Low serum testosterone, arterial stiffness and mortality in male haemodialysis patients

Androgen Deficiency, Associations and Survival of Men With Stage 4 and 5 Chronic Kidney Disease: A Cohort Study

OBJECTIVES

Anaemia is a key cause of morbidity in chronic kidney disease (CKD). Androgen deficiency (AD) in males can contribute to anaemia of all causes, including in CKD. We sought to examine the prevalence of AD in men with CKD, the extent to which it contributed to anaemia and whether it was independently associated with long-term survival.

METHODS

This cross-sectional observational study was conducted among males aged 18 years and over with CKD stages 4 and 5. The study analysed morning blood samples with regard to their full blood count, urea and electrolytes, albumin, lipids, testosterone (T) and sex hormone binding globulin, with calculation of free testosterone by mass action equation. Mortality data were obtained 15 years later for survival analysis.

RESULTS

Among 322 patients with a mean age of 63 years, the overall prevalence of AD was 68.9%. There was a statistically significant negative correlation between erythropoiesis stimulating agent (ESA) dose and testosterone concentrations (Pearson correlation -0.193, p = 0.05). There was a positive correlation between haemoglobin (Hb) and free testosterone level among patients not on ESA therapy (Pearson correlation 0.331, p < 0.001). Kaplan-Meier plots showed p < 0.001 on log-rank analysis, indicating that AD was significantly associated with worse survival. However, in Cox regression analysis, free testosterone was not associated with survival (95% CI for free testosterone 0.997-1.000).

CONCLUSIONS

AD is highly prevalent among this population, and increases further with older age and more severe CKD warranting haemodialysis. Association of lower Hb and higher ESA dose with lower T concentration might be causative, which has important pharmaco-economic as well as clinical implications. Lower survival in men with low T, more likely reflects overall poor health rather than causation. A properly constituted randomised controlled study evaluating the effect of native T replacement is warranted in men with CKD and AD.

Triiodothyronine and Protein Malnutrition Could Influence Pulse Wave Velocity in Pre-Dialysis Chronic Kidney Disease Patients

Cardiovascular diseases (CVD) are the first cause of chronic kidney disease (CKD) mortality. For personalized improved medicine, detecting correctable markers of CVD can be considered a priority. The aim of this study was the evaluation of the impact of nutritional, hormonal and inflammatory markers on brachial-ankle Pulse Wave Velocity (PWV) in pre-dialysis CKD patients. A cross-sectional observational study was conducted on 68 pre-dialysis CKD patients (median age of 69 years, 41.2% with diabetes mellitus, 52.9% male). Laboratory data were collected, including levels of prolactin, triiodothyronine, TGF α, IL-6, and IL-1β. The high values of brachial-ankle PWV were associated with reduced muscle mass (p = 0.001, r = -0.44), low levels of total cholesterol (p = 0.04, r = -0.26), triglycerides (p = 0.03, r = -0.31), triiodothyronine (p = 0.04, r = -0.24), and prolactin (p = 0.02, r = -0.27). High PWV was associated with advanced age (p < 0.001, r = 0.19). In the multivariate analysis, reduced muscle mass (p = 0.018), low levels of triiodothyronine (p = 0.002), and triglycerides (p = 0.049) were significant predictors of PWV, but age (p < 0.001) remained an important factor. In conclusion, reduced triiodothyronine together with markers of malnutrition and age were associated with PWV in pre-dialysis CKD patients.

Establishing and Verifying a Robust Liquid Chromatography–Tandem Mass Spectrometry Method to Simultaneously Measure Seven Androgens Present in Plasma Samples

Objectives: To develop a robust liquid chromatography–tandem mass spectrometry (LC–MS/MS) method to simultaneously measure seven human plasma androgens, namely testosterone (T), dihydrotestosterone (DHT), androstenedione (A4), dehydroepiandrosterone sulfate (DHEAS), dehydroepiandrosterone (DHEA), 11-ketotestosterone (11-KetoT), and 11β-hydroxytestosterone (11β-OHT). Design and Methods: Plasma was extracted via a solid phase extraction method, and the analytical performance of the assay was validated according to the Clinical & Laboratory Standards Institute guidelines. Overall, 73 apparently healthy volunteers were recruited to evaluate the distribution of these seven androgens; their levels in 25 females with acne and 33 obese females were also evaluated. Results: The developed method exhibited a good precision, with the total coefficient variations (CV) and the intra-assay CVs being within 10%. Furthermore, the recoveries of T, DHT, A4, DHEA, DHEAS, 11-KetoT, and 11β-OHT were 90.3–105.8, 88.7–98.1, 92.4–102.5, 90.5–106.7, 87.6–99.9, 93.3–105.3, and 90.2–104.4%, respectively, and no significant matrix effect was observed after internal standard correction (<20%). Moreover, the limits of quantification were 0.01, 0.01, 0.01, 0.10, 5.00, 0.02, and 0.02 ng/mL for T, DHT, A4, DHEA, DHEAS, 11-KetoT, and 11β-OHT, respectively, which are adequate for their accurate measurement in human plasma samples. It was also determined that patients diagnosed with acne had significantly higher levels of DHT, A4, and DHEAS, while those suffering from obesity had significantly higher levels of T and A4 but lower levels of DHT. Conclusions: A robust LC-MS/MS method for the simultaneous determination of seven androgens in plasma samples was successfully established and validated, which plays important roles in clinical application.

Sex hormones and the risk of cardiovascular disease and mortality in male and female patients with chronic kidney disease: A systematic review and meta-analysis

Patients with chronic kidney disease (CKD) commonly experience sex hormone disturbances, which may be associated with the risk of cardiovascular disease (CVD) and mortality. This review aimed to systematically evaluate current findings on the association of sex hormone levels with the risk of CVD events and mortality (CVD and all-cause) in the CKD population. Articles were systematically searched in CINAHL, Cochrane, and PubMed. A total of 1739 articles were independently screened by two reviewers and 17 prospective cohort studies were included. The clinical conditions of the patients were those with non-dialysis CKD [mean/median estimated glomerular filtration rate (eGFR) between 15-51 ml/min/1.73 m2 ] and those on chronic dialysis (mean/median vintage between 6-125 months). The sample size ranged from 111 to 2419 and the mean/median age of subjects ranged from 52 to 72 years. The sex hormones studied were testosterone, estradiol, prolactin, dehydroepiandrosterone sulfate, and relaxin. A random-effects model was used to generate a pooled hazard ratio (HR) to evaluate the association of total testosterone levels with the risk of CVD and all-cause mortality. Most studies examined total testosterone levels (11 out of 17 studies) and studied only male patients (12 out of 17 studies). A lower total testosterone level was associated with a higher risk of CVD mortality [HR 4.37 (95% CI 1.40-13.65)] and all-cause mortality [1.96 (1.35-2.83)] in males with CKD. To conclude, there is a strong need for additional studies examining the association of sex hormones with cardiovascular and mortality risk in female patients with CKD.

Additive damage in the thromboxane related vasoconstriction and bradykinin relaxation of intramural coronary resistance arterioles in a rodent model of andropausal hypertension

Hypertension and andropause both accelerate age–related vascular deterioration. We aimed to evaluate the effects of angiotensin-II induced hypertension and deficiency of testosterone combined regarding the resistance coronaries found intramurally.

Four male groups were formed from the animals: control group (Co, n = 10); the group that underwenr orchidectomy (ORC, n = 13), those that received an infusion of angiotensin-II (AII, n = 10) and a grous that received AII infusion and were also surgically orchidectomized (AII + ORC, n = 8). AII and AII + ORC animals were infused with infusing angiotensin-II (100 ng/min/kg) using osmotic minipumps. Orchidectomy was perfomed in the ORC and the AII + ORC groupsto establish deficiency regarding testosterone. Following four weeks of treatment, pressure-arteriography was performed in vitro, and the tone induced by administration of thromboxane-agonist (U46619) and bradykinin during analysis of the intramural coronaries (well-known to be resistance arterioles) was studied.

U46619-induced vasoconstriction poved to be significantly decreased in the ORC and AII + ORC groups when compared with Co and AII animals. In ORC and AII + ORC groups, the bradykinin-induced relaxation was also significantly reduced to a greater extent compared to Co and AII rats. Following orchidectomy, the vasocontraction and vasodilatation capacity of blood vessels is reduced. The effect of testosterone deficiency on constrictor tone and relaxation remains pronounced even in AII hypertension: testosterone deficiency further narrows adaptation range in the double noxa (AII + ORC) group. Our studies suggest that vascular changes caused by high blood pressure and testosterone deficiency together may significantly increase age-related cardiovascular risk.

