Endogenous testosterone, endothelial dysfunction, and cardiovascular events in men with nondialysis chronic kidney disease

The Usefulness of Testosterone in Saliva Tests to Detect Testosterone Deficiency in Men with Advanced Chronic Kidney Disease: A Single-Center Study

Background: Hypogonadism frequently occurs among men with chronic kidney disease (CKD) and is a highly unfavorable prognostic factor. Therefore, a simple and common screening for testosterone deficiency may be important. The measurement of testosterone in saliva appears to be an attractive alternative to serum testosterone. This study aimed to assess the usefulness of determining free testosterone concentration in saliva to detect testosterone deficiency in men with advanced CKD, including those on dialysis. Methods: A total of 77 adult, male patients (aged 41-89 years old)-30 with CKD stage G3-G4, 30 on hemodialysis (HD), and 17 on peritoneal dialysis (PD)-were evaluated. The concentration of free testosterone was determined in saliva (SalFT), while the concentration of total testosterone (TT) was determined in blood serum. Serum-free testosterone levels were calculated (cFT). Results: SalFT did not differ from cFT in the CKD (p = 0.547) and PD groups (p = 0.409). In the HD group, SalFT was higher than cFT (p = 0.009). SalFT was positively correlated with cFT (r = 0.435 in the CKD and r = 0.479 in the HD) and TT (r = 0.451 in CKD), but only in the group of patients with SalFT levels below 140 pg/mL and 120 pg/mL, respectively. A cut-off value of SalFT ≤ 60.6 pg/mL showed 73.9% sensitivity and 77.8% specificity for testosterone deficiency recognition. Conclusions: Our study supports the value of SalFT measurement as a non-invasive approach in the diagnosis of testosterone deficiency in men with advanced CKD, as well as patients on hemodialysis.

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.

Cardiovascular Disease in Chronic Kidney Disease: Implications of Cardiorespiratory Fitness, Race, and Sex

Cardiovascular disease (CVD) poses a major health burden in adults with chronic kidney disease (CKD). While cardiorespiratory fitness, race, and sex are known to influence the relationship between CVD and mortality in the absence of kidney disease, their roles in patients with CKD remain less clear. Therefore, this narrative review aims to synthesize the existing data on CVD in CKD patients with a specific emphasis on cardiorespiratory fitness, race, and sex. It highlights that both traditional and non-traditional risk factors contribute to CVD development in this population. Additionally, biological, social, and cultural determinants of health contribute to racial disparities and sex differences in CVD outcomes in patients with CKD. Although cardiorespiratory fitness levels also differ by race and sex, their influence on CVD and cardiovascular mortality is consistent across these groups. Furthermore, exercise has been shown to improve cardiorespiratory fitness in CKD patients regardless of race or sex. However, the specific effects of exercise on CVD risk factors in CKD patients, particularly across different races and sexes remains poorly understood and represent a critical area for future research.

Testosterone deficiency and chronic kidney disease

Testosterone's biological functions are extensive, influencing reproductive and systemic health. It plays a vital role in sexual functions, muscle protein synthesis, bone metabolism, fat distribution, and cardiovascular health. The hormone also affects mood, cognitive function, and erythropoiesis, underscoring its importance in both physical and mental health. Testosterone deficiency, or male male hypogonadism, is increasingly recognized as a significant health issue affecting various bodily systems, also in the context of chronic kidney disease (CKD). Recent research indicates a complex interplay between testosterone levels and renal health, suggesting that male male hypogonadism may both impact and be impacted by CKD. The latter is characterized by a gradual loss of kidney function, affects millions globally and is often associated with diabetes mellitus, arterial hypertension, and autoimmune diseases. Men with CKD frequently experience lower testosterone levels, which can exacerbate muscle wasting, reduce quality of life, and increase cardiovascular risk. Overall, low testosterone levels in CKD patients are associated with increased morbidity and mortality. Several mechanisms explain the relationship between CKD and testosterone deficiency. The uremic environment in CKD disrupts the hypothalamic-pituitary-gonadal axis, impairing hormone production. Nutritional deficiencies and chronic inflammation common in CKD patients further suppress gonadal function. The consequences of low testosterone in CKD are profound, with studies suggesting that testosterone replacement therapy (TRT) might improve clinical outcomes, though the long-term effects and causal relationships remain under investigation. The potential benefits of TRT in CKD patients might be significant. TRT can enhance muscle mass and strength, address anemia by stimulating erythropoiesis, improve bone density, and possibly offer cardiovascular benefits by improving body composition and insulin sensitivity. General symptoms of male hypogonadism, such as deteriorated psychological, sexual and physical wellbeing, can be improved by TRT. However, these benefits must be weighed against potential risks. TRT may exacerbate fluid retention, arterial hypertension, or exacerbate existing heart failure, particularly in CKD patients with pre-existing cardiovascular comorbidities. Additionally, concerns about the progression of renal disease via several testosterone affected pathways involving renal tubular integrity exist, highlighting the need for careful patient selection and monitoring. Understanding this relationship is crucial for developing comprehensive treatment strategies that address both renal and endocrine dysfunctions, highlighting the need for integrated patient care, which means good collaboration between subspecialists like nephrologists, endocrinologists, urologists and primary care providers, aiming to improve outcomes and quality of life while mitigating adverse effects.

Low Free Triiodothyronine as a More Sensitive Predictor of Survival Than Total Testosterone among Dialysis Men

BACKGROUND

Some endocrine disorders, previously considered benign, may be related to a poorer prognosis for patients with renal failure. Both low serum free triiodothyronine (fT3) and low total testosterone (TT) concentrations have been considered as predictors of death in dialysis patients, but the results of studies are inconsistent. In our study, we evaluated the relationships of the serum thyroid hormone levels and the total testosterone levels with survival in male dialysis patients.

METHODS

Forty-eight male dialysis patients, 31 on hemodialysis (HD) and 17 on peritoneal dialysis (PD), aged 61.4 ± 10.0, 59.2 ± 12.2 years, respectively, were included in the study. Serum thyroid hormones and total testosterone were measured.

RESULTS

During the 12-month follow-up, nine all-cause deaths were recorded. The concentrations of fT3 were significantly lower in those who died than in the survivors (p = 0.001). We did not observe any statistically considerable differences between the group of men who died and the rest of the participants in terms of the total serum testosterone concentration (p = 0.350). Total testosterone positively correlated with fT3 (r = 0.463, p = 0.009) in the HD group.

