Relation of serum testosterone levels to high density lipoprotein cholesterol and other characteristics in men

The Levels of Cortisol and Selected Biochemical Parameters in Red Deer Harvested during Stalking Hunts

As a reactive species, the red deer is sensitive to both negative exogenous and endogenous stimuli. An intensive hunting period may have a particularly negative impact on game animals. The aim of this study was to determine the plasma cortisol level and biochemical parameters in 25 wild red deer (Cervus elaphus) harvested during stalking hunts in correlation with the sex and age of the animals. The mean cortisol concentrations in the stags and hinds analyzed in this study were similar (20.2 and 21.5 ng/mL, respectively). Higher HDL cholesterol values were found in the blood of the hinds than in stags (p < 0.05). Similarly, the mean levels of LDL cholesterol, lactate dehydrogenase, and alanine aminotransferase were higher by 21%, 16%, and 42%, respectively, in the blood of the hinds. In contrast, the levels of alkaline phosphatase, bilirubin, and aspartate aminotransferase were higher in the stags (by 30%, 49%, and 36%, respectively). There was a negative correlation of the cortisol concentration with urea and bilirubin and a positive correlation between cortisol and aspartate aminotransferase in the stags (p < 0.05). In turn, a negative correlation was found between the cortisol and urea levels in the hinds (p < 0.05). In summary, the stress caused by stalking hunts and the characteristic behavior of red deer during the mating season had an impact on chosen biochemical parameters. The increased concentration of cortisol resulted in a decrease in the carcass mass, which may lead to the deterioration of the physical condition of animals on hunting grounds.

Plasma testosterone is associated with Framingham risk score

INTRODUCTION

The Framingham risk score predicts a patient's 10-year risk of developing cardiovascular disease. Many risk factors included in its calculation influence or are influenced by circulating testosterone. To investigate the possible association between testosterone and cardiovascular risk, as defined by the Framingham score, a Veterans Affairs (VA) database was analyzed.

METHODS

A retrospective chart review was performed. Inclusion criteria were male sex and age ≥ 20 years. Exclusion criteria included pre-existing cardiovascular disease, stroke, and diabetes. Data were collected on veterans who had total plasma testosterone checked in the year 2008.

RESULTS

The study included 1,479 patients (mean age 61 years). Framingham score was negatively associated with both total testosterone (p < 0.0001) and free testosterone (p = 0.0003). There was a positive association between total testosterone and high-density lipoprotein and negative associations between total testosterone and body mass index (BMI), total cholesterol, triglycerides, and blood pressure medication use. Free testosterone was positively associated with total cholesterol, low-density lipoprotein, and current smoking status and negatively associated with age, BMI, and blood pressure medication use. The BMI was not associated with Framingham score.

CONCLUSIONS

Lower plasma testosterone may suggest the presence of cardiovascular risk factors and potentially increased risk for heart disease.

Association of serum cholesterol and cholesterol-lowering drug use with serum sex steroid hormones in men in NHANES III

PURPOSE

Low cholesterol levels and statin drugs may protect against prostate cancer with a worse prognosis. Their protective mechanism is unknown, but has been hypothesized to be related to cholesterol's role as a sex steroid hormone precursor. We evaluated whether serum testosterone and estradiol differ by cholesterol or cholesterol-lowering drug use.

MATERIALS AND METHODS

Testosterone and estradiol were measured for 1,457 male participants in the Third National Health and Nutrition Examination Survey. We estimated multivariable-adjusted geometric mean hormone concentration by quintiles of cholesterol concentration and by cholesterol-lowering drugs use.

RESULTS

Across quintiles of cholesterol, testosterone level did not differ (mean, 95% confidence interval (CI); Q1: 5.25, 5.02-5.49, Q5: 5.05, 4.76-5.37 ng/ml; p-trend = 0.32), whereas estradiol levels were lower (Q1: 38.7, 36.9-40.5; Q5: 33.1, 31.8-34.5 pg/ml; p-trend < 0.0001). Neither testosterone (no: 5.12, 4.94-5.30, yes: 4.91, 4.33-5.57 ng/ml, p = 0.57) nor estradiol (no: 35.9, 34.8-37.1; yes: 33.9, 29.4-39.2 pg/ml; p = 0.39) differed by cholesterol-lowering drugs use.

CONCLUSION

Testosterone did not differ by cholesterol or cholesterol-lowering drug use. Estradiol was lower in men with higher cholesterol, but did not differ by cholesterol-lowering drug use. Our results suggest that the lower risk of advanced prostate cancer among statin users is not readily explained by a cholesterol-mediated effect of statins on sex hormone levels.

Obstructive sleep apnoea, cigarette smoking and serum testosterone levels in a male sleep clinic cohort

This study evaluated the impact of obstructive sleep apnoea (OSA) and smoking on total serum testosterone levels in 96 men (mean age 43.3 years; range 25 - 60 years) attending a sleep clinic. Fifty-five men (57.3%) had OSA, defined as an apnoea-hypopnoea index of > or = 15 events/h, recorded during overnight polysomnography, and 42 (43.8%) were current smokers. Mean serum total testosterone levels were significantly lower in OSA subjects (3.4 ng/ml) than in non-OSA subjects (3.9 ng/ml), whereas no significant difference was observed between current smokers and nonsmokers. In a multiple linear regression analysis, serum testosterone was negatively correlated with body mass index and the apnoea-hypopnoea index, but not with age and pack-years of smoking. Our results support previous observations regarding testosterone levels in men with OSA, but, contrary to some earlier reports, there was no positive relationship between smoking and total testosterone in the present cohort.

