Renal function and renal disease in males or females--vive la petite difference

Body, metabolic and renal changes following cross-sex estrogen/progestogen therapy in a rodent model simulating its use by transwomen

PURPOSE

The use of sex steroids by trans people has been of paramount importance regarding body changes during gender transition. The objective of this study was to assess the effects of an injectable steroid combination frequently used by transwomen, namely estradiol enanthate with dihydroxyprogesterone acetophenide (E2EN/DHPA), on blood pressure and metabolic outcomes using an animal model.

METHODS

Two-month-old male Wistar rats were orchiectomized or sham-operated and divided into groups: (1) Sham treated with sesame oil vehicle (SG), (2) sham treated with E2EN/DHPA (SP), (3) orchiectomized rats treated with vehicle (OG), and (4) orchiectomized rats treated with E2EN/DHPA (OP), with all groups treated every 10 days for 5 months. We evaluated systolic blood pressure (SBP), body weight (BW), abdominal circumference, nasoanal length (NAL), food and water intake (FI, WI), lipid profile (triglycerides, LDL, and HDL), serum C-reactive protein (CRP), plasma concentrations of urea (URpl) and creatinine (CRpl), 24 h urinary volume (V24 h), sodium and potassium excretion (UNa⁺, UK⁺), and proteinuria.

RESULTS

E2EN/DHPA administration reduced BW (SP 324.5 ± 31.1; OP 291.7 ± 41.3 g) and NAL (SP 24.5 ± 0.4; OP 24.6 ± 1.0 cm), without changing blood pressure, but increased URpl concentration (SP 55.0 ± 4.8; OP 42.5 ± 8.8 mg/dL) and CRpl (SP 0.47 ± 0.05; OP 0.46 ± 0.04 mg/dL), sodium (SP 3.1 ± 0.8; OP 3.3 ± 0.4 µEq/min/kg), potassium (SP 0.91 ± 0.22; OP 0.94 ± 0.22 µEq/min/kg) excretions and urinary volume (SP 15.5 ± 2.1; OP 16.4 ± 2.9 mL/24 h).

CONCLUSION

Cross-sex hormone therapy with E2EN/DHPA significantly modified body characteristics in male rats, producing a feminizing change without altering blood pressure or generating harmful metabolic parameters, but larger translational studies are still needed.

Comparison of the Surgical Resection and Infarct 5/6 Nephrectomy Rat Models of Chronic Kidney Disease

The 5/6 nephrectomy rat remnant kidney model is commonly employed to study chronic kidney disease (CKD). This model requires removal of one whole kidney and two-thirds of the other. The two most common ways of producing the remnant kidney are surgical resection of poles, known as the polectomy (Pol) model, or ligation of upper and lower renal arterial branches, resulting in pole infarction (Inf). These models have much in common, but also major phenotypic differences, and thus respectively model unique aspects of human CKD. The purpose of this review is to summarize phenotypic similarities and differences between these two models and their relation to human CKD, while emphasizing their vascular phenotype. In this article we review studies that have evaluated arterial blood pressure, the renin-angiotensin-aldosterone-system (RAAS), autoregulation, nitric oxide, single nephron physiology, angiogenic and anti-angiogenic factors, and capillary rarefaction in these two models. Phenotypic similarities: both models spontaneously develop hallmarks of human CKD including uremia, fibrosis, capillary rarefaction, and progressive renal function decline. They both undergo whole-organ hypertrophy, hyperfiltration of functional nephrons, reduced renal expression of angiogenic factor VEGF, increased renal expression of the anti-angiogenic thrombospondin-1, impaired renal autoregulation, and abnormal vascular nitric oxide physiology. Key phenotypic differences: the Inf model develops rapid-onset, moderate-to-severe systemic hypertension, and the Pol model early normotension followed by mild-to-moderate hypertension. The Inf rat has a markedly more active renin-angiotensin-aldosterone-system. Comparison of these two models facilitates understanding of how they can be utilized for studying CKD pathophysiology (e.g., RAAS dependent or independent pathology).

Does Preoperative Estimated Glomerular Filtration Rate (eGFR) Predict Short-Term Surgical Outcomes in Patients Undergoing Pancreatic Resections?