CONCLUSIONS

In the group of male dialysis patients, the serum concentration of fT3 had a better prognostic value in terms of survival than the total testosterone. A linear relationship between the fT3 levels and testosterone levels in men undergoing hemodialysis may confirm the hypothesis that some of the hormonal changes observed in chronic kidney disease (CKD) may have a common cause.

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.

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.

Reproductive Health in Chronic Kidney Disease: The Implications of Sex and Gender

Chronic kidney disease (CKD) is frequently accompanied by reproductive health challenges in females and males alike. Progression of CKD is associated with escalating impairment of the hypothalamic-pituitary-gonadal axis, which facilitates evolving ovarian, testicular, and sexual dysfunction. Common clinical reproductive health complications in CKD include abnormal menstruation, impaired sexual health, and reduced fertility. Though sex-specific factors, such as sex hormones and gonadal function, have a strong influence on reproductive health outcomes in CKD, a person's gender and gendered experience also have important implications. Institutionalized gender, gendered perceptions of health, and health care-seeking behaviors, as well as adherence to medical care, all have critical effects on reproductive health in CKD. This review endeavors to explore the implications of both sex and gender on overall reproductive health in individuals living with CKD.

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.

Oxidative Stress and Inflammation Are Associated With Age-Related Endothelial Dysfunction in Men With Low Testosterone

CONTEXT

Vascular aging, including endothelial dysfunction secondary to oxidative stress and inflammation, increases the risk for age-associated cardiovascular disease (CVD). Low testosterone in middle-aged/older men is associated with increased CVD risk.

OBJECTIVE

We hypothesized that low testosterone contributes to age-associated endothelial dysfunction, related in part to greater oxidative stress and inflammation.

METHODS

This cross-sectional study included 58 healthy, nonsmoking men categorized as young (N = 20; age 29 ± 4 years; testosterone 500 ± 58 ng/dL), middle-aged/older with higher testosterone (N = 20; age 60 ± 6 years; testosterone 512 ± 115 ng/dL), and middle-aged/older lower testosterone (N = 18; age 59 ± 8 years; testosterone 269 ± 48 ng/dL). Brachial artery flow-mediated dilation (FMDBA) was measured during acute infusion of saline (control) and vitamin C (antioxidant). Markers of oxidative stress (total antioxidant status and oxidized low-density lipoprotein cholesterol), inflammation (interleukin [IL]-6 and C-reactive protein [CRP]), and androgen deficiency symptoms were also examined.

RESULTS

During saline, FMDBA was reduced in middle-aged/older compared with young, regardless of testosterone status (P < 0.001). FMDBA was reduced in middle-aged/older lower testosterone (3.7% ± 2.0%) compared with middle-aged/older higher testosterone (5.7% ± 2.2%; P = 0.021), independent of symptoms. Vitamin C increased FMDBA (to 5.3% ± 1.6%; P = 0.022) in middle-aged/older lower testosterone but had no effect in young (P = 0.992) or middle-aged/older higher testosterone (P = 0.250). FMDBA correlated with serum testosterone (r = 0.45; P < 0.001), IL-6 (r = -0.41; P = 0.002), and CRP (r = -0.28; P = 0.041).

CONCLUSION

Healthy middle-aged/older men with low testosterone appear to have greater age-associated endothelial dysfunction, related in part to greater oxidative stress and inflammation. These data suggest that low testosterone concentrations may contribute to accelerated vascular aging in men.

The impact of long-term Testosterone Therapy (TTh) in renal function (RF) among hypogonadal men: An observational cohort study

OBJECTIVES

Testosterone therapy (TTh) is the main treatment for elderly men with hypogonadism. No evidence of the long-term effectiveness of TTh on renal function is reported to date.

METHODS

In this study, we evaluated the long-term TTh of testosterone undecanoate (TU) administration on renal function parameters in 496 symptomatic hypogonadal men, with T levels ≤350 ng/dL. The treatment group (T-group) consisted of 312 patients and obtained TU 1000 mg for 12 weeks followed by 6-week intervals and for up to 8 years. The remaining 184 hypogonadal men, who opted against TTh, served as a control group (C-group). The two groups were similar in criteria prior to treatment. We evaluated renal function by calculating serum creatinine, urea, uric acid, and glomerular filtration rate (GFR) according to Mayo Clinic guidelines for 8 years. This study obeys the ethical guidelines of German medical association according to Section 15 of the Professional Code, document for AY- Ref. EK/CH/AU signed on Jun 2015.

RESULTS

During the study period, the T-group exhibited lower levels of urea (47.0 ± 11.8 to 34.0 ± 13.9 mg/dL), uric acid (6.57 ± 1.2 to 5.49 ± 1.5 mg/dL), serum creatinine (0.90 ± 0.10 to 1.12 ± 0.9 mg/dL), and higher-level in GFR (87.0 ± 12.9 to 98.0 ± 8.0 mL/min/1.73 m2), which were significant. Alternatively, the C-group exhibited an increase in their serum creatinine (1.16 ± 0.31 to 1.19 ± 0.58 mg/dL), an increase in uric acid (5.54 ± 1.2 to 5.44 ± 1.7 mg/dL), and a decrease in GFR (92.0 ± 20.1 to 87.0 ± 26.1 mL/min/1.73 m2). A total of 25 deaths (7.8%) was recorded in the T-group, among them 11 (44%) were cardiovascular. On the other hand, 28 patients (15.2%) died in C-group and all deaths (100%) were found to cardiovascular causes.

CONCLUSION

The results suggest that long-term TTh could improve renal function in hypogonadal men comparing to slight deterioration observed in patients without intervention. In addition to reduce mortality in cardiovascular patients, almost to the half.

Does endothelial dysfunction correlate with endocrinal abnormalities in patients with polycystic ovary syndrome?

To study and critically analyze the published evidence on correlation of hormonal abnormalities and endothelial dysfunction (ED) in polycystic ovary syndrome (PCOS) through a systematic review. The databases including MEDLINE, PubMed, Up-To-Date, and Science Direct were searched using Medical subject handling terms and free text term keywords such as endocrine abnormalities in PCOS, ED assessment in PCOS, ED in combination with insulin resistance (IR), hyperandrogenism (HA), increased free testosterone, free androgen index (FAI), gonadotrophin levels, luteinizing hormone (LH), prolactin, estrogen, adipocytokines to search trials, and observational studies published from January 1987 to September 2015. Authors of original studies were contacted for additional data when necessary. PCOS increases the risk of cardiovascular disease in women. ED, which is a reliable indicator of cardiovascular risk in general population, is seen in most (but not all) women with PCOS. IR, seen in 70% patients with PCOS, is associated with ED in these women, but patients can have normal endothelial function even in the presence of IR. Free testosterone and FAI are consistently associated with ED, but endothelial function can be normal despite HA. Estradiol (not estrone) appears to be protective against ED though estrone is the predominant estrogen produced in PCOS. Increased levels of adipocytokines (visfatin) are promising in predicting ED and cardiovascular risk. However, more studies are required focusing on direct correlation of levels of prolactin, LH, estrone, and visfatin with ED in PCOS.

