Differences in the epidemiology, management and outcomes of kidney disease in men and women

Clinical implications of serum adropin and clusterin in chronic renal failure patients who received hemodialysis

BACKGROUND

Both Adropin and Clusterin are associated with cardiovascular and cerebrovascular diseases. Unfortunately, the clinical implications of them in Chronic renal failure (CRF) population remains largely unclear.

METHODS

We included 356 CRF patients received hemodialysis. Determination of serum concentrations of Adropin and Clusterin were performed by ELISA.The optimal cutoff values of Adropin or Clusterin for cardiovascular and cerebrovascular complications/death were determined by receiver operating characteristics (ROC) curve analysis. The prognostic value of Adropin and Clusterin was evaluated using Kaplan-Meier survival curves, log-rank tests, and Cox proportional hazards models.

RESULTS

Baseline serum Adropin significantly decreased, while serum Clusterin elevated in CRF patients who suffered cardiovascular or cerebrovascular implications during hemodialysis. Both decreased baseline serum Adropin and increased serum Clusterin showed potentials for predicting cardiovascular/cerebrovascular implications during hemodialysis in CRF patients. Reduced baseline serum Adropin indicated poor prognosis in CRF patient during hemodialysis, whereas increased baseline serum Clusterin indicated poor prognosis in CRF patient during hemodialysis. Combining baseline serum Adropin and Clusterin detection achieved better performance for predicting prognosis in CRF patients.

CONCLUSION

We demonstrated that decreased Adropin, or increased Clusterin could be novel but useful tool for predicting cardiovascular/cerebrovascular complications and overall survival. Importantly, combination of Adropin and Clusterin detection might be help to construct new management system for CRF patients to effectively improve their prognosis in the future.

Performance of Current Chronic Kidney Disease Screening Criteria in Women and Men Across Ethnic Groups: The HELIUS Study

Objective

To investigate whether the currently recommended screening criteria in Kidney Disease: Improving Global Outcomes 2024 guidelines (hypertension, diabetes mellitus, and cardiovascular disease) equally detect women and men across ethnic groups and whether consideration of optional criteria (education level, occupation, obesity, and genetic risk factors) listed in the guideline improves performance.

Patients and Methods

We included 12,384 women and 9046 men of Dutch, South Asian and African Surinamese, Ghanaian, Turkish, and Moroccan origin from the baseline HELIUS Study (January 1, 2011, through December 31, 2015, Amsterdam, the Netherlands). Chronic kidney disease (CKD) was defined as estimated glomerular filtration rate of <60 mL/min/1.73 m2 or albumin-to-creatinine ratio of >3 mg/mmol. Poisson regression analyses estimated associations between CKD and optional criteria on top of current screening criteria. Model comparisons were made with likelihood ratio tests and Akaike information criterion estimations in women and men. Area under the curve (AUC), sensitivity, specificity, and positive and negative predictive values were calculated by sex and ethnicity.

Results

Chronic kidney disease prevalence ranged from 2.9% to 8.8% in women and 3.2% to 8.6% in men. Low educational level (women only) and obesity significantly improved the models with current criteria with CKD. High-risk occupations and polygenic risk score did not improve the model. However, these criteria did not improve predictive measures across ethnic groups. Overall, the AUCs for the current screening criteria were acceptable in men (AUC, 0.75; 95% CI, 0.73-0.77) and poor in women (AUC, 0.65; 95% CI, 0.63-0.67), and showed minimal change after adding the optional criteria.

Conclusion

Current screening criteria may not be equally detecting women and men across ethnic groups with CKD. Optional criteria had limited added value.

The differential effects of sex hormone therapy on kidney function: insights into biological sex differences

There are known sex (i.e., biological) and gender (i.e., social) differences in the epidemiology and outcomes of chronic kidney disease. In this issue of the JCI, van Eeghen et al. provide a prospective multicenter observational study of transgender individuals initiating masculinizing and feminizing hormone therapy. Testosterone and estrogen with testosterone blockade had differential effects on kidney physiology including renal plasma blood flow, measured glomerular filtration rate, tubular biomarkers, and various proteins involved in inflammatory and repair pathways. The findings suggest that estrogen is renoprotective and that testosterone may be harmful to kidney function, but requires validation in larger, more diverse cohorts. The insights gained also need to be examined in the context of both endogenous and exogenous sex hormones in individuals over the life cycle.

Real-world use of complement inhibitors for haemolytic uraemic syndrome: an analysis of the European Rare Kidney Disease Registry cohort

Background

Although terminal complement inhibitors transformed the prognosis of atypical haemolytic uraemic syndrome (aHUS) from dismal to favourable, treatment approaches vary due to the intermittent disease nature and high costs. Occasionally, complement inhibition is applied in infectious (i)HUS. We aimed to examine real-world C5 inhibitor use and its impact on patient outcomes.

Methods

This retrospective cohort study used longitudinal data from the European Rare Kidney Disease Registry, collected from 76 nephrology centres across 24 European countries between January 1, 2019 and January 31, 2024. Eligible patients had aHUS or iHUS with onset after January 1, 2011, and/or documented C5 inhibitor use. Exclusions included complement-unrelated HUS, post-transplant HUS, and prophylactic C5 inhibitor use around kidney transplantation. Data, derived from medical records and focused queries, were used to assess C5 inhibitor duration, via time-to-event analysis, and kidney function based on annual creatinine levels.

Findings

A total of 238 aHUS and 472 patients with iHUS were included in the analysis. C5 inhibition was applied in 76.5% of aHUS and 18.4% of iHUS, with major utilisation differences between countries (p < 0.0001) and less common use in female patients with aHUS (p = 0.0022). Median (interquartile range) treatment duration was 16.1 (3.6-41.2) months in aHUS and 9 (7-32) days in iHUS. After five years, 56% of genetic, 28% of anti-complement factor H (anti-CFH) antibody-mediated, and 23% of aHUS cases with no identified cause remained on treatment. The long-term (>7 years) risk of treatment resumption was 35% in genetic, 15% in aHUS of no identified cause, and 0% in anti-CFH antibody-mediated aHUS. Post-withdrawal aHUS relapses were mostly mild and did not lead to permanent kidney function impairment, ultimately leading to long-term treatment withdrawal in 92.5% of discontinued cases.

Interpretation

Currently, C5 inhibitors are administered in three-quarters of newly diagnosed patients with aHUS in Europe, with varied utilisation and discontinuation practices. Treatment withdrawal is common and safe, although relapses may occur, particularly in genetic aHUS. However, baseline disease severity, selective use in expert centres, and indication bias affect outcome comparability. Findings must be considered in the context of patient-specific factors and disease severity at the time of treatment decisions.

Funding

This research was supported by the European Reference Network for Rare Kidney Diseases, funded by the European Union within the framework of the "EU4Health Programme 2021-2027".

Balancing Efficiency and Equity in Population-Wide CKD Screening

Importance

In the era of sodium-glucose cotransporter 2 (SGLT2) inhibitors, population-wide screening for chronic kidney disease (CKD) may provide good value, yet implications across racial and ethnic groups are unknown.

Objective

To evaluate the health outcomes, costs, and cost-effectiveness of population-wide CKD screening for 4 racial and ethnic groups.

Design, Setting, and Participants

In this cost-effectiveness analysis, a decision-analytic Markov model was separately calibrated to simulate CKD progression among simulated cohorts of US Hispanic adults, non-Hispanic Black adults, non-Hispanic White adults, and adults who belong to additional racial and ethnic groups (ie, Asian and multiracial individuals and those self-reporting other race and ethnicity). Effectiveness of SGLT2 inhibitors was derived from the Dapagliflozin and Prevention of Adverse Outcomes in Chronic Kidney Disease trial. Mortality, quality-of-life weights, and cost estimates were obtained from published cohort studies, randomized clinical trials, and Centers for Medicare & Medicaid Services data. Analyses were conducted from January 1, 2023, to November 6, 2024.

Exposures

One-time or periodic (every 10 or 5 years) screening for albuminuria, initiated between age 35 and 75 years, with and without addition of SGLT2 inhibitors to angiotensin-converting enzyme inhibitor or angiotensin-receptor blocker therapy for CKD.

