG < 100 mg/dL) and Q4 (100 mg/dL ≤ FPG < 126 mg/dL).

Results

FPG was independently, inversely associated with total testosterone in the non-diabetic population after adjusting for age, body mass index, smoking, and alcohol consumption (β = -0.082, P < 0.01). Among the quartiles, subjects in the high-normal FPG groups (Q2, Q3, and Q4 with FPG ≥ 88 mg/dL) had significantly decreased testosterone levels when compared with subjects in the normal FPG group (Q1 with FPG < 88 mg/dL, P < 0.005). Sex hormone binding globulin, estradiol and the ratio of testosterone to estradiol were not correlated with FPG.

Conclusion

Our study indicates that high-normal fasting glucose levels are associated with decreased testosterone levels in non-diabetic and pre-diabetic men.

Metabolic syndrome, adipokines and hormonal factors in pharmacologically untreated adult elderly subjects from the Brisighella Heart Study historical cohort

OBJECTIVE

Our aim was to evaluate the relation of the sex hormone pattern and the serum level of the main adipokines with metabolic syndrome (MS) and its components in a cohort of pharmacologically untreated adult elderly subjects.

METHODS

From the historical cohort of the Brisighella Heart Study we selected 199 adult healthy subjects aged 62.5 ± 12.4 years. Men and women included in the age class subgroups were matched for BMI, waist circumference, blood pressure, heart rate, fasting plasma glucose, and plasma lipids. In these subjects we measured leptin, adiponectin, ghrelin, testosterone, estrone, and deydroepiandrosterone sulphate.

RESULTS

Men without MS had significantly lower leptin/adiponectin ratio than men with MS. Women without MS had a lower leptin level and leptin/adiponectin ratio than women with MS, but had significantly higher adiponectin, estrone, and deydroepiandrosterone levels. In men, the leptin/adiponectin ratio is the main factor associated with MS diagnosis (OR 3.36, 95% CI 1.40-8.08), while in women adiponectin alone appears to be a protective factor (OR 0.87, 95% CI 0.79-0.95).

CONCLUSION

In a sample of pharmacologically untreated adult elderly subjects, leptin/adiponectin ratio seems to be the factor that is more strongly associated with MS (especially in men) and its components, though this is true to a different degree in men and women.

Hypogonadism as a risk factor for cardiovascular mortality in men: a meta-analytic study

OBJECTIVE

To verify whether hypogonadism represents a risk factor for cardiovascular (CV) morbidity and mortality and to verify whether testosterone replacement therapy (TRT) improves CV parameters in subjects with known CV diseases (CVDs).

DESIGN

Meta-analysis.

METHODS

An extensive Medline search was performed using the following words 'testosterone, CVD, and males'. The search was restricted to data from January 1, 1969, up to January 1, 2011.

RESULTS

Of the 1178 retrieved articles, 70 were included in the study. Among cross-sectional studies, patients with CVD have significantly lower testosterone and higher 17-β estradiol (E(2)) levels. Conversely, no difference was observed for DHEAS. The association between low testosterone and high E(2) levels with CVD was confirmed in a logistic regression model, after adjusting for age and body mass index (hazard ratio (HR)=0.763 (0.744-0.783) and HR=1.015 (1.014-1.017), respectively, for each increment of total testosterone and E(2) levels; both P<0.0001). Longitudinal studies showed that baseline testosterone level was significantly lower among patients with incident overall- and CV-related mortality, in comparison with controls. Conversely, we did not observe any difference in the baseline testosterone and E(2) levels between case and controls for incident CVD. Finally, TRT was positively associated with a significant increase in treadmill test duration and time to 1 mm ST segment depression.

CONCLUSIONS

Lower testosterone and higher E(2) levels correlate with increased risk of CVD and CV mortality. TRT in hypogonadism moderates metabolic components associated with CV risk. Whether low testosterone is just an association with CV risk, or an actual cause-effect relationship, awaits further studies.

Endogenous oestradiol but not testosterone is related to coronary artery disease in men

OBJECTIVES

Men die of coronary artery disease (CAD) more often than women. There is evidence that testosterone either is neutral or has a beneficial effect on male cardiovascular disease. The role of oestrogens in male CAD has been less studied. This study was carried out with the purpose of evaluating the relationship between sex hormone levels and CAD.

