Low serum testosterone is associated with atherosclerosis in postmenopausal women undergoing hemodialysis

Serum Testosterone Levels Are Not Modified by Vitamin D Supplementation in Dialysis Patients and Healthy Subjects

INTRODUCTION

Low serum testosterone is related to increased mortality in male dialysis patients. An association of vitamin D status with serum androgen levels with concordant seasonal variation has been described, but it is undecided whether vitamin D supplementation improves testosterone levels.

METHODS

In a randomized, placebo-controlled, and double-blind manner, we investigated the effects of an oral vitamin D supplementation in healthy subjects and hemodialysis patients on testosterone levels. One hundred three healthy individuals received cholecalciferol 800 IE/day (n = 52) or placebo (n = 51) for 12 weeks. Thirty-three hemodialysis patients received cholecalciferol adapted to their serum levels following current guidelines (n = 15) or placebo (n = 18) for 12 weeks.

RESULTS

In healthy individuals, 25(OH)D3 levels rose significantly in the verum group (38.1 ± 13.7 vs. 72.5 ± 15.4 nmol/L, p < 0.001), whereas in the placebo group, levels dropped (37.7 ± 14.7 vs. 31.9 ± 13.1, p < 0.001). Testosterone levels did not change significantly (verum, males: 20.9 ± 6.6 vs. 20.5 ± 7.9 nmol/L, p = 0.6; verum, females: 0.9 ± 0.5 vs. 0.92 ± 0.5, p = 0.4; placebo, males: 18.5 ± 10.2 vs. 21.8 ± 16.5, p = 0.07, placebo, females: 1.6 ± 4.2 vs. 1.6 ± 4.9, p = 0.6). In dialysis patients, the mean cholecalciferol level was only 32.3 ± 17.8 nmol/L, with only 2% of the values being within the normal range. Cholecalciferol levels normalized in the verum group (29.4 ± 11.2 vs. 87.8 ± 22.3, p < 0.001), whereas levels dropped further in the placebo group (33.6 ± 16.6 vs. 24.6 ± 8.0 nmol/L, p < 0.001). Testosterone levels did not change significantly (verum, males: 8.0 ± 3.7 vs. 7.8 ± 3.8, p = 0.8; verum, females: 1.3 ± 1.0 vs. 1.2 ± 1.0 nmol/L, p = 0.5; placebo, males: 11.9 ± 5.0 vs. 11.6 ± 4.0 nmol/L, p = 0.6; placebo, females: 0.8 ± 0.5 vs. 0.7 ± 0.4 nmol/L, p = 0.8).

CONCLUSION

Serum testosterone levels in hemodialysis patients and healthy individuals are independent from vitamin D status and cannot be significantly increased by cholecalciferol supplementation.

Sexual Dysfunction in Women With Kidney Disease

Sexual health is inversely associated with estimated glomerular filtration rate and is associated with adverse cardiovascular outcomes, depression, poor self-image, and impaired quality of life. Many women with chronic kidney disease (CKD) and ESKD experience symptoms of sexual dysfunction which is underrecognized secondary to a variety of factors including physicians' discomfort in discussing sexual health, patients' reluctance to bring up sexual health, difficulty in the assessment of sexual health in comparison to men, and the overall lack of well-conducted clinical studies in women. The pathophysiology is not fully understood but likely involves changes in sex hormones throughout the hypothalamic-pituitary-ovarian axis. Proper evaluation of this axis is necessary as treatment is tailored to these findings and can improve outcomes. A comprehensive assessment of sexual dysfunction inclusive of women with varying gender identification and sexual orientation, partnered with recognition and treatment of contributing factors as well as identifying the underlying cause, is paramount. With the lack of studies, particularly in women with CKD, treatment options, in some cases, can be considered unchartered territory. In this article, we will review available evidence on the pathophysiology, clinical manifestations, and treatment for sexual dysfunction in women with CKD and ESKD.

Analysis of biomarkers and metabolic pathways in patients with unstable angina based on ultra‑high‑performance liquid chromatography‑quadrupole time‑of‑flight mass spectrometry

Unstable angina (UA) is a coronary disease with a high mortality and morbidity worldwide. The present study aimed to use non-invasive techniques to identify urine biomarkers in patients with UA, so as to provide more information for the early diagnosis and treatment of the disease. Based on metabolomics, urine samples from 28 patients with UA and 28 healthy controls (HCs) were analyzed using ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). A total of 16 significant biomarkers that could distinguish between patients with UA and HCs, including D-glucuronic acid, creatinine, succinic acid and N-acetylneuraminic acid, were identified. The major metabolic pathways associated with UA were subsequently analyzed by non-targeted metabolomics. The results demonstrated that amino acid and energy metabolism, fatty acid metabolism, purine metabolism and steroid hormone biosynthetic metabolism may serve important roles in UA. The results of the current study may provide a theoretical basis for the early diagnosis of UA and novel treatment strategies for clinicians. The trial was registered with the Chinese Clinical Trial Registration Center (registration no. ChiCTR-ROC-17013957) at Tianjin University of Traditional Chinese Medicine.