Main Outcomes and Measures

Lifetime cumulative incidence of kidney failure requiring kidney replacement therapy (KRT); discounted life-years (LYs), quality-adjusted LYs (QALYs), lifetime health care costs (in 2024 US dollars), and incremental cost-effectiveness ratios.

Results

Under the status quo, non-Hispanic Black adults aged 35 years had the highest lifetime incidence of kidney failure requiring KRT (6.2% [95% UI, 2.8%-10.6%]) compared with Hispanic adults (3.6% [95% UI, 1.1%-6.7%]), non-Hispanic White adults (2.3% [95% UI, 0.4%-5.2%]), and adults from additional racial and ethnic groups (3.3% [95% UI, 1.2%-6.5%]). Screening every 5 years from ages 55 to 75 years combined with SGLT2 inhibitors reduced incidence of KRT and increased LYs across all racial and ethnic groups, with the largest average changes observed for non-Hispanic Black adults (0.8-percentage point decrease and 0.19-year increase). Every 5-year screening from age 55 to 75 years cost $99 100/QALY gained for the overall population and less than $150 000/QALY gained across racial and ethnic groups, with the lowest cost observed for non-Hispanic Black adults ($73 400/QALY gained). Screening starting at age 35 years was only cost-effective for non-Hispanic Black adults ($115 000/QALY gained).

Conclusions and Relevance

In this cost-effectiveness analysis, population-wide screening for CKD from ages 55 to 75 years was projected to improve population health, was cost-effective, and reduced disparities across 4 racial and ethnic groups. Starting population-wide screening at younger ages was projected to further benefit non-Hispanic Black adults.

Global, regional, and National Burden of chronic kidney disease attributable to dietary risks from 1990 to 2021

Background

Dietary risks are increasingly reported as a cause of chronic kidney disease (CKD). However, the trends in the burden of CKD attributable to dietary risks have yet to be fully elucidated.

Methods

This study extracted two major indicators related to CKD caused by dietary risks from the Global Burden of Disease (GBD) database for the years 1990 to 2021, including deaths and disability-adjusted life years (DALYs). It used estimated annual percentage change (EAPC) and percentage change to assess the trends in the burden of CKD caused by dietary risks. The relationship between Socio-demographic Index (SDI) and disease burden was also further analyzed. Additionally, we utilized the contemporary age-period-cohort model from NORDPRED to project future burden of CKD attributable to dietary risks.

Results

In 2021, globally, the number of deaths due to CKD caused by dietary risks was 317,010, and the number of DALYs was 7,971,281, approximately 2-3 times that of 1990, and it was expected to continue to rise before 2040. The global death rates and DALY rates of CKD related to dietary risks had increased, with EAPCs of 0.63 (95% CI: 0.57 to 0.69) and 0.39 (95% CI: 0.35 to 0.42), respectively. From a gender perspective, men were more likely to suffer from CKD due to dietary risks. From an age pattern perspective, in 2021, the number of deaths due to CKD caused by dietary risks peaked among men aged 70-74 and women aged 85-89. Additionally, the highest number of DALYs due to CKD caused by dietary risks was observed among men and women aged 65-69. In terms of socioeconomic factors, from 1990 to 2021, as the SDI increased, the age-standardized death rates and DALY rates due to CKD caused by dietary risks generally decreased. Among the seven dietary habits related to dietary risks, low vegetable intake, low fruit intake, and high sodium intake had the greatest impact.

Conclusion

In summary, over the past 32 years, the burden of CKD attributable to dietary risks has rapidly increased globally, and it is expected to continue rising until 2040. Therefore, interdisciplinary actions involving education, policy, and healthcare should be taken to mitigate this growing trend.

Higher triglyceride-glucose index is associated with severe proteinuria and decreased renal function in patients with primary membranous nephropathy

BACKGROUND

In recent years, the triglyceride-glucose (TyG) index has emerged as a reliable surrogate marker of insulin resistance (IR). This study aimed to investigate the association between the TyG index and severe proteinuria or decreased renal function in patients with primary membranous nephropathy (PMN).

METHODS

We consecutively enrolled 536 patients with PMN hospitalized at Peking University Third Hospital from January, 2014 to December, 2023. The TyG index was calculated as Ln[fasting triglyceride (mg/dL)×fasting blood glucose (mg/dL)/2]. All participants were categorized into quantiles according to the TyG index. Severe proteinuria was defined as 24 h urine protein > 3.5 g/d, and decreased renal function was defined as the estimated glomerular filtration rate < 90 mL/min/1.73m2. Multivariable logistic regression, restricted cubic spline (RCS) curves, and receiver operating characteristic (ROC) curves were used for analysis.

RESULTS

Among 536 patients with PMN, 355 patients had severe proteinuria and 149 patients had decreased renal function. The levels of TyG index was significantly elevated in PMN patients with severe proteinuria or decreased renal function. The RCS analysis revealed a positive linear relationship of the TyG index with the risk of severe proteinuria (P for non-linear = 0.317) or decreased renal function (P for non-linear = 0.199) in patients with PMN. Using the lowest quantile as the reference, multivariate-adjusted logistic regression indicated that patients in the highest quantile of the TyG index had a significantly increased risk of severe proteinuria [odds ratio (OR) = 2.08, 95% confidence interval (CI): 1.44-3.01, P < 0.001] and decreased renal function (OR = 1.57, 95% CI: 1.04-2.36, P = 0.032). The area under the ROC curve (AUC) of the TyG index is 0.613 (95% CI: 0.564-0.662) for severe proteinuria and 0.590 (95% CI: 0.536-0.643) for decreased renal function.

CONCLUSION

Our findings indicated that the TyG index has a positive linear correlation with severe proteinuria or decreased renal function in patients with PMN.

The hidden interplay between sex and adverse outcomes in incident dialysis patients: the role of aortic calcification

Background

Research on the sex disparity in the prognosis of chronic kidney disease (CKD), particularly among those who are newly initiating dialysis, is limited and inconclusive. This study aimed to investigate the associations between sex, and all-cause mortality and major cardiovascular adverse events (MACE), with a particular focus on the presence of aortic calcification (AC).

Methods

We conducted a post hoc analysis of 1459 incident dialysis patients included in this prospective cohort study. The primary outcome of interest was all-cause mortality, and the secondary endpoint was a composite of MACE.

Results

During a median follow-up period of 3.55 years, 362 (269 male and 93 female) patients died and 477 (342 male and 135 female) patients developed MACE. The risks for all-cause mortality [hazard ratio (HR) 0.61, 95% confidence interval (CI) 0.47-0.79] and MACE (HR 0.74, 95% CI 0.60-0.93) were lower in females than in males. This finding was robust across multiple sensitivity analyses and most subgroups. Moreover, the associations between sex and adverse outcomes were significantly modified by AC status at dialysis initiation (P for interaction <.05). Specifically, among patients without AC, females exhibited lower risks for all-cause mortality (HR 0.45, 95% CI 0.29-0.69; P < .001) and MACE (HR 0.67, 95% CI 0.49-0.93; P = .015), whereas no differences were observed for all-cause mortality (HR 0.82, 95% CI 0.59-1.15; P = .256) or MACE (HR 0.80, 95% CI 0.59-1.10; P = .174) among patients with AC.

Conclusions

In patients with renal failure receiving dialysis, AC abolished the survival and cardiovascular protection observed in female versus male patients. This finding supports the need for greater awareness of the AC burden in female dialysis patients.

Protective role of vitamin D receptor against mitochondrial calcium overload from PM2.5-Induced injury in renal tubular cells

PURPOSE

This research explores the consequences of being exposed to PM2.5 contribute to renal injury while also evaluating the protective role of Vitamin D-VDR signaling in alleviating mitochondrial calcium imbalance and oxidative stress in renal tubular cells.

METHODS

Animal models of chronic PM2.5 exposure were used to simulate environmental conditions in wild type and VDR-overexpressing mice specific to renal tubules. In parallel, HK-2 cell lines were treated with PM2.5 in vitro. Mitochondrial function, calcium concentration, and oxidative stress markers were assessed. VDR activation, achieved through genetic overexpression and paricalcitol, was induced to examine its effect on mitochondrial calcium uniporter (MCU) expression and mitochondrial calcium regulation.

RESULTS

PM2.5 exposure caused significant mitochondrial damage in renal tubular cells, including mitochondrial calcium overload, increased oxidative stress, reduced membrane potential, and diminished ATP production. Elevated MCU expressions were a key contributor to these disruptions. VDR activation effectively reversed these effects by downregulating MCU, restoring mitochondrial calcium balance, reducing oxidative stress, and improving renal function.

