Sex differences in acute kidney injury requiring dialysis

Multi-omic and spatial analysis of mouse kidneys highlights sex-specific differences in gene regulation across the lifespan

There is a sex bias in the incidence and progression of many kidney diseases. To better understand such sexual dimorphism, we integrated data from six platforms, characterizing 76 kidney samples from 68 mice at six developmental and adult time points, creating a molecular atlas of the mouse kidney across the lifespan for both sexes. We show that proximal tubules have the most sex-biased differentially expressed genes emerging after 3 weeks of age and are associated with hormonal regulations. We reveal potential mechanisms involving both direct and indirect regulation by androgens and estrogens. Spatial profiling identifies distinct sex-biased spatial patterns in the cortex and outer stripe of the outer medulla. Additionally, older mice exhibit more aging-related gene alterations in loops of Henle, proximal tubules and collecting ducts in a sex-dependent manner. Our results enhance the understanding of spatially resolved gene expression and hormone regulation underlying kidney sexual dimorphism across the lifespan.

Sex, Acute Kidney Injury, and Age: A Prospective Cohort Study

RATIONALE & OBJECTIVE

Animal models of kidney disease suggest a protective role for female sex hormones, but some authorities assert that female sex in humans is a risk factor for acute kidney injury (AKI). To better understand the risk of AKI, we studied the strength of association between sex and AKI incidence in hormonally distinct age groups across the life span.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

All patients hospitalized in the Montefiore Health System between October 15, 2015, and January 1, 2019, excluding those with kidney failure or obstetrics diagnoses.

EXPOSURE

Male versus female sex.

OUTCOME

AKI occurring during hospitalization based on KDIGO definitions.

ANALYTICAL APPROACH

Generalized estimating equation logistic regression adjusted for comorbidities, sociodemographic factors, and severity of illness. Analyses were stratified into 3 age categories: 6 months to≤16 years,>16 years to<55 years, and≥55 years.

RESULTS

A total of 132,667 individuals were hospitalized a total of 235,629 times. The mean age was 55.2±23.8 (SD) years. The count of hospitalizations for women was 129,912 (55%). Hospitalization count among Black and Hispanic patients was 71,834 (30.5%) and 24,199 (10.3%), respectively. AKI occurred in 53,926 (22.9%) hospitalizations. In adjusted models, there was a significant interaction between age and sex (P<0.001). Boys and men had a higher risk of AKI across all age groups, an association more pronounced in the age group>16 years to<55 years in which the odds ratio for men was 1.7 (95% CI, 1.6-1.8). This age-based pattern remained consistent across prespecified types of hospitalizations. In a sensitivity analysis, women older than 55 years who received prescriptions for estrogen had lower odds of AKI than those without prescriptions.

LIMITATIONS

Residual confounding.

CONCLUSIONS

The greatest relative risk of AKI for males occurred during ages>16 to<55 years. The lower risk among postmenopausal women receiving supplemental estrogen supports a protective role for female sex hormones.

PLAIN-LANGUAGE SUMMARY

Male sex is a risk factor for acute kidney injury (AKI) in animals, but in human studies this association is not as robust. We studied hospitalizations at a single center to examine the association of hospital-acquired AKI and sex. After controlling for various sources of potential bias and stratifying by age categories through the life course, we observed that men have a higher risk of AKI throughout life. This risk was especially high compared with women of fertile age and older women prescribed estrogen. This pattern was consistent in prespecified subgroups of hospitalizations. These results support a protective role for female sex hormones in the occurrence of hospitalized AKI.

Prophylactic proton pump inhibitor usage and new-onset acute kidney injury in critically ill patients: a retrospective analysis

Background

Proton pump inhibitors (PPIs) are widely prescribed for stress ulcer prophylaxis (SUP) in intensive care unit (ICU) patients. However, the potential association between prophylactic PPIs and the development of new-onset acute kidney injury (AKI) remains unclear.

Methods

Patients without AKI or end-stage renal disease and not undergoing renal replacement therapy upon admission to the ICU were identified from the Medical Information Mart for Intensive Care (MIMIC-IV) database. The exposure factor for the study was the initiation of prophylactic PPIs within 48 h of admission, with the primary outcome being the occurrence of new-onset AKI after 48 h. Multivariable regression models were employed to investigate the association between prophylactic PPIs and the risk of new-onset AKI. Various propensity score analyses, along with stratified and subgroup analyses and E-value calculations, were conducted to further evaluate the reliability of the results.

Results

A total of 7498 ICU patients were analyzed. The multivariable analysis showed a higher incidence of new-onset AKI in the PPI group (30.7%) compared with the control group (24.1%), yielding an adjusted odds ratio (OR) of 1.43 (95% confidence interval 1.22-1.67). Propensity score analyses confirmed these results, with ORs ranging from 1.34 to 1.49 (P ≤ .005). Results from multiple sensitivity analyses further supported these findings, with an E-value of 2.34 indicating robustness against unmeasured confounders.

Conclusions

Prophylactic PPI use is associated with an increased risk of new-onset AKI in ICU patients. Indiscriminate use of PPIs should be avoided.

Attenuation of acute kidney injury in a murine model of neonatal Escherichia coli sepsis

Introduction

Sepsis is a risk factor for acute kidney injury (AKI) in neonates, for which no effective treatment exists. The phosphodiesterase inhibitor pentoxifylline (PTX) has demonstrated renal protection from ischemia and inflammation in adult rodents. We hypothesized that addition of PTX to antibiotics may attenuate immune and histological AKI in a murine neonatal sepsis model.

Methods

Postnatal (PN) day 1 C57BL/6J mice were injected with E. coli K1 strain at 105 colony forming units per gram weight or saline control. After 1.5 hours, septic pups randomly received saline, gentamicin or cefotaxime, with/without PTX. 5.5h after sepsis initiation, kidneys and blood were harvested for measurements of biomarkers of inflammation and kidney injury. Renal sections from PN7 mice were used for histology and immunofluorescence. Linear mixed effect models were employed to fit the outcomes including interaction between treatment group and sex.

Results

Septic mice demonstrated robust expression of pro-inflammatory cytokines, chemokines and biomarkers of tubular injury in renal tissue, which were attenuated in response to combined PTX and antibiotics (gentamicin or cefotaxime): chemokines (p<0.001), plasma (p<0.01) and tissue IL-6 (p<0.05), plasma TNF (p<0.001), NGAL (p<0.01), CXCL10 (p<0.01), osteopontin (p<0.05), and VEGF (p<0.05), with a trend for KIM-1 (tissue concentration: p=0.21, fluorescence area: p=0.12). Interactions between treatment and sex were present for several cytokines and kidney injury biomarkers. Immunofluorescence findings for the tubular injury markers (NGAL and KIM-1) were consistent with biomarker expression in tissue lysates.

Conclusion

Neonatal E. coli sepsis leads to increased expression of renal tissue inflammation and injury biomarkers consistent with AKI, which may be attenuated with PTX combined with antibiotic treatment.

Guidelines for sex-specific considerations to improve rigor in renal research and how we got there

Biological sex significantly influences disease presentation, progression, and therapeutic outcomes in chronic kidney disease and acute kidney injury. Sex hormones, including estrogen and testosterone, modulate key renal functions, including renal blood flow, glomerular filtration, and electrolyte transport, thereby affecting disease trajectory in a sex-specific manner. It is critical for researchers to understand why and how to integrate sex as a biological variable in data collection, analysis, and reporting. Integrating a sex-based perspective in kidney research will lead to more personalized and efficacious treatment strategies, optimizing therapeutic interventions for each sex. If addressed properly, the incorporation of sex as a biological variable (SABV) in renal research not only enhances the mechanistic understanding of renal disease, but also paves the way for precision medicine, promising improved clinical outcomes, and tailored treatment protocols for all patients. This paper is designed to serve as a guideline for researchers interested in rigorously incorporating sex as a biological variable in their studies.