INTRODUCTION

Preoperative eGFR has been found to be a reliable predictor of post-operative outcomes in patients with normal creatinine levels who undergo surgery. The aim of our study was to evaluate the impact of preoperative eGFR levels on short-term post-operative outcomes in patients undergoing pancreatectomy.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) pancreatectomy file (2014-2017) was queried for all adult patients (age ≥ 18) who underwent pancreatic resection. Patients were stratified into two groups based on their preoperative eGFR (eGFR < 60 mL/min/1.73m² and eGFR ≥ 60 mL/min/1.73m²). Outcome measures included post-operative pancreatic fistula, discharge disposition, hospital length of stay, 30-day readmission rate, and 30-day morbidity and mortality. Multivariate logistic regression analysis was performed.

RESULTS

A total of 21,148 were included in the study of which 12% (n = 2256) had preoperative eGFR < 60 mL/min/1.73m². Patients in the eGFR < 60 group had prolonged length of stay, were less likely to be discharged home, had higher minor and major complication rates, and higher rates of mortality. On logistic regression analysis, lower preoperative eGFR (< 60 mL/min/1.73m²) was associated with higher odds of prolonged length of stay [aOR: 1.294 (1.166-1.436)], adverse discharge disposition [aOR: 1.860 (1.644-2.103)], minor [aOR: 1.460 (1.321-1.613)] and major complications [aOR: 1.214 (1.086-1.358)], bleeding requiring transfusion [aOR: 1.861 (1.656-2.091)], and mortality [aOR: 2.064 (1.523-2.797)].

CONCLUSION

Preoperative decreased renal function measured by eGFR is associated with adverse outcomes in patients undergoing pancreatic resection. The results of this study may be valuable in improving preoperative risk stratification and post-operative expectations.

Impact of menopausal status on kidney adaptation after unilateral nephrectomy for kidney donation in women

INTRODUCTION

Although living kidney donation is not a high-risk surgery, there is still a need to identify situations at risk of kidney disease after uninephrectomy. Estrogens exhibit a protective role against various nephropathies. The aim of this study was to assess renal adaptation following nephrectomy according to menopausal status in women.

METHODS

A prospective bicentric study including living women donors measured glomerular filtration rate (GFR) (inulin or ^51-Cr-EDTA clearances) and kidney volume (using CT-scan and 3-dimensional reconstruction), before and after 1-year post-uninephrectomy. Renal adaptation was compared according to menopausal status.

RESULTS

Sixteen non-menopausal women and 18 menopausal women were included. One year following uninephrectomy, the mean decrease in GFR (global population) was - 32 ± 12 ml/min/1.73 m², and the mean increase in remnant kidney volume was + 32 ± 13 cm³/1.73 m². No significant difference was observed between the two groups for both the decrease in GFR (-32.9 ± 13.3 in non-menopausal vs - 31.5 ± 9.9 in menopausal, ml/min/1.73 m², p = 0.84), and the increase in kidney volume (+ 36.1 ± 13.4 in non-menopausal vs + 28.1 ± 12.5 in menopausal, cm³/1.73 m², p = 0.09).

DISCUSSION

Menopausal status did not influence kidney adaptation following uninephrectomy, and in this respect is not a potential limiting factor for living kidney donation.

Solitary kidney and risk of chronic kidney disease

The renal outcome of solitary kidney remains controversial. We examined the longitudinal association of congenital or acquired solitary kidney with the development of chronic kidney disease (CKD). A cohort study was performed involving 271,171 Korean men and women free of CKD at baseline who underwent a health screening program and who were followed annually or biennially for an average of 5.4 years. Solitary kidney was determined based on ultrasonographic findings. CKD was defined as an estimated glomerular filtration rate of < 60 ml/min/1.73 m² and/or the presence of proteinuria in two or more consecutive visits. During 1,472,519.6 person-years of follow-up, 2989 participants developed CKD (incidence rate: 2.0 per 1000 person-years). After adjustment for potential confounders, the aHR (95% CIs) for incident CKD comparing solitary kidney to the control was 3.26 (1.63-6.54). In analyses of cause-specific solitary kidney, aHR (95% CIs) for CKD comparing unilateral nephrectomy and congenital solitary kidney to the control were 6.18 (2.31-16.49) and 2.22 (0.83-5.92), respectively. The association between solitary kidney and CKD was stronger in men. Having a solitary kidney was independently associated with an increased risk of CKD development. Therefore, preventive strategies for reducing the risk of CKD are required in individuals with a solitary kidney.