DESIGN

Case-control study.

PARTICIPANTS

Men (aged 40-70) submitted to coronary angiography. A 70% occlusion of at least one major coronary artery defined the cases; subjects with ≤ 50% occlusion constituted the control group.

MEASUREMENTS

Blood samples were collected for total testosterone (TT), oestradiol, luteinizing hormone, follicle-stimulating hormone, sex hormone-binding globulin, lipid profile and albumin measurements. Bioavailable and free testosterone, free androgen index (FAI) and free oestrogen index (FEI) were calculated. Oestradiol and TT levels were examined as terciles, based on the whole study population.

RESULTS

Of the 140 patients included, 72 were cases and 68 were controls. The baseline characteristics of the two groups were similar, except for the older age and lower LDL-C in the cases. Oestradiol and FEI but not total, bioavailable and free testosterone and FAI correlated positively with CAD. After adjustments for potential confounders, oestradiol remained statistically significant. The prevalence of CAD was significantly higher in the 3rd than in the 1st tercile of oestradiol.

CONCLUSION

In this study, men with CAD had higher oestradiol and FEI levels. Additional studies are needed to clarify the direction of causality and possible underlying mechanisms.

Vitamin E dose-dependently reduces aortic fatty lesion formation in orchidectomized aged rats

BACKGROUND AND AIMS

Although the cardioprotective effects of supplemental doses of vitamin E have been investigated in several conditions, its role in gonadectomy- induced fatty lesion formation is unclear. The present study was designed to examine the efficacy of vitamin E in a dose-dependent manner on indices of oxidative stress and in preventing the formation of aortic fatty lesions in orchidectomized (Orx) aged rats.

METHODS

Forty 12-month old male Sprague-Dawley rats were either sham-operated (Sham) or Orx and fed a semi-purified control diet for 120 days. Thereafter, rats were assigned to four treatment groups (n=10): Sham and one Orx group received 75 IU vitamin E and served as controls, and the other two Orx groups received either 250 or 500 IU vitamin E per kg diet for 90 days.

RESULTS

Vitamin E at the highest dose (500 IU) was able to lower serum total cholesterol by 16% and significantly increase superoxide dismutase by 9% compared to Orx controls. Similarly, this dose was able to significantly reduce the development of atherosclerotic lesion formation and aortic fatty streak area by 93% compared to Orx controls.

CONCLUSIONS

The findings of this study suggest that dietary vitamin E supplementation in Orx aged rats provide anti-atherogenic effects, in part, due to vitamin E's antioxidative properties. Clinical studies are needed to confirm whether supplemental doses of vitamin E can prevent the development of atherosclerosis in older men particularly with low testosterone level.

Adipokines and sexual hormones associated with the components of the metabolic syndrome in pharmacologically untreated subjects: data from the brisighella heart study

We evaluated the association of the sex hormone pattern and the serum level of the main adipokines to metabolic syndrome (MS) and its components in 199 pharmacologically untreated subjects. Men and women included in the age-class subgroups were matched for body mass index, waist circumference, blood pressure, heart rate, fasting plasma glucose, and plasma lipids. Men without MS had significantly lower leptin/adiponectin ratio than men with MS. Women without MS had lower leptin and leptin/adiponectin ratio than women with MS but had significantly higher adiponectin, estrone, and dehydroepiandrosterone levels. In men, the leptin/adiponectin ratio is the main factor associated to MS diagnosis (OR: 3.36, 95% CI 1.40-8.08), while in women adiponectin alone appears to be a protective factor (OR: 0.87, 95% CI 0.79-0.95). In conclusion, in a sample of pharmacologically untreated subjects, leptin/adiponectin ratio seems to be the factor more strongly associated to MS and its components.

Endogenous testosterone attenuates neointima formation after moderate coronary balloon injury in male swine

AIMS

Previous studies from our laboratory have demonstrated that testosterone increases coronary smooth muscle protein kinase C delta (PKC delta) both in vivo and in vitro and inhibits coronary smooth muscle proliferation by inducing G(0)/G(1) cell cycle arrest in a PKC delta-dependent manner. The purpose of the present study was to determine whether endogenous testosterone limits coronary neointima (NI) formation in a porcine model of post-angioplasty restenosis.