Cardiovascular issues in hypogonadism and testosterone therapy

A systematic literature search was conducted to investigate the cardiovascular issues related to hypogonadism and testosterone therapy. Vascular cells contain sex steroid hormone receptors. Testosterone can exert effects on the vascular wall, either by itself or through aromatization as estrogen. Hypogonadism is associated with central obesity; insulin resistance; low levels of high-density lipoprotein (HDL); high cholesterol levels; and high levels of low-density lipoprotein (LDL), triglycerides, fibrinogen, and plasminogen activator-1. Some observational studies show a correlation between low testosterone and cardiovascular disease (CVD), and others show no correlation. Interventional studies do not reveal a direct long-term relation between testosterone therapy and CVD. Short-term data suggest cardiovascular benefits of testosterone. Testosterone therapy has beneficial and deleterious effects on cardiovascular risk factors. It improves insulin sensitivity, central obesity, and lowers total cholesterol and LDL. In some studies, testosterone therapy has an HDL-lowering effect, and in other studies this effect is insignificant. This should not be assumed to be atherogenic because it might be related to reverse cholesterol transport and effects on the HDL(3) subfraction. The cardiovascular effects of testosterone therapy may be neutral to beneficial. There is no contraindication for testosterone therapy in men with CVD and diagnosed hypogonadism with or without erectile dysfunction. Caution should be exercised regarding occasional increases in hematocrit levels, especially in patients with congestive heart failure. Conversely, evidence does not support testosterone therapy in aging men for the purpose of cardiovascular benefit, despite claims to this effect. Further research on the cardiovascular benefits and risks of testosterone is strongly recommended.

Androgen levels in older men who have or who are at risk of acquiring HIV infection

OBJECTIVE

To determine the prevalence of, risk factors for, and clinical manifestations of low androgen levels in older men who have or who are at risk of acquiring human immunodeficiency virus (HIV) infection, we performed a cross-sectional analysis of an observational cohort of men aged > or =49 years old.

METHODS

A standardized interview (regarding demographic characteristics, behaviors, and medical history) was performed, and body mass index, HIV serologic data, CD4+ cell count, the presence of hepatitis C virus (HCV) markers, and serum testosterone and human sex-binding hormone levels were determined. Factors associated with androgen levels were assessed using logistic regression models.

RESULTS

Among 502 men (age, 49-81 years) who were not taking androgens, 54% had total testosterone levels of <300 ng/dL. Low androgen levels were associated with injection drug use, HCV infection, high body mass index, and use of psychotropic medications (P<.05); black race was associated with higher androgen levels. Only among men who reported having sex with men was low testosterone level associated with HIV infection (adjusted odds ratio [OR(adj)] for total testosterone level of <300 ng/dL, 5.1; 95% confidence interval [CI], 1.2-22.4), but among all HIV-seropositive men, HIV load of >10,000 copies/mL was associated with a testosterone level of <200 ng/dL (OR(adj), 2.1; 95% CI, 1.1-4.3; P=.03). On univariate analysis, low androgen levels were associated with decreased interest in sex, depressive symptoms, loss of concentration/memory, difficulty sleeping, osteopenia, and poorer subjective health (P<.05).

CONCLUSIONS

Most older men at risk for HIV infection have low androgen levels. Injection drug use, high body mass index, HCV infection, and use of psychotropic medications are associated with low androgen levels, and low androgen levels are associated with symptoms of hypogonadism.

The decline of androgen levels in elderly men and its clinical and therapeutic implications

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.

Gonadal dysfunction in systemic diseases

Gonadal function is significantly affected in many acute and chronic systemic diseases. As the function of the testes and the ovaries is determined by the integrity of the hypothalamic-pituitary-gonadal axis, it is obvious that a systemic disease may affect one or more levels of the axis in such a manner that the gonadal dysfunction may have various clinical and laboratory manifestations. In this brief review, the most common disturbances seen in the main systemic diseases will be discussed.

Effect of aromatase inhibition on lipids and inflammatory markers of cardiovascular disease in elderly men with low testosterone levels

OBJECTIVE

Although androgen replacement has been shown to have beneficial effects in hypogonadal men, there is concern that androgens may deleteriously affect cardiovascular risk in elderly men.

DESIGN

Anastrozole is an oral aromatase inhibitor that normalizes serum testosterone levels and decreases oestradiol levels modestly in elderly men with mild hypogonadism. Thirty-seven elderly hypogonadal men were randomized to receive either anastrozole 1 mg daily (n = 12), anastrozole 1 mg twice weekly (n = 11), or daily placebo (n = 14) for 12 weeks in a double-blind fashion.

PATIENTS

Men aged 62-74 years with mild hypogonadism defined by testosterone levels less than 350 ng/dl.