Tacrolimus-Based Immunosuppressive Therapy Influences Sex Hormone Profile in Renal-Transplant Recipients-A Research Study

Simple Summary

Although renal-transplant-recipients can lead much more comfortable life in comparison to patients on dialysis, they need to face other problems. One of them is lifetime immunosuppressive therapy on daily basis. Immunosuppressive regimen contains usually three different drugs and although each one of them is crucial to keep graft in good condition and to suppress immune response against the transplanted organ, they influence, among the other, reproductive system. In current paper we have observed that immunosuppressive therapy based on tacrolimus significantly affected the hormonal balance of sex hormones in both men and women. It is of great importance, as nowadays infertility is rising problem even in health people, therefore more attention should be paid to choose the best suitable immunosuppressive regiment for recipient in reproductive age.

Abstract

It is estimated that approximately 20% of couples suffer from infertility worldwide and within renal-transplant recipients, this problem is 10 times more common. An intake of immunosuppressants may lead to hormonal imbalance. The aim of the study was to investigate the influence of tacrolimus-based therapy on the hormonal status of grafted patients. Blood samples were obtained from patients from the Department of Nephrology, Transplantology, and Internal Medicine of Independent Public Clinical Hospital No. 2, Pomeranian Medical University. All 121 patients had stable graft function for over 6 months. The blood plasma concentrations of luteinizing hormone, follicle-stimulating hormone, prolactin, testosterone, estradiol, cortisol were assessed by the electrochemiluminescence method. We observed decreased levels of prolactin (11.9 ng/mL) and cortisol (87.4 μg/mL) in patients under tacrolimus-based therapy. Tacrolimus-based therapy was also associated with increased testosterone and follicle-stimulating hormone in males, 4.04 ng/mL and 6.9 mLU/mL, respectively, and decreased testosterone levels in females, 0.121 ng/mL. We also assessed that immunosuppressive therapy based on tacrolimus is less nephrotoxic in comparison to other regimens. Concluding, tacrolimus-based therapy may influence the hormonal status of transplant recipients in the current study. Results presented here are believed to be helpful for clinicians and patients, especially within the aspect of willingness for biological offspring.

Erectile dysfunction pattern in patients with end stage renal disease on regular dialysis

INTRODUCTIONS

Evaluating the epidemiology, pattern, and contributing factors of sexual dysfunction in end-stage renal disease (ESRD) patients is the cornerstone in understanding and enhancing these patients' quality of life. In this study, we aimed to identify the different patterns of erectile dysfunction (ED) among 100 patients undergoing hemodialysis.

MATERIALS AND METHODS

A single-center, cross-sectional, study was conducted on 100 patients with ESRD on hemodialysis. Patients were assessed using the International index of erectile dysfunction (IIEF) and Doppler assessment of the penis.

RESULTS

A total of 100 patients were included in this study with a mean age of 48.77 ± 9.66 years old. The mean erectile index was 7.10 ± 4.62; while the mean free and total testosterone were 10.07 ± 7.69 and 2.93 ± 1.4 ng/dL, respectively. Overall, 67% of the patients had abnormal hormonal levels. Concerning the penile vasculature, 71% of the patients had arterogenic importance and 19% had venous impotence. The comparative analysis demonstrated that hypertensive patients had lower erectile index (p = 0.002). In addition, smokers had lower erectile index (p < 0.001). There was statistical significance between normal hormonal and abnormal hormone level according to erectile index, with lower index in patients with abnormal hormonal level (p = 0.03).

CONCLUSION

In conclusion, our findings indicate that the most common causes of ED with renal failure were hormonal disturbance, including testosterone, and prolactin. Hypertension and smoking are major contributing factors that should be managed carefully to reduce the risk of ED and improve the quality of life.

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.

TWEAK-Fn14 as a common pathway in the heart and the kidneys in cardiorenal syndrome

There is a complex relationship between cardiac and renal disease, often referred to as the cardiorenal syndrome. Heart failure adversely affects kidney function, and both acute and chronic kidney disease are associated with structural and functional changes to the myocardium. The pathological mechanisms and contributing interactions that surround this relationship remain poorly understood, limiting the opportunities for therapeutic intervention. The cytokine tumor necrosis factor-like weak inducer of apoptosis (TWEAK) and its receptor, fibroblast growth factor-inducible 14 (Fn14), are abundantly expressed in injured kidneys and heart. The TWEAK-Fn14 axis promotes responses that drive tissue injury such as inflammation, proliferation, fibrosis, and apoptosis, while restraining the expression of tissue protective factors such as the anti-aging factor Klotho and the master regulator of mitochondrial biogenesis peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α). High levels of TWEAK induce cardiac remodeling, and promote inflammation, tubular and podocyte injury and death, fibroblast proliferation, and, ultimately, renal fibrosis. Accordingly, targeting the TWEAK-Fn14 axis is protective in experimental kidney and heart disease. TWEAK has also emerged as a biomarker of kidney damage and cardiovascular outcomes and has been successfully targeted in clinical trials. In this review, we update our current knowledge of the roles of the TWEAK-Fn14 axis in cardiovascular and kidney disease and its potential contribution to the cardiorenal syndrome. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

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.

Vascular Dysfunction, Oxidative Stress, and Inflammation in Chronic Kidney Disease

Background

Increased arterial stiffness and vascular endothelial dysfunction are important nontraditional cardiovascular risk factors evident in patients with CKD. Vascular oxidative stress and inflammation may contribute to vascular dysfunction in CKD, but direct evidence is lacking.

Methods

We assessed carotid-femoral pulse-wave velocity (arterial stiffness) and brachial artery flow-mediated dilation (vascular endothelial function) in participants with moderate-to-severe CKD (eGFR 15-59 ml/min per 1.73 m²) and in healthy controls. Change in brachial artery flow-mediated dilation after an acute infusion of ascorbic acid to inhibit vascular oxidative stress (versus saline) was also measured. Protein expression of vascular endothelial cells collected from a peripheral vein and ELISAs to assess circulating markers were also performed.