METHODS AND RESULTS

Sexually mature, male Yucatan miniature swine were either left intact (IM), castrated (CM), or castrated with testosterone replacement (CMT; Androgel, 10 mg/day). Angioplasty was performed in both the left anterior descending and left circumflex coronary arteries with balloon catheter overinflation to induce either moderate (1.25-1.3 x diameter; 3 x 30 s) or severe (1.4x diameter; 3 x 30 s) injury, and animals were allowed to recover for either 10 or 28 days. Injured coronary sections were dissected, fixed, stained (Verheoff-Van Gieson, Ki67, PKC delta, p27), and analysed. Vessels without internal elastic laminal rupture were excluded. Following moderate injury, intimal area, intima-to-media ratio (I/M), and I/M normalized to rupture index (RI) were increased in CM compared with IM and CMT. RI, medial area, and intimal/medial thickness (IMT) were not different between groups. NI formation was inversely related to serum testosterone concentration. Conversely, following severe injury, there were no significant differences between the groups. Testosterone inhibited proliferation and stimulated PKC delta and p27(kip1) expression during NI formation (10 days post-injury).

CONCLUSION

These findings demonstrate that endogenous testosterone limits coronary NI formation in male swine and provides support for a protective role for testosterone in coronary vasculoproliferative diseases, such as restenosis and atherosclerosis.

Is androgenetic alopecia a risk for atherosclerosis?

BACKGROUND

Several studies have demonstrated the presence of an association between androgenetic alopecia (AGA) and cardiovascular disease. The aim of this study was to evaluate subclinical atherosclerosis in patients with AGA and healthy controls by the incorporation of carotid intima-media thickness (IMT) and high-sensitive C-reactive protein (hs-CRP) along with echocardiography (ECHO) and exercise electrocardiography (ExECG).

METHODS

We performed a case-control study in 50 male patients with AGA and 31 age-matched healthy male controls with normal hair status. Both the AGA patients and controls with a history of diabetes mellitus, cigarette smoking, hypertension, cardiovascular or cerebrovascular disease, and renal failure were excluded. AGA was classified according to the Hamilton-Norwood scale. Serum lipids, serum hs-CRP, total testosterone, and dehydroepiandrosterone sulphate were examined in all study subjects. Carotid ultrasonography was used to measure the IMT of the common carotid arteries (CCA). ECHO and ExECG were performed in all subjects.

RESULTS

IMT of the CCA was found to be significantly higher in patients with severe vertex pattern AGA when compared to patients with other patterns of AGA and healthy controls (P < 0.05). Hs-CRP in patients with any group of AGA was not significantly different from those healthy controls (P > 0.05). ECHO showed that cardiac structural and functional measures were in normal ranges. ExECG was also normal in all subjects.

CONCLUSION

Severe vertex pattern AGA should be considered to have an increased risk of subclinical atherosclerosis. For this reason, CCA IMT measurement can be recommended as a non-invasive and early diagnostic method.

Polymorphisms of steroid 5-alpha-reductase type I (SRD5A1) gene are associated to peripheral arterial disease

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.

Prevalence of Metabolic Syndrome in Patients With Clinically Advanced Peripheral Vascular Disease

The aim of this cross-sectional study was to determine the prevalence of metabolic syndrome (MetS) and its components among 100 patients with progressive peripheral arterial disease (PAD) referred for diagnostic angiography in preparation for a revascularization procedure. The prevalence of MetS was more than 95%. Diabetes mellitus was the most prevalent component followed by hypertension and low high-density lipoprotein. Almost half the patients aggregated in the highest metabolic score category. A direct relationship was identified between the number of MetS components and serum uric acid ( P = .001) and C-reactive protein ( P = .826), whereas an inverse relationship was seen between the clustering of components and androgen levels in men ( P < .001). For PAD, which could have a benign clinical course, early screening for MetS might identify those at greater risk of failing conservative therapy and progressing to a more aggressive atherosclerotic disease typically associated with high morbidity and mortality.