MEASUREMENTS

Serum levels of fasting lipids, C-reactive protein (CRP), interleukin-6 (IL-6), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and homeostatic model assessment (HOMA) scores were measured at 4-week intervals.

RESULTS

Treatment with anastrozole did not significantly affect fasting lipids, inflammatory markers (IL-6, CRP), adhesion molecules (ICAM-1, VCAM-1) or insulin sensitivity (HOMA). There was, however, a positive correlation between changes in serum triglycerides and changes in serum oestradiol levels (P = 0.04).

CONCLUSIONS

While short-term administration of anastrozole is an effective method of normalizing serum testosterone levels in elderly men with mild hypogonadism, it does not appear to adversely affect lipid profiles, inflammatory markers of cardiovascular risk or insulin resistance.

Androgens and coronary artery disease

A significant and independent association between endogenous testosterone (T) levels and coronary events in men and women has not been confirmed in large prospective studies, although cross-sectional data have suggested coronary heart disease can be associated with low T in men. Hypoandrogenemia in men and hyperandrogenemia in women are associated with visceral obesity; insulin resistance; low high-density lipoprotein (HDL) cholesterol (HDL-C); and elevated triglycerides, low-density lipoprotein cholesterol, and plasminogen activator type 1. These gender differences and confounders render the precise role of endogenous T in atherosclerosis unclear. Observational studies do not support the hypothesis that dehydroepiandrosterone sulfate deficiency is a risk factor for coronary artery disease. The effects of exogenous T on cardiovascular mortality or morbidity have not been extensively investigated in prospective controlled studies; preliminary data suggest there may be short-term improvements in electrocardiographic changes in men with coronary artery disease. In the majority of animal experiments, exogenous T exerts either neutral or beneficial effects on the development of atherosclerosis. Exogenous androgens induce both apparently beneficial and deleterious effects on cardiovascular risk factors by decreasing serum levels of HDL-C, plasminogen activator type 1 (apparently deleterious), lipoprotein (a), fibrinogen, insulin, leptin, and visceral fat mass (apparently beneficial) in men as well as women. However, androgen-induced declines in circulating HDL-C should not automatically be assumed to be proatherogenic, because these declines may instead reflect accelerated reverse cholesterol transport. Supraphysiological concentrations of T stimulate vasorelaxation; but at physiological concentrations, beneficial, neutral, and detrimental effects on vascular reactivity have been observed. T exerts proatherogenic effects on macrophage function by facilitating the uptake of modified lipoproteins and an antiatherogenic effect by stimulating efflux of cellular cholesterol to HDL. In conclusion, the inconsistent data, which can only be partly explained by differences in dose and source of androgens, militate against a meaningful assessment of the net effect of T on atherosclerosis. Based on current evidence, the therapeutic use of T in men need not be restricted by concerns regarding cardiovascular side effects. Available data also do not justify the uncontrolled use of T or dehydroepiandrosterone for the prevention or treatment of coronary heart disease.

Gene-drug interaction: additive influence of mutant APOA1 and testosterone on plasma HDL-cholesterol

OBJECTIVES

Factors associated with decreased plasma high-density lipoprotein (HDL) cholesterol concentration, or hypoalphalipoproteinemia, include androgenic steroids and mutations in APOA1, encoding apolipoprotein (apo) A-I, the main structural protein of HDL. However, there is little information regarding the extent of plasma HDL lowering when exogenous testosterone is used in subjects with monogenic low HDL.

DESIGN AND METHODS

A man with coronary heart disease (CHD) had been receiving exogenous testosterone post-orchidectomy. He had marked hypoalphalipoproteinemia, which was not responsive to diet or medication. To identify a possible genetic contribution to his biochemical phenotype, we sequenced the LCAT and APOA1 genes.

RESULTS

There were no sequence abnormalities in LCAT, but we found that he was a heterozygote for a novel APOA1 mutation in codon 107 (AAG->TGG), which predicted the replacement of lysine by tryptophan (K107W). Serial biochemical measurements over 11 years showed that plasma HDL cholesterol on either intramuscular or oral testosterone was 0.19 +/- 0.06 mmol/L, while plasma HDL cholesterol on transdermal testosterone was significantly higher at 0.52 +/- 0.18 mmol/L (p = 0.015, unpaired t-test).

CONCLUSIONS

The findings suggest that the low plasma HDL cholesterol associated with heterozygosity for mutant APOA1 can become extremely depressed during treatment with oral or intramuscular androgens. The findings also suggest that transdermal testosterone may perturb HDL to a lesser extent than other routes of delivery in such patients.

DDT metabolite and androgens in African-American farmers

BACKGROUND

The ubiquitous dichlorodiphenyltrichloroethane (DDT) metabolite 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) is an androgen receptor antagonist. Data on potential antiandrogenic activity of DDE in humans are limited.

METHODS

The relations between concentrations of plasma DDE and several serum androgens (total testosterone, bioavailable testosterone, 5alpha-dihydrotestosterone, and free androgen index) were examined in 137 North Carolina black male farmers, using multiple linear regression.