Role of Diabetes Education Program in Controlling Posttransplant Diabetes in a Recent Renal Transplant Bodybuilder: Case Report and Review of the Literature

Posttransplant diabetes is a common complication of solid-organ transplantation. We present the possible role of diabetes education in improvement of posttransplant diabetes in a 36-year-old bodybuilder who was a kidney transplant recipient. The patient had been abusing some medications to help in bodybuilding. He underwent living unrelated-donor renal transplant with thymoglobulin induction and was maintained on steroids, tacrolimus, and mycophenolate mofetil. Posttransplant diabetes was confirmed by blood tests. His blood sugar was partially controlled by 3 oral agents. The patient participated in our structured diabetes education program. This program was created to cover different items related to diabetes control, including diet, proper exercise, blood sugar monitoring, sick day management, and pathophysiologic roles of diabetes medications. Within 4 months of participation in this program, the patient's blood sugar became well controlled and his diabetes medications started to be minimized. He presently has stable graft function with hemoglobin A1c level around 5.6% on only diet management. Bodybuilders are at risk of deterioration of their kidney function. A proper diabetes education program is recommended to help renal transplant recipients with early posttransplant diabetes mellitus to control their disease. Success requires close evaluation and a multidisciplinary approach.

Reversible effects of anabolic steroid abuse on cyto-architectures of the heart, kidneys and testis in adult male mice

The importance of the present study comes from the lack of sufficient information about the reversibility of the histopathological alterations which may result from anabolic androgenic drugs abuse after some times of stop treatment, as it is one of the prior studies which explored the negative effects of Deca-Durabolin abuse in particular on the hearts, kidneys and testis structures. For this aim, study was performed on 40 male adult mices. Animals were divided into five groups of 8 animals each as follows: treated by Deca-Durabolin (nandrolone decanoate) at 30 g/kg of BW, weekly during one month (GI); two months (GII); three months (GIII); three months followed by six weeks of treatment discontinuation (GIV) and Control (C). Cytohistological exam was performed to determine histopathological damage in heart, kidney and testis tissues. Results showed that the treated animals supported very well the administrated substance. The increase in muscle strength and the absence of aggression were the most noticeable traits in longer-term treated groups. In addition, the gains in body and heart weights increase with duration of treatment and even more after stopping treatment. Our study showed important degenerative changes and disorganization of the histological structure of heart, kidney and testis in the animals of GIII. These damages worsen again 6 weeks after stopping treatment in heart and kidney, and repairs incompletely in the testis. In conclusion, these results confirmed that the use of AAS is associated with a lot of deleterious effects on the cardiac, nephritic and gonadic tissues which cannot be reversible.

Sub-acute administration of lower doses of nicotine caused sex-dependent improvement of renal function in Wistar rats

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Exposure to nicotine is associated with sex-dependent variation in electrolyte disturbances.

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Lower doses of sub-acute nicotine administration enhanced renal function.

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Nicotine-enhanced renal function is more pronounced in female than in male Wistar rats.

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Nicotine-enhanced renal function may be mediated through α7-nAchR.

The adverse and beneficial health effects of nicotine (NIC), the major alkaloid found in cigarettes and tobacco, are controversial. Most studies on NIC have focused on its effects on cardiovascular and nervous functions. This study aimed at determining dose- and sex-specific effects of sub-acute (28 days) NIC administration on some indices of kidney function in Wistar rats. Forty rats (20 males and 20 females), 8–9 weeks old (each housed in separate metabolic cage), were used for this study such that graded doses of NIC (1, 2 and 4 mg/kg i.p. for 28 days) were administered to both sexes while each control received distilled water at 0.2 mL/100 g i.p. Blood was collected under ketamine anesthesia (10 mg/kg i.m) for analyses and results obtained were compared at p < 0.05. The result showed beneficial alterations in plasma and urine level of creatinine, urea and uric acid (p < 0.05) as well as plasma and urine electrolyte level (Na⁺ and K⁺) in both sexes (p < 0.05). Also, there was significant improvement in creatinine clearance (p < 0.05) with no appreciable difference in their histological examination. Although these beneficial effects were more pronounced in the female than in the male (p < 0.05), administration at the highest dose showed potentially deleterious alterations from normal beneficial trend (p < 0.05) in both sexes. It was concluded that sub-acute administration of lower doses of NIC improves kidney function of Wistar rats; an effect that was more pronounced in the females than their male counterparts.