The many faces of testosterone

Testosterone is more than a “male sex hormone”. It is an important contributor to the robust metabolic functioning of multiple bodily systems. The abuse of anabolic steroids by athletes over the years has been one of the major detractors from the investigation and treatment of clinical states that could be caused by or related to male hypogonadism. The unwarranted fear that testosterone therapy would induce prostate cancer has also deterred physicians form pursuing more aggressively the possibility of hypogonadism in symptomatic male patients. In addition to these two mythologies, many physicians believe that testosterone is bad for the male heart. The classical anabolic agents, 17-alkylated steroids, are, indeed, potentially harmful to the liver, to insulin action to lipid metabolism. These substances, however, are not testosterone, which has none of these adverse effects. The current evidence, in fact, strongly suggests that testosterone may be cardioprotective. There is virtually no evidence to implicate testosterone as a cause of prostate cancer. It may exacerbate an existing prostate cancer, although the evidence is flimsy, but it does not likely cause the cancer in the first place. Testosterone has stimulatory effects on bones, muscles, erythropoietin, libido, mood and cognition centres in the brain, penile erection. It is reduced in metabolic syndrome and diabetes and therapy with testosterone in these conditions may provide amelioration by lowering LDL cholesterol, blood sugar, glycated hemoglobin and insulin resistance. The best measure is bio-available testosterone which is the fraction of testosterone not bound to sex hormone binding globulin. Several forms of testosterone administration are available making compliance much less of an issue with testosterone replacement therapy.

PKCδ mediates anti-proliferative, pro-apoptic effects of testosterone on coronary smooth muscle

Sex hormone status has emerged as an important modulator of coronary physiology and cardiovascular disease risk in both males and females. Our previous studies have demonstrated that testosterone increases protein kinase C (PKC) δ expression and activity in coronary smooth muscle (CSMC). Because PKCδ has been implicated in regulation of proliferation and apoptosis in other cell types, we sought to determine if testosterone modulates CSMC proliferation and/or apoptosis through PKCδ. Porcine CSMC cultures (passages 2–6) from castrated males were treated with testosterone for 24 h. Testosterone (20 and 100 nM) decreased [3H]thymidine incorporation in proliferating CSMC to 59 ± 5.3 and 33.1 ± 4.5% of control. Flow cytometric analysis demonstrated that testosterone induced G1arrest in CSMC with a concomitant reduction in the S phase cells. Testosterone reduced protein levels of cyclins D1and E and phosphorylation of retinoblastoma protein while elevating levels of p21cip1and p27kip1. There were no significant differences in the levels of cyclins D3, CDK2, CDK4, or CDK6. Testosterone significantly reduced kinase activity of CDK2 and -6, but not CDK4, -7, or -1. PKCδ small interfering RNA (siRNA) prevented testosterone-mediated G1arrest, p21cip1upregulation, and cyclin D1and E downregulation. Furthermore, testosterone increased CSMC apoptosis in a dose-dependent manner, which was blocked by either PKCδ siRNA or caspase 3 inhibition. These findings demonstrate that the anti-proliferative, pro-apoptotic effects of testosterone on CSMCs are substantially mediated by PKCδ.

Testosterone deficiency impairs glucose oxidation through defective insulin and its receptor gene expression in target tissues of adult male rats

Testosterone and insulin interact in their actions on target tissues. Most of the studies that address this issue have focused on the physiological concentration of testosterone, which maintains normal insulin sensitivity but has deleterious effects on the same when the concentration of testosterone is out of this range. However, molecular basis of the action of testosterone in the early step of insulin action is not known. The present study has been designed to assess the impact of testosterone on insulin receptor gene expression and glucose oxidation in target tissues of adult male rat. Adult male albino rats were orchidectomized and supplemented with testosterone (100 microg/100 g b. wt., twice daily) for 15 days from the 11th day of post orchidectomy. On the day after the last treatment, animals were euthanized and blood was collected for the assay of plasma glucose, serum testosterone and insulin. Skeletal muscles, such as gracilis and quadriceps, liver and adipose tissue were dissected out and used for the assay of various parameters such as insulin receptor concentration, insulin receptor mRNA level and glucose oxidation. Testosterone deprivation due to orchidectomy decreased serum insulin concentration. In addition to this, insulin receptor number and its mRNA level and glucose oxidation in target tissues were significantly decreased (p<0.05) when compared to control. However, testosterone replacement in orchidectomized rats restored all these parameters to control level. It is concluded from this study that testosterone deficiency-induced defective glucose oxidation in skeletal muscles, liver and adipose tissue is mediated through impaired expression of insulin and its receptor gene.