RESULTS

Participants ranged in age from 30 to 88 years (mean = 62 years). Most had farmed for about 30 years and 27% reported having used DDT. The median DDE level was 7.7 microg per liter (1213 microg per kg lipid), slightly higher than in other recent studies. Overall, concentrations of DDE and androgens were unrelated. Total testosterone decreased 2% (95% confidence limits [CL] = -9%, 5%) per increase in interquartile distance of lipid-adjusted DDE. The percentage change in other hormones was similarly negligible. However, among those whose DDE level was in the top tenth percentile, compared with all others, total testosterone and free androgen index were lower by 23% (CL= -40%, 1%) and 22% (CL =-41%, 4%) respectively. Plasma androgen levels decreased with age, a relation that has previously been studied only in whites.

CONCLUSIONS

Studies of more highly exposed populations may be needed to evaluate effects, if any, of DDE.

Intramuscular testosterone esters and plasma lipids in hypogonadal men: a meta-analysis

PURPOSE

It is unclear whether intramuscular administration of testosterone esters to hypogonadal men is associated with changes in plasma lipids. We therefore analyzed 19 studies published between 1987 and 1999 that focused on male subjects with nonexperimental hypogonadism, treated subjects with an intramuscular testosterone ester and reported pretreatment and post-treatment concentrations of total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL) cholesterol, or total triglyceride.

METHODS

We calculated study-specific, post-treatment minus pretreatment differences in each plasma lipid concentration (mean [95% confidence interval]). After testing of between-study homogeneity, we combined the study-specific differences. We then determined whether heterogeneity of differences could be explained in models of the differences on study and patient characteristics (mean +/- SE) before and after excluding extreme values using a multiple outlier procedure.

RESULTS

The studies represented 272 hypogonadal men (age 44 +/- 4 years; 20% with hypergonadotropic hypogonadism; total testosterone 0.5 +/- 0.2 ng/mL) who received, on average, 179 +/- 13 mg intramuscular testosterone ester every 16 +/- 1 days for 6 +/- 1 months. Fixed-effects estimates of post-treatment minus pretreatment differences were -14 [-17 to -11] mg/dL (total cholesterol), -5 [-8 to -1] mg/dL (LDL cholesterol), -4 [-5 to -2] mg/dL (HDL cholesterol), and -1 [-6 to + 4] mg/dL (triglyceride). Decreases in HDL cholesterol were larger at lower dosages of testosterone ester (r = -0.54, P = 0.055), but were not explained by attrition, regression to the mean, dosing frequency or duration, concomitant elevation of plasma total testosterone, aromatization of testosterone to estradiol, or other study and patient characteristics.

CONCLUSION

Intramuscular administration of testosterone esters to hypogonadal men is associated with a small, dosage-dependent decrease in HDL cholesterol and concomitant declines in total cholesterol and LDL cholesterol. The aggregate effect of these changes on cardiovascular risk remains unknown but deserves further study.

Testosterone and men's health

Medical and behavioral research depicts the influence of testosterone on health in opposite ways, the former finding beneficial effects and the latter potentially detrimental ones. We investigate the relationship between testosterone and health risk behavior, indicators of disease, and overall health in a sample of 4393 men who were interviewed and medically examined. Analysis revealed that having a high level of testosterone, compared to a low level, increased the odds of health risk behavior. With respect to disease, high testosterone increased the odds of some health problems but decreased the chances of others. At very high levels testosterone loses many of its beneficial effects. Overall, men with high testosterone would be healthier if they did not engage in health risk behavior.

Sex hormones and lipoproteins in adolescent male offspring of parents with premature coronary heart disease and a control group

OBJECTIVE

To compare pubertal maturation, sex steroid hormones, and lipoproteins and their interrelationships in male offspring of parents with premature coronary heart disease (cases) and a control group.

DESIGN

This was a cross-sectional comparison of cases and members of a control group 10 to 15 years of age.

SUBJECTS AND METHODS

Offspring were recruited from patient lists of area physicians. Members of the control group were recruited from area schools. Body mass (kg/m2), serum lipids, lipoproteins, apolipoproteins, estradiol, and free testosterone were measured.

RESULTS

Differences in age were not significant, but offspring were taller, heavier, and more mature. Offspring had higher total and low density lipoprotein cholesterol. Offspring had lower estradiol levels in early puberty but higher levels in late puberty. With family history and body mass in the regression models for lipid parameters, free testosterone was a significant explanatory factor for total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein, and estradiol was a significant predictor for apolipoprotein B. The percent of the variance in the lipid parameters explained by testosterone and estradiol was small.

CONCLUSION

Sex hormone concentrations appear to be modest but significant predictors of lipoprotein and apolipoprotein concentrations in offspring and a control group in cross-sectional analysis. After controlling for pubertal maturation, hormone and lipid concentrations differed in offspring and the control group.