Testosterone and dihydrotestosterone reduce platelet activation and reactivity in older men and women

The cardiovascular effects of testosterone and dihydrotestosterone are generally attributed to their modulatory action on lipid and glucose metabolism. However, no ex vivo studies suggest that circulating androgen levels influence the activation and reactivity of blood platelets - one of the main components of the haemostasis system directly involved in atherosclerosis. The levels of testosterone, dihydrotestosterone and oestradiol in plasma from men and women aged from 60 to 65 years were measured by LC-MS; the aim was to identify any potential relationships between sex steroid levels and the markers of platelet activation (surface membrane expression of GPII/IIIa complex and P-selectin) and platelet reactivity in response to arachidonate, collagen or ADP, monitored with whole blood aggregometry and flow cytometry. The results of the ex vivo part of the study indicate that the concentrations of testosterone and its reduced form, dihydrotestosterone are significantly negatively associated with platelet activation and reactivity. These observations were confirmed in an in vitro model: testosterone and dihydrotestosterone significantly inhibited platelet aggregation triggered by arachidonate or collagen. Our findings indicate that testosterone and dihydrotestosterone are significant haemostatic steroids with inhibitory action on blood platelets in older people.

Sex hormones and their influence on chronic kidney disease

PURPOSE OF REVIEW

The majority of end-stage renal disease including dialysis and kidney transplant patients are men. In contrast, the incidence of chronic kidney disease (CKD) is higher in women compared with men. In this review, we dissect the sex hormone levels and its effects on experimental models and patients with CKD.

RECENT FINDINGS

Sex hormones are clearly involved in CKD progression to end-stage renal disease (ESRD). A significant reduction in lipid peroxidation as a mechanism of renoprotection has been observed in kidneys of streptozotocin (STZ)-diabetic ovariectomized rats after estradiol administration. Furthermore, a G-protein-coupled estrogen receptor inhibits podocyte oxidative stress maintaining the integrity of the mitochondrial membrane. Sex hormone depletion has been shown to modulate RAS system and protect against kidney injury in the male STZ-diabetic model. In human primary proximal tubular epithelial cells, a proteomic study showed that dihydrotestosterone dysregulated metabolic, suggesting that the deleterious effect of androgens within the kidney maybe related to altered energy metabolism in renal tubules.

SUMMARY

Male gender is associated with worse CKD progression and this fact may be ascribed to sex hormone. Although male hormones exert a deleterious effect in terms of increasing oxidative stress, activating RAS system, and worsening fibrosis within the damaged kidney, female hormones exert a renoprotective effect.

Relationship Between Serum Total Testosterone Concentration and Augmentation Index at Radial Artery in Japanese Postmenopausal Patients

Background

The significance of testosterone as a risk factor for cardiovascular disease (CVD) in females is controversial. This cross-sectional study aimed to elucidate the relationship between serum total testosterone concentration (T-T) and augmentation index at the radial artery (r-AIx) as a marker of arterial function in Japanese postmenopausal patients.

Methods

A total of 447 postmenopausal patients with traditional cardiovascular risk factors and/or a history of CVD (age (mean ± standard deviation (SD)), 73 ± 10 years) were enrolled. r-AIx was measured using tonometry, and the association between r-AIx and various clinical parameters, including T-T, was determined.

Results

r-AIx significantly increased (CVD vs. non-CVD: 99±11% vs. 91±11%, P < 0.001) and T-T significantly decreased (CVD vs. non-CVD: 0.31 ± 0.13 ng/mL vs. 0.49 ± 0.23 ng/mL, P < 0.001) in patients with CVD than in those without CVD. A significant negative correlation (r = -0.48; P < 0.001) between r-AIx and T-T was observed. Furthermore, multiple regression analysis indicated that T-T (t value = -7.7; P < 0.001), height (t value = -5.3; P < 0.001), d-ROMs test as a marker of oxidative stress in vivo (t value = 3.2; P < 0.001), CVD (t value = 2.9; P < 0.01), and pulse rate (t value = -2.7; P < 0.01) were independent variables for r-AIx as a subordinate factor.