Testosterone Deficiency and Nutritional Parameters as Predictors of All-Cause Mortality among Male Dialysis Patients

Background: Chronic kidney disease (CKD) is associated with an accelerated risk of cardiovascular mortality. Hormonal and metabolic disorders in CKD may constitute novel risk factors. Our objective was to characterize and evaluate prognostic implications of circulating sex steroids and selected nutritional parameters in patients at different stages of CKD. Methods: Studied groups were composed of 78 men: 31 on hemodialysis (HD), 17 on peritoneal dialysis (PD), 30 with CKD stage G3-G4. Total testosterone (TT), dehydroepiandrosterone sulphate (DHEA-S), androstenedione, luteinizing hormone (LH), prolactin (PRL), and biochemical parameters were measured; Free testosterone (FT) was calculated. Results: The lowest TT and FT were observed in HD, the highest- in CKD (p = 0.006 for TT, p = 0.005 for FT). TT positively correlated with total cholesterol in HD (p = 0.012), FT negatively correlated with BMI in CKD (p = 0.023). During the 12 months, 9 patients died (5 in the HD, 4 in the PD group). The deceased group had significantly lower concentrations of albumin (p = 0.006) and prealbumin (p = 0.001), and a significantly higher concentration of androstenedione (p = 0.019) than the surviving group. In the group of men on dialysis, a serum TT concentration <2.55 ng/mL (Q1-first quartile) was associated with a 3.7-fold higher risk of death, although statistical significance was not achieved (p = 0.198). After analysis of the ROC curves, the FT level was the best prognostic marker in HD (AUC = 0.788; 95% CI: 0.581−0.996; p = 0.006) Conclusions: Total and free testosterone levels were lower in the HD group than in the CKD group. The nutritional status undoubtedly affects the survival of dialysis patients but also the concentrations of testosterone significantly contributes to further worsening the prognosis.

Low Testosterone Level and Risk of Adverse Clinical Events among Male Patients with Chronic Kidney Disease: A Systematic Review and Meta-Analysis of Cohort Studies

The phenomenon of low testosterone level is extremely common in male patients with chronic kidney diseases (CKDs). This meta-analysis aimed to evaluate whether the low circulating testosterone could independently predict adverse outcomes among male patients with chronic kidney diseases (CKDs). The data till May 2022 were systematically searched from Pubmed, Web of Science, and Embase from inception. Studies meeting the PICOS (population, intervention/exposure, control/comparison, outcomes, and study design) principles were included in this meta-analysis. Study-specific effect estimates were pooled using fixed-effects (I² > 50%) or random-effects models (I² < 50%). Ultimately, 9 cohort studies covering 5331 patients with CKDs were involved in this meta-analysis. The results suggested that per 1-standard deviation (SD) decrease in total testosterone independently increased the risk of all-cause mortality by 27% [hazard risk (HR) 1.27, 95% confidence interval (CI) 1.16–1.38], cardiovascular mortality by 100% (HR 2.00, 95% CI 1.39–2.86), cardiovascular events by 20% (HR 1.20, 95% CI 1.04–1.39), and infectious events by 41% (HR 1.41, 95% CI 1.08–1.84). Besides, with per 1-SD decrease in free testosterone, the risk of overall adverse events increased by 66% (HR 1.66, 95% CI 1.34–2.05). Stratified analyses indicated that the negative relationship of the total testosterone with all-cause death risk was independent of factors involving age, race, body mass index, diabetes, hypertension, C-reactive protein, creatinine, and sex hormone binding globulin. In conclusion, it was identified that low endogenous testosterone could serve as an independent predictor of adverse clinical events among male patients with CKDs.

Testosterone Deficiency as One of the Major Endocrine Disorders in Chronic Kidney Disease

Reduced testosterone concentration is nowadays thought to be one of the main endocrine disorders in chronic kidney disease (CKD). It is caused by the dysfunction of the hypothalamic-pituitary-gonadal axis. The role of testosterone is multifactorial. Testosterone is responsible not only for reproductive processes, but it is a hormone which increases bone and muscle mass, improves lipid profile, insulin sensitivity, erythropoiesis, reduces blood pressure, and ameliorates mood and perception. The implications of hypogonadism in CKD are infertility and loss of libido, reduction of muscle mass and strength, disorders in bone mineralization, the development of sarcopenia and protein energy wasting (PEW), progression of atherosclerosis, increased visceral adiposity, insulin resistance, and anaemia. Reduced testosterone serum concentrations in CKD are associated with increased mortality rate. Testosterone supplementation improves sexual functions, reduces the level of inflammatory markers and blood pressure, stimulates muscle protein synthesis, improves insulin sensitivity and lipid profile, and increases muscle mass, bone mineral density, and haemoglobin concentration. It positively affects mood and well-being. The modes of testosterone supplementation are intramuscular injections, subcutaneous pellets, and percutaneous methods—patches and gels. Successful kidney transplantation may improve gonadal function and testosterone production, however, half of men with low testosterone concentrations before kidney transplantation do not restore hormonal function.

The role of serum testosterone and dehydroepiandrosterone sulfate in kidney function and clinical outcomes in chronic kidney disease: a systematic review and meta-analysis

OBJECTIVE/DESIGN

Testosterone might mediate sex differences in kidney function and chronic kidney disease (CKD). However, few studies analyzing the association between testosterone and kidney function showed conflicting results. Therefore, we performed a systematic review and meta-analysis.

METHODS

Six electronic databases were searched from inception to March 4, 2020, for studies that investigated the association of (i) testosterone status with kidney function in the general population or (ii) testosterone status with clinical outcomes (kidney function decline, kidney failure, cardiovascular (CV) events, and cardiovascular and all-cause mortality) in CKD patients. We used random and fixed-effect models to obtain pooled effect estimates with 95% confidence intervals (CIs).

RESULTS

No randomized-controlled trials that met the inclusion criteria were identified. One study was conducted in the general population and reported an increased risk of incident CKD with low vs normal testosterone (hazard ratio (HR): 1.38, 95% CI: 1.05;1.80). Seven studies were conducted in men with CKD and included testosterone as determinant, of which six could be meta-analyzed. Low testosterone was associated with an increased risk of all-cause mortality and CV events (pooled HR: 1.98, 95% CI: 1.36;2.89; pooled HR of 2.40, 95% CI: 1.22;4.71, respectively). Two studies showed an increased risk of all-cause mortality with decreased dehydroepiandrosterone sulfate (DHEAS) in men with CKD; results regarding CV events were conflicting.

CONCLUSIONS

Although literature is scarce, evidence suggests that lower testosterone may increase CKD risk in the general population and risk of all-cause mortality and CV events in men with CKD. Whether testosterone supplementation could prevent these potential detrimental outcomes should be determined in future intervention studies.

Chronic Kidney Disease in the Transgender, Nonbinary, or Gender Diverse Person

Nephrologists are increasingly providing care to transgender, nonbinary, and gender diverse (TNBGD) individuals with chronic kidney disease. This narrative review discusses the care of TNBGD individuals from a nephrology perspective. TNBGD individuals are under-represented in the nephrology literature. TNBGD individuals are at an increased risk of adverse outcomes compared with the cisgender population including mental health, cardiovascular disease, malignancy, sexually transmitted infections, and mortality. Gender-affirming hormone therapy (GAHT) with estradiol in transfeminine individuals potentially increases the risk of venous thromboembolism and cardiovascular disease. GAHT with testosterone in transmasculine individuals potentially increases the risk of erythrocytosis and requires careful monitoring. GAHT modifies body composition and lean muscle mass, which in turn influence creatinine generation and excretion, which may impact the performance of estimated glomerular filtration rate (GFR) equations and the estimation of 24-hour urine values from spot urine albumin/protein to creatinine ratios. There are limited studies regarding TNBGD individuals with chronic kidney disease. Additional research is needed to evaluate the effects of GAHT on GFR and biomarkers of kidney function and the performance of the estimated GFR equation in TNBGD populations.