Excess dietary sodium restores electrolyte and water homeostasis caused by loss of the endoplasmic reticulum molecular chaperone, GRP170, in the mouse nephron

The maintenance of fluid and electrolyte homeostasis by the kidney requires proper folding and trafficking of ion channels and transporters in kidney epithelia. Each of these processes requires a specific subset of a diverse class of proteins termed molecular chaperones. One such chaperone is GRP170, which is an Hsp70-like, endoplasmic reticulum (ER)-localized chaperone that plays roles in protein quality control and protein folding in the ER. We previously determined that loss of GRP170 in the mouse nephron leads to hypovolemia, electrolyte imbalance, and rapid weight loss. In addition, GRP170-deficient mice develop an acute kidney injury (AKI)-like phenotype, typified by tubular injury, elevation of kidney injury markers, and induction of the unfolded protein response (UPR). By using an inducible GRP170 knockout cellular model, we confirmed that GRP170 depletion induces the UPR, triggers apoptosis, and disrupts protein homeostasis. Based on these data, we hypothesized that UPR induction underlies hyponatremia and volume depletion in these rodents and that these and other phenotypes might be rectified by sodium supplementation. To test this hypothesis, control and GRP170 tubule-specific knockout mice were provided a diet containing 8% sodium chloride. We discovered that sodium supplementation improved electrolyte imbalance and kidney injury markers in a sex-specific manner but was unable to restore weight or tubule integrity. These results are consistent with UPR induction contributing to the kidney injury phenotype in the nephron-specific GR170 knockout model and indicate that GRP170 function in kidney epithelia is essential to both maintain electrolyte balance and ER homeostasis.NEW & NOTEWORTHY Loss of the endoplasmic reticulum chaperone, GRP170, results in widespread kidney injury and induction of the unfolded protein response (UPR). We now show that sodium supplementation is able to at least partially restore electrolyte imbalance and reduce kidney injury markers in a sex-dependent manner.

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.

Urban-Rural Differences in Acute Kidney Injury Mortality in the United States

INTRODUCTION

Acute kidney injury (AKI) is associated with increased mortality. AKI-related mortality trends by U.S. urban and rural counties were assessed.

METHODS

In the cross-sectional study, based on the Centers for Disease Control and Prevention WONDER (Wide-ranging ONline Data for Epidemiologic Research) Multiple Cause of Death data, age-standardized mortality with AKI as the multiple cause was obtained among adults aged ≥25 years from 2001-2020, by age, sex, race and ethnicity, stratified by urban-rural counties. Joinpoint regressions were used to assess trends from 2001-2019 in AKI-related mortality rate. Pairwise comparison was used to compare mean differences in mortality between urban and rural counties from 2001-2019.

RESULTS

From 2001-2020, age-standardized AKI-related mortality was consistently higher in rural than urban counties. AKI-related mortality (per 100,000 population) increased from 18.95 in 2001 to 29.46 in 2020 in urban counties and from 20.10 in 2001 to 38.24 in 2020 in rural counties. In urban counties, AKI-related mortality increased annually by 4.6% during 2001-2009 and decreased annually by 1.8% until 2019 (p<0.001). In rural counties, AKI-related mortality increased annually by 5.0% during 2001-2011 and decreased by 1.2% until 2019 (p<0.01). The overall urban-rural difference in AKI-related mortality was greater after 2009-2011. AKI-related mortality was significantly higher among older adults, men, and non-Hispanic Black adults than their counterparts in both urban and rural counties. Higher mortality was concentrated in rural counties in the Southern United States.

CONCLUSIONS

Multidisciplinary efforts are needed to increase AKI awareness and implement strategies to reduce AKI-related mortality in rural and high-risk populations.

Female sex hormones inversely regulate acute kidney disease susceptibility throughout life

While epidemiological and experimental studies have demonstrated kidney-protective effects of estrogen and female sex in adulthood, some epidemiological data showed deterioration of kidney function during puberty when estrogen production increases. However, molecular mechanisms explaining these conflicting phenomena remain unknown. Here, we showed that the pubertal sex hormone surge in female mice increases susceptibility to kidney ischemia reperfusion injury partly via downregulation of insulin-like growth factor 1 receptor (IGF-1R) expression in proximal tubules. Adult mice ovariectomized pre-pubertally (at postnatal day 21) showed strong tolerance to kidney ischemia, which was partly reversed by the administration of 17β-estradiol, while adult mice ovariectomized post-pubertally (at 8 weeks of age) were vulnerable to kidney ischemia. Kidney tubular IGF-1R protein expression decreased during postnatal growth but was highly expressed in adult mice ovariectomized pre-pubertally and in infant mice, which might be partly explained by different expression of an E3 ligase (MDM2) of IGF-1R. Mice deficient of Igf-1r in proximal tubules (iIGF-1RKO mice) during postnatal kidney growth showed increased susceptibility to ischemic injury. RNA-seq and western blotting analysis using proximal tubular cells from pre-pubertally ovariectomized iIGF-1RKO and control mice revealed altered expression of cell cycle-associated molecules such as cyclin D1. These results suggest that Igf-1r deletion during postnatal growth renders proximal tubular cells susceptible to ischemia possibly via altered cell cycle regulation. Thus, our findings provide evidence that exposure to pubertal sex hormones leads to increased susceptibility to kidney ischemia, which is partly mediated by modulation of IGF-1R signaling.

Sex-Related Differences in Outcome of Patients Treated With Microaxial Percutaneous Left Ventricular Assist Device for Cardiogenic Shock

BACKGROUND

The use of microaxial percutaneous left ventricular assist devices (pLVADs) in cardiogenic shock (CS) has increased in recent years, despite limited evidence, and data on sex disparities are particularly scarce. This study aimed to compare short-term outcomes between males and females.

METHODS

Data were retrospectively collected from the Dresden Impella Registry, which is a large, prospective, single-centre registry that consecutively enrolled patients who received microaxial pLVAD. Inclusion criteria were CS due to left ventricular failure with serum lactate >4 mM. Patients with pLVAD other than Impella CP were excluded. The primary endpoint was the composite of all-cause mortality at 30 days or requirement of renal replacement therapy (RRT). Secondary endpoints were the components of the primary endpoint alone. Propensity score matched (PSM) analysis was used to adjust for baseline characteristics.

RESULTS

A total of 319 male (69 years; body mass index, 26.7 kg/m2) and 113 female patients (74 years; 27.9 kg/m2) were included in the study. The primary composite endpoint occurred less frequently in female patients in the unmatched analysis (♂ 75.9% [n=239] vs ♀ 64.4% [n=72]; p=0.040) but not in the PSM analysis (♂ 81.1% [n=73] vs ♀ 68.9% [n=42]; p=0.056). However, females less frequently required RRT in both analyses (♂ 48.2% [n=126] vs ♀ 25.9% [n=25]; p=0.001; PSM: ♂ 49.1% [n=36] vs ♀ 23.3% [n=12]; p=0.007). All-cause mortality did not differ between the cohorts.

CONCLUSIONS

This study showed no differences in all-cause mortality at 30 days between male and female patients receiving microaxial pLVAD in CS. Larger studies are required to confirm whether female sex is associated with reduced requirement of RRT in CS treated with microaxial pLVAD.

SACrA score to predict the initiation of renal replacement therapy in critically ill patients: a single-center retrospective study

BACKGROUND

Acute kidney injury (AKI) is a prevalent complication in critically ill patients that affects the timing of renal replacement therapy (RRT) initiation. This study aimed to develop and validate the SACrA score for predicting non-emergent initiations (BUN ≥112 mg/dL or oliguria for >72 h) of RRT in critically ill patients.

METHODS

We conducted a retrospective cohort study using data from two cohorts. The derivation cohort included patients admitted to the ICU between November 2021 and December 2023, whereas the validation cohort included patients admitted between September 2019 and October 2021. The primary outcome was non-emergent RRT initiation. The multivariate logistic regression with stepwise selection based on the Akaike information criterion finalized the model, including the variables, such as sex, albumin (Alb), creatinine (Cr), and APACHE II score (SACrA).

RESULTS

The derivation and validation cohorts comprised 470 and 476 patients, respectively. The SACrA score showed a strong predictive performance for non-emergent RRT initiation in both the cohorts. Cohort 1 had an ROC-AUC of 0.971, with a calibration slope of 0.982 and an intercept of 0.009, whereas cohort 2 had an ROC-AUC of 0.918, with a calibration slope of 0.988 and an intercept of 0.004.