CONCLUSION

This study shows that activating Vitamin D-VDR signaling shields the kidneys from PM2.5-induced damage by reestablishing mitochondrial calcium balance and lowering oxidative stress via inhibition of the MCU. These results unveil a new protective role of VDR in defending against environmental pollutants and suggest that targeting the MCU could offer a potential therapeutic strategy for treating chronic kidney disease linked to pollution exposure.

Gender disparities in the association between atherogenic index of plasma and chronic kidney disease

OBJECTIVE

This study investigates the relationship between the atherogenic index of plasma (AIP) and chronic kidney disease (CKD) occurrence in the general population, with a focus on potential gender disparities.

METHODS

The study included 22,952 adults from the National Health and Nutrition Examination Survey (NHANES). Various statistical models were employed to evaluate the association between AIP and CKD occurrence and explore gender-specific differences.

RESULTS

Adjusted for confounding factors, higher AIP levels showed a mild association with increased CKD risk in the general population. Specifically, individuals in the highest AIP quartile had a slightly elevated odds ratio (OR) for CKD compared to the lowest quartile (OR: 1.24, 95% CI: 1.02-1.52, P for trend = 0.023). Gender-stratified analysis revealed significant differences. Among males, higher AIP levels were significantly associated with CKD risk (OR: 1.49, 95% CI: 1.15-1.94, P for trend < 0.001), whereas in females, the association was weaker and statistically non-significant (P for trend = 0.055). U-shaped relationships between AIP and CKD were observed. Mediation analysis provided insights into potential pathways underlying this association. Among males, changes in uric acid accounted for 44.50% of CKD prevalence related to AIP, while glomerular filtration rate (eGFR), BMI, and bicarbonate levels contributed 44.09%, 17.55%, and 15.36%, respectively. Among females, uric acid changes accounted for 45.53%, while eGFR, bicarbonate, C-reactive protein (CRP), sodium, and potassium levels contributed 37.96%, 12.43%, 6.37%, 5.58%, and 3.14%, respectively.

CONCLUSION

Our findings suggest that elevated AIP levels may increase CKD risk, particularly among males in the general U.S.

POPULATION

Global, regional, and national burden of chronic kidney disease and its underlying etiologies from 1990 to 2021: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND

We aimed to investigate global, regional, and national burden of chronic kidney disease (CKD) and its underlying etiologies from 1990 to 2021.

METHODS

We summarized the results of the Global Burden of Disease (GBD) 2021 to derive the disease burden of CKD by considering four distinct types of epidemiological data, namely incidence, prevalence, mortality, and disability-adjusted life years (DALYs). The Joinpoint regression analysis, which is skilled in calculating annual percentage change (APC) and average annual percentage change (AAPC), was used to estimate global trends for CKD from 1990 to 2021.

RESULTS

The age-standardized mortality rate (ASMR) and age-standardized DALYs rate of CKD were more prominent in regions with Low and Low-middle socio-demographic index (SDI) quintiles. From 1990 to 2021, the countries with the largest increases in ASMR were Ukraine. Globally, the most common cause of death for CKD was type 2 diabetes mellitus (T2DM), while the most common cause of prevalence, incidence, and DALYs was the other and unspecified causes. The main causes of death and DALYs from CKD varied in different parts of the world. The disease burden of CKD increased with age. In most age groups, the global prevalence and incidence of CKD were higher in females than males. At all ages, the global mortality rate and DALYs rate of CKD were higher in males compared to females. Joint point regression analysis found that from 1990 to 2021 the global age-standardized prevalence rate (ASPR) revealed a downward trend, while age-standardized incidence rate (ASIR), ASMR, and age-standardized DALYs rate showed an upward trend, with the most notable increase in ASMR during the 1997-2000 period and in age-standardized DALYs rate during the 1996-2003 period.

CONCLUSIONS

The study unveiled the uneven global distribution of the burden of CKD and its attributable causes. From 1990 to 2021, an increase in the burden of incidence, mortality, and DALYs due to CKD was observed. Population growth and aging will contribute to a further increase in the burden of CKD. Healthcare providers should develop health policies, and optimize the allocation of medical resources, based on age, sex, region, and disease type.

CerS6 links ceramide metabolism to innate immune responses in diabetic kidney disease

Ectopic lipid deposition, mitochondrial injury, and inflammatory responses contribute to the development of diabetic kidney disease (DKD); however, the mechanistic link between these processes remains unclear. In this study, we demonstrate that the ceramide synthase 6 (CerS6) is primarily localized in podocytes of the glomeruli and is upregulated in two different models of diabetic mice. Podocyte-specific CerS6 knockout ameliorates glomerular injury and inflammatory responses in male diabetic mice and in male mice with adriamycin-induced nephropathy. In contrast, podocyte-specific overexpression of CerS6 sufficiently induces proteinuria. Mechanistically, CerS6-derived ceramide (d18:1/16:0) can bind to the mitochondrial channel protein VDAC1 at Glu59 residue, initiating mitochondrial DNA (mtDNA) leakage, activating the cGAS-STING signaling pathway, and ultimately promoting an immune-inflammatory response in the kidney. Importantly, CERS6 expression is increased in podocytes from kidney biopsies of patients with DKD and focal segmental glomerulosclerosis (FSGS), and the expression level of CERS6 is correlated negatively with glomerular filtration rate and positively with proteinuria. Thus, our findings suggest that targeting CerS6 may be a potential therapeutic strategy for proteinuric kidney diseases.

KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease in Children and Adults: a commentary from the European Renal Best Practice (ERBP)

The Kidney Disease: Improving Global Outcomes (KDIGO) 2024 Guideline for Identification and Management of Chronic Kidney Disease (CKD) is a welcome development, coming 12 years after the paradigm-changing 2012 guidelines. We are living in an unprecedented era in nephrology with novel therapies, including sodium-glucose cotransporter-2 inhibitors, glucagon-like peptide-1 receptor agonists and non-steroidal mineralocorticoid receptor antagonists, now being proven in multiple randomized controlled clinical trials to reduce both the progression of CKD and cardiovascular morbidity and mortality. The KDIGO 2024 CKD Guideline is aimed at a broad audience looking after children and adults with CKD and provide practical and actionable steps to improve care. This commentary reviews the guideline sections pertaining to the evaluation and risk assessment of individuals with CKD from a European perspective. We feel that despite the last guideline being published 12 years ago, and the fact that the assessment of CKD has been emphasized by many other national/international nephrology, cardiology and diabetology guidelines and societies, the diagnosis and treatment of CKD remains poor across Europe. As such, the KDIGO 2024 CKD Guideline should be seen as an urgent call to action to improve diagnosis and care of children and adults with CKD across Europe. We know what we need to do. We now need to get on and do it.

Patient and Caregiver Perspectives on Gender Disparity in CKD: An Interview Study

Key Points

Women felt vulnerable and felt that their housework obligations may interfere with CKD treatment, especially dialysis. Women felt they were good at protecting their health, whereas men might expect help from others and live in denial when confronted with advanced CKD.

Background

CKD affects more women than men worldwide; however, men comprise most patients who receive KRT. We aimed to describe the perspectives of patients and their caregivers regarding gender disparities in CKD.

Methods

Semi-structured interviews were conducted with 45 patients with CKD (20 women) and 14 caregivers (12 women) from seven clinics in Austria. The interviews were analyzed thematically.

Results

Five themes were identified in this study. Participants perceived that women were disadvantaged and vulnerable (silent and intimidated, single mother predicament, impeded access to care and support because of socioeconomic disadvantage, had to fend for themselves); fulfilling gender roles and norms (primarily responsible for childcare, pressure to perform well as homemakers, put others' needs before their own, encouraging husband's treatment adherence); and protecting their own health (self-disciplined, vigilant, confronted health challenges, advocated for their needs). Men were seen to place the onus of care on others (expected help from family, relied on others for decisions). Both men and women experienced a disease-related identity crisis and distress (women: impaired body image, mental distress; men: denial and self-destruction, emasculated by sickness).