Sex moderations in the relationship between aortic stiffness, cognition, and cerebrovascular reactivity in healthy older adults

It is well established that sex differences exist in the manifestation of vascular diseases. Arterial stiffness (AS) has been associated with changes in cerebrovascular reactivity (CVR) and cognitive decline in aging. Specifically, older adults with increased AS show a decline on executive function (EF) tasks. Interestingly, the relationship between AS and CVR is more complex, where some studies show decreased CVR with increased AS, and others demonstrate preserved CVR despite higher AS. Here, we investigated the possible role of sex on these hemodynamic relationships. Acquisitions were completed in 48 older adults. Pseudo-continuous arterial spin labeling (pCASL) data were collected during a hypercapnia challenge. Aortic pulse wave velocity (PWV) data was acquired using cine phase contrast velocity series. Cognitive function was assessed with a comprehensive neuropsychological battery, and a composite score for EF was calculated using four cognitive tests from the neuropsychological battery. A moderation model test revealed that sex moderated the relationship between PWV and CVR and PWV and EF, but not between CVR and EF. Together, our results indicate that the relationships between central stiffness, cerebral hemodynamics and cognition are in part mediated by sex.

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.

Providing Care for Transgender Persons With Kidney Disease: A Narrative Review

Purpose of review

Nephrologists are increasingly providing care to transgender individuals with chronic kidney disease (CKD). However, they may lack familiarity with this patient population that faces unique challenges. The purpose of this review is to discuss the care of transgender persons and what nephrologists should be aware of when providing care to their transgender patients.

Sources of information

Original research articles were identified from MEDLINE and Google Scholar using the search terms "transgender," "gender," "sex," "chronic kidney disease," "end stage kidney disease," "dialysis," "transplant," and "nephrology."

Methods

A focused review and critical appraisal of existing literature regarding the provision of care to transgender men and women with CKD including dialysis and transplant to identify specific issues related to gender-affirming therapy and chronic disease management in transgender persons.

Key findings

Transgender persons are at an increased risk of adverse outcomes compared with the cisgender population including mental health, cardiovascular disease, malignancy, sexually transmitted infections, and mortality. Individuals with CKD have a degree of hypogonadotropic hypogonadism and decreased levels of endogenous sex hormones; therefore, transgender persons with CKD may require reduced exogenous sex hormone dosing. Exogenous estradiol therapy increases the risk of venous thromboembolism and cardiovascular disease which may be further increased in CKD. Exogenous testosterone therapy increases the risk of polycythemia which should be closely monitored. The impact of gender-affirming hormone therapy on glomerular filtration rate (GFR) trajectory in CKD is unclear. Gender-affirming hormone therapy with testosterone, estradiol, and anti-androgen therapies changes body composition and lean body mass which influences creatinine generation and the performance for estimated glomerular filtration rate (eGFR) equations in transgender persons. Confirmation of eGFR with measured GFR is reasonable if an accurate knowledge of GFR is needed for clinical decision-making.

Limitations

There are limited studies regarding the intersection of transgender persons and kidney disease and those that exist are mostly case reports. Randomized controlled trials and observational studies in nephrology do not routinely differentiate between cisgender and transgender participants.

Implications

This review highlights important considerations for providing care to transgender persons with kidney disease. Additional research is needed to evaluate the performance of eGFR equations in transgender persons, the effects of gender-affirming hormone therapy, and the impact of being transgender on outcomes in persons with kidney disease.

Providing Care for Transgender Persons With Kidney Disease: A Narrative Review

Purpose of review:

Nephrologists are increasingly providing care to transgender individuals with chronic kidney disease (CKD). However, they may lack familiarity with this patient population that faces unique challenges. The purpose of this review is to discuss the care of transgender persons and what nephrologists should be aware of when providing care to their transgender patients.

Sources of information:

Original research articles were identified from MEDLINE and Google Scholar using the search terms “transgender,” “gender,” “sex,” “chronic kidney disease,” “end stage kidney disease,” “dialysis,” “transplant,” and “nephrology.”

Methods:

A focused review and critical appraisal of existing literature regarding the provision of care to transgender men and women with CKD including dialysis and transplant to identify specific issues related to gender-affirming therapy and chronic disease management in transgender persons.

Key findings:

Transgender persons are at an increased risk of adverse outcomes compared with the cisgender population including mental health, cardiovascular disease, malignancy, sexually transmitted infections, and mortality. Individuals with CKD have a degree of hypogonadotropic hypogonadism and decreased levels of endogenous sex hormones; therefore, transgender persons with CKD may require reduced exogenous sex hormone dosing. Exogenous estradiol therapy increases the risk of venous thromboembolism and cardiovascular disease which may be further increased in CKD. Exogenous testosterone therapy increases the risk of polycythemia which should be closely monitored. The impact of gender-affirming hormone therapy on glomerular filtration rate (GFR) trajectory in CKD is unclear. Gender-affirming hormone therapy with testosterone, estradiol, and anti-androgen therapies changes body composition and lean body mass which influences creatinine generation and the performance for estimated glomerular filtration rate (eGFR) equations in transgender persons. Confirmation of eGFR with measured GFR is reasonable if an accurate knowledge of GFR is needed for clinical decision-making.

Limitations:

There are limited studies regarding the intersection of transgender persons and kidney disease and those that exist are mostly case reports. Randomized controlled trials and observational studies in nephrology do not routinely differentiate between cisgender and transgender participants.

Implications:

This review highlights important considerations for providing care to transgender persons with kidney disease. Additional research is needed to evaluate the performance of eGFR equations in transgender persons, the effects of gender-affirming hormone therapy, and the impact of being transgender on outcomes in persons with kidney disease.

Sex differences in vascular aging in response to testosterone

Large elastic arterial stiffening and endothelial dysfunction are phenotypic characteristics of vascular aging, a major risk factor for age-associated cardiovascular diseases. Compared to men, vascular aging in women appears to be slowed until menopause, whereafter vascular aging accelerates to match that seen in men. These sex differences in vascular aging have been attributed to changes in sex hormones that occur with aging. Although the role of estradiol in vascular aging in women has been highlighted in recent aging research, little is known about the impact of declining testosterone concentrations in both sexes. Importantly, while androgen concentrations generally decline with age in men, there are data that indicate reductions in androgen concentrations in women as well. Evidence suggests that low testosterone is associated with impaired endothelial function and increased arterial stiffness in men, although the effect of androgens on vascular aging in women remains unclear. Testosterone may modulate vascular aging by mitigating the effects of oxidative stress and inflammation, although there is sex specificity to this effect. The purpose of this review is to present and summarize the research regarding sex differences in vascular aging in response to androgens, specifically testosterone. Because exercise is a potent lifestyle factor for slowing and reversing vascular aging, we briefly summarize the available literature regarding the regulatory function of testosterone on vascular adaptations to exercise training.

The association of decreased testosterone with atherosclerosis and inflammation in male predialysis patients with chronic kidney disease

PURPOSE

To investigate the frequency of hypogonadism and its relationship to inflammation and carotid intima-media thickness (CIMT) in male patients with predialysis chronic kidney disease (CKD).

METHODS

A total of 105 patients with CKD, 55 (52.4%) as stage 3, 33 (31.4%) as stage 4 and 17 (16.2%) as stage 5, were enrolled into the study. Total testosterone (TT) and free testosterone (FT), interleukin 6 (IL-6), C-reactive protein (CRP) levels, and CIMT were measured.

RESULTS

According to TT and FT, hypogonadism was detected in 18 (17.1%) and 22 (20.9%) patients, respectively. There was no difference in terms of TT and FT, CIMT, CRP and IL-6 between the stages of CKD. According to TT, the patients with hypogonadism had significantly higher CRP and high-density lipoprotein cholesterol (HDL-cholesterol) levels (p=0.004 and p=0.005, respectively). There was no significant difference in other parameters. According to FT, the patients with hypogonadism had significantly higher CRP (p=0.017), and TT were negatively correlated with body mass index (BMI), waist circumference (WC), hip circumference, and CRP levels. FT was negatively correlated with age, waist circumference, systolic blood pressure, diastolic blood pressure (DBP) and CRP.

CONCLUSIONS

The frequency of hypogonadism was found around 17-21% among the patients with CKD. Despite similar IL-6 and CIMT levels, CRP was found to be higher in the patients with hypogonadism. We consider that further studies with larger populations are needed to elucidate the entity.

Bone-Vascular Axis in Chronic Kidney Disease

Patients with chronic kidney disease (CKD) are at increased risk of osteoporosis and vascular calcification. Bone demineralization and vascular mineralization go often hand in hand in CKD, similar to as in the general population. This contradictory association is independent of aging and is commonly referred to as the "calcification paradox" or the bone-vascular axis. Various common risk factors and mechanisms have been identified. Alternatively, calcifying vessels may release circulating factors that affect bone metabolism, while bone disease may infer conditions that favor vascular calcification. The present review focuses on emerging concepts and major mechanisms involved in the bone-vascular axis in the setting of CKD. A better understanding of these concepts and mechanisms may identify therapeutics able to target and exert beneficial effects on bone and vasculature simultaneously.