CONCLUSIONS

The SACrA score is a robust tool for predicting non-emergent RRT initiation in critically ill patients using readily available clinical variables. Though additional data are needed to validate the SACrA score, our analysis suggests the tool may help clinicians make informed decisions, reduce unnecessary RRT, and thereby improve patient outcomes.

Association of Neighborhood Social Determinants of Health with Acute Kidney Injury during Hospitalization

Key Points

AKI is common among hospitalized patients. However, the contribution of neighborhood social determinants of health to AKI risk is not known. We found that among 26,769 hospitalized patients, 26% developed AKI. Patients who lived in the most disadvantaged areas (highest tertile of Area Deprivation Index) had a 10% greater odds of developing AKI than counterparts in the lowest Area Deprivation Index tertile. Patients who lived in rural areas had 25% greater odds of not recovering from AKI by hospital discharge. This study demonstrates an association between neighborhood disadvantage and rurality on the development of AKI and lack of recovery from AKI. Further work is needed to understand the mechanisms of these associations and to develop community-level interventions to mitigate the health care burden of AKI for disadvantaged populations.

Background

AKI is common among hospitalized patients. However, the contribution of social determinants of health (SDOH) to AKI risk remains unclear. This study evaluated the association between neighborhood measures of SDOH and AKI development and recovery during hospitalization.

Methods

This is a retrospective cohort study of adults without ESKD admitted to a large Southern US health care system from October 2014 to September 2017. Neighborhood SDOH measures included (1 ) socioeconomic status: Area Deprivation Index (ADI) scores, (2 ) food access: Low-Income, Low-Access scores, (3 ) rurality: Rural–Urban Commuting Area scores, and (4 ) residential segregation: dissimilarity and isolation scores. The primary study outcome was AKI on the basis of serum creatinine Kidney Disease Improving Global Outcomes criteria. Our secondary outcome was lack of AKI recovery (requiring dialysis or elevated serum creatinine at discharge). The association of SDOH measures with AKI was evaluated using generalized estimating equation models adjusted for demographics and clinical characteristics.

Results

Among 26,769 patients, 26% developed AKI during hospitalization. Compared with those who did not develop AKI, those who developed AKI were older (median 60 versus 57 years), more commonly men (55% versus 50%), and more commonly self-identified as Black (38% versus 33%). Patients residing in most disadvantaged neighborhoods (highest ADI tertile) had 10% (95% confidence interval, 1.02 to 1.19) greater adjusted odds of developing AKI during hospitalization than counterparts in least disadvantaged areas (lowest ADI tertile). Patients living in rural areas had 25% higher adjusted odds of lack of AKI recovery by hospital discharge (95% confidence interval, 1.07 to 1.46). Food access and residential segregation were not associated with AKI development or recovery.

Conclusions

Hospitalized patients from the most socioeconomically disadvantaged neighborhoods and from rural areas had higher odds of developing AKI and not recovering from AKI by hospital discharge, respectively. A better understanding of the mechanisms underlying these associations is needed to inform interventions to reduce AKI risk during hospitalization among disadvantaged populations.

Gender Disparity in Hemodialysis Practices and Mortality: A Nationwide Cross-Sectional Observational Study

Background

Disparities between genders are well documented in incidence, progression, and outcomes of chronic kidney disease (CKD). This study aimed to describe demographic characteristics, clinical and socio-economic factors among males and females on maintenance hemodialysis and to determine any association with mortality among males and females.

Materials and Methods

A nationwide cross-sectional study was conducted in a hemodialysis network in India. All adult (>18 years) patients who died while receiving maintenance hemodialysis and an equal number of surviving control patients on maintenance hemodialysis (MHD) between January 1, 2021 to March 31, 2021 were included in the study. The demographic, socioeconomic, and hemodialysis factors were compared between both the genders.

Results

A total of 1177 patients who died during the study period were included. The majority were males (824, 70.01%). Males were more educated than females (P < 0.001). The proportion of female patients dialysed with temporary catheters where more than males, who had definite vascular access such as AV fistula or AV graft (P < 0.001). More female patients required out-of-pocket expenditure (P = 0.005). Multivariate logistic regression demonstrated that lower educational status, hypoalbuminemia, previous history of hospitalization, and dialysis in centres run by Public Private Partnership (PPP) were associated with mortality in males. Lower educational status, heart failure and previous history of hospitalization were the factors associated with mortality in females.

Conclusion

Males predominated on hemodialysis. Females were less educated and were less likely to be covered under public or private health insurance compared to males.

Association Between the Aggregate Index of Systemic Inflammation and Clinical Outcomes in Patients with Acute Myocardial Infarction: A Retrospective Study

Purpose

The Aggregate Index of Systemic Inflammation (AISI) has emerged as a novel marker for inflammation and prognosis, but its role in patients with acute myocardial infarction has not been studied. Therefore, this study aimed to investigate the impact of different AISI levels on the clinical outcomes of patients with acute myocardial infarction.

Patients and Methods

This study was a retrospective study, including 1044 patients with acute myocardial infarction (AMI) who were treated at the Fujian Medical University Affiliated Union Hospital, China from May 2017 to December 2022. The patients were divided into high and low AISI groups based on the median value (Q1 Group, ≤ 416.15, n=522; Q2 Group, ≥ 416.16, n=522), and the differences in baseline characteristics and clinical outcomes between the two groups were analyzed. The primary outcome included major adverse cardiovascular and cerebrovascular events (MACCEs), while the secondary outcomes included contrast-induced nephropathy (CIN) risk and all-cause rehospitalization rate.

Results

The findings of the single-factor analysis suggest that a significant association between high AISI levels and the occurrence of MACCEs in AMI patients. After adjusting for confounding factors, the results indicated that compared to Q1, patients in the Q2 group had a higher risk of all-cause mortality [adjusted odds ratio (aOR) 4.64; 95% CI 1.37-15.72; p=0.032], new-onset atrial fibrillation (aOR 1.75; 95% CI 1.02-3.00; p=0.047), and CIN (aOR 1.75; 95% CI 1.02-3.01; p=0.043), with all differences being statistically significant.

Conclusion

In the population of AMI patients, an elevated AISI level is significantly associated with an increased risk of cardiovascular death and can serve as an early marker for adverse prognosis.

The comorbidity burden of type 2 diabetes mellitus (T2DM): sex differences and associated factors among 830 cases in North-Eastern Morocco

Background and aim

Type 2 diabetes is prone to numerous comorbidities resulting from complex mechanisms involving hyperglycemia, insulin resistance, low-grade inflammation and accelerated atherogenesis. The purpose of the present study was to investigate these disorders and their associated risk factors according to patient sex in a population of type 2 diabetics in North-Eastern Morocco.

Methods

This study was conducted in a medical analysis laboratory over a 1-year period from 01/10/2018 to 01/10/2019. This epidemiological study was carried out on 830 subjects aged 18 and over. Quantitative variables were expressed as means ± standard deviation, and qualitative variables as frequencies and percentages. Hypothesis tests used to compare means and proportions were Student's t-test and Chi-square test of independence, respectively. Logistic regression was used to predict risk factors for each diabetes.

Results

830 patients were surveyed. 95.66% had diabetes-related comorbidities. Hypertension (23.7%), nephropathy (18.19%), dyslipidemia (14.82%), thyroid dysfunction (10.72%), cataract (10.12%), diabetic foot (7.23%), ketoacidosis (6.27%), retinopathy (3.49%), and skin disorders (2.77%) were observed. Sex was associated with dyslipidemia (p = 0.025), hypertension (p = 0.032) and retinopathy (p = 0.029). Uncontrolled blood sugar, unbalanced lipid profile, age, physical activity, obesity, smoking, and alcohol consumption were risk factors with differential involvement in the occurrence of the mentioned pathologies.

Conclusions

The results of our study showed that a significant proportion of the population suffers from diabetic comorbidities. To meet this challenge, further research is needed to identify the mechanisms of action of these factors, to control them and combat diabetogenic environments by setting up adapted educational programs.