Relationships between endogenous steroid hormone, sex hormone-binding globulin and lipoprotein levels in men: contribution of visceral obesity, insulin levels and other metabolic variables

Excess visceral adipose tissue (AT) and hyperinsulinemia are important correlates of an altered lipoprotein profile. It has also been reported that testosterone, adrenal C19 steroids and sex hormone-binding globulin (SHBG) concentrations are associated with plasma lipoprotein levels. The aim of the present study was to investigate the relative contributions of endogenous steroid hormone and SHBG levels, of visceral AT accumulation measured by computed tomography, and of fasting insulin and free fatty acid (FFA) concentrations to the variation of plasma lipoprotein levels in men. For this purpose, plasma concentrations of testosterone, dehydroepiandrosterone (DHEA), androstene-3beta,17beta-diol (delta5-DIOL), androstenedione (delta4-DIONE), estrone and estradiol, as well as SHBG levels were determined in a sample of 76 men covering a wide range of body fatness values. Higher testosterone levels were associated with a more favorable lipoprotein profile as it showed significant correlations with triglyceride (TG), total cholesterol and LDL-cholesterol (LDL-C) concentrations (r= -0.25, -0.25 and -0.27, respectively; P < 0.05). Higher plasma adrenal C19 steroid levels were also associated with a favorable lipoprotein profile as DHEA, delta4-DIONE and delta5-DIOL levels were negatively correlated with total cholesterol (r = -0.24, -0.33 and -0.24, respectively; P < 0.05) and LDL-C (r = -0.23, -0.31 and -0.28, respectively; P < 0.05). SHBG levels were negatively correlated with TG concentrations (r = -0.33; P < 0.005) whereas delta5-DIOL, testosterone and SHBG were negatively correlated with apolipoprotein B levels (-0.32 < or = r < or = -0.43; P < 0.005). Statistical adjustment for visceral AT area, fasting insulin, fasting free fatty acid (FFA) levels and total body fat mass eliminated most of the correlations between steroid and lipoprotein levels, while SHBG remained significantly correlated with lipoprotein concentrations after such adjustments. Multivariate analyses revealed that SHBG, delta4-DIONE, delta5-DIOL and metabolic variables all contributed to the variance in plasma lipoprotein concentrations (from 10 to 29% of explained variance). Visceral AT, fasting FFA and insulin levels as well as SHBG concentrations appeared to be independent correlates of lipoprotein concentrations. Thus, metabolic and anthropometric variables examined in the present study could have represented important confounding factors in previous studies which have examined the relationship of steroid hormones to plasma lipoprotein concentrations.

Declining gonadal function in elderly men

Ageing in men is accompanied by a progressive decline of gonadal function with, in particular, a decline of total and free testosterone (T) plasma levels resulting in a significant proportion of elderly men over age 60 years presenting with subnormal T levels compared with the levels in young adults. A great interindividual variation in T levels is observed in elderly men, a variability explained in part by physiological variables and differences in life style, while associated acute or chronic diseases may accentuate the age-related decline of T levels. The progressive decrease of plasma T levels has been shown to result from both primary testicular changes and altered neuroendocrine regulation of Leydig cell function. At present, little is known about the clinical relevance of the relative hypoandrogenism of elderly men and there is an urgent need for more longitudinal studies, which may clarify a possible role of decreased T levels in the modulation of the clinical consequences of ageing in men. In view of the lack of relevant controlled clinical trials having careful assessment of the risks and benefits of androgen replacement therapy in elderly men, this treatment should be reserved for selected patients with clinically and biochemically manifest hypogonadism, after careful screening for contraindications.

Behavioral correlates of plasma sex hormones and their relationships with plasma lipids and lipoproteins in Japanese men

In contrast to the hypothesis that endogenous testosterone decreases plasma high-density lipoprotein (HDL) cholesterol levels, many, but not all, studies have reported a positive correlation between plasma total testosterone and HDL cholesterol. We examined behavioral correlates of plasma testosterone and estradiol and the relationships between these sex hormones and plasma lipoproteins, in middle-aged Japanese men. Plasma, lipids, including HDL subfractions, total and free testosterone, and total estradiol were determined with 313 men aged 50-54 years who received a preretirement health examination at the Self-Defence Forces Fukuoka Hospital from January to June in 1992. Body mass index and waist-hip ratio were also measured. Smoking habit, alcohol use, and physical activity were ascertained by a self-administered questionnaire. Obesity, especially waist-hip ratio, was a strong correlate of both total and free testosterone, but not of estradiol. Smoking was associated with elevated levels of testosterone without a dose-effect relation. Neither alcohol use nor physical activity was associated with total or free testosterone, but plasma estradiol levels were higher among current alcohol drinkers. HDL and HDL2 cholesterol were unrelated to either total or free testosterone in the univariate analysis, but negatively associated with free, not total, testosterone after adjustment for obesity. HDL and HDL2 cholesterol also were positively associated with estradiol regardless of adjustment for obesity and other covariates. These findings add to evidence for a hypothesis that high levels of endogenous testosterone and low estradiol levels may cause a decrease in plasma HDL cholesterol, thereby being linked with atherosclerosis in middle aged men.