A robust LC-MS/MS assay with online cleanup for measurement of serum testosterone

Accurate measurement of low levels of testosterone is critical for diagnosis and treatment of androgen disorders. The very low concentrations of testosterone in children, females, and males with androgen suppression therapies necessitate the use of mass spectrometry-based methods. We aimed to develop a liquid chromatography with tandem mass spectrometry method with simplified sample preparation and online solid-phase extraction cleanup to achieve enhanced precision, accuracy, robustness, and cost-effectiveness. The assay was linear from 10 to 20 000 pg/mL with an analytical recovery of 93-104%. The total coefficient of variation was 2.5, 1.9, and 1.7% at concentration levels of 348, 5432, and 10 848 pg/mL, respectively. No significant carryover was observed from samples with concentrations up to 20 000 pg/mL. No significant interference was observed from androstenedione, dehydroepiandrosterone, epi-testosterone, and estriol. Comparison with CDC Hormone Standardization program (HoSt) reference samples with defined values (n = 40) showed a Deming regression slope of 0.963, intercept of 28.06 pg/mL, standard error of estimate was 66.9, a correlation coefficient of 0.9996, and a mean bias of -0.6%. The method met the accuracy criteria by the CDC HoSt program. In addition, we achieved >12 000 injections on a single analytical column without significant performance deterioration due to the specific online solid-phase extraction settings.

Sex differences in mechanisms of arterial stiffness

Arterial stiffness progressively increases with aging and is an independent predictor of cardiovascular disease (CVD) risk. Evidence supports that there are sex differences in the time course of aging-related arterial stiffness and the associated CVD risk, which increases disproportionately in postmenopausal women. The association between arterial stiffness and mortality is almost twofold higher in women versus men. The differential clinical characteristics of the development of arterial stiffness between men and women indicate the involvement of sex-specific mechanisms. This review summarizes the current literature on sex differences in vascular stiffness induced by aging, obesity, hypertension, and sex-specific risk factors as well as the impact of hormonal status, diet, and exercise on vascular stiffness in males and females. An understanding of the mechanisms driving sex differences in vascular stiffness has the potential to identify novel sex-specific therapies to lessen CVD risk, the leading cause of death in males and females. LINKED ARTICLES: This article is part of a themed section on The Importance of Sex Differences in Pharmacology Research. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.21/issuetoc.

New insights into arterial stiffening: does sex matter?

This review discusses sexual dimorphism in arterial stiffening, disease pathology interactions, and the influence of sex on mechanisms and pathways. Arterial stiffness predicts cardiovascular mortality independent of blood pressure. Patients with increased arterial stiffness have a 48% higher risk for developing cardiovascular disease. Like other cardiovascular pathologies, arterial stiffness is sexually dimorphic. Young women have lower stiffness than aged-matched men, but this sex difference reverses during normal aging. Estrogen therapy does not attenuate progressive stiffening in postmenopausal women, indicating that currently prescribed drugs do not confer protection. Although remodeling of large arteries is a protective adaptation to higher wall stress, arterial stiffening increases afterload to the left ventricle and transmits higher pulsatile pressure to smaller arteries and target organs. Moreover, an increase in aortic stiffness may precede or exacerbate hypertension, particularly during aging. Additional studies are needed to elucidate the mechanisms by which females are protected from arterial stiffness to provide insight into its mechanisms and, ultimately, therapeutic targets for treating this pathology.

Erectile function and gonadal hormones levels in men with end-stage renal disease: It's relevance to duration of haemodialysis

In this study, we evaluated the relationship between haemodialysis (HD) duration and erectile function status and gonadal hormones serum levels in adult men with end-stage renal disease (ESRD). A total of 118 men with ESRD on chronic HD were eligible for analysis. The erectile dysfunction (ED) was defined and graded according to the international index of erectile function (IIEF-5) score. The serum levels of follicle stimulating hormones (FSH), luteinising hormone (LH), testosterone (TST), prolactin (PRL) and estradiol (E2) were measured using the standard laboratory technique. The mean age was 48.97 ± 14.68 years and mean duration of HD was 4.58 ± 3.03 years. The overall prevalence of ED was 78.8%; from them 31.2% had severe grade. The prevalence of ED was comparable in HD duration categories [≤5 years (79.7%), 5-10 years (76.5%), >10 years (80.0%); p > 0.05]. The percentage of abnormal serum levels of FSH, LH, TST, PRL, E2 were 5.1%, 1.6%, 18.6%, 90.7% and 0.0% respectively. No significant relationships were observed between HD duration and IIEF-5 score or gonadal hormones serum levels (p < 0.05). We concluded that HD duration has no effect on erectile function status and gonadal hormones serum levels. Other factors may be relevant to these conditions in this particular group of patients.

Relation of Testosterone Levels to Mortality in Men With Heart Failure

We aimed to investigate the impact of testosterone on the prognosis of heart failure (HF), as well as the underlying cardiac function, cardiac damage, and exercise capacity. We analyzed consecutive 618 men with HF (age 65.9 years). These patients were divided into quartiles based on their serum levels of total testosterone (TT): first (TT > 631 ng/dl, n = 154), second (462 < TT ≤ 631 ng/dl, n = 155), third (300 < TT ≤ 462 ng/dl, n = 156), and fourth (TT ≤ 300 ng/dl, n = 153) quartiles. In the Kaplan-Meier analysis (mean 1,281 days), all-cause mortality progressively increased throughout from the first to the fourth groups. In the multivariable Cox proportional hazard analysis, TT was found to be an independent predictor of all-cause mortality (hazard ratio 0.929, p = 0.042). In addition, we compared the parameters of echocardiography and cardiopulmonary exercise testing, as well as levels of B-type natriuretic peptide and cardiac troponin I, among the 4 groups. Left ventricular ejection fraction and B-type natriuretic peptide did not differ among the groups. In contrast, the fourth quartile, compared with the first, second, and third groups, had higher levels of troponin I and lower peak VO₂ (p <0.05, respectively). Decreased serum testosterone is associated with myocardial damage, lower exercise capacity, and higher mortality in men with HF.

Rapid recovery of hypogonadism in male patients with end stage renal disease after renal transplantation

PURPOSE

End stage renal disease (ESRD) in male patients is associated with a high prevalence of hypogonadism. After renal transplantation (RTx) an improvement in gonadal function is often observed. However, the time course of changes in pituitary-gonadal axis after RTx and the influence of renal function, age and anthropometric parameters are not well characterized. We prospectively evaluated pituitary-gonadal axis in male patients with ESRD before and after RTx for up to 1 year.

METHODS

Ninety-seven male patients with ESRD were consecutively investigated on day of surgery and 1, 3, 6, and 12 months after RTx. Time course of changes in sex hormones (total testosterone ((TT)), calculated free testosterone ((cfT)), estradiol (E₂), LH, FSH and prolactin), and interdependence with renal function, age, anthropometric factors, cause of ERDS, time on dialysis, and transplant associated factors were analyzed.

RESULTS

Hypogonadism (TT < 8 nmol/l) was present in 40% of pts prior to RTX and in only 18% at 1 year after RTX. Recovery from hypogonadism was significantly higher in pts < 50 years and occurred within 3 months. RTx resulted in a decrease in E₂/T ratio starting at 1 month and suggesting a shift from estrogen to testosterone production. BMI and waist circumference had the similar impact on T levels after successful RTx compared to patients without renal disease. No specific impact on recovery of hypogonadism was found for time on dialysis prior to RTx and living or cadaver transplantation.

CONCLUSIONS

Successful RTx is associated with a rapid recovery from hypogonadism within 3 months preceeded by improvement in renal function particularly in patients younger than 50 years.

The Triglycerides and Glucose Index rather than HOMA-IR is more associated with Hypogonadism in Chinese men

Previous studies have reported that insulin resistant and low testosterone are related. The triglyceride and glucose index (TyG) well mirrors insulin sensitivity. No study investigated the application of TyG in male hypogonadism. We aimed to explore whether TyG was associated with hypogonadism, and also evaluate the ability of TyG compared to HOMA-IR as a possible hypogonadism predictor. A total of 4299 male subjects were enrolled from 22 sites in East China. Hypogonadism was defined as total testosterone <11.3 nmol/L. 695 (16.2%) hypogonadal men had significantly higher TyG index. The prevalence of hypogonadism stepwise increased across increasing TyG quartiles (P < 0.01). TyG was negatively associated with sex hormones and hypogonadism after adjustment for age, current smoking status, hypertension and overweight/obesity (all P for trend <0.01). The full-adjusted odds ratio was 6.1 for the highest quartile compared with the lowest quartile of TyG (95% CI 4.51, 8.25, P < 0.001). On ROC curve analysis, a larger area under the curve was found for TyG (0.71, 95% CI 0.69,0.73) than for HOMA-IR (0.68, 95% CI 0.66,0.70). Thus, the TyG was significantly associated with a higher prevalence of hypogonadism in Chinese men. TyG had a better predictive power for hypogonadism than HOMA-IR.