A pharmacovigilance study on clinical factors of active vitamin D3 analog-related acute kidney injury using the Japanese Adverse Drug Event Report Database

Acute kidney injury (AKI) due to vitamin D therapy for osteoporosis is encountered in clinical practice, but epidemiological studies are scarce. We aimed to determine the association between AKI and vitamin D therapy and to identify risk factors for AKI using the Japanese Adverse Drug Event Report database. We used reporting odds ratios (RORs) to detect signals and evaluate risk factors using multiple logistic regression analysis. Among 298,891 reports from April 2004 to September 2023, 1071 implicated active vitamin D3 analogs as suspect drugs for adverse events. There was a significant association between AKI and active vitamin D3 analogs (ROR [95% confidence interval {CI}], eldecalcitol: 16.75 [14.23-19.72], P < 0.001; alfacalcidol: 5.29 [4.07-6.87], P < 0.001; calcitriol: 4.46 [1.88-10.59], P < 0.001). The median duration of administration before AKI onset was 15.4 weeks. Multiple logistic regression analysis showed a significant association between AKI and age ≥ 70 years (odds ratio [95% CI], 1.47 [1.04-2.07]; P = 0.028), weight < 50 kg (1.55 [1.12-2.13]; P = 0.007), hypertension (1.90 [1.42-2.54]; P < 0.001), and concomitant use of nonsteroidal anti-inflammatory drugs (1.58 [1.10-2.25], P = 0.012) and magnesium oxide (1.96 [1.38-2.78]; P < 0.001). Our results suggest that active vitamin D3 analogs are associated with AKI development. Physicians prescribing these medications to patients with risk factors should consider the possibility of AKI, especially during the first 6 months.

Sex disparities in the risk of urgent dialysis following acute aortic dissections in Japan

The global outcome of acute aortic dissection (AD) remains poor, with a high risk of the need for urgent dialysis. This study aimed to clarify the association between sex and the requirement for urgent dialysis within 30 days after admission among patients with AD. This study included 79,998 cases who were hospitalized due to AD in Japan from 2010 to 2020 using an administrative claims database. The association between the risk of urgent dialysis and sex was investigated using the Fine and Gray model. Patients were classified into two groups based on the Stanford classification: type A AD (TAAD) and type B AD (TBAD). The lower subdistribution hazard ratio (SHR) in women was observed in both groups: TAAD (SHR: 0.58, 95% confidence interval [CI]: 0.54-0.62); TBAD (SHR: 0.49, 95% CI: 0.41-0.58). Our study revealed that women had a lower risk of requiring urgent dialysis than men in TAAD and TBAD.

Acute Kidney Injury Receiving Dialysis and Dialysis Care after Hospital Discharge

The number of patients with AKI receiving outpatient hemodialysis (AKI-D) is increasing. At present, on the basis of limited data, approximately one third of patients with AKI-D who receive outpatient dialysis after hospital discharge survive and regain sufficient kidney function to discontinue dialysis. Data to inform dialysis management strategies that promote kidney function recovery and processes of care among patients with AKI-D receiving outpatient dialysis are lacking. In this article, we detail current trends in the incidence, risk factors, clinical outcomes, proposed management, and health policy landscape for patients with AKI-D receiving outpatient dialysis and identify areas for further research.

Decadal Analysis of Age-Adjusted Mortality Rates for Acute and Chronic Kidney Disease in Brazil, 2000-2021

Introduction Renal failure, comprising acute kidney injury (AKI) and chronic kidney disease (CKD), involves a decline or loss of kidney function. AKI is sudden and reversible, with a rapid decline in function over hours to days, while CKD involves persistent abnormalities lasting at least three months. Developing countries are seeing a rise in AKI cases, especially in critically ill patients. Globally, there's a growing occurrence and mortality rate linked to CKD. Methods The study used a retrospective cross-sectional design to analyze AKI and CKD mortality rates in Brazil from 2019 to 2022. Data on population and demographics, including sex and age, were obtained from the Brazilian Institute of Geography and Statistics. Mortality data for kidney diseases were sourced from the Brazilian Hospital Information System. The analysis utilized the Joinpoint Regression Program to calculate average annual percentage changes (AAPCs) and their respective 95% confidence intervals. Weighted Bayesian information criterion was used to determine the significance levels and identify the best-fitting combination of line segments and joinpoints. Results The study findings revealed a significant rise in AKI mortality rates for both males and females, from 2008 to 2021 (APC = 3.16; CI: 2.29 to 5.93), with higher mortality rates recorded among males compared to women over the entire study period. Analyses according to age groups showed that males between the ages 40 to 49 experienced the most rapid increase in mortality during the 2019 - 2021 period (APC = 35.41; CI: 16.72 to 46.57); meanwhile, the most rapid increase in mortality for females was observed from 2019 to 2021, and this was among those aged 30 to 39 (APC = 40.33; CI = 6.48 to 59.78). Furthermore, there was an observable upward trend in mortality related to CKD (APC = 0.70; CI: 0.41 to 1.01), with males consistently having higher mortality rates throughout the entire study period. The elderly population, both males and females, experienced the most rapid increase in CKD-related mortality, with AAPC values of 2.32 (CI: 1.82 to 2.89) for males and 1.62 (CI: 1.08 to 2.10) for females. Conclusion We observed a consistent increase in mortality rates from acute kidney diseases for both males and females since 2008, with males experiencing higher mortality rates overall. The study highlighted the need for further research to understand the underlying factors contributing to these trends. Additionally, interventions targeting modifiable risk factors and improving access to healthcare could help reduce mortality related to renal failure.

Regional variation of COVID-19 admissions, acute kidney injury and mortality in England - a national observational study using administrative data

BACKGROUND

This study explores regional variations in COVID-19 hospitalization rates, in-hospital mortality, and acute kidney injury (AKI) in England. We investigated the influence of population demographic characteristics, viral strain changes, and therapeutic advances on clinical outcomes.

METHODS

Using hospital episode statistics, we conducted a retrospective cohort study with 749,844 admissions in 337,029 adult patients with laboratory-confirmed COVID-19 infection (March 1, 2020, to March 31, 2021). Multivariable logistic regression identified factors predicting AKI and mortality in COVID-19 hospitalized patients.

RESULTS

London had the highest number of COVID-19 admissions (131,338, 18%), followed by the North-west region (122,683, 16%). The North-west had the highest population incidence of COVID-19 hospital admissions (21,167 per million population, pmp), while the South-west had the lowest (9,292 admissions pmp). Patients in London were relatively younger (67.0 ± 17.7 years) than those in the East of England (72.2 ± 16.8 years). The shortest length of stay was in the North-east (12.2 ± 14.9 days), while the longest was in the North-west (15.2 ± 17.9 days). All eight regions had higher odds of death compared to London, ranging from OR 1.04 (95% CI 1.00, 1.07) in the South-west to OR 1.24 (95% CI 1.21, 1.28) in the North-west. Older age, Asian ethnicity, emergency admission, transfers from other hospitals, AKI presence, ITU admission, social deprivation, and comorbidity were associated with higher odds of death. AKI incidence was 30.3%, and all regions had lower odds of developing AKI compared to London. Increasing age, mixed and black ethnicity, emergency admission, transfers from other providers, ITU care, and different levels of comorbidity were associated with higher odds of developing AKI.

CONCLUSIONS

London exhibited higher hospital admission numbers and AKI incidence, but lower odds of death compared to other regions in England.

TRIAL REGISTRATION

Registered on National Library of Medicine website ( www.

CLINICALTRIALS

gov ) with registration number NCT04579562 on 8/10/2020.

Improving acute kidney injury alerts in tertiary care by linking primary care data: An observational cohort using routine care data

Objective

Acute kidney injury (AKI) is easily missed and underdiagnosed in routine clinical care. Timely AKI management is important to decrease morbidity and mortality risks. We recently implemented an AKI e-alert at the University Medical Center Utrecht, comparing plasma creatinine concentrations with historical creatinine baselines, thereby identifying patients with AKI. This alert is limited to data from tertiary care, and primary care data can increase diagnostic accuracy for AKI. We assessed the added value of linking primary care data to tertiary care data, in terms of timely diagnosis or excluding AKI.

Methods

With plasma creatinine tests for 84,984 emergency department (ED) visits, we applied the Kidney Disease Improving Global Outcome guidelines in both tertiary care-only data and linked data and compared AKI cases.

