Clinical correlates of sex steroids and gonadotropins in men over the late adulthood: the Framingham Heart Study

Male subclinical hypogonadism and late-onset hypergonadotrophic hypogonadism: mechanisms, endothelial function, and interplay between reproductive hormones, undercarboxylated osteocalcin, and endothelial dysfunction

BACKGROUND

Pathogenesis and endothelial function in subclinical hypogonadism (SCH) remain unclear. Undercarboxylated osteocalcin (ucOC) participates in atherosclerosis and reproduction. We explored the underlying mechanisms and interplay of endothelial dysfunction, unOC and reproductive hormones in SCH and primary late-onset hypogonadism (LOH).

METHODS

In the SCH, LOH, and healthy eugonadal male groups, we measured serum unOC, calculated luteinizing hormone/testosterone (LH/T), LH.T product, and estradiol/T (E/T) as indicators of impaired Leydig cells, androgen sensitivity index (ASI), and aromatase activity, respectively (LH set-point regulators), and assessed flow-mediated dilation of the brachial artery (FMD%), carotid-intima media thickness (CIMT), and aortic stiffness (AS).

RESULTS

↑LH/T, ↑ASI, ↓aromatase activity, normal T, follicle-stimulating hormone (FSH) and sex hormone-binding globulin (SHBG) levels, ↑unOC, and enhanced atherosclerotic markers (↓FMD%, ↑CIMT, ↑AS) are characteristics of SCH. Testosterone was positively correlated with FMD% in SCH. The independent predictors were: SHBG and LH for FMD% and CIMT, respectively, and LH/T, ucOC, FSH, estradiol, and E/T ratio for AS in the LOH group; and LH for FMD% & AS and LH and LH/T for CIMT in all study subjects.

CONCLUSIONS

SCH is a distinct clinical entity characterized by impaired androgen sensitivity and aromatase activity, compensatory elevated unOC, endothelial dysfunction, and anti-atherogenic role of testosterone.

Testosterone Disorders and Male Hypogonadism in Kidney Disease

Chronic kidney disease (CKD) causes substantial alterations in the male endocrine system, which affect puberty, libido, and sexual function. A major effect of CKD is a reduction in testosterone levels because of both primary and hypogonadotrophic hypogonadism. In addition to impairment of pubertal growth and sexual maturation in children with CKD, clinical evidence suggests that uremic hypogonadism strongly contributes to several CKD complications, including erectile dysfunction, muscle wasting and frailty, anemia, decreased bone mineralization, depression, and cognitive impairment. This review focuses on a reappraisal of the physiologic role of testosterone, with an emphasis on the hypogonadal condition linked to CKD and its complications.

Age-related changes in estradiol and longitudinal associations with fat mass in men

Context

In men, circulating 17β-estradiol originates primarily from peripheral aromatization of testosterone particularly in adipose tissue. The effect of ageing and obesity on circulating estradiol remains unclear.

Objective

Determine five-year changes in serum estradiol and the association with testosterone and fat mass in Australian men.

Design

Longitudinal cohort study. At baseline and five-year follow-up, socio-demographic and health-related data including behaviors, chronic conditions, and medication use were collected by questionnaire. Estradiol and testosterone were assayed by liquid chromatography-tandem mass spectrometry and sex hormone-binding globulin by immunochemiluminescent assay. Fat mass was assessed by dual-energy X-ray absorptiometry.

Participants

Community-dwelling men aged 35 years and older at enrollment, resident in the northern and western suburbs of Adelaide without established disease of, or medications affecting, the hypothalamus-pituitary-gonadal axis (n = 725).

Main outcome measures

The dependence of change in serum estradiol over five years on age, testosterone and fat mass after adjustment for multiple confounders.

Results

At baseline, mean age was 53.0 ± 10.8 years. Mean serum estradiol levels at baseline and five-year follow-up were 94.9 ± 34.8 and 89.4 ± 30.4 pmol/L respectively (-1.1 pmol/L/year). On multivariable analyses, estradiol change was associated with changes in testosterone (B-estimate = 2.719, standard error = 0.369, p˂0.001), but not age or total fat mass. Change in testosterone/estradiol ratio was inversely associated with change in fat mass (B = -1.450, SE = 0.575, p = 0.012), and this was consistent across quartiles of fat mass change.