Orange pulp improves antioxidant status and suppresses lipid peroxidation in orchidectomized male rats

OBJECTIVE

Oxidative stress is linked to an increased incidence of cardiovascular disease in men. The objective of this research was to delineate whether daily consumption of orange pulp (OP) modifies antioxidant status and decreases cardiovascular risk factors in orchidectomized rats.

METHODS

In the present study, 45 1-y-old male rats were randomized to a sham-control group (n = 9) and an orchidectomized group (n = 36). The orchidectomized group was equally divided among the following five treatments: orchidectomy (ORX), ORX + 2.5% OP, ORX + 5% OP, and ORX + 10% OP. One hundred twenty days after the study began, all rats were sacrificed and plasma was harvested for its antioxidant status, C-reactive protein (CRP), lipid profile, and indices of peroxidation. Superoxide dismutase (SOD) and catalase activities in the liver were also monitored.

RESULTS

Orchidectomy decreased (P < 0.05) plasma levels of antioxidant, SOD, catalase, and CRP and increased (P < 0.05) plasma levels of malondialdehyde, nitrite, and lipid profile compared with the sham-control group. In contrast to ORX, ORX + OP increased (P < 0.05) plasma antioxidant, dose-dependently increased (P < 0.05) SOD and catalase, decreased (P < 0.05) plasma malondialdehyde, nitrite, cholesterol, and triacylglycerol concentrations in the liver; and had no effect (P > 0.1) on plasma CRP or lipid profiles.

CONCLUSION

The beneficial effect of eating an orange is demonstrated by the increasing antioxidant status and by the decreasing peroxidation independent of plasma triacylglycerol, cholesterol, or CRP concentrations.

Why men's hearts break: cardiovascular effects of sex steroids

Coronary artery disease (CAD) mortality differs in men and women, leading to the speculation that differences in sex steroids contribute to risk. Controlled clinical trials have shown that estrogen replacement is not cardioprotective in certain women, and recent cross-sectional studies associate low testosterone with a greater incidence of CAD in men. Testosterone has demonstrated effects on insulin resistance, obesity, myocardium, coagulation, inflammation, vasodilation, and endothelial function. Imbalance of sex steroids contributes to adverse cardiac effects in men.

Experimental arterial thrombosis regulated by androgen and its receptor via modulation of platelet activation

OBJECTIVES

The aim of our study is to elucidate whether experimental arterial thrombosis is regulated by physiological doses of androgen and its receptor via modulation of platelet activation.

METHODS

Surgical castration was performed in male rats and ferric chloride (FeCl(3)), as a stimulator, induced the experimental arterial thrombosis. Testosterone was measured directly by chemiluminescent immunoassay on the Bayer ADVIA Centaur analyzer. Dihydrotestosterone (DHT) was determined by ELISA using a commercially available kit. A platelet aggregometer was used to assess aggregation, and a platelet adherometer was used to measure adhesion. The contents of TXB(2) and 6-Keto-PGF(1alpha) were assayed by radio-immunoassay using commercially available kits.

RESULTS

Our data showed that DHT replaced restored circulating DHT of castrated rats to physiological levels, without being altered by treatment with flutamide. Castration caused significant increases in the thrombus area and weight in castrated rats as compared with control group. In PRP diluted with autologous PPP, ADP-induced platelet aggregation rate was only 9.10%. However, in PRP diluted with Tyrode's buffer, 1 microM ADP-induced platelet aggregation rate rose to 63.65%. In PRP diluted with Tyrode's buffer, and pretreated with DHT (1 nM, 2 nM), ADP-induced platelet aggregation was significantly lowered again. Platelet aggregation in PRP diluted with autologous PPP was enhanced in castrated rats as compared with sham-operated rats, and DHT (2 nM) replacement suppressed platelet aggregation in castrated PRP to the level similar to that of sham-operated rats. However, presence of flutamide (3 microM) significantly increased platelet aggregation in PRP diluted with autologous PPP or Tyrode's buffer. DHT (2 nM) replacement significantly inhibited the ADP-induced platelet adhesion. However, presence of flutamide (3 microM) increased ADP-induced platelet adhesion again. DHT replacement obviously reduced the ratio of TXB(2) to 6-keto-PGF(1alpha) in castrated rats. However, administration of flutamide and DHT to castrated rats caused an increase in the ratio of TxB(2) to 6-keto-PGF1alpha.