Results

A total of 64 participants with CKD (mean±SD, 65±8 years) and 17 healthy controls (60±5 years) were included. Carotid-femoral pulse-wave velocity was greater in participants with CKD compared with healthy controls (1071±336 versus 732±128 cm/s; P<0.001). Brachial artery flow-mediated dilation was lower in participants with CKD compared with healthy controls (3.5%±2.8% versus 5.5%±3.2%; P=0.02). Circulating inflammation markers (C-reactive protein and IL-6) were elevated in the CKD group (P≤0.02). Endothelial cell protein expression of NADPH (intensity versus human umbilical vein endothelial cell control, 1.48±0.28 versus 1.25±0.31; P=0.05) was greater in participants with CKD. However, ascorbic acid significantly improved brachial artery flow-mediated dilation in control participants (saline, 5.5±3.2; ascorbic acid, 6.8±3.6); as compared with participants with CKD (saline, 3.5±2.8; ascorbic acid, 3.6±3.2) (group×condition interaction P=0.04), suggesting vascular oxidative stress could not be overcome with ascorbic acid in participants with CKD.

Conclusions

Vascular oxidative stress is present in CKD, which cannot be overcome with acute infusion of ascorbic acid.

Advanced Chronic Kidney Disease is a Strong Predictor of Hypogonadism and is Associated with Decreased Lean Tissue Mass

Purpose

In patients with chronic kidney disease (CKD), hypogonadism is more frequent than in the general population and its prevalence ranges between 40% and 60%. The aim of the study was to investigate the prevalence of hypogonadism and its association with kidney function, body composition, inflammatory markers and lipid disorders in patients with CKD.

Materials and Methods

The study population consisted of 112 men aged ≥40 years in different stages of CKD: 33 participants with eGFR ≥60 mL/min/1.73 m², 27 men with eGFR 30–59 mL/min/1.73 m², 17 predialysis patients with eGFR <30 mL/min/1.73 m², and 35 men on hemodialysis therapy three times a week for more than 3 months (G5D stage). Total testosterone (TT) levels were measured and free testosterone (FT) levels were calculated. Body composition was assessed using bioimpedance spectroscopy (Body Composition Monitor, FMC). Statistical analysis was performed using Statistica version 13.1.

Results

CKD stage was a strong predictor of hypogonadism (providing an information value of 0.83). The weight of evidence technique allowed us to differentiate the high-risk group, which was a group of patients with advanced CKD, defined as eGFR <30 mL/min/1.73 m². In this group, the likelihood of hypogonadism was 69.23%. Another significant predictor of hypogonadism was lean tissue index (LTI). TT and FT levels were significantly lower in the advanced CKD group in comparison to the control group, whereas prolactin, luteinizing hormone and C-reactive protein levels were significantly higher in the advanced CKD group. The LTI was significantly lower in advanced CKD and was positively correlated with TT and FT.

Conclusion

Decreased eGFR and decreased LTI are predictors of hypogonadism associated with CKD. The study results suggest that hypogonadism screening should be carried out when eGFR deceases below 30 mL/min/1.73 m².

Erectile Dysfunction after Kidney Transplantation

Patients with kidney transplantation often have a worse quality of life than the general population. One of the reasons for this, in male patients, is the high prevalence of erectile dysfunction. This is mainly due to the presence of comorbidities, surgery for kidney transplantation, adverse drug effects, psychological changes related to chronic disease, as well as hyperprolactinemia and hypogonadism. Whenever these endocrine dysfunctions occur after kidney transplantation, they must be corrected with appropriate treatment, i.e., testosterone replacement therapy. Administration of the phosphodiesterase-5 inhibitor (PDE5i) sildenafil at the recommended posology does not significantly alter the pharmacokinetics of the calcineurin inhibitors cyclosporin A or tacrolimus and does not impair kidney allograft function. Tacrolimus increases the peak concentration and prolongs the half-life of PDE5i in kidney transplant patients and, therefore, daily administration cannot be recommended due to the significant drop in blood pressure. Intracavernous injection or topical application of alprostadil can be a second-line option for the treatment of erectile dysfunction after kidney transplantation, which does not alter cyclosporine concentrations and does not deteriorate kidney function. Finally, penile prostheses can be successfully implanted following pelvic organ transplantation after eliminating the risk of infection associated with surgery.

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.

Sex Differences in the Progression of CKD Among Older Patients: Pooled Analysis of 4 Cohort Studies

RATIONALE & OBJECTIVE

Data for the association of sex with chronic kidney disease (CKD) progression are conflicting, a relationship this study sought to examine.

STUDY DESIGN

Pooled analysis of 4 Italian observational cohort studies.

SETTING & PARTICIPANTS

1,311 older men and 1,024 older women with estimated glomerular filtration rate (eGFR)<45mL/min/1.73m² followed up in renal clinics.

PREDICTOR

Sex.

OUTCOMES

End-stage kidney disease (ESKD), defined as maintenance dialysis or kidney transplantation, as the primary outcome; all-cause mortality and eGFR decline as secondary outcomes.

ANALYTICAL APPROACH

Cox proportional hazard analysis to estimate the relative risk for ESKD and mortality and linear mixed models to estimate the rate of eGFR decline.

RESULTS

Age, systolic blood pressure, and use of renin-angiotensin system inhibitors were similar in men and women. Baseline eGFRs were 27.6±10.2 in men and 26.0±10.6mL/min/1.73m² in women (P<0.001), while median proteinuria was lower in women (protein excretion, 0.45 [IQR, 0.14-1.10] g/d) compared with men (0.69 [IQR 0.19-1.60] g/d; P<0.001). During a median follow-up of 4.2 years, 757 developed ESKD (59.4% men) and 471 died (58.4% men). The adjusted risks for ESKD and mortality were higher in men (HRs of 1.50 [95% CI, 1.28-1.77] and 1.30 [95% CI, 1.06-1.60], respectively). This finding was consistent across CKD stages. We observed a significant interaction between sex and proteinuria, with the risk for ESKD in men being significantly greater than for women at a level of proteinuria of ∼0.5g/d or greater. The slope of decline in eGFR was steeper in men (-2.09; 95% CI, -2.21 to-1.97mL/min/1.73m² per year) than in women (-1.79; 95% CI, -1.92 to-1.66mL/min/1.73m² per year; P<0.001). Although sex differences in eGFR decline were not different across CKD stages (P=0.3), the difference in slopes between men and women was progressively larger with proteinuria >0.5g/d (P = 0.04).