Results

Using linked data, the presence of AKI could be evaluated in an additional 7886 ED visits. Sex- and age-stratified analyses identified the largest added value for women (an increase of 4095 possible diagnoses) and patients ≥60 years (an increase of 5190 possible diagnoses). We observed 398 additional visits where AKI was diagnosed, as well as 185 cases where AKI could be excluded. We observed no overall decrease in time between baseline and AKI diagnosis (28.4 days vs. 28.0 days). For cases where AKI was diagnosed in both data sets, we observed a decrease of 2.8 days after linkage, indicating a timelier diagnosis of AKI.

Conclusions

Combining primary and tertiary care data improves AKI diagnostic accuracy in routine clinical care and enables timelier AKI diagnosis.

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

Improved understanding of differences in kidney disease epidemiology, management and outcomes in men and women could help nephrologists to better meet the needs of their patients from a sex- and gender-specific perspective. Evidence of sex differences in the risk and outcomes of acute kidney injury is mixed and dependent on aetiology. Women have a higher prevalence of chronic kidney disease (CKD) stages 3-5 than men, whereas men have a higher prevalence of albuminuria and hence CKD stages 1-2. Men show a faster decline in kidney function, progress more frequently to kidney failure and have higher mortality and risk of cardiovascular disease than women. However, the protective effect of female sex is reduced with CKD progression. Women are less likely than men to be aware of, screened for and diagnosed with CKD, started on antiproteinuric medication and referred to nephrologist care. They also consistently report a poorer health-related quality of life and a higher symptom burden than men. Women experience greater barriers than men to access the waiting list for kidney transplantation, particularly with respect to older age and obesity. However, women also have longer survival than men after transplantation, which may partly explain the comparable prevalence of transplantation between the sexes.

Sex and Gender Differences in AKI

Sex differences in AKI continue to be identified. Generally, women are protected from AKI when compared to men. Much of the protection exhibited in women is diminished after menopause. These sex and age effects have also been noted in animal models of AKI. Gonadal hormones, as modifiers of incidence, severity, and progression of AKI, have been offered as likely contributors to this sex and age effect. In animal models of AKI, estrogen and testosterone seem to modulate susceptibility. Questions remain however regarding cellular and molecular changes that are initiated by modulation of these hormones because both estrogen and testosterone have effects across cell types that play a role in AKI. Although findings have largely been informed by studies in males, molecular pathways that are involved in the initiation and progression of AKI may be modulated by gonadal hormones. Compounding the hormone-receptor effects are developmental effects of sex chromosomal complement and epigenetic influences that may confer sex-based baseline differences in gene and protein expression, and gene dosage effects of X inactivation and escape on molecular pathways. Elucidation of sex-based protection may afford a more complete view of AKI and potential therapeutic interventions. Furthermore, the effect on susceptibility to AKI in transgender patients, who receive life-altering and essential gender-affirming hormone therapy, requires greater attention. In this review, several potential contributors to the sex differences observed in humans and animal models are discussed.

Sustained activation of 12/15 lipoxygenase (12/15 LOX) contributes to impaired renal recovery post ischemic injury in male SHR compared to females

BACKGROUND

Acute kidney injury (AKI) due to ischemia-reperfusion (IR) is a serious and frequent complication in clinical settings, and mortality rates remain high. There are well established sex differences in renal IR, with males exhibiting greater injury following an ischemic insult compared to females. We recently reported that males have impaired renal recovery from ischemic injury vs. females. However, the mechanisms mediating sex differences in renal recovery from IR injury remain poorly understood. Elevated 12/15 lipoxygenase (LOX) activity has been reported to contribute to the progression of numerous kidney diseases. The goal of the current study was to test the hypothesis that enhanced activation of 12/15 LOX contributes to impaired recovery post-IR in males vs. females.

METHODS

13-week-old male and female spontaneously hypertensive rats (SHR) were randomized to sham or 30-minute warm bilateral IR surgery. Additional male and female SHR were randomized to treatment with vehicle or the specific 12/15 LOX inhibitor ML355 1 h prior to sham/IR surgery, and every other day following up to 7-days post-IR. Blood was collected from all rats 1-and 7-days post-IR. Kidneys were harvested 7-days post-IR and processed for biochemical, histological, and Western blot analysis. 12/15 LOX metabolites 12 and 15 HETE were measured in kidney samples by liquid chromatography-mass spectrometry (LC/MS).

RESULTS

Male SHR exhibited delayed recovery of renal function post-IR vs. male sham and female IR rats. Delayed recovery in males was associated with activation of renal 12/15 LOX, increased renal 12-HETE, enhanced endoplasmic reticulum (ER) stress, lipid peroxidation, renal cell death and inflammation compared to females 7-days post-IR. Treatment of male SHR with ML355 lowered levels of 12-HETE and resulted in reduced renal lipid peroxidation, ER stress, tubular cell death and inflammation 7-days post-IR with enhanced recovery of renal function compared to vehicle-treated IR male rats. ML355 treatment did not alter IR-induced increases in plasma creatinine in females, however, tubular injury and cell death were attenuated in ML355 treated females compared to vehicle-treated rats 7 days post-IR.

CONCLUSION

Our data demonstrate that sustained activation 12/15 LOX contributes to impaired renal recovery post ischemic injury in male and female SHR, although males are more susceptible on this mechanism than females.

The prevention and treatment of COVID-19 in patients treated with hemodialysis

Patients treated with hemodialysis are often immunocompromised due to concomitant disease. As a result, this population is at high risk of infection and mortality from COVID-19. In addition to symptomatic treatment, a series of antiviral drugs targeting COVID-19 are now emerging. However, these antivirals are used mainly in mild or moderate patients with high-risk factors for progression to severe disease and are not available as pre- or post-exposure prophylaxis for COVID-19. There is a lack of clinical data on the use of anti-COVID-19 drugs, especially in patients treated with hemodialysis, therefore, vaccination remains the main measure to prevent SARS-CoV-2 infection in these patients. Here, we review the clinical features and prognosis of patients on hemodialysis infected with SARS-CoV-2, the main anti-COVID-19 drugs currently available for clinical use, and the safety and efficacy of anti-COVID-19 drugs or COVID-19 vaccination in patients treated with hemodialysis. This information will provide a reference for the treatment and vaccination of COVID-19 in patients treated with hemodialysis and maximize the health benefits of these patients during the outbreak.

Benefit of continuous kidney replacement therapy for managing tumor lysis syndrome in children with hematologic malignancies

Introduction

Tumor lysis syndrome (TLS) is often diagnosed in children with hematological malignancies and can be life threatening due to metabolic disturbances. Continuous renal replacement therapy (CKRT) can reverse these disturbances relatively quickly when conventional medical management fails. Our objective was to investigate the benefit of CKRT in the management of TLS in children admitted to the intensive care unit with hematologic malignancies. In addition, we sought to assess risk factors for acute kidney injury (AKI) in the setting of TLS.

Methods

Retrospective review of all children admitted to the intensive care unit with TLS who received CKRT from January 2012 to August 2022.

Results

Among 222 children hospitalized with TLS from January 2012 to August 2022, 20 (9%) underwent CKRT to manage TLS in the intensive care unit. The patients' median age was 13 years (range 3-17 y), and most were males (18/20). T-cell acute lymphoblastic leukemia was the most common diagnosis (n=10), followed by acute myeloid leukemia (n=4), Burkitt lymphoma (n=4), and B-cell acute lymphoblastic leukemia (n=2). Five patients required mechanical ventilation, and 2 required vasopressors. The most common indication for CKRT was hyperphosphatemia, followed by, hyperuricemia, and hyperkalemia. All metabolic abnormalities corrected within 12 h of initiation of CKRT. CKRT courses were brief, with a median duration of 2 days (range 1-7 days). Having higher serum phosphorus levels 12 h preceding CKRT was significantly associated with severe acute kidney injury (AKI). The median phosphorus level was 6.4 mg/dL in children with no/mild AKI and 10.5 mg/dL in children with severe AKI (p=0.0375). Serum uric acid levels before CKRT were not associated with AKI. All children survived to hospital discharge, and the one-year survival rate was 90%.