Conclusions

In healthy men, circulating estradiol is primarily dependent on testosterone. With increasing fat mass, estradiol decreases less than testosterone. From a clinical standpoint these data indicate that obesity is associated with a change in the testosterone to estradiol ratio, but a change in estradiol does not occur unless some other pathology is present.

A Perspective on Middle-Aged and Older Men With Functional Hypogonadism: Focus on Holistic Management

CONTEXT

Middle-aged and older men (≥50 years), especially those who are obese and suffer from comorbidities, not uncommonly present with clinical features consistent with androgen deficiency and modestly reduced testosterone levels. Commonly, such men do not demonstrate anatomical hypothalamic-pituitary-testicular axis pathology but have functional hypogonadism that is potentially reversible.

EVIDENCE ACQUISITION

Literature review from 1970 to October 2016.

EVIDENCE SYNTHESIS

Although definitive randomized controlled trials are lacking, evidence suggests that in such men, lifestyle measures to achieve weight loss and optimization of comorbidities, including discontinuation of offending medications, lead to clinical improvement and a modest increase in testosterone. Also, androgen deficiency-like symptoms and end-organ deficits respond to targeted treatments (such as phosphodiesterase-5 inhibitors for erectile dysfunction) without evidence that hypogonadal men are refractory. Unfortunately, lifestyle interventions remain difficult and may be insufficient even if successful. Testosterone therapy should be considered primarily for men who have significant clinical features of androgen deficiency and unequivocally low testosterone levels. Testosterone should be initiated either concomitantly with a trial of lifestyle measures, or after such a trial fails, after a tailored diagnostic work-up, exclusion of contraindications, and appropriate counseling.

CONCLUSIONS

There is modest evidence that functional hypogonadism responds to lifestyle measures and optimization of comorbidities. If achievable, these interventions may have demonstrable health benefits beyond the potential for increasing testosterone levels. Therefore, treatment of underlying causes of functional hypogonadism and of symptoms should be used either as an initial or adjunctive approach to testosterone therapy.

Clinical correlates of sex hormones in women: The study of health in Pomerania

BACKGROUND

Despite associations of sex hormones in women with increased cardiometabolic risk and mortality, the clinical correlates of altered sex hormone concentrations in women are less clearly understood. We investigated a broad range of clinical correlates of sex hormones in women from a large population-based sample.

METHODS

Data from 2560 women from two cohorts of the Study of Health in Pomerania were used. Stepwise multivariable regression models were implemented to investigate a broad range of behavioral, socio-demographic, and cardiometabolic clinical correlates related to total testosterone (TT), free testosterone (fT), androstenedione (ASD), dehydroepiandrosterone-sulfate (DHEAS), estrone (E1), estradiol (E2), and sex hormone-binding globulin (SHBG).

RESULTS

Waist circumference and BMI (β-coefficient: -0.03; 95% CI: -0.04; 0.03) were inversely related to SHBG, and BMI was positively related to TT (β-coefficient: 0.005; 95% CI: 0.001; 0.009), fT, E1, and E2. Smoking was positively related to TT (β-coefficient: 0.04; 95% CI: 0.01; 0.06), ASD, and fT. Systolic blood pressure (TT: β-coefficient: 0.002; 95% CI: 0.001; 0.003), hypertension (TT: β-coefficient: 0.05; 95% CI: 0.003; 0.11), low-density lipoprotein (LDL) cholesterol (TT: β-coefficient: 0.02; 95% CI: 0.01; 0.05), and total cholesterol (TT: β-coefficient: -0.03; 95% CI: 0.01; 0.05) were positively related to TT and ASD. Finally, type 2 diabetes mellitus (T2DM), and metabolic syndrome (MetS) were positively related to fT, but inversely related to SHBG.

CONCLUSIONS

Our population-based study, with sex hormone concentrations measured by liquid chromatography tandem mass spectrometry, revealed associations between clinical correlates including waist circumference, smoking, cohabitation, systolic blood pressure, cholesterol, and MetS with sex hormones. Thus, sex hormones and SHBG may play a role in the cardiovascular risk profile of women.