Association between Testosterone and Mortality Risk among U.S. Males Receiving Dialysis

BACKGROUND

Among the general population, low circulating testosterone levels are associated with higher risk of cardiovascular disease and death. While testosterone deficiency is common in dialysis patients, studies of testosterone and mortality in this population are ambiguous and overlapping. We hypothesized that lower testosterone levels are associated with higher mortality in male dialysis patients.

METHODS

We examined a nationally representative cohort of male dialysis patients from a large US dialysis organization who underwent one or more total testosterone measurements from 1/2007 to 12/2011. The association between total testosterone categorized as quartiles and all-cause mortality was studied using Cox models adjusted for expanded case-mix and laboratory covariates. We also examined total testosterone as a continuous predictor of all-cause mortality using restricted cubic splines.

RESULTS

Among 624 male dialysis patients, 51% of patients demonstrated testosterone deficiency (total testosterone <300 ng/dL); median (IQR) total testosterone levels were 297 (190-424) ng/mL. In expanded case-mix + laboratory adjusted Cox analyses, we observed a graded association between lower testosterone levels and higher mortality risk (ref: quartile 3): adjusted hazard ratios (95% CI) 2.32 (1.33-4.06), 1.80 (0.99-3.28), and 0.68 (0.32-1.42) for Quartiles 1, 2, and 4, respectively. In adjusted spline analyses, the lower testosterone-higher mortality risk association declined with higher testosterone levels until the value reached a threshold of 400 ng/dL above which risk plateaued.

CONCLUSION

Lower testosterone levels were independently associated with higher mortality risk in male dialysis patients. Further studies are needed to determine underlying mechanisms, and whether testosterone replacement ameliorates death risk in this population.

Associations Between Low Serum Testosterone and All-Cause Mortality and Infection-Related Hospitalization in Male Hemodialysis Patients: A Prospective Cohort Study

Introduction

Infectious diseases are the second highest cause of death in patients on dialysis. In addition, testosterone deficiency or hypogonadism is prevalent in dialysis patients. However, to our knowledge, no studies have investigated the association between testosterone levels and infectious events. We aimed to evaluate whether serum testosterone levels are associated with infection-related hospitalization in male hemodialysis patients in a prospective cohort study.

Methods

We divided the study population into 3 groups based on serum testosterone levels. Associations between testosterone levels and clinical outcomes of infection-related hospitalization, all-cause mortality, and cardiovascular disease (CVD) events were analyzed using the Cox proportional hazard model.

Results

Nine hundred two male patients were enrolled and followed up for a median of 24.7 months. Their mean ± SD age was 63.4 ± 11.8 years, and their median (interquartile range) of total testosterone was 11.7 nmol/l (7.9–14.9 nmol/l). During follow-up, 123 participants died. Infection-related hospitalization and CVD events occurred in 116 and 151 patients, respectively. Infection-related hospitalization was more frequent in the lower testosterone tertile than in the higher testosterone tertile (hazard ratio [HR]: 2.12; 95% confidence interval [CI]: 1.18–3.79; P = 0.01) in adjusted models. Moreover, all-cause mortality was significantly greater in the lower testosterone tertile than in the higher testosterone tertile in adjusted analysis (HR: 2.26; 95% CI: 1.21–4.23; P = 0.01). In contrast, there were no significant differences in CVD events by testosterone level.

Discussion

Low levels of testosterone may be associated with higher rates of infection-related hospitalization and all-cause mortality in male hemodialysis patients.

Hormonal changes in hemodialysis patients: Novel risk factors for mortality?

Patients with end-stage renal disease undergoing dialysis commonly experience derangements in the hypothalamic-pituitary-gonadal axis together with alterations at the level of synthesis and clearance of many hormones. This hormonal imbalance, even if asymptomatic, has recently been associated with increased mortality in these patients. In this review, we summarize observational and mechanistic evidence linking hormonal alterations at the level of the thyroid and sex-hormone systems with this mortality risks.

Male Sexual Dysfunction and Chronic Kidney Disease

Male sexual dysfunction is common in chronic kidney disease (CKD), particularly in end-stage renal disease. Historically, this cause of considerable morbidity has been under-reported and under-recognized. The ideal approach to diagnosis and management remains unclear due to a paucity of good quality data, but an understanding of the pathophysiology is necessary in order to address the burden of this important complication of CKD. This paper will review the endocrine dysfunction that occurs in renal disease, particularly the hypothalamic–pituitary–gonadal axis, discuss the causes of erectile dysfunction, infertility, and altered body image and libido in these patients and suggest appropriate treatment interventions.

Low testosterone and clinical outcomes in Chinese men with type 2 diabetes mellitus - Hong Kong Diabetes Registry

AIMS

To assess the implications of low testosterone on cardiovascular risk factors, metabolic syndrome (MES) and clinical outcomes in Chinese men with Type 2 Diabetes (T2D).

METHODS

A prospective cohort study carried out in a university hospital involving a consecutive cohort of 1239 Chinese men with T2D and a median disease duration of 9years followed up for 4.8years. Clinical characteristics, frequency of MES, serum total testosterone and clinical events were analyzed. Multivariate logistic regression was performed to examine the independent association of low testosterone with MES after adjustment for confounding covariates. Cox proportional hazards regression analysis was used to derive hazard ratio for clinical outcomes.

RESULTS

More men with low testosterone had cardiovascular-renal disease and MES than those with normal testosterone. The adjusted odds ratio (OR) of low testosterone for MES was 2.63 (95% Confidence Interval [CI] 1.56-4.61). After a median follow-up of 4.8years, the hazard ratio (HR) of low testosterone was 2.22 (95% CI 1.23-4.01) for incident non-prostate cancer. In a multivariate Cox-regression model, the HRs were attenuated but remained significant with adjustment for MES and renal parameters.

CONCLUSIONS

Chinese men with low testosterone had high prevalence of cardiovascular disease and MES with high incidence non-prostate cancer.

Hypogonadism associated with muscle atrophy, physical inactivity and ESA hyporesponsiveness in men undergoing haemodialysis

BACKGROUND

Testosterone deficiency (hypogonadism) is common among men undergoing haemodialysis, but its clinical implications are not well characterized. Testosterone is an anabolic hormone that induces erythrocytosis and muscle synthesis. We hypothesized that testosterone deficiency would be associated with low muscle mass, physical inactivity and higher dosages of erythropoietin-stimulating agents (ESA).

METHODS

Single-center cross-sectional study of 57 male haemodialysis patients. None of the patients was undergoing testosterone replacement therapy. Total testosterone was measured in serum. Body composition (by bioelectrical impedance analysis) and physical activity (by the use of pedometers) were assessed. Patients with testosterone levels below the normal range were considered hypogonadal.

RESULTS

Mean testosterone level was 321±146ng/dL; 20 patients (35%) were hypogonadal. Hypogonadal patients were older and had lower mean arterial blood pressure, higher interleukin-6 levels, lower lean body mass and higher fat body mass. A negative association between testosterone and normalized ESA dose was found in uni- and multivariate regression analyses. Testosterone levels directly correlated with lean body mass regardless of confounders. Hypogonadal patients had lower physical activity than their counterparts [2753±1784 vs. 4291±3225steps/day (p=0.04)]. The relationship between testosterone and physical activity was independent of age, comorbidities and inflammatory markers, but dependent on the proportion of muscle mass.

CONCLUSION

Hypogonadism is common in our male haemodialysis population and is associated with higher ESA doses, reduced muscle mass and lower physical activity. The link between low testosterone levels and physical inactivity may conceivably relate to reduced muscle mass due to inadequate muscle protein synthesis.

Inverse association of total testosterone with central haemodynamics and left ventricular mass in hypertensive men

BACKGROUND

There is evidence for inverse association between endogenous testosterone and blood pressure. Furthermore, low plasma testosterone is associated with increased risk of major cardiovascular events in middle-aged hypertensive men. Central (aortic) blood pressures determine left ventricular hypertrophy and predict cardiovascular mortality. The aim of the present study was to assess the relationship of total testosterone (TT) with central haemodynamics and left ventricular mass in hypertensive men.