LIMITATIONS

Residual confounding; only whites were included.

CONCLUSIONS

Excess renal risk in men may, at least in part, be related to higher levels of proteinuria in men compared with women.

Novel associations between sex hormones and diabetic vascular complications in men and postmenopausal women: a cross-sectional study

Background

Associations between sex hormones and vascular remodeling have been extensively studied, but the results vary widely among different races and sex. We aimed to investigate whether total testosterone (TT), estrogen (E2), and dehydroepiandrosterone (DHEA) associate with macrovascular complications and diabetic kidney disease (DKD) among community-dwelling patients with diabetes.

Methods

A total of 4720 participants with type 2 diabetes were recruited from Shanghai, China. Common carotid artery (CCA) plaques and diameter were assessed by ultrasound. Cardiovascular disease (CVD) was defined by prior diagnosis of coronary heart disease, myocardial infarction or stroke. DKD was defined according to the ADA Guidelines.

Results

(1) In men, TT was negatively associated with CCA diameter (regression coefficient (β) − 0.044, 95% CI − 0.087, 0). E2 levels were positively associated with CVD and CCA plaque prevalence (OR 1.151, 95% CI 1.038, 1.277 and OR 1.13, 95% CI 1.017, 1.255, respectively). DHEA was negatively associated with CVD (OR 0.809, 95% CI 0.734, 0.893). In postmenopausal women, TT levels were negatively associated with CCA diameter (β − 0.046, 95% CI − 0.083, − 0.010) and positively associated with CVD (OR 1.154, 95% CI 1.038, 1.284). (2) In both men and postmenopausal women, TT levels were negatively associated with the albumin/creatinine ratio and DKD (β − 0.098, 95% CI − 0.154, − 0.043 and OR 0.887, 95% CI 0.790, 0.997 vs. β − 0.084, 95% CI − 0.137, − 0.031 and OR 0.822, 95% CI 0.731, 0.924, respectively) and DHEA levels were positively associated with DKD (OR 1.167, 95% CI 1.038, 1.313 vs. OR 1.251, 95% CI 1.104, 1.418, respectively).

Conclusions

Our study indicates that macrovascular complications were associated with low TT, DHEA and high E2 in men and with high TT in postmenopausal women. DKD was associated with low TT and high DHEA levels in both genders. Sex hormone replacement therapy requires careful and comprehensive consideration.

Trial registration ChiCTR1800017573, http://www.chictr.org.cn. Registered 04 August 2018

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0901-6) contains supplementary material, which is available to authorized users.

Dietary patterns in relation to testosterone levels and severity of impaired kidney function among middle-aged and elderly men in Taiwan: a cross-sectional study

Background

Chronic Kidney Disease (CKD), characterized by an impaired kidney function, is associated with low testosterone levels. This study investigated the association between dietary patterns, testosterone levels, and severity of impaired kidney function among middle-aged and elderly men.

Methods

This cross-sectional study used the database from a private health-screening institute in Taiwan between 2008 and 2010. Men aged 40 years old and older (n = 21,376) with estimated glomerular filtration rate (eGFR) < 90 mL/min/1.73 m² and proteinuria were selected. Among 21,376 men, 256 men had available measurements of testosterone levels. Dietary assessment was conducted using a food frequency questionnaire and three dietary patterns (fried-processed, vege-seafood, and dairy-grain dietary patterns) were identified using principal component analysis.

Results

Men in the lower tertiles (T1 and T2) of eGFR had significantly decreased testosterone levels by 0.8 (95% CI: − 1.40, − 0.20) and 0.9 nmol/L (95% CI: − 1.43, − 0.33). Furthermore, serum triglycerides (TG) levels were inversely associated with testosterone levels (β = − 0.51, 95% CI: − 0.77, − 0.24). Men in the higher tertile of fried-processed dietary pattern scores were associated with decreased testosterone levels by 0.8 nmol/L (95% CI: − 1.40, − 0.16), reduced testosterone-to-TG (T/TG) ratio by 1.8 units (95% CI: − 2.99, − 0.53), and increased risk of moderate/severe impaired kidney function (eGFR < 60 mL/min/1.73 m²) and proteinuria severity by 1.35 (95% CI: 1.15, 1.58) and 1.18 (95% CI: 1.02, 1.37) times respectively. In contrast, the vege-seafood dietary pattern was negatively associated with severity of impaired kidney function and proteinuria after multivariable adjustment, but had no association with testosterone levels and T/TG ratio.

Conclusions

The fried-processed dietary pattern is negatively associated with testosterone levels but positively associated with the severity of impaired kidney function. However, the vege-seafood and dairy-grain dietary patterns appear to have beneficial effects.

Electronic supplementary material

The online version of this article (10.1186/s12937-019-0467-x) contains supplementary material, which is available to authorized users.

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.

TRAIL, OPG, and TWEAK in kidney disease: biomarkers or therapeutic targets?

Ligands and receptors of the tumor necrosis factor (TNF) superfamily regulate immune responses and homeostatic functions with potential diagnostic and therapeutic implications. Kidney disease represents a global public health problem, whose prevalence is rising worldwide, due to the aging of the population and the increasing prevalence of diabetes, hypertension, obesity, and immune disorders. In addition, chronic kidney disease is an independent risk factor for the development of cardiovascular disease, which further increases kidney-related morbidity and mortality. Recently, it has been shown that some TNF superfamily members are actively implicated in renal pathophysiology. These members include TNF-related apoptosis-inducing ligand (TRAIL), its decoy receptor osteoprotegerin (OPG), and TNF-like weaker inducer of apoptosis (TWEAK). All of them have shown the ability to activate crucial pathways involved in kidney disease development and progression (e.g. canonical and non-canonical pathways of the transcription factor nuclear factor-kappa B), as well as the ability to regulate cell proliferation, differentiation, apoptosis, necrosis, inflammation, angiogenesis, and fibrosis with double-edged effects depending on the type and stage of kidney injury. Here we will review the actions of TRAIL, OPG, and TWEAK on diabetic and non-diabetic kidney disease, in order to provide insights into their full clinical potential as biomarkers and/or therapeutic options against kidney disease.

Differences in association of lower bone mineral density with higher coronary calcification in female and male end-stage renal disease patients

Background

Risk of cardiac events and cardiovascular disease (CVD) in end-stage renal disease (ESRD) patients are predicted by coronary artery calcification (CAC) independently. It is not clear to what extent low bone mineral density (BMD) is associated with higher risk of CAC and if sex interacts. We investigated the sex-specific associations of CAC score with total body BMD (tBMD) as well as with BMD of different skeletal sub-regions.