Conclusion

CKRT is safe in children with hematologic malignancies with severe TLS and reverses metabolic derangements within 6-12 h. Most patients had AKI at the initiation of CKRT but did not require long-term kidney replacement therapy. Hyperphosphatemia before initiation of CKRT is associated with higher risk of AKI.

Association of the perfusion index with postoperative acute kidney injury: a retrospective study

BACKGROUND

Many studies have examined the risk factors for postoperative acute kidney injury (AKI), but few have focused on intraoperative peripheral perfusion index (PPI) that has recently been shown to be associated with postoperative morbidity and mortality. Therefore, this study aimed to evaluate the relationship between intraoperative PPI and postoperative AKI under the hypothesis that lower intraoperative PPI is associated with AKI occurrence.

METHODS

We retrospectively searched electronic medical records to identify patients who underwent surgery at the general surgery department from May 2021 to November 2021. Patient baseline characteristics, pre- and post-operative laboratory test results, comorbidities, intraoperative vital signs, and discharge profiles were obtained from the Institutional Clinical Data Warehouse and VitalDB. Intraoperative PPI was the primary exposure variable, and the primary outcome was postoperative AKI.

RESULTS

Overall, 2,554 patients were identified and 1,586 patients were included in our analysis. According to Kidney Disease Improving Global Outcomes (KDIGO) criteria, postoperative AKI occurred in 123 (7.8%) patients. We found that risks of postoperative AKI increased (odds ratio: 2.00, 95% CI [1.16, 3.44], P = 0.012) when PPI was less than 0.5 for more than 10% of surgery time. Other risk factors for AKI occurrence were male sex, older age, higher American Society of Anesthesiologists physical status, obesity, underlying renal disease, prolonged operation time, transfusion, and emergent operation.

CONCLUSIONS

Low intraoperative PPI was independently associated with postoperative AKI.

Detection of potential drug-drug interactions for risk of acute kidney injury: a population-based case-control study using interpretable machine-learning models

Background: Acute kidney injury (AKI), with an increase in serum creatinine, is a common adverse drug event. Although various clinical studies have investigated whether a combination of two nephrotoxic drugs has an increased risk of AKI using traditional statistical models such as multivariable logistic regression (MLR), the evaluation metrics have not been evaluated despite the fact that traditional statistical models may over-fit the data. The aim of the present study was to detect drug-drug interactions with an increased risk of AKI by interpreting machine-learning models to avoid overfitting. Methods: We developed six machine-learning models trained using electronic medical records: MLR, logistic least absolute shrinkage and selection operator regression (LLR), random forest, extreme gradient boosting (XGB) tree, and two support vector machine models (kernel = linear function and radial basis function). In order to detect drug-drug interactions, the XGB and LLR models that showed good predictive performance were interpreted by SHapley Additive exPlanations (SHAP) and relative excess risk due to interaction (RERI), respectively. Results: Among approximately 2.5 million patients, 65,667 patients were extracted from the electronic medical records, and assigned to case (N = 5,319) and control (N = 60,348) groups. In the XGB model, a combination of loop diuretic and histamine H₂ blocker [mean (|SHAP|) = 0.011] was identified as a relatively important risk factor for AKI. The combination of loop diuretic and H₂ blocker showed a significant synergistic interaction on an additive scale (RERI 1.289, 95% confidence interval 0.226-5.591) also in the LLR model. Conclusion: The present population-based case-control study using interpretable machine-learning models suggested that although the relative importance of the individual and combined effects of loop diuretics and H₂ blockers is lower than that of well-known risk factors such as older age and sex, concomitant use of a loop diuretic and histamine H₂ blocker is associated with increased risk of AKI.

Gender-Related Discrepancies in Short-Term Outcomes in Patients Undergoing Off-Pump Coronary Artery Bypass Grafting Surgery

The sex differences in patients undergoing off-pump coronary artery bypass grafting (OPCAB) surgery are still unclear. Our aim was to investigate the impact of gender on short-term outcomes in males and females after off-pump bypass procedures. Our research was designed as a double-center retrospective analysis. Generally, 343 patients (men (n = 255) and women (n = 88)) who underwent an OPCAB procedure were included in our study. To provide a statistical analysis of unequal cohorts, we created a propensity score-based matching (PSM) analysis (men, n = 61; women, n = 61). The primary endpoint was all-cause in-hospital mortality. Dialysis, transient ischemic attack (TIA), low cardiac output syndrome (LCOS), reoperation due to postoperative bleeding, wound infection and duration of hospital stay were secondary outcomes in our analysis. No significant differences were detected within the male and female groups regarding age (p = 0.116), BMI (p = 0.221), diabetes (p = 0.853), cardiogenic shock (0.256), STEMI (p = 0.283), NSTEMI (p = 0.555) and dialysis (p = 0.496). Males underwent significantly more frequently (p = 0.005) total-arterial revascularization with T-graft technique (p = 0.005) than females. In contrast, temporary pacer use was significantly higher (p = 0.022) in females compared to males. The in-hospital mortality rate was not significantly higher (p = 0.496) in the female group compared to the male group. Likewise, secondary outcomes did not differ significantly between the non-adjusted and the adjusted groups. Based on our findings, gender has no impact on short-term outcomes after OPCAB surgery.

FGFR regulator Memo1 is dispensable for FGF23 expression by osteoblasts during folic acid-driven kidney injury

Loss of the mediator Of cell motility 1 (Memo1) in mice caused kidney disease and a bone disease with diminished osteoblast and osteoclast biomarkers in serum, resembling alterations occurring in adynamic bone disease in humans with chronic kidney disease or in Klotho-deficient mice. Here, we investigated whether Memo1 expression in osteoblasts is required for normal bone structure and FGF23 expression. We deleted Memo1 in the osteoblast-osteocyte lineage in Memo fl/fl mice using a Cre under Col1a1 promotor to obtain osteoblast-specific knockout (obKO) mice. We studied organs by micro-computed tomography, qPCR, and western blot. We challenged mice with folic acid for acute kidney injury (AKI) and analyzed organs. Memo obKO were viable without changes in gross anatomy, serum electrolytes, or circulating FGF23 concentrations compared to controls. Memo1 expression was blunted in bones of Memo obKO, whereas it remained unchanged in other organs. Micro-CT revealed no differences between genotypes in bone structure of vertebrae, femur, and tibia. During AKI, Fgf23 expression in calvaria, and renal transcriptional changes were comparable between genotypes. However, renal injury marker expression, circulating FGF23, and parathyroid hormone revealed a sex difference with more severely affected females than males of either genotype. The present data imply that Memo1 in osteoblasts is dispensable for bone structure and expression of Fgf23. Moreover, we found evidence of potential sex differences in murine folic acid nephropathy similar to other experimental models of renal injury that are important to consider when using this experimental model of renal injury.

Postoperative Acute Kidney Injury by Age and Sex: A Retrospective Cohort Association Study

BACKGROUND

Acute kidney injury (AKI) after noncardiac surgery is common and has substantial health impact. Preclinical and clinical studies examining the influence of sex on AKI have yielded conflicting results, although they typically do not account for age-related changes. The objective of the study was to determine the association of age and sex groups on postoperative AKI. The authors hypothesized that younger females would display lower risk of postoperative AKI than males of similar age, and the protection would be lost in older females.

METHODS

This was a multicenter retrospective cohort study across 46 institutions between 2013 and 2019. Participants included adult inpatients without pre-existing end-stage kidney disease undergoing index major noncardiac, nonkidney/urologic surgeries. The authors' primary exposure was age and sex groups defined as females 50 yr or younger, females older than 50 yr, males 50 yr or younger, and males older than 50 yr. The authors' primary outcome was development of AKI by Kidney Disease-Improving Global Outcomes serum creatinine criteria. Exploratory analyses included associations of ascending age groups and hormone replacement therapy home medications with postoperative AKI.