METHODS

We investigated 134 non-diabetic, middle-aged, hypertensive men and 60 age-matched normotensive males. All participants were subject to measurement of aortic systolic (aoSBP) and pulse pressure (aoPP) by pulse wave analysis using the SphygmoCor device. Wave reflections were assessed by the measurement of heart rate corrected augmentation index (AIx75). Echocardiography was performed in all individuals and left ventricular mass (LVM) was calculated using the Devereux's formula. Plasma TT was measured by enzyme immunoassay.

RESULTS

In hypertensive men, univariate analysis showed an inverse, significant correlation between TT and aoSBP (r = -20, p = 0.02), aoPP (r = -0.21, p = 0.01), AIx75 (r = -0.22, p = 0.01) and LVM (r = -0.19, p = 0.008). Multivariate regression analysis demonstrated an independent inverse association of TT with aoPP (b = -0.21, p = 0.02), AIx75 (b = -0.19, p = 0.03) and LVM (b = -0.28, p = 0.005) after adjustment for age, BMI, smoking, total cholesterol, triglycerides, fasting glucose, mean arterial pressure, antihypertensive treatment and statin use. Independent associations were retained even after inclusion of normotensive subjects in the analysis.

CONCLUSIONS

In hypertensive men, TT is independently and inversely associated with central pulse pressure, wave reflections and left ventricular mass. Considering the adverse prognostic role of central blood pressures and LV hypertrophy on cardiovascular outcomes in hypertensive patients, the present findings might explain part of the increased cardiovascular risk associated with low testosterone. Whether measurement of central haemodynamics may improve risk stratification in hypertensive men with low testosterone warrants further investigation.

Controversies in testosterone replacement therapy: testosterone and cardiovascular disease

The role of testosterone in the cardiovascular (CV) health of men is controversial. Data suggest that both the condition and treatment of clinical hypogonadism is associated with decreased CV mortality; however, two recent studies suggest that hypogonadal subjects treated with testosterone replacement therapy have a higher incidence of new CV events. There has been increased media attention concerning the risk of CV disease in men treated with testosterone. Until date, there are no long-term prospective studies to determine safety. Literature spanning over the past 30 years has suggested that not only is there a possible increased CV risk in men with low levels of testosterone, but the benefits from testosterone therapy may even lower this risk. We review here the recent studies that have garnered such intense scrutiny. This article is intended as a thorough review of testosterone levels and CV risk, providing the clinician with the facts needed to make informed clinical decisions in managing patients with clinical hypogonadism.

The Associations Between Body Cell Mass and Nutritional and Inflammatory Markers in Patients With Chronic Kidney Disease and in Subjects Without Kidney Disease

OBJECTIVES

Body cell mass (BCM), a component of lean tissue mass (LTM), is a metabolically active part of the body. Lean tissue loss is one of the diagnostic criteria of protein energy wasting. In patients with chronic kidney disease (CKD), a decrease of lean tissue, including BCM, may be replaced by an increase of extracellular water. Bioimpedance spectroscopy (BIS) enables the assessment of the amount of BCM, LTM, and fluid overload. The aim of our study was to assess the relationship between BCM measured by BIS and anthropometric measurements, biochemical markers of nutrition and also inflammatory markers.

METHODS

Forty-eight patients treated with hemodialysis (HD; 32 males and 16 females) with a mean age 59.8 ± 15.5 (HD group), 61 patients with CKD Stage 4 to 5 (35 males and 26 females) with a mean age of 60.1 ± 17.7 (predialysis group) and 33 individuals with normal renal function (18 males and 15 women) with a mean age 58.7 ± 17.0 (control group) were included. Body mass index, handgrip strength (HGS), body composition measured by BIS, and biochemical analyses were performed on all of them.

RESULTS

Positive correlations were observed between BCM and LTM, HGS, serum creatinine and insulin-like growth factor 1 concentrations in all groups. Serum prealbumin concentration correlated positively with BCM only in the predialysis group (r = 0.406; P = .001). The amount of lymphocytes also correlated passively with BCM in predialysis group (r = 0.314; P = .024). Negative correlations were noted between BCM and fat mass in all groups and between BCM and interleukin 6 concentrations only in the HD group. In this study, BCM neither correlated with body mass index and serum albumin nor with C-reactive protein.

CONCLUSIONS

BCM is strongly associated with biochemical determinants of muscle mass (serum creatinine, insulin-like growth factor 1) and muscle function (HGS) in patients treated with HD, with CKD Stage 4 to 5 and in individuals without kidney disease. Its significance requires further investigation.

Prevalence of subnormal testosterone concentrations in men with type 2 diabetes and chronic kidney disease

BACKGROUND

One-third of men with type 2 diabetes have subnormal testosterone concentrations along with inappropriately normal LH and FSH concentrations. It is not known if the presence of renal insufficiency affects free testosterone concentrations in men with type 2 diabetes.

HYPOTHESIS

We hypothesized that type 2 diabetic men with chronic renal disease (CKD; estimated glomerular filtration rate (eGFR) < 60 ml/min per 1.73 m(2)) have lower free testosterone concentrations than men with normal renal function (eGFR ≥ 60 ml/min per 1.73 m(2)).

STUDY DESIGN AND SETTING

This is a retrospective chart review of patients attending diabetes and nephrology clinics. Men with type 2 diabetes who had the following information available were included in the study: testosterone (total and free) done by LC/MS-MS followed by equilibrium dialysis, sex hormone binding globulin, LH, FSH and prolactin concentrations.

PARTICIPANTS

We present data on T and gonadotropin concentrations in 111 men with type 2 diabetes and CKD (stages 3-5) and 182 type 2 diabetic men without CKD.

RESULTS

The prevalence of subnormal free testosterone concentrations was higher in men with type 2 diabetes and CKD as compared to those without CKD (66% vs 37%, P < 0.001). Men with CKD had a higher prevalence of hypergonadotropic hypogonadism (26% vs 5%, P < 0.001) but not of hypogonadotropic hypogonadism (HH; 40% vs 32%, P = 0.22). There was an increase in the prevalence of hypergonadotropic hypogonadism with decreasing eGFR. Fifty-two percent of men with renal failure (CKD stage 5) had hypergonadotropic hypogonadism and 25% had HH. In men with CKD, the hemoglobin concentrations were lower in those with subnormal free T concentrations as compared to men with normal free T concentrations (119 ± 19 vs 128 ± 19 g/l, P = 0.04).

CONCLUSIONS

Two-thirds of men with type 2 diabetes and CKD have subnormal free T concentrations. The hypogonadism associated with CKD is predominantly hypergonadotropic.

Arterial Stiffening and Clinical Outcomes in Dialysis Patients

Cardiovascular disease (CVD) is an important cause of morbidity and mortality in dialysis patients. Brachial-ankle pulse wave velocity (baPWV) is more efficient to handily assess arteriosclerosis than aortic PWV. The cardio-ankle vascular index (CAVI) is also a novel blood pressure-independent arterial stiffness parameter. In dialysis patients, both baPWV and CAVI are increased compared to general subjects. Several studies have demonstrated that increased baPWV is associated with carotid atherosclerosis and diastolic left ventricular dysfunction in hemodialysis (HD) patients. In addition, higher baPWV is related to all-cause and cardiovascular (CV) mortality. CAVI is similarly associated with CVD. However, baPWV is superior to CAVI as a predictor of CV outcomes in HD patients. Besides these outcomes, a close relationship exists between sarcopenia, abdominal visceral obesity and arterial stiffening. Reduction of thigh muscle mass is inversely correlated with baPWV and CAVI in males. Abdominal fatness is also associated with increased arterial stiffness in females. These observations provide further evidence of higher risk of CV events in HD patients with sarcopenic obesity. In addition, arterial stiffness is associated with cerebral small vessel disease and decreased cognitive function in the elderly. However, it is unknown whether arterial stiffness may be useful as an early indicator of cognitive decline in dialysis patients. Because dialysis patients are at risk of developing dementia, more studies are needed to elucidate the causal link between arterial stiffness and cognitive impairment.