Late-onset hypogonadism: beyond testosterone

Late-onset hypogonadism is defined as a combination of low testosterone (T) levels and typical symptoms and signs. A major area of uncertainty is whether T concentrations are always really sufficient to fully reflect Leydig cell (dys)function. Mild testicular alteration could be diagnosed only by additional biochemical markers, such as luteinizing hormone (LH) and 25-hydroxyvitamin D levels. These markers help in identifying the so-called “subclinical” hypogonadism (normal T, high LH levels). Patients with hypogonadism have frequently low levels of 25-hydroxyvitamin D due to impairment of the hydroxylating enzyme CYP2R1 in the testis. However, no data have been published dealing with the best treatment option (cholecalciferol – the Vitamin D precursor, or calcidiol - 25-hydroxylated form of Vitamin D) in these patients. We studied 66 patients with classic hypogonadism (total T [TT] <12 nmol l⁻¹, LH ≥ 8 IU l⁻¹) (n = 26) and subclinical hypogonadism (TT ≥ 12 nmol l⁻¹, LH ≥ 8 IU l⁻¹) (n = 40) and low 25-hydroxyvitamin D (<50 nmol l⁻¹). Subjects received cholecalciferol (5000 IU per week) (n = 20) or calcidiol (4000 IU per week) (n = 46), and 25-hydroxyvitamin D and parathyroid hormone (PTH) were evaluated after 3 months of therapy. Supplementation with calcidiol significantly increased 25-hydroxyvitamin D and significantly decreased PTH levels in both groups of men with hypogonadism (primary, n = 16 and subclinical, n = 30), whereas supplementation with cholecalciferol did not modify their levels. This study shows for the first time that the administration of the 25-hydroxylated form of Vitamin D (calcidiol), and not the administration of the precursor cholecalciferol, restores 25-hydroxyvitamin D levels in subjects with hypogonadism.

High DHEAS/free testosterone ratio is related to better metabolic parameters in women with PCOS

AIMS

To demonstrate the effects of DHEAS/free testosterone (DHEAS/FT) ratio on metabolic parameters in women with and without polycystic ovary syndrome (PCOS).

METHODS

The data of 91 women with PCOS and 66 women in the control group were collected retrospectively.

RESULTS

DHEAS/FT of the control group was higher than that of PCOS group (684.93 ± 300.54 to 517.2 ± 300.8, p < 0.001). DHEAS/FT correlated with BMI (r = -0.352, p = 0.001), WHR (r = -0.371, p = 0.0219), LDL (r = -0.227, p = 0.031), HOMA-IR (r = -0.36, p = 0.001) and FAI (r = -0.639, p = 0.001) negatively and with HDL (r = 0.344, p = 0.001) and SHBG (r = 0.646, p = 0.001) positively. In the control group, DHEAS/FT correlated with BMI (r = -0.334, p = 0.007), CRP (r = -0.297, p = 0.016) and FAI (r = -0.399, p = 0.01) negatively.

CONCLUSIONS

High DHEAS/FT ratios are related to a better metabolic phenotype in women with PCOS and low levels can be used to detect women with PCOS that have a higher risk of metabolic problems.

An update on testosterone, HDL and cardiovascular risk in men

Testosterone prescriptions have risen steadily and sharply in the USA despite a lack of clear understanding of the relationship between androgens and cardiovascular disease. In men with increasing age, testosterone levels decline and cardiovascular disease risk goes up. Ties between hypogonadism and cardiovascular disease are suggested by observational data, yet therapy with testosterone replacement has not been shown to mitigate that risk. To the contrary, recent literature has raised concern for increased cardiovascular disease in certain groups of men receiving testosterone therapy. In this article, we review current literature in an attempt to better understand what it suggests is the true relationship between testosterone and cardiovascular disease. We also take a closer look at effects of testosterone on lipids and HDL in particular, to see if this explains the cardiovascular effects seen in clinical studies.

Analysis of relationships between the concentrations of total testosterone and dehydroepiandrosterone sulfate and the occurrence of selected metabolic disorders in aging men

OBJECTIVE

The evaluation of relationships between the concentrations of dehydroepiandrosterone sulfate (DHEAS) and total testosterone (TT) and the occurrence of metabolic disorders, including metabolic syndrome (MetS).

METHOD

The participants were subjected to anthropometric measurements and were tested for DHEAS, TT, lipid parameters and carbohydrate parameters.