RESULTS

Among 390,382 patients, 25,809 (6.6%) developed postoperative AKI (females 50 yr or younger: 2,190 of 58,585 [3.7%]; females older than 50 yr: 9,320 of 14,4047 [6.5%]; males 50 yr or younger: 3,289 of 55,503 [5.9%]; males older than 50 yr: 11,010 of 132,447 [8.3%]). When adjusted for AKI risk factors, compared to females younger than 50 yr (odds ratio, 1), the odds of AKI were higher in females older than 50 yr (odds ratio, 1.51; 95% CI, 1.43 to 1.59), males younger than 50 yr (odds ratio, 1.90; 95% CI, 1.79 to 2.01), and males older than 50 yr (odds ratio, 2.06; 95% CI, 1.96 to 2.17).

CONCLUSIONS

Younger females display a lower odds of postoperative AKI that gradually increases with age. These results suggest that age-related changes in women should be further studied as modifiers of postoperative AKI risk after noncardiac surgery.

EDITOR’S PERSPECTIVE

Association of prognostic nutritional index with risk of contrast induced nephropathy: A meta-analysis

Background

Although prognostic nutritional index (PNI) has been frequently applied in patients with malignancy or those during postoperative recovery, whether it is also an optimal indicator of the risk of contrast-induced nephropathy (CIN) in patients receiving coronary angiography remains uncertain. This meta-analysis aimed at investigating the clinical association of PNI with the risk of CIN in patients receiving coronary angiography or percutaneous coronary intervention.

Methods

Embase, Medline, Cochrane Library, and Google scholar were searched for studies until January 2023. The relationship between CIN risk and PNI (i.e., low vs. high) (primary outcome) as well as other variables (secondary outcomes) were analyzed using a random-effects model.

Results

Overall, 10 observational studies with 17,590 patients (pooled incidence of CIN: 18%) were eligible for analysis. There was a higher risk of CIN in patients with a low PNI compared to those with a high PNI [odd ratio (OR) = 3.362, 95% confidence interval (CI): 2.054 to 5.505, p < 0.0001, I ² = 89.6%, seven studies, 12,972 patients, certainty of evidence: very low]. Consistently, a lower PNI was noted in patients with CIN compared to those without (Mean difference = -5.1, 95% CI: -6.87 to -3.33, p < 0.00001, I ² = 96%, eight studies, 15,516 patients, certainty of evidence: very low). Other risks of CIN included diabetes and hypertension, while male gender and the use of statins were associated with a lower risk of CIN. Patients with CIN were older, had a higher creatinine level, and received a higher contrast volume compared to those without. On the other hand, pre-procedural albumin, estimated glomerular filtration rate, ejection fraction, hemoglobin, lymphocyte ratio were found to be lower in patients with CIN than in those without.

Conclusion

This meta-analysis highlighted an inverse association of PNI with the risk of CIN, which required further studies for verification.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/], identifier [CRD42023389185].

Gender and Renal Insufficiency: Opportunities for Their Therapeutic Management?

Acute kidney injury (AKI) is a major clinical problem associated with increased morbidity and mortality. Despite intensive research, the clinical outcome remains poor, and apart from supportive therapy, no other specific therapy exists. Furthermore, acute kidney injury increases the risk of developing chronic kidney disease (CKD) and end-stage renal disease. Acute tubular injury accounts for the most common intrinsic cause of AKI. The main site of injury is the proximal tubule due to its high workload and energy demand. Upon injury, an intratubular subpopulation of proximal epithelial cells proliferates and restores the tubular integrity. Nevertheless, despite its strong regenerative capacity, the kidney does not always achieve its former integrity and function and incomplete recovery leads to persistent and progressive CKD. Clinical and experimental data demonstrate sexual differences in renal anatomy, physiology, and susceptibility to renal diseases including but not limited to ischemia-reperfusion injury. Some data suggest the protective role of female sex hormones, whereas others highlight the detrimental effect of male hormones in renal ischemia-reperfusion injury. Although the important role of sex hormones is evident, the exact underlying mechanisms remain to be elucidated. This review focuses on collecting the current knowledge about sexual dimorphism in renal injury and opportunities for therapeutic manipulation, with a focus on resident renal progenitor stem cells as potential novel therapeutic strategies.

Sex differences in resilience to ferroptosis underlie sexual dimorphism in kidney injury and repair

In both humans and mice, repair of acute kidney injury is worse in males than in females. Here, we provide evidence that this sexual dimorphism results from sex differences in ferroptosis, an iron-dependent, lipid-peroxidation-driven regulated cell death. Using genetic and single-cell transcriptomic approaches in mice, we report that female sex confers striking protection against ferroptosis, which was experimentally induced in proximal tubular (PT) cells by deleting glutathione peroxidase 4 (Gpx4). Single-cell transcriptomic analyses further identify the NFE2-related factor 2 (NRF2) antioxidant protective pathway as a female resilience mechanism against ferroptosis. Genetic inhibition and pharmacological activation studies show that NRF2 controls PT cell fate and plasticity by regulating ferroptosis. Importantly, pharmacological NRF2 activation protects male PT cells from ferroptosis and improves cellular plasticity as in females. Our data highlight NRF2 as a potential therapeutic target to prevent failed renal repair after acute kidney injury in both sexes by modulating cellular plasticity.

Sex disparities in mortality among patients with kidney failure receiving dialysis

Females are known to have a better survival rate than males in the general population, but previous studies have shown that this superior survival is diminished in patients on dialysis. This study aimed to investigate the risk of mortality in relation to sex among Korean patients undergoing hemodialysis (HD) or peritoneal dialysis (PD). A total of 4994 patients with kidney failure who were receiving dialysis were included for a prospective nationwide cohort study. Cox multivariate proportional hazard models were used to determine the association between sex and the risk of cause-specific mortality according to dialysis modality. During a median follow-up of 5.8 years, the death rate per 100 person-years was 6.4 and 8.3 in females and males, respectively. The female-to-male mortality rate in patients on dialysis was 0.77, compared to 0.85 in the general population. In adjusted analyses, the risk of all-cause mortality was significantly lower for females than males in the entire population (hazard ratio [HR] 0.79, 95% confidence interval [CI] 0.71-0.87, P < 0.001). No significant differences in the risk of cardiovascular and infection-related deaths were observed according to sex. The risk of mortality due to sudden death, cancer, other, or unknown causes was significantly lower for females than males in the entire population (HR 0.66, 95% CI 0.56-0.78, P < 0.001), in patients on HD (HR 0.75, 95% CI 0.62-0.90, P = 0.003), and in patients on PD (HR 0.49, 95% CI 0.34-0.70, P < 0.001). The survival advantage of females in the general population was maintained in Korean dialysis patients, which was attributed to a lower risk of noncardiovascular and noninfectious death.Trial registration: ClinicalTrials.gov Identifier: NCT00931970.

Sex-Related Differences in Short-Term Outcomes after Mobile VA-ECMO Implantation: Five-Year Experience of an ECMO Retrieval Program

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) represents an increasingly used method for circulatory support. Despite the ongoing research, survival following VA-ECMO therapy remains low. Sex-related differences might impact the outcome of therapeutic measures. We aimed to compare all-cause mortality among female and male patients who underwent VA-ECMO as a bridge to recovery investigating sex-related differences. From January 2015 until August 2020, 87 patients were supported by VA-ECMO as a part of our out-of-center mobile ECMO program. In order to analyze sex-associated differences in early clinical outcomes, patients were divided into two sex categories: men (n = 62) and women (n = 25). All relevant data (in-hospital mortality, ICU and hospital stay, renal failure requiring dialysis, lung failure, bleeding, stroke and septic shock) were analyzed retrospectively after the extraction from our institutional database. Mean age of the study population was 53 ± 14 years. Mean EuroSCORE II predicted mortality was 6.5 ± 3.7. In-hospital mortality rate was not significantly lower in the female group (58.3%) vs. the male group (71.2%), p = 0.190. The mean length of ICU and hospital stay was 9 ± 11 in the male group vs. 10 ± 13 in the female group, p = 0.901, and 10 ± 12 (male group) vs. 11 ± 13 (female group), p = 0.909, respectively. Renal failure requiring hemodialysis (36.2% (males) vs. 28.6% (females), p = 0.187) was comparable between both groups. Respiratory failure was diagnosed in 31 (56.4%) male vs. 8 (34.8%) female patients, p = 0.068, while 16 (28.6%) male vs. 3 (13.0%) female patients (p = 0.118) suffered from septic shock. Based on our data, there were no sex-specific outcome discrepancies in patients treated with mobile VA-ECMO implantation.