Recent trends in testosterone testing, low testosterone levels, and testosterone treatment among Veterans

Low serum testosterone (T) is common and increasingly prevalent with increased age. Recent studies report an 'epidemic' of T prescribing and concern about unnecessary T treatment. We investigated the number of men tested for T, the prevalence of low serum T levels, and initiation of T treatment among those with low T levels in men treated at Veterans Affairs (VA) facilities in the Northwest US (VISN 20). We identified male Veterans aged 40-89 years and examined yearly proportions of men tested for T, found to have low T levels (total T < 280 ng/dL, free T < 34 pg/mL, or bioavailable T < 84 ng/dL), and subsequently treated with T from 2002 to 2011. We excluded men who had T treatment in the year prior and men with diagnoses of prostate or breast cancer. Treatment initiation was defined as the first prescription for T within a year following a low T test. From 2002 to 2011, the yearly population of eligible men in VISN 20 increased from 129 247 to 163 572. The proportion of men who had serum T tests increased from 3.2% in 2002 to 5.8% in 2011. Among the tested men, the percentage of men with low T levels increased from 35.0 to 47.3%. However, the proportion of men with low T levels who were given T treatment within a year decreased from 31.0 to 28.0%. Despite large increases in T testing, and detection of men with low T levels, there was a slight decrease in the proportion of men with low T levels who were treated with T. The decrease in T treatment during this time period contrasts with other studies and may be related to higher comorbidity in Veterans and/or VA formulary restrictions on the use of transdermal T formulations.

Testosterone therapy and cardiovascular risk: advances and controversies

Two recent studies raised new concerns regarding cardiovascular (CV) risks with testosterone (T) therapy. This article reviews those studies as well as the extensive literature on T and CV risks. A MEDLINE search was performed for the years 1940 to August 2014 using the following key words: testosterone, androgens, human, male, cardiovascular, stroke, cerebrovascular accident, myocardial infarction, heart attack, death, and mortality. The weight and direction of evidence was evaluated and level of evidence (LOE) assigned. Only 4 articles were identified that suggested increased CV risks with T prescriptions: 2 retrospective analyses with serious methodological limitations, 1 placebo-controlled trial with few major adverse cardiac events, and 1 meta-analysis that included questionable studies and events. In contrast, several dozen studies have reported a beneficial effect of normal T levels on CV risks and mortality. Mortality and incident coronary artery disease are inversely associated with serum T concentrations (LOE IIa), as is severity of coronary artery disease (LOE IIa). Testosterone therapy is associated with reduced obesity, fat mass, and waist circumference (LOE Ib) and also improves glycemic control (LOE IIa). Mortality was reduced with T therapy in 2 retrospective studies. Several RCTs in men with coronary artery disease or heart failure reported improved function in men who received T compared with placebo. The largest meta-analysis to date revealed no increase in CV risks in men who received T and reduced CV risk among those with metabolic disease. In summary, there is no convincing evidence of increased CV risks with T therapy. On the contrary, there appears to be a strong beneficial relationship between normal T and CV health that has not yet been widely appreciated.

Carnitine deficiency is associated with late-onset hypogonadism and depression in uremic men with hemodialysis

Late-onset hypogonadism (LOH) and depression contribute to cardiovascular disease (CVD) in male hemodialysis (HD) patients. Carnitine deficiency is frequently observed in HD patients, playing a role in CVD. We examined whether carnitine deficiency was independently associated with LOH and depression in these patients. Twenty-six male HD patients underwent determinations of serum levels of free carnitine and testosterone. Status of LOH and depression were evaluated by questionnaires using aging male symptoms' (AMS) scale and self-rating depression scale (SDS), respectively. Free carnitine and testosterone levels in male HD patients were significantly lower than those in age-matched healthy male subjects. Linear regression analysis showed that AMS scale was positively associated with SDS. Univariate regression analysis revealed that total carnitine (inversely), free carnitine (inversely) and HD duration were correlated with AMS scale. Multiple stepwise regression analysis revealed that free carnitine was an independent determinant of AMS scale. Furthermore, free carnitine was also independently correlated with SDS in male HD patients. This study demonstrated that decreased free carnitine levels were independently associated with AMS scale and SDS in male HD patients. The observations suggest that decreased free carnitine levels could be a marker and therapeutic target of LOH and depression in uremic men with HD.

Testosterone and mortality

Epidemiological studies have found that men with low or low normal endogenous testosterone are at an increased risk of mortality than those with higher levels. Cardiovascular disease accounts for the greater proportion of deaths in those with low testosterone. Cancer and respiratory deaths in some of the studies are also significantly more prevalent. Disease-specific studies have identified that there are higher mortality rates in men with cardiovascular, respiratory and renal diseases, type 2 diabetes and cancer with low testosterone. Obesity, metabolic syndrome, type 2 diabetes, cardiovascular disease and inflammatory disorders are all associated with an increased prevalence of testosterone deficiency. Two major questions that arise from these findings are (1) is testosterone deficiency directly involved in the pathogenesis of these conditions and/or a contributory factor impairing the body's natural defences or is it merely a biomarker of ill health and the severity of underlying disease process? (2) Does testosterone replacement therapy retard disease progression and ultimately enhance the clinical prognosis and survival? This review will discuss the current state of knowledge and discuss whether or not there are any answers to either of these questions. There is convincing evidence that low testosterone is a biomarker for disease severity and mortality. Testosterone deficiency is associated with adverse effects on certain cardiovascular risk factors that when combined could potentially promote atherosclerosis. The issue of whether or not testosterone replacement therapy improves outcomes is controversial. Two retrospective studies in men with diagnosed hypogonadism with or without type 2 diabetes have reported significantly improved survival.

The implications of low testosterone on mortality in men

Testosterone levels in men slowly decline with aging and also decline more abruptly due to medical illness or medications. Prescriptions for testosterone have increased dramatically over the past decade, since a testosterone-gel formulation was approved and since numerous studies reported an association between low serum testosterone and increased mortality. However, recent observational studies of testosterone treatment have reported conflicting results with some studies reporting decreased risks for mortality while others reported increased mortality risks with testosterone treatment. This paper will summarize recent studies of low serum testosterone and mortality and testosterone treatment and mortality and what the potential implications of these studies are for the clinician.

Effect of testosterone on Cisplatin-induced nephrotoxicity in surgically castrated rats

BACKGROUND

Cisplatin (CP) is an important antitumor drug with serious side effects such as nephrotoxicity. Estrogens can affect CP-induced nephrotoxicity; however, the role of testosterone (TS), the main male sex hormone, is not clear.

OBJECTIVES

This study aimed to investigate the effect of TS on CP-induced nephrotoxicity in castrated male rats.

MATERIALS AND METHODS

A total of 54 male Wistar rats were castrated and allocated into eight groups. Groups 1 through 3 respectively received 10, 50, and 100 mg/kg/wk of TS and group 4 received sesame oil for four weeks; then all four groups received 2.5 mg/kg/d CP for one week. Groups 5 through 8 received the same treatment regimen as groups 1 through 4 during first four weeks but instead of CP, they received saline for one week. Then the animals were sacrificed for biochemical and histopathologic studies.

RESULTS

CP increased the serum levels of blood urea nitrogen (BUN), creatinine (Cr), and malondialdehyde (SMDA) as well as kidney weight (KW), bodyweight (BW) loss, and kidney tissue damage score (KTDS). It significantly decreased the serum and kidney levels of nitrite and serum level of TS in comparison with the control group (P < 0.05). However, coadministration of CP and low dose of TS significantly decreased the serum levels of BUN as well as Cr and KTDS (P < 0.05). Administration of high-dose TS alone increased the SMDA level, KTDS, and KW while decreased the BW significantly (P < 0.05).

CONCLUSIONS

It seems that testosterone in low dose, i.e. physiologic dose, protects kidneys against CP-induced nephrotoxicity; however, special care is needed in CP therapy of patients with high levels of TS.

Systematic Literature Review of the Epidemiology of Nongenetic Forms of Hypogonadism in Adult Males

This study summarizes the literature on the prevalence, incidence, and proportion of patients receiving treatment for male hypogonadism and a systematic literature search was performed for articles published in the last 20 years. Of the 97 studies identified, 96 examined the prevalence, 2 examined the incidence, and 4 examined the proportion of males with hypogonadism patients receiving treatment. Based on studies conducted in Europe and USA, the prevalence of hypogonadism in the general population ranged from 2.1% to 12.8% of middle-aged to older men, with an estimated incidence of 12 new cases per 1,000 person-years. Prevalence was higher among patients with comorbid conditions, such as type 2 diabetes mellitus and obesity. Approximately 10–12% of men with hypogonadism were receiving testosterone treatment. This literature review suggests that there is potentially a significant burden of hypogonadism in the general population. Burden seems to increase with age and in the presence of certain disease conditions. Data suggests that many hypogonadal men who may benefit from testosterone replacement are not receiving treatment. This may be the result of underdiagnosis of the disease, lack of awareness by patients or physicians, irregularities surrounding the diagnostic criteria, and deficiency of long-term safety studies.