Methods

In 174 ESRD patients, median age 57 (10th–90th percentiles 29–75) years, 63% males, BMD (measured by dual-energy X-ray absorptiometry; DXA), CAC score (measured by cardiac CT) and circulating inflammatory biomarkers were analysed.

Results

A total of 104 (60%) patients with CAC > 100 AUs were older, had higher prevalence of both clinical CVD and diabetes, higher level of high sensitivity C-reactive protein, tumour necrosis factor, interleukin-6 and lower T-score of tBMD. Female patients had significantly lower tBMD and BMD of all skeletal sub-regions, except head, than male patients. Female patients with high CAC (> 100 AUs) had significantly decreased T-score of tBMD, and lower BMD of arms, legs than those low CAC (≤ 100 AUs); elevated CAC score were associated with tBMD, T-score, Z-score of tBMD and BMD of arms and legs, while no such differences was observed in males. Multivariate generalized linear model (GLM) analysis adjusted for age, diabetes and hsCRP showed that in females per SD higher CAC score (1057 AUs) was predicted by either per SD (0.13 g/cm²) lower tBMD or per SD (0.17 g/cm²) lower BMD at legs. No such associations were found in male ESRD patients.

Conclusions

In female, but not male, lower BMD, in particular sub-regions of legs, was associated with higher CAC score independently. Low BMD has the potential to identify increased risk for high CAC score in ESRD patients.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1235-z) contains supplementary material, which is available to authorized users.

Gonadal Hormones in the Pathogenesis and Treatment of Bone Health in Patients with Chronic Kidney Disease: a Systematic Review and Meta-Analysis

PURPOSE OF REVIEW

Patients with chronic kidney disease (CKD) have a greatly increased fracture risk compared with the general population. Gonadal hormones have an important influence on bone mineral density (BMD) and fracture risk, and hormone therapies can significantly improve these outcomes. Gonadal dysfunction is a frequent finding in patients with CKD; yet, little is known about the impact of gonadal hormones in the pathogenesis and treatment of bone health in patients with CKD. This systematic review and meta-analysis aimed to examine the effects of gonadal hormones and hormone therapies on bone outcomes in men and women with CKD.

METHODS

EMBASE, MEDLINE, SCOPUS, and clinical trial registries were systematically searched from inception to February 14, 2018 for studies that assessed gonadal hormones or hormone treatments with bone outcomes in patients with CKD stage 3-5D. Two independent reviewers screened the titles and abstracts of search results according to inclusion criteria and assessed study quality and risk of bias using validated assessment tools.

RECENT FINDINGS

Thirteen studies met the inclusion criteria. Six moderate-to-high quality observational studies showed inconsistent association between any gonadal hormone and bone outcomes, limited by significant study heterogeneity. Five moderate-high risk of bias interventional studies examined treatment with selective oestrogen receptor modulators in post-menopausal women (four using raloxifene and one bazedoxifene) and demonstrated variable effects on BMD and fracture outcomes. Meta-analysis of raloxifene treatment in post-menopausal women demonstrated improvement in lumbar spine (SMD 3.30; 95% CI 3.21-3.38) and femoral neck (SMD 3.29; 95% CI 3.21-3.36) BMD compared with placebo. Transdermal oestradiol/norethisterone in pre-menopausal women receiving dialysis (n = 1 study), demonstrated BMD improvement over 12 months. Testosterone treatment for 6 months in dialysis-dependant men (n = 1 study) did not improve BMD. There is evidence that raloxifene treatment may be beneficial in improving BMD in post-menopausal women with CKD. There is insufficient evidence for other hormone treatments in men or women. Despite high fracture rates and frequent gonadal dysfunction in patients with CKD, significant evidence gaps exist, and well-designed studies are required to specifically assess the impact of gonadal status in the pathogenesis of CKD-related bone fragility and its treatment.

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.

Sex hormone-binding globulin is a biomarker associated with nonvertebral fracture in men on dialysis therapy

Gonadal hormones impact bone health and higher values of sex hormone-binding globulin (SHBG) have been independently associated with fracture risk in men without chronic kidney disease. People with chronic kidney disease have a greatly increased fracture risk, and gonadal dysfunction is common in men receiving dialysis treatment. Nevertheless, in these men the effect of gonadal steroids and SHBG on bone mineral density (BMD) and fracture risk is unknown. Here we investigate relationships between gonadal steroids, SHBG, BMD and fracture in men on long-term dialysis therapy, awaiting kidney or simultaneous pancreas kidney transplantation. Results of serum biochemistry, SHBG, gonadal steroids (total testosterone, calculated free testosterone and estradiol), BMD by dual-energy X-ray absorptiometry and thoracolumbar X-rays were obtained. Multivariable regression models were used to examine associations between SHBG, gonadal steroids, BMD and fracture of 321 men with a mean age of 47 years. Diabetes mellitus was present in 45% and their median dialysis vintage was 24 months. Prior fractures occurred in 42%, 18% had vertebral fracture on lateral spine X-ray, 17% had non-vertebral fragility fracture within 10 years and 7% had both. After adjustment for age, body mass index and dialysis vintage, higher SHBG levels were significantly associated with nonvertebral fractures [odds ratio 1.81 (1.30-2.53)] and remained significant after adjustment for BMD. Calculated free testosterone and estradiol values were not associated with fracture. Prevalent fracture rates were high in relatively young men on dialysis awaiting transplantation. Thus, SHBG is a novel biomarker associated with fracture, which warrants investigation in prospective studies.

Sex and gender disparities in the epidemiology and outcomes of chronic kidney disease

Improved understanding of sex and gender-specific differences in the aetiology, mechanisms and epidemiology of chronic kidney disease (CKD) could help nephrologists better address the needs of their patients. Population-based studies indicate that CKD epidemiology differs by sex, affecting more women than men, especially with regard to stage G3 CKD. The effects of longer life expectancy on the natural decline of glomerular filtration rate (GFR) with age, as well as potential overdiagnosis of CKD through the inappropriate use of GFR equations, might be in part responsible for the greater prevalence of CKD in women. Somewhat paradoxically, there seems to be a preponderance of men among patients starting renal replacement therapy (RRT); the protective effects of oestrogens in women and/or the damaging effects of testosterone, together with unhealthier lifestyles, might cause kidney function to decline faster in men than in women. Additionally, elderly women seem to be more inclined to choose conservative care instead of RRT. Dissimilarities between the sexes are also apparent in the outcomes of CKD. In patients with predialysis CKD, mortality is higher in men than women; however, this difference disappears for patients on RRT. Although access to living donor kidneys among men and women seems equal, women have reduced access to deceased donor transplantation. Lastly, health-related quality of life while on RRT is poorer in women than men, and women report a higher burden of symptoms. These findings provide insights into differences in the underlying pathophysiology of disease as well as societal factors that can be addressed to reduce disparities in access to care and outcomes for patients with CKD.