Conclusions

Women with CKD felt vulnerable and were inclined to fulfill gender norms and responsibilities as caregivers, but were also vigilant about protecting their own health. Men tended to be reluctant to accept CKD and appeared to depend on others for disease management. Better awareness and addressing these concerns can inform strategies to minimize gender disparities in access to care and outcomes in CKD.

Association between estrogen and kidney function: population based evidence and mutual bidirectional Mendelian randomization study

BACKGROUND

Previous studies have suggested a potential role of estrogen in the pathophysiology of chronic kidney disease (CKD); however, the association and causality between estrogen and kidney function remain unclear.

METHODS

The cross-sectional correlation between serum estradiol concentration and estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio (ACR) was analyzed using data from the National Health and Nutrition Examination Survey 2013-2016. Causality was tested using mutual bidirectional Mendelian randomization (MR) approaches based on six large-scale GWAS studies. Weighted generalized multivariate linear regression was employed to estimate the association between estradiol and eGFR and ACR, and a restricted cubic spline analysis was utilized to investigate potential nonlinear relationships.

RESULTS

A total of 8932 participants were included. Serum estradiol concentration was positively associated with eGFR after adjusting for potential covariates (β, 0.76; 95% CI 0.24 to 1.27) and with ACR (β, 5.99; 95% CI 1.62 to 10.36). A nonlinear positive association was found between estradiol and eGFR, while an inverse "V"-shaped relationship was seen with ACR. Sensitivity analyses confirmed the stability of the relationship between estradiol and eGFR but indicated a less robust association with ACR. Stratified analysis showed that the association between estradiol and eGFR was particularly significant in populations with CKD and hypertension. All forward MR analyses demonstrated a positive causal relationship between estradiol and eGFR, but no causality was found between estradiol and ACR. No reverse causal association was observed.

CONCLUSIONS

Serum estradiol concentration was causally associated with eGFR. Further longitudinal research is needed to validate these findings.

Global, regional, and national burden inequality of chronic kidney disease, 1990-2021: a systematic analysis for the global burden of disease study 2021

Background

Chronic kidney disease (CKD) is a significant global health issue, often linked to diabetes, hypertension, and glomerulonephritis. However, aggregated statistics can obscure heterogeneity across subtypes, age, gender, and regions. This study aimed to analyze global CKD trends from 1990 to 2021, focusing on age, gender, socio-demographic index (SDI), and regional variations.

Methods

Data were extracted from the Global Burden of Disease (GBD) 2021 database, covering prevalence, incidence, mortality, and disability-adjusted life years (DALYs). These were presented as counts per 100,000 population and age-standardized rates, with uncertainty intervals (UIs) to highlight variability. Joinpoint regression was used to assess trends over the 30-year period.

Results

In 2021, global CKD prevalence was 359 million, with 11.13 million new cases, 1.53 million deaths, and 44.45 million DALYs-up 92, 156, 176, and 114% since 1990. While prevalence slightly declined, incidence, mortality, and DALYs increased significantly. CKD burden varied by region and age, with notable gender disparities.

Conclusion

The study highlights a dramatic rise in CKD burden linked to population growth and aging, emphasizing the need for targeted treatment and effective global healthcare policies.

Sex dimorphism in kidney health and disease: mechanistic insights and clinical implication

Sex is a key variable in the regulation of human physiology and pathology. Many diseases disproportionately affect one sex: autoimmune diseases, such as systemic lupus erythematosus, are more common in women but more severe in men, whereas the incidence of other disorders such as gouty arthritis and malignant cancers is higher in men. Besides the pathophysiology, sex may also influence the efficacy of therapeutics; participants in clinical trials are still predominately men, and the side effects of drugs are more common in women than in men. Sex dimorphism is a prominent feature of kidney physiology and function, and consequently affects the predisposition to many adult kidney diseases. These differences subsequently influence the response to immune stimuli, hormones, and therapies. It is highly likely that these responses differ between the sexes. Therefore, it becomes imperative to consider sex differences in translational science from basic science to preclinical research to clinical research and trials. Under-representation of one sex in preclinical animal studies or clinical trials remains an issue and key reported outcomes of such studies ought to be presented separately. Without this, it remains difficult to tailor the management of kidney disease appropriately and effectively. In this review, we provide mechanistic insights into sex differences in rodents and humans, both in kidney health and disease, highlight the importance of considering sex differences in the design of any preclinical animal or clinical study, and propose guidance on how to optimal design and conduct preclinical animal studies in future research.

Sodium glucose transporter 2 inhibitors: Will these drugs benefit non-diabetic veterinary patients with cardiac and kidney diseases?

Sodium glucose transporter type 2 (SGLT2) inhibitors have been introduced into human medicine where their beneficial effects go beyond the expected improvement in blood glucose control. These drugs appear to prevent progression of both cardiovascular and kidney diseases, not only in diabetic but also in non-diabetic human patients. As these drugs have received conditional approval for use in diabetic cats and are being used in other veterinary species, the intriguing question as to whether they will have similar cardioprotective and nephroprotective effects in dogs and cats is being asked. The primary mechanism(s) by which SGLT2 inhibitors are cardio- and nephroprotective remain to be fully characterized. This paper reviews these suggested mechanisms in the context of the pathophysiology of progressive cardiovascular and kidney diseases in dogs and cats with the goal of predicting which categories of non-diabetic veterinary patients these drugs might be of most benefit.

Transgenic rat with ubiquitous expression of angiotensin-(1-7)-producing fusion protein: a new tool to study the role of protective arm of the renin-angiotensin system in the pathophysiology of cardio-renal diseases

The aim of the present study was to assess systemic circulatory and tissue activities of both the classical arm and of the alternative arm of the renin-angiotensin system (RAS) in a new transgenic rat line (TG7371) that expresses angiotensin-(1-7) (ANG 1-7)-producing fusion protein; the results were compared with the activities measured in control transgene-negative Hannover Sprague-Dawley (HanSD) rats. Plasma and tissue concentrations of angiotensin II (ANG II) and ANG 1-7, and kidney mRNA expressions of receptors responsible for biological actions of ANG II and ANG 1-7 [i.e. ANG II type 1 and type 2 (AT1 and AT2) and Mas receptors] were assessed in TG7371 transgene-positive and in HanSD rats. We found that male TG7371 transgene-positive rats exhibited significantly elevated plasma, kidney, heart and lung ANG 1-7 concentrations as compared with control male HanSD rats; by contrast, there was no significant difference in ANG II concentrations and no significant differences in mRNA expression of AT1, AT2 and Mas receptors. In addition, we found that in male TG7371 transgene-positive rats blood pressure was lower than in male HanSD rats. These data indicate that the balance between the classical arm and the alternative arm of the RAS was in male TGR7371 transgene-positive rats markedly shifted in favor of the latter. In conclusion, TG7371 transgene-positive rats represent a new powerful tool to study the long-term role of the alternative arm of the RAS in the pathophysiology and potentially in the treatment of cardio-renal diseases.

Disparities in the Prevalence of Urinary Diseases Among Prisoners in Taiwan: Population-Based Cross-Sectional Study

BACKGROUND

Prisoner health is a major global concern, with prisoners often facing limited access to health care and enduring chronic diseases, infectious diseases, and poor mental health due to unsafe prison environments, unhygienic living conditions, and inadequate medical resources. In Taiwan, prison health is increasingly an issue, particularly concerning urinary diseases such as urinary tract infections. Limited access to health care and unsanitary conditions exacerbate these problems. Urinary disease epidemiology varies by sex and age, yet studies in Asia are scarce, and comprehensive data on urinary diseases in Taiwanese prisons remain limited.

OBJECTIVE

This study aimed to investigate the prevalence of urinary diseases among Taiwanese prisoners and explore the differences in disease prevalence between men and women, as well as across different age groups.

METHODS

This study used data on prisoners from the National Health Insurance Research Database covering the period from January 1 to December 31, 2013. Prisoners covered by National Health Insurance who were diagnosed with urinary diseases, identified by ICD-9-CM (International Classification of Diseases, Ninth Revision, Clinical Modification) codes 580-599 based on their medical records, and had more than one medical visit to ambulatory care or inpatient services were included. Sex- and age-stratified analyses were conducted to determine the differences in the prevalence of urinary diseases.