CONCLUSION

Inhibition of experimental arterial thrombosis by androgen at physiological doses and its receptor is mediated via modulation of platelet activation.

Cranberry Juice Increases Antioxidant Status Without Affecting Cholesterol Homeostasis in Orchidectomized Rats

Oxidative stress and hypogonadism are linked to the increased incidence of cardiovascular disease in males. The objective of this research was to delineate whether drinking cranberry juice for 4 months affects antioxidant capacity and lipid profile in orchidectomized rats. Thirty-two 1-year-old male rats were randomized to two groups: a sham-control group (n = 8) and an orchidectomized group (n = 24). The orchidectomized group was divided into three groups of eight and assigned to one of the following treatments: orchidectomy, orchidectomy plus 27% cranberry juice, and orchidectomy plus 45% cranberry juice. At 120 days after initiation of the study, all rats were killed, blood was collected, and plasma was harvested for total antioxidant status, malondialdehyde, nitrate + nitrite, and superoxide dismutase (SOD) activity in liver, and concentrations of cholesterol and triglyceride in liver and in plasma. Orchidectomy depressed (P < .05) plasma antioxidant capacity and SOD activity, elevated (P < .05) nitrate + nitrite and malondialdehyde in plasma, and increased (P < .05) triglyceride and cholesterol values in liver and in plasma. Cranberry juice increased (P < .05) plasma antioxidant capacity and SOD activity and reduced (P < .05) nitrate + nitrite and malondialdehyde concentrations. Drinking cranberry juice did not affect cholesterol concentrations in liver and in plasma. Triglyceride concentration in plasma of orchidectomized rats that were drinking cranberry juice increased (P < .05), but its concentration in liver decreased (P < .05) to the level of shams. The protective effect of cranberry juice from oxidative damage may be mediated by a decrease in nitrate + nitrite and dose-dependent decrease in peroxidation.

Citrus juice modulates antioxidant enzymes and lipid profiles in orchidectomized rats

Oxidative stress and hypogonadism are two factors linked to the increased incidence of cardiovascular disease in males. Eating fruits and vegetables is known to reduce the incidences of oxidative stress. The objective of this research was to delineate whether drinking daily squeezed orange juice (OJ) or grapefruit juice (GJ) modulates oxidative stress and antioxidant enzymes while impacting cardiovascular risk factors in hypogonad male rats. In the present study, 36 1-year-old male rats were equally divided among the following four treatments: sham (control), orchidectomized (ORX), ORX + OJ, and ORX + GJ. After 60 days of drinking OJ or GJ, antioxidant capacity, cholesterol, and triglycerides in serum and superoxide dismutase (SOD), catalase (CAT), cholesterol, and triglycerides in liver were evaluated. Serum antioxidant capacity and SOD and CAT activities decreased (P < .05), while serum cholesterol and liver triglycerides increased (P < .05) in the ORX group compared with the sham group. In contrast to the ORX group, drinking OJ was ineffective while drinking GJ decreased (P < .05) cholesterol concentration in liver and in serum. Nevertheless, OJ and GJ decreased (P < .05) triglyceride concentration in liver and increased (P < .05) serum antioxidant capacity and SOD and CAT activities compared with the ORX group. In conclusion, drinking OJ or GJ prevented oxidative stress by enhancing total antioxidant capacity and elevating liver antioxidant enzymes while modulating cardiovascular risk factors.

Andropause: a quality-of-life issue in older males

Testosterone deficiency occurs commonly in men as they grow older. This deficiency often is associated with a decline in sexual activity and a loss of muscle mass. Testosterone replacement can reverse many of these effects. At present, no ideal form of testosterone replacement is available. Like the phosphodiesterase-5 inhibitors, testosterone replacement in older men is a quality of life issue.