Sex and gender disparities in the epidemiology and outcomes of chronic kidney disease

Improved understanding of sex and gender-specific differences in the aetiology, mechanisms and epidemiology of chronic kidney disease (CKD) could help nephrologists better address the needs of their patients. Population-based studies indicate that CKD epidemiology differs by sex, affecting more women than men, especially with regard to stage G3 CKD. The effects of longer life expectancy on the natural decline of glomerular filtration rate (GFR) with age, as well as potential overdiagnosis of CKD through the inappropriate use of GFR equations, might be in part responsible for the greater prevalence of CKD in women. Somewhat paradoxically, there seems to be a preponderance of men among patients starting renal replacement therapy (RRT); the protective effects of oestrogens in women and/or the damaging effects of testosterone, together with unhealthier lifestyles, might cause kidney function to decline faster in men than in women. Additionally, elderly women seem to be more inclined to choose conservative care instead of RRT. Dissimilarities between the sexes are also apparent in the outcomes of CKD. In patients with predialysis CKD, mortality is higher in men than women; however, this difference disappears for patients on RRT. Although access to living donor kidneys among men and women seems equal, women have reduced access to deceased donor transplantation. Lastly, health-related quality of life while on RRT is poorer in women than men, and women report a higher burden of symptoms. These findings provide insights into differences in the underlying pathophysiology of disease as well as societal factors that can be addressed to reduce disparities in access to care and outcomes for patients with CKD.

Association of adiposity with hemoglobin levels in patients with chronic kidney disease not on dialysis

Background

In the general population, adiposity influences erythropoiesis and iron metabolism. We aimed to assess the relationships between adiposity [estimated by body mass index (BMI) and abdominal circumference (AC)] and biomarkers of erythropoiesis in patients with chronic kidney disease (CKD) not on dialysis.

Methods

A total of 2322 patients from the Chronic Kidney Disease Japan Cohort study were included. Patients were grouped according to BMI (low: < 18.5 kg/m², normal: 18.5–24.5 kg/m², and high: ≥ 25 kg/m²) and AC categories (large: ≥ 90 cm for men and ≥ 80 cm for women; small: < 90 cm and < 80 cm, respectively). Body composition and laboratory data were assessed at baseline, and at 1 and 2 years of follow-up.

Results

Multivariate regression analysis of the 3 time-points showed that high BMI and large AC in male patients were significantly associated with higher hemoglobin levels. Hemoglobin levels were lower in female patients with low BMI and small AC than that in female patients with normal BMI and large AC, respectively; however, hemoglobin levels plateaued above a threshold of 25 kg/m² for BMI and 80 cm for AC. While BMI and AC were positively associated with C-reactive protein levels, they were not associated with levels of transferrin saturation, ferritin, and erythropoietin in multivariate models.

Conclusions

Body composition appears to be associated with erythropoiesis; however, adiposity may be only associated with increased erythropoiesis in male patients. In addition, body composition does not appear to hamper iron metabolism in CKD patients not on dialysis.

Electronic supplementary material

The online version of this article (10.1007/s10157-017-1501-y) contains supplementary material, which is available to authorized users.

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.

Sex and gender differences in chronic kidney disease: progression to end-stage renal disease and haemodialysis

Sex and gender differences are of fundamental importance in most diseases, including chronic kidney disease (CKD). Men and women with CKD differ with regard to the underlying pathophysiology of the disease and its complications, present different symptoms and signs, respond differently to therapy and tolerate/cope with the disease differently. Yet an approach using gender in the prevention and treatment of CKD, implementation of clinical practice guidelines and in research has been largely neglected. The present review highlights some sex- and gender-specific evidence in the field of CKD, starting with a critical appraisal of the lack of inclusion of women in randomized clinical trials in nephrology, and thereafter revisits sex/gender differences in kidney pathophysiology, kidney disease progression, outcomes and management of haemodialysis care. In each case we critically consider whether apparent discrepancies are likely to be explained by biological or psycho-socioeconomic factors. In some cases (a few), these findings have resulted in the discovery of disease pathways and/or therapeutic opportunities for improvement. In most cases, they have been reported as merely anecdotal findings. The aim of the present review is to expose some of the stimulating hypotheses arising from these observations as a preamble for stricter approaches using gender for the prevention and treatment of CKD and its complications.

Sexual Function and Testosterone Level in Men With Conservatively Treated Chronic Kidney Disease

Sexual dysfunctions are common, but underrecognized, in patients with chronic kidney disease (CKD) and are inversely associated with the glomerular filtration rate (GFR). Sexual dysfunctions may affect quality of life in males with CKD. The aim of this study was to analyze the relationship among sex hormones, sexual function, and sexual satisfaction in a group of men between 18 and 50 years of age with CKD Stages 1 to 5 not treated with hemodialysis or peritoneal dialysis. Fasting blood samples for hemoglobin, testosterone, prolactin, and luteinizing hormone and questionnaire surveys (Sexual Complaints Screener for Men, International Index of Erectile Function, and Aging Male Symptom scale) were evaluated in 100consecutive men. Higher CKD stage (i.e., lower renal function) had a statistically significant ( p < .01) correlation with lower total testosterone, free testosterone, and hemoglobin levels, and higher luteinizing hormone and prolactin levels. Sexual function/dysfunctions were not significantly associated with CKD stage, even after adjustment for age and serum testosterone. The results indicate that CKD stage is a factor affecting testosterone levels in combination with age in men between 18 and 50 years of age at different stages of CKD but not treated with hemodialysis or peritoneal dialysis. Sexual dysfunctions are common but not strongly correlated to testosterone levels, prolactin levels, and survey (Sexual Complaints Screener for Men, International Index of Erectile Function, and Aging Male Symptom scale) responses in patients with CKD.

Shear Wave Sonoelastography Findings of Testicles in Chronic Kidney Disease Patients Who Undergo Hemodialysis

OBJECTIVE

Chronic kidney disease (CKD) is known to cause significant deterioration in the function of the testicles and sexual dysfunction in male patients who undergo hemodialysis. The aim of this study was to show the changes in the testicles that occur as a result of hypogonadism secondary to CKD and to analyze the elasticity of the parenchyma by shear wave sonoelastography.