Conclusion

This study revealed that low T-T is an important determining factor for an increase in r-AIx in Japanese postmenopausal patients. A prospective multicenter study with a large sample size is required to confirm the results of this study.

Androgens and cardiovascular disease in women and men

Cardiovascular disease is the leading cause of death in both women and men. Its pathogenesis is multifactorial, with sex hormones playing an important role. Androgens have both direct and indirect effects on the vasculature. This review summarizes evidence on the association of both endogenous and exogenous androgens with subclinical and overt cardiovascular disease in women and men. Concerning women, both high and low levels of endogenous androgens have been associated with cardiovascular disease, while other studies have reported no association. Adiposity, impaired glucose metabolism, dyslipidemia and estrogen levels may mediate the observed associations. Regarding testosterone therapy in women, there have been no large prospective studies on cardiovascular outcomes. Concerning men, most studies indicate that low levels of circulating testosterone are associated with increased rates of cardiovascular disease in the general population; the causality, however, of this association remains to be proven. Testosterone replacement therapy in men with symptoms of hypogonadism and low serum testosterone merits caution with regard to cardiovascular safety, as evidence is still conflicting.

Association of free testosterone and sex hormone binding globulin with metabolic syndrome and subclinical atherosclerosis but not blood pressure in hypertensive perimenopausal women

INTRODUCTION

Data on the role of androgens as potential mediators of increasing cardiovascular risk in women at midlife are controversial. The aim of the study was to analyze the relationship of free testosterone (FT) and sex hormone binding globulin (SHBG) with blood pressure and subclinical organ damage and metabolic syndrome (MS) in middle aged hypertensive women.

MATERIAL AND METHODS

One hundred and fifty-two women with newly diagnosed arterial hypertension were included in the study. In all subjects blood pressure measurements were performed as well as echocardiographic examination with left ventricular structure and function assessment (GE Vivid 7.0), carotid ultrasound with measurement of intima-media thickness (IMT), and carotid-femoral pulse wave velocity (PWV) measurement (Sphygmocor). A fasting blood sample was taken to measure glucose and lipid concentrations. Serum testosterone and SHBG were measured. Free testosterone was calculated according to the Vermeulen formula. Metabolic syndrome was defined following the International Diabetes Federation (IDF) recommendations.

RESULTS

Free testosterone was significantly higher and SHBG lower in women with MS independently of menopausal status. The odds ratio of MS per quartile increment in FT after adjustment for covariates was 2.06 (95% CI: 1.16-3.65). There was no correlation between FT, SHBG and blood pressure. Free testosterone was associated with decreased left ventricular diastolic function (E/A ratio β = -0.19, p = 0.05) and subclinical atherosclerosis (IMT β = 0.34, p = 0.009), but not arterial stiffness.

CONCLUSIONS

Free testosterone and SHBG independently of menopause status are related to MS. Free testosterone is associated with worse metabolic profile, subclinical atherosclerosis and impaired diastolic function of the left ventricle.

Independent association between serum sclerostin levels and carotid artery atherosclerosis in prevalent haemodialysis patients

Background

Sclerostin is a soluble inhibitor of the Wnt signalling pathway and has been shown to be associated with decreased bone turnover and vascular and/or valvular calcification in patients with chronic kidney disease. Common carotid artery intima-media thickness (CIMT) assessment and common carotid artery (CCA) plaque identification with ultrasound imaging are well-recognized tools for the identification and monitoring of atherosclerosis. The aim of the present study was to investigate whether the circulating levels of sclerostin might be associated with carotid artery atherosclerosis in prevalent haemodialysis patients.

Methods

In this cross-sectional study, serum sclerostin concentrations were measured using a commercially available enzyme-linked immunosorbent assay kit. CIMT was measured and carotid plaques were identified by B-mode and Doppler ultrasound imaging.

Results

One hundred and twenty-two prevalent haemodialysis patients were involved in the study. Serum sclerostin levels were higher in patients with plaques in CCA than patients free of plaques (227 ± 166 versus 117 ± 91 pmol/L, P = 0.016). A significant correlation was recorded between serum sclerostin levels and CIMT (r = 0.459, P < 0.0001). In the multiple regression analysis, sclerostin concentrations were one of the independent factors that remained significantly associated with CIMT.

Conclusion

Sclerostin is independently associated with CIMT although further studies are needed.