Low-level cadmium exposure and effects on kidney function

OBJECTIVES

The nephrotoxicity of cadmium at low levels of exposure, measured by urinary cadmium, has recently been questioned since co-excretion of cadmium and proteins may have causes other than cadmium toxicity. The aim of this study was to explore the relation between kidney function and low or moderate cadmium levels, measured directly in kidney biopsies.

METHODS

We analysed cadmium in kidney biopsies (K-Cd), blood (B-Cd) and urine (U-Cd) from 109 living kidney donors in a cross-sectional study. We measured glomerular filtration rate (GFR), cystatin C in serum, albumin, β-2-microglobulin (B2M), retinol-binding protein (RBP), α-1-microglobulin (A1M), N-acetyl-β-d-glucosaminidase and kidney injury molecule 1 (KIM-1) in 24 h and overnight urine.

RESULTS

We found significant positive associations between A1M excretion and K-Cd in multiple regression models including age, sex, weight, smoking and urinary flow rate. This association was also present in never-smokers. A1M was also positively associated with B-Cd and U-Cd. GFR and the other biomarkers of kidney function were not associated with K-Cd. GFR estimated from serum cystatin C showed a very poor correlation with measured GFR. KIM-1, RBP and possibly albumin were positively associated with U-Cd, but only in overnight urine. No associations were found with B2M.

CONCLUSIONS

Our results suggest that A1M in urine is a sensitive biomarker for effects of low-level cadmium exposure. A few associations between other renal biomarkers and U-Cd, but not K-Cd, were probably caused by physiological co-excretion or chance.

[Difference in urine concentration according to gender and ethnicity: possible involvement in the different susceptibility to various renal and cardiovascular diseases]

Men and African-Americans are known to be at greater risk of urolithiasis and cardiovascular and renal diseases than women and Caucasians. Previous studies suggest that the antidiuretic effects of vasopressin and/or a greater urine concentration are associated with the rate of progression of these diseases. The present review addresses possible sex and ethnic-related differences in urine volume and osmolality which could participate in this male and black higher predominance. We reanalyzed 24h-urine data collected previously by different investigators for other purposes. In studies concerning healthy subjects (six studies) or patients with chronic kidney disease or Diabetes mellitus (three studies), men excreted a larger osmolar load than women, with a 15 to 30% higher urinary osmolality (or another index of urine concentration based on the urine/plasma creatinine concentration ratio) and a similar 24h urine volume than in women. In two American studies, African-Americans showed a significantly higher urinary concentration than Caucasians and a lower 24h-urine volume. Sex and ethnic differences in thirst threshold, vasopressin level, or other regulatory mediators may contribute to the higher urinary concentration of men and of African Americans. These differences could play a role in the greater susceptibility of these subjects to these pathologies. New prospective studies should take into account the antidiuretic effects of vasopressin as a potential risk factor in the initiation and progression of cardiovascular and renal diseases.

Smoking induces glomerulosclerosis in aging estrogen-deficient mice through cross-talk between TGF-beta1 and IGF-I signaling pathways