MATERIALS AND METHODS

In our study we included 28 male patients who undergo dialysis three times per week and 25 healthy volunteers. Firstly, B-mode ultrasonographic evaluation was performed in both testicles for structural analysis and to detect the presence of focal lesions. Afterward, the stiffness of the parenchyma was measured in kilopascals by shear wave sonoelastography.

RESULTS

The CKD group had lower right, left, and mean testicular volumes (p<0.001). The CKD group also displayed greater right, left, and mean testicular parenchymal stiffness (p<0.001).

CONCLUSION

CKD patients who undergo hemodialysis demonstrated significant changes in testicular size and stiffness in comparison to healthy volunteers.

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.

Gonadal dysfunction in chronic kidney disease

Sexual dysfunction is a common finding in both men and women with chronic kidney failure. Common disturbances include erectile dysfunction in men, menstrual abnormalities in women, and decreased libido and fertility in both sexes. These abnormalities are primarily organic in nature and are related to uremia as well as the other comorbid conditions that frequently occur in the chronic kidney failure patient. Fatigue and psycho social factors related to the presence of a chronic disease are also contributory factors. Disturbances in the hypothalamic-pituitary-gonadal axis can be detected prior to the need for dialysis but continue to worsen once dialytic therapy is initiated. Impaired gonadal function is prominent in uremic men while the disturbances in the hypothalamic-pituitary axis are more subtle. By contrast, central disturbances are more prominent in uremic women. Therapy is initially directed towards optimizing the delivery of dialysis, correcting anemia with recombinant erythropoietin, and controlling the degree of secondary hyperparathyroidism with vitamin D. For many practicing nephrologists sildenafil has become the first line therapy in the treatment of impotence. In the hypogonadal man whose only complaint is decreased libido, testosterone may be of benefit. Regular gynecologic follow up is required in uremic women to guard against potential complications of unopposed estrogen effect. Uremic women should be advised against pregnancy while on dialysis. Successful transplantation is the most effective means of restoring normal sexual function in both men and women with chronic kidney failure.

Endothelial maintenance in health and disease: Importance of sex differences

The vascular endothelium has emerged as more than just an inert monolayer of cells lining the vascular bed. It represents the interface between the blood stream and vessel wall, and has a strategic role in regulating vascular homeostasis by the release of vasoactive substances. Endothelial dysfunction contributes to the development and progression of cardiovascular disease. Recognition of sex-specific factors implicated in endothelial cell biology is important for the identification of clinically relevant preventive and/or therapeutic strategies. This review aims to give an overview of the recent advances in understanding the importance of sex specific observations in endothelial maintenance, both in healthy and diseased conditions. The female endothelium is highlighted in the context of polycystic ovary syndrome and pre-eclampsia. Furthermore, sex differences are explored in chronic kidney disease, which is currently appreciated as one of public health priorities. Overall, this review endorses integration of sex analysis in experimental and patient-oriented research in the exciting field of vascular biology.

A case series of the safety and efficacy of testosterone replacement therapy in renal failure and kidney transplant patients

Background

Hypogonadism is common in patients with renal dysfunction and does not always correct following transplantation. Recent studies show increased mortality for dialysis and transplant patients with low testosterone (T). These patients are often not treated due to concerns over efficacy and complications (both real and imagined). There is surprisingly scant literature supporting the use of T therapy in these patients. We wished to examine the results of T therapy in our patients with renal failure or following transplant.

Methods

We identified 15 men in our Men’s Health Registry treated with T who either were on dialysis or had a functioning transplant at time of therapy. Demographic, laboratory and clinical outcome data were collected from the electronic medical record.

Results

There were 3 men on dialysis and 12 with a functioning transplant. Mean age was 53.7 years (range, 39–71 years) and mean total serum T was 207.9 ng/mL (range, 45–330 ng/mL). All had bothersome symptoms including fatigue (15/15) and erectile dysfunction (ED) (14/15). Mean hematocrit was 35.8% and 9/15 were anemic. Therapy included patches in 1, topical gels in 6 and testopel pellets in 8. With a mean follow-up of 22.7 months (range, 11–58 months), mean T post therapy was 528 (range, 226–869). Mean hematocrit improved to 42.6% and 7/9 anemic patients improved out of the anemic range. There were no cardiovascular or infectious complications.

Conclusions

Symptomatic hypogonadism is common in dialysis and transplant patients and T replacement therapy can be safely given with improvement in T values and symptoms in most patients. Anemia is usually improved. Testopel pellets can be used in immunosuppressed transplant recipients without infectious complications.

Improvement of endothelial function following initiation of testosterone replacement therapy

Background

Isolated recent studies have suggested an increased risk of heart attack as early as 3 months following testosterone replacement therapy (TRT). Such a rapid risk increase would likely require rapid deterioration of arterial endothelial function. Our goal was to assess arterial endothelial function in hypogonadal men prior to and at least 3 months after initiation of TRT.

Methods

Adult men were consented if they had symptoms of hypogonadism, a total testosterone <350 ng/dL, and planned to begin TRT. Endothelial function was non-invasively assessed using the EndoPAT-2000 machine. We measured the augmentation index (AI) (normal <3%), a measure of arterial stiffness and reactive hyperemia index (RHI), a measure of endothelial vasodilation (normal >1.69). Prior studies suggest that a 10% level of day-to-day test variability is expected. Endothelial function was reassessed at the next clinic visit, between 3 and 6 months if the patients were compliant with therapy. Changes in continuous variables were assessed with the paired t test.

Results

Twenty-three patients were consented with a mean age of 52.7 years (range, 34–68 years) and starting testosterone 196.9 ng/dL (range, 35–339 ng/dL). There was a history of diabetes in four, hypertension in ten and coronary artery disease in five. Mean RHI was 1.67±0.37 (70% were abnormal) and mean AI was 2.57%±14.0% (39% were abnormal). There were no cardiac events. At follow-up 20 patients were compliant with therapy and retested. Mean testosterone increased from 203 to 511 (P<0.0001). Mean RHI improved from 1.70 to 2.14 (P=0.01). Mean AI improved from 2.9% to −1.75% (P=0.01). In four men RHI worsened but in each case less than the 10% error of the test. No man had worsened AI.

Conclusions

Men with symptomatic hypogonadism often have abnormal arterial endothelial function. Following TRT, endothelial function either remains unchanged or improves.