Genetic correlations between lipoprotein phenotypes and indicators of sex hormone levels in Mexican Americans

Previous studies have shown that the inverse relationship between HDL cholesterol (HDL-C) and triglyceride (TG) levels, risk factors for cardiovascular disease, is due largely to the effects of shared genes. HDL-C and TG are also known to be related to endogenous sex hormone levels, however the nature of the relationships is unclear. The objective of this study is to ascertain the extent to which these relationships are determined by shared genes. We conducted a multivariate quantitative genetic analysis of HDL-C, TG, dehydroepiandrosterone sulfate (DHEAS) and sex hormone-binding globulin (SHBG) in 635 people from 27 pedigrees participating in the San Antonio Family Heart Study. Heritabilities (h2) and genetic and environmental correlations (rho G and rho E) were estimated simultaneously by maximum likelihood methods. All four traits showed significant (P < 0.05) heritabilities: h2HDL-C = 0.38, h2TG = 0.54, h2DHEAS = 0.43, h2SHBG = 0.26. Significant genetic correlations were detected between HDL and each of the other traits: rho G(HDL-TG) = -0.56, rho G(HDL-DHEAS) = 0.23 and rho G(HDL-SHBG) = -0.56. However, there were no significant genetic correlations between TG and either measure of sex hormones. Thus, at least three separate groups of genes influence HDL-C levels in Mexican Americans: one group that has pleiotropic effects on HDL and TG, one group influences both HDL-C and SHBG and a third influences both HDL-C and DHEAS.

Urinary excretion of testosterone and estradiol in Chinese men and relationships with serum lipoprotein concentrations

Urinary excretion of total and free testosterone and estradiol was measured in 46 healthy Chinese men, along with serum concentrations of total testosterone and estradiol and the calculated free (unbound) concentrations. Associations with serum concentrations of total, low-density lipoprotein (LDL), high-density lipoprotein-2 (HDL2), and HDL3 cholesterol, apolipoproteins (apos) A-I and B, lipoprotein(a) [Lp(a)] were studied. Serum total and free testosterone concentrations were positively correlated with HDL and HDL2 cholesterol and apo A-I. Serum total and free estradiol levels showed borderline-significant negative associations with total and LDL cholesterol levels. Among urinary variables, total estradiol excretion was negatively associated with apo B levels and showed borderline-significant associations with total and LDL cholesterol. Adjustment for potential confounders, including age, body mass index (BMI), and waist to hip ratio (WHR), strengthened the associations between urinary total estradiol and serum total cholesterol, LDL cholesterol, and apo B. Urinary free estradiol showed a significant correlation with HDL3 cholesterol. Urinary excretion of total testosterone was significantly negatively associated with serum cholesterol and LDL cholesterol levels only after controlling for confounding variables. There were no significant associations between hormone variables and Lp(a) values. This study suggests that variation in sex hormone production accounts for some of the variation in serum lipid levels.

Effect of testosterone replacement therapy on lipids and lipoproteins in hypogonadal and elderly men

We investigated the effects of long-term testosterone replacement in hypogonadal and elderly men on lipids and lipoproteins. Twenty-two men with initial serum testosterone concentrations below 3.5 ng/ml took part in the study: 11 with hypopituitarism (1st group) and 11 otherwise healthy elderly men with low testosterone levels (2nd group). Testosterone deficiency was replaced by intramuscular injections of testosterone enanthate 200 mg every second week. Plasma levels of sex hormones, gonadotropins, SHBG, lipids and lipoproteins were determined before the treatment and after 3, 6 and 12 months of treatment. During the treatment serum testosterone and estradiol increased significantly, reaching normal levels. This was associated with a decrease in total cholesterol (from 225 +/- 16.9 mg/dl to 202 +/- 13.6 mg/dl after 6 months and 198 +/- 12.8 mg/dl after 1 year of testosterone administration, P < 0.0001 in men with hypoandrogenism associated with aging and from 255 +/- 12.1 mg/dl to 214 +/- 10.6 mg/dl after 6 months and 206 +/- 9 mg/dl after 1 year of treatment, P < 0.0001 in men with hypopituitarism) and LDL-cholesterol concentrations (from 139 +/- 12.5 mg/dl to 126 +/- 10.7 mg/dl after 6 months and 118 +/- 9.8 mg/dl after 1 year of testosterone administration, P < 0.0001 in men with hypoandrogenism associated with aging and from 178 +/- 10.3 mg/dl to 149 +/- 10.2 mg/dl after 6 months and 140 +/- 7.3 mg/dl after 1 year of treatment, P < 0.001 in men with hypopituitarism). However, no significant decrease in HDL-cholesterol levels or HDL2- and HDL3-cholesterol subfractions was observed. The effects of testosterone replacement therapy on lipids and lipoproteins were similar in both groups with different aetiology of hypogonadism. No side effects on the prostate were observed. The results of this study indicate that testosterone replacement therapy in hypogonadal and elderly men may have a beneficial effect on lipid metabolism through decreasing total cholesterol and atherogenic fraction of LDL-cholesterol without significant alterations in HDL-cholesterol levels or its subfractions HDL2-C and HDL3-C.