Smoking is a known risk factor for the progression of chronic kidney diseases. However, its independent contribution to the development of ESRD and the underlying molecular mechanism have not been well elucidated. Although the risk for ESRD is higher in postmenopausal women according to the US Renal Data System, the number of women who smoke is on the rise worldwide. Therefore, the effects of smoking and estrogen status on glomerular function and structure were studied in female B6 mice that were ovariectomized at 3 (young) and 15 mo (aged) of age. The mice received either 17beta-estradiol (E(2)) replacement or placebo (Pla) and were divided further into groups that were exposed to cigarette smoke (S) and not exposed (NS). Six months of exposure to smoke had no effect on young mice, although aging S/Pla mice exhibited a phenotype of increased albumin excretion associated with a moderately increased glomerular collagen type IV deposition compared with NS/Pla mice. S/Pla mice also had a two-fold increase in glomerular TGF-beta, Smad3, and IGF-I receptor mRNA expression compared with the NS group. Mesangial cells that were isolated from S/Pla mice had an increase of IGF-I receptor protein, and IGF-I stimulated a TGF-beta reporter construct promoter three-fold. This was blocked by pretreatment with a neutralizing antibody to IGF-I, LY294002 (phosphatidylinositol-3 kinase inhibitor) or a dominant negative Smad construct. In addition, Smad3 activation was stimulated by IGF-I and blocked by LY294002, suggesting cross-talk between Smad and the phosphatidylinositol-3 kinase/AKT pathways. The smoking phenotype was reversed by E(2) replacement. In conclusion, smoking induces a phenotype in E(2)-deficient mice that is characterized by activation and cross-talk between the TGF-beta1 and IGF-I signaling pathways.

Sex difference in urine concentration across differing ages, sodium intake, and level of kidney disease

Men are known to be at greater risk of urolithiasis and cardiovascular and renal diseases than women. Previous studies suggest that greater urine concentration is associated with acceleration of progression of chronic kidney disease (CKD), increased urinary albumin excretion, and delayed renal sodium excretion. The present review addresses possible sex-related differences in urine volume and osmolality (U(osm)) that could participate in this male risk predominance. Because of the scarcity of information, we reanalyzed 24-h urine data collected previously by different investigators for other purposes. In nine studies concerning healthy subjects (6 studies) or patients with CKD or diabetes mellitus, U(osm) (or another index of urine concentration based on the urine/plasma creatinine concentration ratio) was 21-39% higher (i.e., about a 150 mosm/kgH2O difference) in men than in women. Urine volume was not statistically different. Thus, the larger osmolar load of men (related to their higher food intake) is excreted in a more concentrated urine with no difference in urine volume. This sex difference was not influenced by the level of sodium excretion and was still present in CKD patients. Sex differences in thirst threshold, AVP level, and other regulatory mediators may all contribute to the higher male U(osm). Because of the previously demonstrated adverse effects of vasopressin and/or high urine concentrating activity, the greater tendency of men to concentrate urine could participate in their greater susceptibility to urolithiasis and hypertension and to the faster progression towards end-stage renal failure.

Severe vesicoureteral reflux and chronic renal failure: a condition peculiar to male gender? Data from the ItalKid Project

Primary vesicoureteral reflux (VUR), one of the principal causes of chronic renal failure (CRF), occurs as a result of two distinct and sex-related mechanisms: congenital renal hypoplasia, which is prevalent in males, and acquired renal scarring in females. We used data from the ItalKid Project, a prospective population-based CRF registry of patients undergoing conservative treatment, to evaluate the gender distribution and severity of primary VUR, the age at diagnosis, and the diagnostic and therapeutic methods adopted in children with CRF. The prevalence of males (77.5%), the severity of VUR (grade IV-V), and the early age at diagnosis (18% prenatally) seem to suggest that congenital renal damage is the major cause of pediatric CRF.

Counteracting progression of renal disease: A look into the future

It is the very nature of research, including medical research, that truly novel results are not predictable. Nevertheless, some predictions concerning the understanding and management of progression of renal disease are plausible. It is very likely that in the future, exploding health budgets will force authorities and nephrologists to more effectively apply existing knowledge in this field to patients with early renal disease, particularly diabetics. We hope that this optimistic note is justified, although experience admittedly indicates that it is very much against human nature to behave rationally. With the powerful methodological tools available today, it is safe to predict that insight into the mechanisms underlying progression will also increase. Although pharmacological blockade of the renin-angiotensin system has been one of the great success stories of the past two decades, in many patients, progression is seen despite administration of angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers. Fortunately, additional targets for intervention, such as endothelin-1, inflammatory cascades, chemokines, etc., are on the horizon. A particularly fertile target for prevention of progression will be kidney grafts, since it has become increasingly clear that factors unrelated to allo-immunity play an important role in chronic allograft nephropathy.