A prospective study in male recipients of kidney transplantation reveals divergent patterns for inhibin B and testosterone secretions

Background

Male patients with chronic kidney disease often exhibit the biological and clinical hallmarks of an abnormal hypothalamo–pituitary–gonadal axis. It is known that dialysis does not reverse this impaired endocrine status; however, the impact of kidney transplantation (KT) is still controversial. The aim of our study was to investigate the levels of serum gonadotropins, testosterone, and inhibin B during dialysis and after KT.

Methods

A longitudinal and prospective single center study was led in an academic setting. Blood hormones levels were assayed by immunoassays in 53 men (mean age: 37 years) receiving dialysis (T₀) and at 6 months post-KT (T₁₈₀). These data were compared with those from 46 fertile semen donors (mean age: 37 years). The main outcome measure was the between-groups differences in hormones levels. A second criterion was the comparison of T₀ and T₁₈₀ hormones levels according to the immunosuppressive regimen.

Results

For patients ongoing dialysis, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) mean levels were high, whereas testosterone and inhibin B mean levels remained normal. After KT, LH levels returned to normal whereas FSH was significantly increased. Testosterone levels remained normal whereas inhibin B levels significantly decreased. We found that the combination tacrolimus plus mycophenolic acid significantly decreased post-KT inhibin B levels. Moreover, we found that pre-graft inhibin-B level was independent of testosterone and could predict low post-operative inhibin B level with a sensitivity of 77% and a specificity of 92%.

Conclusions

Our study suggests that endocrine secretions of Leydig and Sertoli cells are differently impacted by dialysis, KT and immunosuppressive regimen raising new issues to explore.

Testosterone, aging and survival: biomarker or deficiency

PURPOSE OF REVIEW

The purpose of this study is to review recent studies that examined the association of endogenous and exogenous testosterone and mortality in older men.

RECENT FINDINGS

Over the past several years, there has been a steep rise in testosterone prescriptions. The increased use of testosterone occurred in the context of several studies that reported an association between low serum testosterone and increased cardiovascular events and mortality. In contrast, recent studies have reported an association between testosterone treatment and adverse events. A testosterone treatment trial of mobility-impaired elderly men with prevalent cardiovascular disease was stopped due to increased cardiovascular events in the T-treated men and a meta-analysis reported increased cardiovascular events in T-treated men. In two recent large observational studies, testosterone treatment was associated with an increased risk for serious adverse cardiovascular events.

SUMMARY

Low testosterone is associated with mortality in multiple cohort studies; however, it is unclear if this is a causal association or due to low testosterone being a biomarker of poor health. Given recent reports of adverse outcomes associated with testosterone treatment, a conservative use of testosterone is warranted in men with cardiovascular disease who may be at greater risk for adverse outcomes.

Resistance training and testosterone levels in male patients with chronic kidney disease undergoing dialysis

BACKGROUND

We investigated serum testosterone and insulin-like growth factor 1 (IGF-1) levels' associations with muscle fibre size and resistance training in male dialysis patients.

METHODS

Male patients were included in a 16-week control period followed by 16 weeks of resistance training thrice weekly. Blood samples were obtained to analyse testosterone, luteinizing hormone (LH), IGF-1, and IGF-binding protein 3. Muscle fibres' size was analysed in biopsies from m. vastus lateralis.

RESULTS

The patients' testosterone levels were within the normal range at baseline (n = 20) (19.5 (8.2-52.1) nmol/L versus 17.6 (16.1-18.0), resp.) whereas LH levels were higher (13.0 (5.5-82.8) U/L versus 4.3 (3.3-4.6), P < 0.001, resp.). IGF-1 and IGF-binding protein 3 levels were higher in the patients compared with reference values (203 (59-590) ng/mL versus 151 (128-276), P = 0.014, and 5045 (3370-9370) ng/mL versus 3244 (3020-3983), P < 0.001, resp.). All hormone levels and muscle fibre size (n = 12) remained stable throughout the study. Age-adjusted IGF-1 was associated with type 1 and 2 fibre sizes (P < 0.05).

CONCLUSION

Patients' total testosterone values were normal due to markedly increased LH values, which suggest a compensated primary insufficiency of the testosterone producing Leydig cell. Even though testosterone values were normal, resistance training was not associated with muscle hypertrophy. This trial is registered with ISRCTN72099857.

Serum testosterone levels and mortality in men with CKD stages 3-4

BACKGROUND

Hypogonadism in men (total testosterone <350 ng/dL) is associated with higher risk of cardiovascular disease and mortality in men on dialysis therapy. We evaluated the association of hypogonadism with all-cause mortality in men with non-dialysis-dependent chronic kidney disease (CKD).

STUDY DESIGN

Retrospective, cohort study.

SETTING & PARTICIPANTS

2,419 men with CKD stages 3-4 (estimated glomerular filtration rate, 15-59 mL/min/1.73 m2) who had total testosterone measured for cause between January 1, 2005, and October 31, 2011, at a tertiary-care center in Cleveland, OH.

PREDICTORS

Total testosterone measured using an immunoassay measurement in 3 forms: (1) categorized as low or testosterone replacement therapy versus normal, (2) continuous log testosterone, and (3) quintiles (100-226, 227-305, 306-392, 393-511, and 512-3,153 ng/dL).

OUTCOMES

Factors associated with low total testosterone level and the association between low total testosterone level and all-cause mortality were evaluated using logistic regression, Cox proportional hazard models, and Kaplan-Meier survival curves.

RESULTS

Hypogonadism was found in 1,288 of 2,419 (53%) men. In a multivariable logistic regression analysis, African American ethnicity and higher estimated glomerular filtration rate were associated with lower odds of having hypogonadism. Diabetes and higher body mass index were associated with higher odds of having hypogonadism. 357 of 2,419 (15%) patients died during a median follow-up of 2.3 years. In the multivariate Cox model, testosterone level <350 ng/dL or testosterone replacement therapy was not associated with mortality. In a multivariable model also adjusted for testosterone supplementation, higher log testosterone was associated with significantly lower mortality (HR per 1 log unit, 0.70; 95% CI, 0.55-0.89). When compared to the highest quintile, the second lowest quintile of testosterone was associated with higher mortality (HR, 1.53; 95% CI, 1.09-2.16).

LIMITATIONS

Single-center study, timing of testosterone testing, lack of adjustment for proteinuria, and sampling bias.

CONCLUSIONS

Low total testosterone level may be associated with higher mortality in men with CKD stages 3-4, but more studies are needed.

Low testosterone at time of transplantation is independently associated with poor patient and graft survival in male renal transplant recipients

PURPOSE

Low testosterone is common in men with renal disease and it increases the risk of death in those on dialysis. We studied serum testosterone at transplantation and correlated it with patient and graft outcomes.

MATERIALS AND METHODS

We identified serum samples collected and frozen at the time of transplantation in male recipients of primary kidney transplants done more than 6 years ago at our institution. In 197 recipients there was sufficient serum to determine total testosterone. We analyzed contingency outcomes by the Fisher exact test, continuous values by the Student t-test and survival by the Gehan-Breslow-Wilcoxon test.

RESULTS

Mean patient age was 48.9 years (range 14 to 75). There were 100 living and 97 cadaveric donors, and 53 recipients (27%) had diabetes. Mean ± SD serum testosterone was 477 ± 251.3 ng/dl (range 48 to 2,013). Testosterone was low (less than 220 ng/dl) in 24 patients. Age did not correlate with testosterone. Low testosterone recipients had worse 1-year patient survival (75% vs 95%, p = 0.003), 3-year patient survival (62.5% vs 86.1%, p = 0.008), 1-year graft survival (62.5% vs 92.4%) and 3-year graft survival (50% vs 76.3%, p = 0.01). Survival curves showed significantly worse patient survival (p = 0.004) and graft survival (p = 0.02) for low testosterone. On multivariable analysis low testosterone was independently associated with patient death (HR 2.27, 95% CI 1.19-4.32) and graft loss (HR 2.05, 95% CI 1.16-3.62).

CONCLUSIONS

Low testosterone at transplantation is associated with patient death and graft loss. If due to causality, testosterone therapy may impact survival. Without causality low testosterone may still be a marker for posttransplant risk.