RESULTS

We examined 83,048 prisoners, including 2998 with urinary diseases. The overall prevalence of urinary system diseases among prisoners was 3.61% (n=2998; n=574, 6.64% in men and n=2424, 3.26% in women). The prevalence rate in men was significantly lower than that in women (prevalence ratio: 0.46, P<.001). In age-stratified analysis, the prevalence rate among prisoners aged >40 years was 4.5% (n=1815), compared to 2.77% (n=1183) in prisoners aged ≤40 years. Prisoners aged >40 years had a higher prevalence (prevalence ratio: 1.69, P<.001). Other disorders of the urethra and urinary tract (ICD-9-CM: 599), including urinary tract infection, urinary obstruction, and hematuria, were the most prevalent diseases of the urethra and urinary tract across age and sex groups. Women and older prisoners had a higher prevalence of most urinary tract diseases. There were no significant sex-specific differences in adjusted prevalence ratios for acute glomerulonephritis, nephrotic syndrome, kidney infections, urethritis (nonsexually transmitted), or urethral syndrome. However, based on the age-specific adjusted prevalence ratio analysis, cystitis was more prevalent among younger prisoners (prevalence ratio: 0.69, P=.004).

CONCLUSIONS

Urinary system infections and inflammation are common in prisons. Our findings advocate for policy reforms aimed at improving health care accessibility in prisons, with a particular focus on the needs of high-risk groups such as women and older prisoners. Further research linking claims data with prisoner information is crucial to providing more comprehensive medical services and achieving health equity.

International Nephrology Masterclass in Chronic Kidney Disease: Rationale, Summary, and Future Perspectives

Chronic kidney disease (CKD) is a progressive condition that affects more than 10% of the population worldwide, accounting for more than 843 million (M) individuals. The prevalence of CKD (844 M patients) is higher than that of diabetes mellitus (422 M patients), cancer (42 M patients), and HIV (37 M patients), but people are often less aware of it. Global expert groups predict reductions in the nephrology workforce in the next decade, with a declining interest in nephrology careers. Over time, KDIGO guidelines have also focused on topics related to the prevention or management of CKD patients in real-life settings. On these premises, a new educational program with international experts in the field of nephrology took place from November 2022 until March 2023 in Milan, Italy. This multinational masterclass provided an educational platform providing unbiased education on diagnosis and treatment by sharing the most recent research data on CKD and comorbidities, therefore creating a snowball effect to increase the implementation of best practices worldwide, using examples from 'real-life' patient outcomes. This paper provides an overview of the International Nephrology Masterclass (INM) concept, summarizing the key lectures and discussions, and giving an outline of future key developments.

Unraveling Sex Differences in Kidney Health and CKD: A Review of the Effect of Sex Hormones

Sexual dimorphism plays an important role in the pathogenesis and progression of CKD. Men with CKD often exhibit faster kidney function decline, leading to higher rates of kidney failure and mortality compared with women. Studies suggest that sex hormones may influence this apparent dimorphism, although the mechanisms underlying these influences remain poorly understood. In this review, we first summarize recent findings on sex differences in the prevalence and progression of CKD. Subsequently, we will focus on ( 1 ) the role of sex hormones in these sex differences, ( 2 ) kidney structural and hemodynamic differences between men and women, ( 3 ) the influence of sex hormones on pathophysiological processes leading to kidney disease, including glomerular hyperfiltration and key pathways involved in kidney inflammation and fibrosis, and finally, focus on the consequences of the underrepresentation of women in clinical trials. Understanding these sex differences is critical for advancing precision medicine and improving outcomes for both men and women with CKD.

Symptom Burden and Its Impact on Quality of Life in Patients With Moderate to Severe CKD: The International Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps)

RATIONALE & OBJECTIVE

Recent evidence suggests people with nondialysis chronic kidney disease (ND-CKD) experience a substantial burden of symptoms, but informative large-scale studies have been scarce. We assessed the prevalence of symptoms and the association of overall symptom burden with quality of life in patients with moderate to severe CKD.

STUDY DESIGN

Cross-sectional study.

SETTING & PARTICIPANTS

4,430 patients with ND-CKD stages 3-5 enrolled in the Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps) in Brazil, France, and the United States between 2013 and 2021.

EXPOSURE

13 individual patient-reported symptoms from the Kidney Disease Quality of Life Short Form (KDQOL-SF) questionnaire and an overall symptom burden score (low, intermediate, and high).

OUTCOME

Physical and mental component summary scores (PCS and MCS) of the KDQOL-SF.

ANALYTICAL APPROACH

Adjusted prevalence ratios and generalized estimating equations.

RESULTS

Patients (mean age, 68 years; 40% women; mean baseline estimated glomerular filtration rate [eGFR], 30mL/min/1.73m2) were very much to extremely bothered by numerous symptoms ("soreness in muscles," 23%; "washed out or drained," 21%; "cramps, shortness of breath, dry skin, diminished sex life, or numbness in hands or feet," 14%-17%). The adjusted prevalences of "cramps," "washed out or drained," "lack of appetite," "nausea/upset stomach," and "sex life" were greater with more severe CKD and in women (except for "sex life"). A high overall symptom burden was more common in women, in France, and in patients with severe albuminuria and various comorbidities, but not with lower eGFR. The PCS and MCS scores were 13.4 and 7.7 points lower, respectively, for high versus low overall symptom burden.

LIMITATIONS

Generalizability limited to patients under nephrology care, residual confounding, and inaccurate Brazilian translation of some symptoms.

CONCLUSIONS

The high symptom burden observed in this large cohort of ND-CKD patients across 3 diverse countries and its strong association with poorer health-related quality of life should inform clinical management of and clinical research in CKD.

PLAIN-LANGUAGE SUMMARY

Little is known about symptoms in patients with non-dialysis-dependent chronic kidney disease (ND-CKD). In the Chronic Kidney Disease Outcomes and Practice Patterns Study, which enrolled 4,430 patients with CKD stages 3-5 in Brazil, France, and the United States, patients most often reported soreness in muscles, feeling washed out or drained, cramps, shortness of breath, dry skin, altered sex life, and numbness in hands or feet. Cramps, feeling washed out or drained, lack of appetite, and nausea were more often reported at lower levels of kidney function. The overall symptom burden was higher in women than men, in French than in Brazilian or US patients, and in those with severe albuminuria. The higher the symptom burden, the lower were the physical and mental health quality of life scores. The high symptom burden observed in this large cohort of ND-CKD patients across 3 diverse countries and its strong association with poorer health-related quality of life should inform clinical management of and clinical research in CKD.

Inclusive Laboratory Reference Intervals and Clinical Studies to Reduce Health Disparities

Health inequities are common and in part a consequence of non-inclusive health research. The underrepresentation of specific populations in research, including women, children, youth and the elderly, racialized and ethnic groups, and sexual and gender minorities, results in limited ability to develop appropriate reference intervals, determine effective treatments, and establish health guidelines to optimize health outcomes for all. By working together toward greater inclusivity in all aspects of health research and care, health care providers and professional medical societies, including laboratory medicine practitioners, have the ability to achieve health equity.

Gucy1α1 specifically marks kidney, heart, lung and liver fibroblasts

Fibrosis is a common outcome of numerous pathologies, including chronic kidney disease (CKD), a progressive renal function deterioration. Current approaches to target activated fibroblasts, key effector contributors to fibrotic tissue remodeling, lack specificity. Here, we report Gucy1α1 as a specific kidney fibroblast marker. Gucy1α1 levels significantly increased over the course of two clinically relevant murine CKD models and directly correlated with established fibrosis markers. Immunofluorescent (IF) imaging showed that Gucy1α1 comprehensively labelled cortical and medullary quiescent and activated fibroblasts in the control kidney and throughout injury progression, respectively. Unlike traditionally used markers platelet derived growth factor receptor beta (Pdgfrβ) and vimentin (Vim), Gucy1α1 did not overlap with off-target populations such as podocytes. Notably, Gucy1α1 labelled kidney fibroblasts in both male and female mice. Furthermore, we observed elevated GUCY1α1 expression in the human fibrotic kidney and lung. Studies in the murine models of cardiac and liver fibrosis revealed Gucy1α1 elevation in activated Pdgfrβ-, Vim- and alpha smooth muscle actin (αSma)-expressing fibroblasts paralleling injury progression and resolution. Overall, we demonstrate Gucy1α1 as an exclusive fibroblast marker in both sexes. Due to its multiorgan translational potential, GUCY1α1 might provide a novel promising strategy to specifically target and mechanistically examine fibroblasts.