Androgen supplementation in eugonadal men with osteoporosis-effects of 6 months of treatment on bone mineral density and cardiovascular risk factors

This open, prospective therapeutic trial studied the effects of regular moderate androgen supplementation on bone mineral density in eugonadal men with established osteoporosis, and collected data on the safety of androgen therapy used in this setting. 23 men, aged 34-73 years, with vertebral crush fractures and back pain, in whom secondary causes of osteoporosis had been excluded, were treated with fortnightly intramuscular injections of 250 mg testosterone esters (Sustanon 250(R)) for 6 months. Blood pressure was recorded monthly; fasting lipids, glucose, haematocrit, plasma viscosity, and testosterone levels were measured every 3 months. Psychological effects were assessed using the Hospital Anxiety and Depression Scale (HADS) and General Health Questionnaire (GHQ), together with questioning on libido changes. Principal outcomes measured were changes in bone mineral density at the hip and spine by dual-energy X-ray absorptiometry (DEXA) over the treatment period. 21 men completed the study period. Mean bone mineral density at the lumbar spine increased from 0.799 g/cm(2) to 0.839 g/cm(2) during treatment (p < 0. 001), a rise of 5% in 6 months. Bone mineral density at the hip did not change. There were significant, favorable changes in diastolic blood pressure (-4.7 mmHg, p < 0.01), serum triglyceride levels (-0.405 mmol/L,p < 0.01), and total cholesterol (-0.27 mmol/L, p < 0.05). Adverse changes included a fall in HDL cholesterol (-0.087 mmol/L, p < 0.05) and a rise in plasma viscosity which was significant at 3 months but not at 6 months. The expected rises in hematocrit (0.434 to 0.456) and FAI (0.504 to 0.887) occurred. We conclude that testosterone supplementation significantly increased bone mineral density in this heterogeneous group of men with idiopathic primary osteoporosis, without an overall adverse effect on cardiovascular risk factors. This treatment warrants further evaluation in a randomized, controlled trial.

Biosocial models of deviant behavior among male army veterans

Measures of hormones (testosterone, cortisol and thyroxin) and of deviant or antisocial behavior are examined in a sample of 4179 Vietnam veterans. Hormone levels were found to vary with veterans' age, social status and race, and all three hormones were significantly related to deviant behavior. Biosocial models, combining hormonal variables with social background variables, tended to explain more variance in deviance than did traditional models based on social background alone. Several propositions regarding hormones and behavior were assessed. While the role of hormones in causing deviance remains unclear, it is argued that hormones should be included in models of deviant behavior.

Interrelations between sex hormone-binding globulin (SHBG), plasma lipoproteins and cardiovascular risk

The incidence of coronary artery disease is significantly higher in men than in women, at least until menopause. This gender difference could be explained by the action of sex steroids on the lipoprotein profile. In prepubertal children, high-density lipoprotein (HDL) cholesterol and triglyceride levels are similar between sexes, while adult men have generally lower HDL cholesterol and higher triglyceride levels than premenopausal adult women. Most cross-sectional studies have reported that sex hormone binding globulin (SHBG) and testosterone levels correlate positively with HDL cholesterol levels between sexes. Thus SHBG by modulating the balance in the biodisposal of testosterone and estradiol, might have a profound effect on the risk of cardiovascular disease. However, adjustment for body weight and body fat distribution weakens the association between SHBG, testosterone and HDL cholesterol. The negative correlation of fasting insulin with SHBG and HDL cholesterol levels in both sexes, and some evidence that insulin is an inhibitor of SHBG production in vitro, has suggested that hyperinsulinism might negatively regulate SHBG and HDL levels. It remains to be determined whether the inverse relationship between SHBG and insulin levels is coincidental or has a causal effect on the increase of atherosclerosis. Decreased SHBG has been shown to be predictive of the incidence of non-insulin-dependent diabetes mellitus in women but not in men, and of subsequent development of cardiovascular disease and overall mortality in postmenopausal women. SHBG is an index of androgenism in women and of insulin-resistance in both sexes, and might be useful in epidemiological studies of cardiovascular risk. However, in men, SHBG is not predictive of the occurrence of cardiovascular disease. Whether SHBG might have an intrinsic protective effect on the arterial wall through SHBG-receptors is still highly speculative.

Adrenal androgens and testosterone as coronary risk factors in the Helsinki Heart Study

We investigated the role of adrenal androgens, cortisol, testosterone and sex-hormone binding globulin (SHBG) as coronary risk factors using a nested case-control design. The study population consisted of 62 cases with cardiac end-points and 97 controls on placebo during the last 4 years in the Helsinki Heart Study. Serum concentrations of dehydroepiandrosterone, dehydroepiandrosterone sulfate (DHEAS), androstenedione, androstanediol glucuronide, cortisol, testosterone, and SHBG at the first annual visit of the 5-year study period were determined by radioimmunoassays. The only significant difference was found in DHEAS, with cases having higher levels than controls (P < 0.04). DHEAS levels were positively associated with smoking (P < 0.001), alcohol consumption (P < 0.04) and triglyceride levels (P < 0.002) and with systolic (P < 0.04) and diastolic (P < 0.006) blood pressures, and negatively associated with age (P < 0.01) and HDL-cholesterol (P < 0.03). The association between DHEAS and the CHD risk was studied using logistic regression analyses with the classical risk factors--age, smoking, blood pressure, and lipid levels--as covariates in the models. Studies of the joint effects of age and DHEAS disclosed that the risk associated with elevated DHEAS was confirmed to older men (odds ratio (OR) 7.3, 95%, CI 2.3-23.3). A similar analysis with smoking revealed that the DHEAS-related risk was mainly found in smokers (OR 3.4, 95% CI 1.5-8.2). One possible explanation for these results is that some form of mild steroid biosynthetic defect of the adrenals or functional adrenal hyperplasia associated with high DHEAS levels increases the CHD risk in this population.