RESULT

We observed a lower concentration of DHEAS in the men with hypertension (HT) compared to those without HT. In the men with MetS, HT, overweight and obesity, the concentration of TT was lower than in the men without these problems. We found statistically significant positive correlations (DHEAS- total cholesterol [TCh], DHEAS- low-density lipoprotein [LDL], TT- high-density lipoprotein [HDL], TT-waist-to-hip ratio [WHR]) and negative correlations (DHEAS-age, TT-body weight, TT- body mass index [BMI], TT-abdominal circumference [AC], TT-hip circumference [HC], TT- triglyceride [TG], TT- fasting plasma glucose [FPG], TT- serum insulin levels [I], TT- Homeostasis Model Assessment-Insulin Resistance [HOMA-IR]). Using logistic regression it was ascertained that lower TT levels increase the risk of HT, and were also associated with obesity.

CONCLUSION

Our research indicates relationships between TT and the occurrence of MetS and its individual components. Excess body weight in men is a factor associated with lower TT levels. It seems necessary to determine TT in men with MetS and overweight or obesity. DHEAS did not show any significant relations with MetS and its parameters. Age was the most crucial factor responsible for the decrease in DHEAS.

Total testosterone is the most valuable indicator of metabolic syndrome among various testosterone values in middle-aged Japanese men

Endogenous testosterone is known to be protective against metabolic syndrome (MetS) in men. While various markers of testosterone status including serum total testosterone (TT), free testosterone (measured using analogue ligand RIA [aFT]), calculated FT (cFT), calculated bioavailable testosterone (cbT), and sex-hormone binding globulin (SHBG) are recognized, it is unclear which of these markers are the most appropriate ones for the detection of MetS. We measured various testosterone values and metabolic markers in 249 healthy Japanese males (mean age 52.7 ± 7.4 yr) and analyzed which testosterone value is most associated with various metabolic parameters, including MetS as diagnosed according to the International Diabetes Federation (IDF, 2009 version) or with the Japanese criteria. Age had no effect on the TT level but significantly decreased aFT, cFT, and cbT levels and significantly increased the SHBG level. All testosterone values and SHBG showed weak inverse relationships with the metabolic markers BMI, waist circumference, insulin, HOMA-R, and HOMA-β, with the strongest relationship being to TT. TT and SHBG were significantly lower in men with MetS than in men without MetS. All testosterone values gradually decreased as the number of MetS components increased. Multivariate analysis revealed that the TT median value of <4.0 ng/mL was the only significant marker for the detection of MetS. These results were essentially the same regardless of whether the diagnosis of MetS was based on the IDF or the Japanese criteria. In conclusion, among various testosterone values, TT is the most reliable indicator of MetS in middle-aged Japanese men.

Genome-wide association studies on serum sex steroid levels

Even though the levels of circulating sex steroid hormones are to a large extent heritable, their genetic determinants are largely unknown. With the advent of genome-wide association studies (GWAS), much progress has been made and several genetic loci have been identified to be associated with serum levels of dehydroepiandrosterone sulfate, testosterone and sex hormone-binding globulin. The variants identified so far only explain a small amount of the overall heritability, but may help to elucidate the role of sex steroid hormones in common disorders such as hypogonadism, type 2 diabetes and hormone-sensitive cancers. This review provides an overview of the current state of knowledge of the genetic determinants of sex steroid hormones, with a focus on recent GWAS and brief directions for elucidating the remaining heritability.

The effect of androgens on lipids

PURPOSE OF REVIEW

To review recent data concerning the relationship between endogenous testosterone and lipids as well as testosterone replacement therapy and lipids. To describe the effects of sex hormones on cardiovascular disease (CVD) that may act via serum lipids.

RECENT FINDINGS

Low endogenous testosterone is associated with high low-density lipoprotein and low high-density lipoprotein in both cross-sectional and prospective observational studies. Exogenous testosterone administration is associated with decreased high-density lipoprotein coupled with beneficial decreases in low-density lipoprotein and total cholesterol. The overall impact of testosterone administration on CVD is still unclear, with mixed safety results from recent randomized controlled trials.

SUMMARY

There may be CVD risk reduction benefits, including an improved lipid profile, from testosterone administration in hypogonadal men. The overall effect of testosterone on CVD risk has not been definitively determined.