Genome-wide association analysis of cystatin c and creatinine kidney function in Chinese women

BACKGROUND

With increasing incidence and treatment costs, chronic kidney disease (CKD) has become an important public health problem in China, especially in females. However, the genetic determinants are very limited. The estimated glomerular filtration rate (eGFR) based on creatinine is commonly used as a measure of renal function but can be easily affected by other factors. In contrast, eGFR based on both creatinine and cystatin C (eGFRcr-cys) improved the diagnostic accuracy of CKD. To our knowledge, no genome-wide association analysis of eGFRcr-cys has been conducted in the Chinese population.

METHODS

By conducting a Genome-Wide association study(GWAS), a method used to identify associations between genetic regions (genomes) and traits/diseases, we examined the relationship between genetic factors and eGFRcr-cys in Chinese women, with 1983 participants and 3,838,121 variants included in the final analysis.

RESULT

One significant locus (20p11.21) was identified in the Chinese female population, which has been reported to be associated with eGFR based on cystatin C (eGFRcys) in the European population. More importantly, we found two new suggestive loci (1p31.1 and 11q24.2), which have not yet been reported. A total of three single nucleotide polymorphisms were identified as the most important variants in these regions, including rs2405367 (CST3), rs66588571(KRT8P21), and rs626995 (OR8B2).

CONCLUSION

We identified 3 loci 20p11.21, 1p31.1, and 11q24.2 to be significantly associated with eGFRcr-cys. These findings and subsequent functional analysis describe new biological clues related to renal function in Chinese women and provide new ideas for the diagnosis and treatment development of CKD.

Sex and the Risk of Atheromatous and Nonatheromatous Cardiovascular Disease in CKD: Findings From the CKD-REIN Cohort Study

RATIONALE & OBJECTIVE

Sex differences in cardiovascular disease (CVD) are well established, but whether chronic kidney disease (CKD) modifies these risk differences and whether they differ between atheromatous CVD (ACVD) and nonatheromatous CVD (NACVD) is unknown. Assessing this interaction was the principal goal of this study.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

Adults enrolled in the CKD-REIN (CKD-Renal Epidemiology and Information Network) cohort, a nationally representative sample of 40 nephrology clinics in France, from 2013 to 2020.

EXPOSURE

Sex.

OUTCOMES

Fatal and nonfatal composite ACVD events (ischemic coronary, cerebral, and peripheral artery disease) and composite NACVD events (heart failure, hemorrhagic stroke, and arrhythmias).

ANALYTICAL APPROACH

Multivariable cause-specific Cox proportional hazards models.

RESULTS

1,044 women and 1,976 men with moderate to severe CKD (median age, 67 vs 69y; mean estimated glomerular filtration rate [eGFR], 32±12 vs 33±12mL/min/1.73m2) were studied. During a median follow-up of 5.0 (IQR, 4.8-5.2) years, the ACVD rate (per 100 patient-years) was significantly lower in women than in men, at 2.1 (95% CI, 1.6-2.5) versus 3.6 (3.2-4.0; P<0.01), whereas the NACVD rate was not, at 5.7 (5.0-6.5) versus 6.4 (5.8-7.0; P=0.55). NACVD had a steeper relationship with eGFR than did ACVD. There was an interaction (P<0.01) between sex and baseline eGFR and the ACVD hazard: the adjusted HR for women versus men was 0.42 (0.25-0.71) at 45mL/min/1.73m2 and gradually attenuated at lower levels of eGFR, reaching 1.00 (0.62-1.63) at 16mL/min/1.73m2. In contrast, the NACVD hazard did not differ between sexes across the eGFR range studied.

LIMITATIONS

Cardiovascular biomarkers and sex hormones were not assessed.

CONCLUSIONS

This study shows how the lower risk of ACVD among women versus men attenuates fully with kidney disease progression. The equal risk of NACVD between sexes across CKD stages and its steeper association with eGFR suggest an important contribution of CKD to the development of this CVD type.

PLAIN-LANGUAGE SUMMARY

Sex differences in the risks of atheromatous and nonatheromatous cardiovascular disease (CVD) are well established in the general population. If or how chronic kidney disease (CKD) might modify these risks is unknown. In this large cohort of 3,010 patients with CKD, women had a lower risk than men of atheromatous CVDs such as coronary artery disease or stroke when they were at an early stage of CKD. This advantage, partly due to women's better cardiovascular risk profile, tended to attenuate as CKD progressed to kidney failure. In contrast, the risk of nonatheromatous CVDs such as heart failure for women with CKD appeared similar to that of men with CKD at all kidney function levels.

Revealing the burden of chronic kidney disease in Mexican women, 1990-2021

BACKGROUND

Chronic kidney disease (CKD) has become a concerning public health issue, affecting people regardless of their sex, age, or socioeconomic status. We aimed to analyze the burden of female CKD in Mexico between 1990 and 2021, expressed in terms of years lived with disability (YLDs), mortality, years of life lost (YLLs), and disability-adjusted life-years (DALYs). Additionally, we evaluated the relationship between DALYs and the Socio-Demographic Index (SDI) and the Healthcare Access and Quality Index (HAQI).

METHODS

Secondary data analysis from the Global Burden of Disease, Injuries, and Risk Factors Study (GBD) 2021. We used mortality, years of life lost due to premature mortality (YLLs), years lived with disability (YLDs), and disability-adjusted life years (DALYs to analyze CKD in women between 1990 and 2021. We used a log-linear segmented regression model to analyze trends in female CKD DALY rates over time. The information was disaggregated by age groups and sub-causes nationally and across the 32 states. Age-standardized rates (ASR) were used.

RESULTS

Between 1990 and 2021, the ASR mortality and ASR-DALYs due to CKD increased significantly at the national level. The DALYs are almost entirely explained by YLLs, indicating that a large proportion of women with CKD in Mexico die prematurely. Disparities in the burden of this disease were observed across different states and age groups within the country. In 2021, the highest ASR-DALY rate was recorded in Tabasco (1,972.0), while the lowest was in Sinaloa (865.1). The SDI and HAQI were associated with the CKD DALYs in most states.

CONCLUSIONS

Mexican women experience a significant burden due to CKD, reflected in premature deaths and years lived with disability, while disparities between states need to be addressed to reduce inequities. Over the past 32 years, improvements in socioeconomic indicators and the quality and access to healthcare have not contributed to reducing the DALYs rate due to CKD, indicating a need to redirect policies to impact women's well-being and health positively.

Global health inequalities of chronic kidney disease: a meta-analysis

BACKGROUND

Chronic kidney disease (CKD) is a significant contributor to global morbidity and mortality. This study investigated disparities in age, sex and socio-economic status in CKD and updated global prevalence estimates through systematic review and meta-analysis.

METHODS

Five databases were searched from 2014 to 2022, with 14 871 articles screened, 119 papers included and data analysed on 29 159 948 participants. Random effects meta-analyses were conducted to determine overall prevalence, prevalence of stages 3-5 and prevalence in males and females. Influences of age, sex and socio-economic status were assessed in subgroup analyses and risk of bias assessment and meta-regressions were conducted to explore heterogeneity.

RESULTS

The overall prevalence of CKD was 13.0% [95% confidence interval (CI) 11.3-14.8] and 6.6% (95% CI 5.6-7.8) for stages 3-5. The prevalence was higher in studies of older populations (19.3% for stages 1-5, 15.0% for stages 3-5) and meta-regression demonstrated an association of age, body mass index, diabetes and hypertension with prevalence of stages 3-5. The prevalence of CKD stages 1-5 was similar in males and females (13.1% versus 13.2%), but the prevalence of stages 3-5 was higher in females (6.4% versus 7.5%). Overall prevalence was 11.4%, 15.0% and 10.8% in low-, middle- and high-income countries, respectively; for stages 3-5, prevalence was 4.0%, 6.7% and 6.8%, respectively. Included studies were at moderate-high risk of bias in the majority of cases (92%) and heterogeneity was high.

CONCLUSION

This study provides a comprehensive assessment of CKD prevalence, highlighting important disparities related to age, sex and socio-economic status. Future research should focus on targeted screening and treatment approaches, improving access to care and more effective data monitoring, particularly in low- and middle-income countries.