The Cincinnati Myocardial Infarction and Hormone Family Study: family resemblance for dehydroepiandrosterone sulfate in control and myocardial infarction families

Dehydroepiandrosterone sulfate (DHEAS) was examined in random (control) and nonrandom (case) families participating in the Cincinnati Myocardial Infarction and Hormone (CIMIH) family study. The case families were ascertained through white men who survived a myocardial infarction (MI) before the age of 56, whereas control families were recruited through advertisements and through an adolescent boy maturation study. Both familial correlations and genetic effects of DHEAS were investigated. First, maximum likelihood estimates of the sex-specific familial correlations (corrected for nonrandom ascertainment) suggested that there was significant heterogeneity between the two sampling types. This heterogeneity was isolated to the male sibling correlation, which was higher in the case than control families. Post hoc analyses suggested that the sibling group heterogeneity may be in part a function of age, since the control sample offspring were on average much younger than those in case families. No sex differences other than those for the siblings were noted in the familial correlations. Second, heritability was investigated in control families using a simple path model (TAU) that allowed for sex differences. The only significant model parameter was the sex-specific familiarity (combined polygenic and familial environmental effects), which was larger in females (74%) than in males (29%). In general, these analyses suggested that (1) DHEAS may play only a limited role in the increased risk for premature MI, and (2) the degree of heritable (familial) variation may be dependent on sex.

Cincinnati myocardial infarction and hormone family study: family resemblance for testosterone in random and MI families

Familial correlations for total testosterone and free testosterone were examined in both random and nonrandom families participating in the Cincinnati Myocardial Infarction and Hormone Family Study (CIMIH). The non-random families were ascertained through Caucasian males who had survived a myocardial infarction (MI) prior to age 56 years, while random families were recruited largely through an adolescent boy maturation study. Eight sex-specific familial correlations were estimated (father-mother, father-son, father-daughter, mother-son, mother-daughter, son-son, daughter-daughter, and son-daughter) for each of the MI and random samples using maximum likelihood methods with appropriate ascertainment correction. These familial correlations were examined for differences between the random and MI samples, as well as for sex-specific familial patterns. The results suggest that total testosterone levels may have a limited role in determining MI risk, as evidenced by the overall heterogeneity between samples, and lower serum levels in MI than random probands. The pattern of correlations for both androgens suggests that a simple genetic model appears unlikely; however, familiarity cannot be ruled out. Although possible covariate effects such as age and sex may have masked some potentially significant results, especially in males, familiarity in females is suggested (correlations ranging from .3-.9). The relative stability of these hormones in females as compared to that in males may have contributed to its identification, and suggests the familial transmissibility may be associated with adrenal production and/or metabolic clearance of testosterone.

Endogenous sex hormones and ischemic heart disease in men. The Caerphilly prospective study

Numerous case-control studies have suggested that elevated levels of endogenous estrogen and low levels of testosterone are associated with ischemic heart disease (IHD) in men. These findings were tested in the Caerphilly study of 2,512 men from the general population who were aged 45-59 years at baseline and were followed for 5 years. Some 153 men experienced a new episode of IHD (fatal and nonfatal) during the period of follow-up. Baseline values of estradiol were marginally higher in subjects who developed IHD than in those who did not, but the difference was not statistically significant. Plasma values of testosterone were similar in the two groups. Among quintiles of the distribution of the hormone values, the incidence of IHD was similar in the case of estradiol; there was also no clear trend in the case of testosterone. These findings provide no support for the suggestion that plasma estradiol or testosterone are primary risk factors for IHD, although the associations between plasma testosterone and other probable risk markers (triglycerides, insulin, body mass index, and high density lipoprotein cholesterol) indicate the possibility that testosterone may play an indirect role in the pathogenesis of IHD.

Interpretation of linear regression models that include transformations or interaction terms

In linear regression analyses, we must often transform the dependent variable to meet the statistical assumptions of normality, variance stability, or linearity. Transformations, however, can complicate the interpretation of results because they change the scale on which the dependent variable is measured. In this setting, the inclusion of product terms or the transformation of some independent (or predictor) variables may further complicate interpretation. In this article, we present some interpretations of linear models that include transformations or product terms. We illustrate these interpretations using regression analyses designed to study determinants of serum testosterone levels. These examples show how one can present results using simple measures, such as medians, and interpret regression parameters.

Interrelation between plasma testosterone and plasma insulin in healthy adult men: the Telecom Study

Plasma insulin is a risk factor for diabetes mellitus and cardiovascular disease in men. We investigated the association between plasma testosterone and plasma insulin in an occupational sample of 1292 healthy adult men. Total plasma testosterone decreased with each decade of age and insulin increased with each decade of age. In these cross-sectional data, this significant graded inverse association between testosterone and insulin was independent of age. The association was reduced but not explained by the addition of obesity and subscapular skinfold to the model. Adjustment for alcohol consumption, cigarette smoking and plasma glucose did not materially alter the association. These results are the reverse of the positive association of androgens with insulin in women and suggest alternative possible explanations for the effect of hyperinsulinaemia on cardiovascular disease risk. Prospective studies will be necessary to determine the direction and causal nature of this association.