Sex dimorphism in cardiac pathophysiology: experimental findings, hormonal mechanisms, and molecular mechanisms

The higher cardiovascular risk in men and post-menopausal women implies a protective action of estrogen. A large number of experimental studies have provided strong support to this concept. However, the recent clinical trials with negative outcomes regarding hormone replacement therapy call for "post hoc" reassessment of existing information, models, and research strategies as well as a summary of recent findings. Sex steroid hormones, in particular estrogen, regulate numerous processes that are related to the development and progression of cardiovascular disease through a variety of signaling pathways. Use of genetically modified models has resulted in interesting information on diverse actions mediated by steroid receptors. By focusing on experimental findings, we have reviewed hormonal, cellular, and signaling mechanisms responsible for sex dimorphism and actions of hormone replacement therapy and addressed current limitations and future directions of experimental research.

PKCδ Mediates Testosterone-induced Increases in Coronary Smooth Muscle Cav1.2

Sex hormones have emerged as important modulators of cardiovascular physiology and pathophysiology. Our previous studies demonstrated that testosterone increases expression and activity of L-type, voltage-gated calcium channels (Cav1.2) in coronary arteries of males. The purpose of the present study was to determine whether testosterone (T) alters coronary protein kinase C delta (PKCdelta) expression and whether PKCdelta plays a role in coronary Cav1.2 expression. For in vitro studies, porcine right coronary arteries (RCA) and post-confluent (passages 3-6) 5-day, serum-restricted coronary smooth muscle cell cultures (CSMC) were incubated in the presence and absence of T or dihydrotestosterone (10 and 100 nm) for 18 h at 37 degrees C in a humidified chamber. For sex and endogenous testosterone-dependent effects, RCA were obtained from intact males, castrated males, castrated males with T replacement, and intact females. In vitro T and dihydrotestosterone caused an approximately 2-3-fold increase in PKCdelta protein levels, approximately 1.5-2-fold increase in PKCdelta kinase activity, and localization of PKCdelta toward the plasma membrane and nuclear envelope. PKCdelta protein levels were higher in coronary arteries of intact males compared with intact females. Elimination of endogenous testosterone by castration reduced RCA PKCdelta protein levels, an effect partially (approximately 45%) reversed by exogenous T (castrated males with T replacement). In CSMC, PKC inhibition with either the general PKC inhibitor, cheylerythrine, or the putative PKCdelta inhibitor, rottlerin, completely inhibited the T-mediated increase in coronary Cav1.2 protein levels. Conversely, Go6976, a conventional PKC isoform inhibitor, failed to inhibit T-induced increases in coronary Cav1.2 protein levels. PKCdelta short interference RNA completely blocked T-induced increases in Cav1.2 protein levels in CSMC. These results demonstrate for the first time that 1) endogenous T is a primary modulator of coronary PKCdelta protein and activity in males and 2) T increases Cav1.2 protein expression in a PKCdelta-dependent manner.

Age-related changes in testosterone and SHBG among Turkana males

To determine age-related changes in biologically available testosterone (T) among men in a subsistence society and their relationship to energetic status, T, sex hormone binding globulin (SHBG) and anthropometric measures were compared among nomadic and settled Turkana pastoralists of northern Kenya. Hormonal measures were available for 104 nomadic men and 72 settled men, estimated ages 20-90 years. Comparison of the two subpopulations revealed significantly higher blood T (32.7+/- 15.1 vs. 23.4+/-15.2 nM) and SHBG (53.8+/- 19.5 vs. 39.7+/- 20.nM) but not free testosterone index (FTI) (65.6+/- 39.3 vs.66.3+/- 45.9) among the nomads. Total blood T did not exhibit a significant linear decline with age in either subgroup, while SHBG values showed a significant linear increase among the nomads. When controlled for energetic status, FTI showed a significant decrease with age among the nomads, but not the settled males. Total blood T was negatively associated with waist circumference among the nomads, but not the settled males. FTI showed a marginally significant negative association with waist circumference, suprailiac skinfold, and % body fat among the nomads but no associations with body composition among the settled group. These results add additional evidence that T is related to energetic status under conditions of negative energy balance and suggest that cross-population variation in the slope of age-related declines in free serum T and salivary T may be related to energetic status through the effects of SHBG.