Sex-specific molecular signature of mouse podocytes in homeostasis and in response to pharmacological challenge with rapamycin

BACKGROUND

Sex differences exist in the prevalence and progression of major glomerular diseases. Podocytes are the essential cell-type in the kidney which maintain the physiological blood-urine barrier, and pathological changes in podocyte homeostasis are critical accelerators of impairment of kidney function. However, sex-specific molecular signatures of podocytes under physiological and stress conditions remain unknown. This work aimed at identifying sexual dimorphic molecular signatures of podocytes under physiological condition and pharmacologically challenged homeostasis with mechanistic target of rapamycin (mTOR) inhibition. mTOR is a crucial regulator involved in a variety of physiological and pathological stress responses in the kidney and inhibition of this pathway may therefore serve as a general stress challenger to get fundamental insights into sex differences in podocytes.

METHODS

The genomic ROSAmT/mG-NPHS2 Cre mouse model was used which allows obtaining highly pure podocyte fractions for cell-specific molecular analyses, and vehicle or pharmacologic treatment with the mTOR inhibitor rapamycin was performed for 3 weeks. Subsequently, deep RNA sequencing and proteomics were performed of the isolated podocytes to identify intrinsic sex differences. Studies were supplemented with metabolomics from kidney cortex tissues.

RESULTS

Although kidney function and morphology remained normal in all experimental groups, RNA sequencing, proteomics and metabolomics revealed strong intrinsic sex differences in the expression levels of mitochondrial, translation and structural transcripts, protein abundances and regulation of metabolic pathways. Interestingly, rapamycin abolished prominent sex-specific clustering of podocyte gene expression and induced major changes only in male transcriptome. Several sex-biased transcription factors could be identified as possible upstream regulators of these sexually dimorphic responses. Concordant to transcriptomics, metabolomic changes were more prominent in males. Remarkably, high number of previously reported kidney disease genes showed intrinsic sexual dimorphism and/or different response patterns towards mTOR inhibition.

CONCLUSIONS

Our results highlight remarkable intrinsic sex-differences and sex-specific response patterns towards pharmacological challenged podocyte homeostasis which might fundamentally contribute to sex differences in kidney disease susceptibilities and progression. This work provides rationale and an in-depth database for novel targets to be tested in specific kidney disease models to advance with sex-specific treatment strategies.

Revisiting sex as a biological variable in hypertension research

Half of adults in the United States have hypertension as defined by clinical practice guidelines. Interestingly, women are generally more likely to be aware of their hypertension and have their blood pressure controlled with treatment compared with men, yet hypertension-related mortality is greater in women. This may reflect the fact that the female sex remains underrepresented in clinical and basic science studies investigating the effectiveness of therapies and the mechanisms controlling blood pressure. This Review provides an overview of the impact of the way hypertension research has explored sex as a biological variable (SABV). Emphasis is placed on epidemiological studies, hypertension clinical trials, the genetics of hypertension, sex differences in immunology and gut microbiota in hypertension, and the effect of sex on the central control of blood pressure. The goal is to offer historical perspective on SABV in hypertension, highlight recent studies that include SABV, and identify key gaps in SABV inclusion and questions that remain in the field. Through continued awareness campaigns and engagement/education at the level of funding agencies, individual investigators, and in the editorial peer review system, investigation of SABV in the field of hypertension research will ultimately lead to improved clinical outcomes.

Experience of Diagnosis and Initiation of Renal Replacement Therapy in Women with Chronic Kidney Disease

Chronic kidney disease (CKD) has considerable effects on the quality of life of female patients. Receiving the diagnosis and beginning renal replacement therapy (RRT) has a great personal impact on patients. The purpose of this study was to describe the experience of female patients with CKD at an ambulatory dialysis unit regarding diagnosis, life changes, and initiation of RRT. A qualitative exploratory study was conducted based on a social contructivism framework. Participants were recruited using purposeful sampling. In total, 18 women who received treatment for CKD with RRT were included. The women were attending the Ambulatory Dialysis Unit at a hospital belonging to the public health system of Madrid (Spain). Unstructured and semi-structured in-depth interviews, researchers' field notes, and women's personal letters were used. A systematic text condensation analysis was performed. The criteria used to control trustworthiness were credibility, transferability, dependability, and confirmability. Two themes emerged from the data: (a) A turning point in their lives, and (b) The emotional journey of beginning RRT. The diagnosis of CKD and the beginning of treatment implies changing routines and adapting to a new life with CKD. The first dialysis and puncture of the arteriovenous fistula is a major experience. Support from other CKD patients with more experience is perceived as a necessity and a tool to share their experiences and resolve doubts among peers. The diagnosis and initiation of RRT leads to numerous changes in the lives of women with CKD, which may influence the acceptance of treatment.

[Sex differences in hepatobiliary and transplantation surgery]

Gender-specific differences in hepatobiliary and transplantation surgery are decisive for the diagnosis, treatment and long-term outcomes. Men exhibit a higher risk of late recurrences and cancer-specific death after liver cancer resection. The emphasis on screening recommendations and ensuring equal access to treatment options are vital to minimize disparities. In kidney and liver transplantations, women are less frequently listed and endure longer waiting times, while men dominate the waiting list. Gender-specific disparities in drug compatibility necessitate differentiated dosing. Further studies are needed to ensure equity in transplantation treatment. Individualized treatment considering these differences can enhance treatment outcomes and the quality of life of patients.

Patient and Caregiver Perspectives on Gender Disparity in Chronic Kidney Disease: Questionnaire Survey, Based on an Interview Study

INTRODUCTION

Chronic kidney disease (CKD) in stages 3-5 without albuminuria occurs more often in women than in men; however, most patients initiating and receiving kidney replacement therapy are men. Sex-determined biological factors and gender-related aspects both likely account for this discrepancy. Patient opinions on gender-related discrepancies in kidney care have not been investigated.

METHODS

Building upon the findings of semi-structured interviews previously conducted with CKD patients and their caregivers, two questionnaires were developed to investigate patient behavior and opinions relating to gender and CKD. These questionnaires containing 39 items were distributed to eight outpatient clinics in Austria. Responses were descriptively analyzed and compared between genders, as well as between age-groups and CKD stages.

RESULTS

Questionnaires from 783 patients and 98 caregivers were included in the analysis and covered health awareness and self-management of disease, the impact of gender roles and gender equality, and patient autonomy and trust in the health-care system. A total of 56.1% of men patients and 63.1% of women patients found that women were better at looking after their health compared to men (41.1%/34.3% no difference, 2.8%/2.6% men better). A total of 95.4% of men patients, 95.0% of women patients, 100% of men caregivers, and 95.5% of women caregivers stated that all patients with kidney disease were treated completely equally, irrespective of gender.

CONCLUSION

Neither the patients nor the caregivers stated gender-determined treatment decisions in CKD care. Both men and women however agreed that women are better at maintaining their own health and excel in disease self-management.

Gucy1α1 specifically marks kidney, heart, lung and liver fibroblasts

Fibrosis is a common outcome of numerous pathologies, including chronic kidney disease (CKD), a progressive renal function deterioration. Current approaches to target activated fibroblasts, key effector contributors to fibrotic tissue remodeling, lack specificity. Here, we report Gucy1α1 as a specific kidney fibroblast marker. Gucy1α1 levels significantly increased over the course of two clinically relevant murine CKD models and directly correlated with established fibrosis markers. Immunofluorescent (IF) imaging showed that Gucy1α1 comprehensively labelled cortical and medullary quiescent and activated fibroblasts in the control kidney and throughout injury progression, respectively. Unlike traditionally used markers platelet derived growth factor receptor beta (Pdgfrβ) and vimentin (Vim), Gucy1α1 did not overlap with off-target populations such as podocytes. Notably, Gucy1α1 labelled kidney fibroblasts in both male and female mice. Furthermore, we observed elevated GUCY1α1 expression in the human fibrotic kidney and lung. Studies in the murine models of cardiac and liver fibrosis revealed Gucy1α1 elevation in activated Pdgfrβ-, Vim- and alpha smooth muscle actin (αSma)-expressing fibroblasts paralleling injury progression and resolution. Overall, we demonstrate Gucy1α1 as an exclusive fibroblast marker in both sexes. Due to its multiorgan translational potential, GUCY1α1 might provide a novel promising strategy to specifically target and mechanistically examine fibroblasts.

Sex-Specific Differences in Kidney Function and Blood Pressure Regulation

Premenopausal women generally exhibit lower blood pressure and a lower prevalence of hypertension than men of the same age, but these differences reverse postmenopause due to estrogen withdrawal. Sexual dimorphism has been described in different components of kidney physiology and pathophysiology, including the renin-angiotensin-aldosterone system, endothelin system, and tubular transporters. This review explores the sex-specific differences in kidney function and blood pressure regulation. Understanding these differences provides insights into potential therapeutic targets for managing hypertension and kidney diseases, considering the patient's sex and hormonal status.

Secondary hyperparathyroidism in chronic kidney disease: pathophysiology, current treatments and investigational drugs

INTRODUCTION

Secondary hyperparathyroidism (SHPT) is a common complication of chronic kidney disease (CKD). It begins as an adaptive increase in parathyroid hormone levels to prevent calcium and phosphate derangements. Over time, this condition becomes maladaptive and is associated with increased morbidity and mortality. Current therapies encompass phosphate-lowering strategies, vitamin D analogues, calcimimetics and parathyroidectomy. These approaches harbor inherent limitations, stimulating interest in the development of new drugs for SHPT to overcome these limitations and improve survival and quality of life among CKD patients.

AREAS COVERED

This review delves into the main pathophysiological mechanisms involved in SHPT, alongside the treatment options that are currently available and under active investigation. Data presented herein stem from a comprehensive search conducted across PubMed, Web of Science, ClinicalTrials.gov and International Clinical Trials Registry Platform (ICTRP) spanning from 2000 onwards.

EXPERT OPINION

The advancements in investigational drugs for SHPT hold significant promise for enhancing treatment efficacy while minimizing side effects associated with conventional therapies. Although several challenges still hinder their adoption in clinical practice, ongoing research will likely continue to expand the available therapeutic options, refine treatment strategies, and tailor them to individual patient profiles.

A Holistic Framework for the Evaluation of Kidney Function in a Gender-Diverse Landscape

The most commonly used equations to estimate glomerular filtration rate incorporate a binary male-female sex coefficient, which has important implications for the care of transgender, gender-diverse, and nonbinary (TGD) people. Whether "sex assigned at birth" or a binary "gender identity" is most appropriate for the computation of estimated glomerular filtration rate (eGFR) is unknown. Furthermore, the use of gender-affirming hormone therapy (GAHT) for the development of physical changes to align TGD people with their affirmed gender is increasingly common, and may result in changes in serum creatinine and cystatin C, the biomarkers commonly used to estimate glomerular filtration rate. The paucity of current literature evaluating chronic kidney disease (CKD) prevalence and outcomes in TGD individuals on GAHT makes it difficult to assess any effects of GAHT on kidney function. Whether alterations in serum creatinine reflect changes in glomerular filtration rate or simply changes in muscle mass is unknown. Therefore, we propose a holistic framework to evaluate kidney function in TGD people. The framework focuses on kidney disease prevalence, risk factors, sex hormones, eGFR, other kidney function assessment tools, and the mitigation of health inequities in TGD people.

Sex Differences in Primary Care-Based Chronic Kidney Disease Management

This retrospective study uses electronic health record data to investigate the sex differences in guideline-based management outcomes between male and female patients with chronic kidney disease.

Chronic kidney disease and the global public health agenda: an international consensus

Early detection is a key strategy to prevent kidney disease, its progression and related complications, but numerous studies show that awareness of kidney disease at the population level is low. Therefore, increasing knowledge and implementing sustainable solutions for early detection of kidney disease are public health priorities. Economic and epidemiological data underscore why kidney disease should be placed on the global public health agenda - kidney disease prevalence is increasing globally and it is now the seventh leading risk factor for mortality worldwide. Moreover, demographic trends, the obesity epidemic and the sequelae of climate change are all likely to increase kidney disease prevalence further, with serious implications for survival, quality of life and health care spending worldwide. Importantly, the burden of kidney disease is highest among historically disadvantaged populations that often have limited access to optimal kidney disease therapies, which greatly contributes to current socioeconomic disparities in health outcomes. This joint statement from the International Society of Nephrology, European Renal Association and American Society of Nephrology, supported by three other regional nephrology societies, advocates for the inclusion of kidney disease in the current WHO statement on major non-communicable disease drivers of premature mortality.

Role of Histone Modifications in Kidney Fibrosis

Chronic kidney disease (CKD) is characterized by persistent kidney dysfunction, ultimately resulting in end-stage renal disease (ESRD). Renal fibrosis is a crucial pathological feature of CKD and ESRD. However, there is no effective treatment for this condition. Despite the complex molecular mechanisms involved in renal fibrosis, increasing evidence highlights the crucial role of histone modification in its regulation. The reversibility of histone modifications offers promising avenues for therapeutic strategies to block or reverse renal fibrosis. Therefore, a comprehensive understanding of the regulatory implications of histone modifications in fibrosis may provide novel insights into more effective and safer therapeutic approaches. This review highlights the regulatory mechanisms and recent advances in histone modifications in renal fibrosis, particularly histone methylation and histone acetylation. The aim is to explore the potential of histone modifications as targets for treating renal fibrosis.

Gucy1α1 specifically marks kidney, heart, lung and liver fibroblasts

Fibrosis is a common outcome of numerous pathologies, including chronic kidney disease (CKD), a progressive renal function deterioration. Current approaches to target activated fibroblasts, key effector contributors to fibrotic tissue remodeling, lack specificity. Here, we report Gucy1α1 as a specific kidney fibroblast marker. Gucy1α1 levels significantly increased over the course of two clinically relevant murine CKD models and directly correlated with established fibrosis markers. Immunofluorescent (IF) imaging showed that Gucy1α1 comprehensively labelled cortical and medullary quiescent and activated fibroblasts in the control kidney and throughout injury progression, respectively. Unlike traditionally used markers platelet derived growth factor receptor beta (Pdgfrβ) and vimentin (Vim), Gucy1α1 did not overlap with off-target populations such as podocytes. Notably, Gucy1α1 labelled kidney fibroblasts in both male and female mice. Furthermore, we observed elevated GUCY1α1 expression in the human fibrotic kidney and lung. Studies in the murine models of cardiac and liver fibrosis revealed Gucy1α1 elevation in activated Pdgfrβ-, Vim- and alpha smooth muscle actin (αSma)-expressing fibroblasts paralleling injury progression and resolution. Overall, we demonstrate Gucy1α1 as an exclusive fibroblast marker in both sexes. Due to its multiorgan translational potential, GUCY1α1 might provide a novel promising strategy to specifically target and mechanistically examine fibroblasts.

PPARα/δ dual agonist H11 alleviates diabetic kidney injury by improving the metabolic disorders of tubular epithelial cells

Diabetic kidney disease (DKD) is responsible for nearly half of all end-stage kidney disease and kidney failure is a major driver of mortality among patients with diabetes. To date, few safe and effective drugs are available to reverse the decline of kidney function. Kidney tubules producing energy by fatty acid metabolism are pivotal in development and deterioration of DKD. Peroxisome proliferator-activated receptors (PPARs), comprising PPARα, PPARδ and PPARγ play a senior role in the pathogenesis of DKD for their functions in glycemic control and lipid metabolism; whereas systemic activation of PPARγ causes serious side-effects in clinical settings. Compound H11 was a potent PPARα and PPARδ (PPARα/δ) dual agonist with potent and well-balanced PPARα/δ agonistic activity and a high selectivity over PPARγ. In this study, the potential therapeutic effects of compound H11 were determined in a db/db mouse model of diabetes. Expressions of PPARα and PPARδ in nuclei of tubules were markedly reduced in diabetes. Transcriptional changes of tubular cells showed that H11 was an effective PPARα/δ dual agonist taking effects both in vivo and in vitro. Systemic administration of H11 showed glucose tolerance and lipid metabolic benefits in db/db mice. Moreover, H11 treatment exerted protective effects on diabetic kidney injury. In addition to fatty acid metabolism, H11 also regulated diabetes-induced metabolic alternations of branch chain amino acid degradation and glycolysis. The present study demonstrated a crucial role of H11 in regulation of energy homeostasis and metabolism in glucose-treated tubular cells. Overall, compound H11 holds therapeutic promise for DKD.