Sex- and gender-differences in chronic long-term complications of type 1 and type 2 diabetes mellitus in Italy

AIMS

This review summarizes the contribution of Italian diabetologists devoted to a better understanding of the complex relationship linking sex/gender and long-term complications of type 1 (T1DM) and type 2 diabetes (T2DM) over the last fifteen years.

DATA SYNTHESIS

Microvascular and macrovascular complications of diabetes show sex- and gender-related differences, involving pathophysiological mechanisms, epidemiological features and clinical presentation, due to the interaction between biological and psychosocial factors. These differences greatly impact on the progression of diabetes and its long-term complications, especially in the cardiovascular, renal and liver districts.

CONCLUSION

A better knowledge of such sex- and gender-related characteristics is required for a more precise patient phenotypization, and for the choice of a personalized antihyperglycemic treatment. Despite such mounting evidence, current diabetes clinical guidelines do not as yet adequately consider sex/gender differences.

Integrated single-cell transcriptomics and proteomics reveal cellular-specific responses and microenvironment remodeling in aristolochic acid nephropathy

Aristolochic acid nephropathy (AAN) is characterized by acute proximal tubule necrosis and immune cell infiltration, contributing to the global burden of chronic kidney disease and urothelial cancer. Although the proximal tubule has been defined as the primary target of aristolochic acids I (AAI), the mechanistic underpinning of gross renal deterioration caused by AAI has not been explicitly explained, prohibiting effective therapeutic intervention. To this point, we employed integrated single-cell RNA-Seq, bulk RNA-Seq, and mass spectrometry-based proteomics to analyze the mouse kidney after acute AAI exposure. Our results reveal a dramatic reduction of proximal tubule epithelial cells, associated with apoptotic and inflammatory pathways, indicating permanent damage beyond repair. We found the enriched development pathways in other nephron segments, suggesting activation of reparative programs triggered by AAI. The divergent response may be attributed to the segment-specific distribution of organic anion channels along the nephron, including OAT1 and OAT3. Moreover, we observed dramatic activation and recruitment of cytotoxic T and macrophage M1 cells, highlighting inflammation as a principal contributor to permanent renal injury. Ligand-receptor pairing revealed that critical intercellular crosstalk underpins damage-induced activation of immune cells. These results provide potentially novel insight into the AAI-induced kidney injury and point out possible pathways for future therapeutic intervention.

Does G Protein-Coupled Estrogen Receptor 1 Contribute to Cisplatin-Induced Acute Kidney Injury in Male Mice?

Nephrotoxicity is the dose-limiting side-effect of the chemotherapeutic agent cisplatin (Cp). Recent evidence points to renal protective actions of G protein-coupled estrogen receptor 1 (GPER1). In addition, it has been shown that GPER1 signaling elicits protective actions against acute ischemic injuries that involve multiple organ systems; however, the involvement of GPER1 signaling in Cp-induced acute kidney injury (AKI) remains unclear. This study tested whether genetic deletion of GPER1 exacerbates Cp-induced AKI in male mice. We subjected male mice, homozygous (homo) and heterozygous (het) knockout for the GPER1 gene, and wild-type (WT) littermates to Cp or saline injections and assessed markers for renal injury on the third day after injections. We also determined serum levels of proinflammatory markers in saline and Cp-treated mice. Given the protective role of heme oxygenase-1 (HO-1) in Cp-mediated apoptosis, we also investigated genotypic differences in renal HO-1 abundance, cell death, and proliferation by Western blotting, the TUNEL assay, and Ki67 immunostaining, respectively. Cp increased serum creatinine, urea, and neutrophil gelatinase-associated lipocalin (NGAL) levels, the renal abundance of kidney injury molecule-1, and NGAL in all groups. Cp-induced AKI resulted in comparable histological evidence of injury in all genotypes. WT and homo mice showed greater renal HO-1 abundance in response to Cp. Renal HO-1 abundance was lower in Cp-treated homo, compared to Cp-treated WT mice. Of note, GPER1 deletion elicited a remarkable increase in renal apoptosis; however, no genotypic differences in cell proliferation were observed. Cp augmented kidney Ki67-positive counts, regardless of the genotype. Overall, our data do not support a role for GPER1 in mediating Cp-induced renal injury. GPER1 deletion promotes renal apoptosis and diminishes HO-1 induction in response to Cp, suggesting that GPER1 may play cytoprotective and anti-apoptotic actions in AKI. GPER1-induced regulation of HO-1 and apoptosis may offer novel therapeutic targets for the treatment of AKI.

Intraoperative risk factors of acute kidney injury after liver transplantation

Acute kidney injury (AKI) is one of the most common complications of liver transplantation (LT). We examined the impact of intraoperative management on risk for AKI following LT. In this retrospective observational study, we linked data from the electronic health record with standardized transplant outcomes. Our primary outcome was stage 2 or 3 AKI as defined by Kidney Disease Improving Global Outcomes guidelines within the first 7 days of LT. We used logistic regression models to test the hypothesis that the addition of intraoperative variables, including inotropic/vasopressor administration, transfusion requirements, and hemodynamic markers improves our ability to predict AKI following LT. We also examined the impact of postoperative AKI on mortality. Of the 598 adult primary LT recipients included in our study, 43% (n = 255) were diagnosed with AKI within the first 7 postoperative days. Several preoperative and intraoperative variables including (1) electrolyte/acid-base balance disorder (International Classification of Diseases, Ninth Revision codes 253.6 or 276.x and International Classification of Diseases, Tenth Revision codes E22.2 or E87.x, where x is any digit; adjusted odds ratio [aOR], 1.917, 95% confidence interval [CI], 1.280-2.869; p = 0.002); (2) preoperative anemia (aOR, 2.612; 95% CI, 1.405-4.854; p = 0.002); (3) low serum albumin (aOR, 0.576; 95% CI, 0.410-0.808; p = 0.001), increased potassium value during reperfusion (aOR, 1.513; 95% CI, 1.103-2.077; p = 0.01), and lactate during reperfusion (aOR, 1.081; 95% CI, 1.003-1.166; p = 0.04) were associated with posttransplant AKI. New dialysis requirement within the first 7 days postoperatively predicted the posttransplant mortality. Our study identified significant association between several potentially modifiable variables with posttransplant AKI. The addition of intraoperative data did not improve overall model discrimination.

Sex-specific differences in early renal impairment associated with arsenic, lead, and cadmium exposure among young adults in Taiwan

Exposure to a single metal has been reported to damage renal function in humans. However, information regarding the association between multiple-metal exposure and markers for early renal impairment in different sexes among the young adult Taiwanese population is scarce. We assessed the association between exposure to arsenic (As), cadmium (Cd), and lead (Pb), and early renal impairment markers using urinary microalbumin (MA), β2-microglobulin (β2MG), and N-acetyl-beta-D-glucosaminidase (NAG) by analyzing 157 young adults aged 20‒29 years, in Taiwan. Inductively coupled plasma mass spectrometry was used to determine urinary As, Cd, and Pb levels. Regression models were applied to different sex groups. The results showed that after adjusting for potential confounding factors and each metal, urinary Cd levels were significantly positively associated with urinary MA (β = 0.523, 95% CI: 0.147-0.899) and β2MG (β = 1.502, 95% CI: 0.635-2.370) in males. However, the urinary Cd level was significantly positively associated with only urinary NAG (β = 0.161, 95% CI: 0.027-0.296) in females. This study thus indicates that the effect of exposure to metals (especially Cd) on early renal impairment among young adults in Taiwan is sex-specific. Our study results could contribute toward developing early intervention programs for decreasing the incidence of renal dysfunction. Further studies are warranted to confirm our findings and clarify the potential mechanisms involved.

Caloric restriction reduces the pro-inflammatory eicosanoid 20- hydroxyeicosatetraenoic acid to protect from acute kidney injury

Acute kidney injury is a frequent complication in the clinical setting and associated with significant morbidity and mortality. Preconditioning with short-term caloric restriction is highly protective against kidney injury in rodent ischemia reperfusion injury models. However, the underlying mechanisms are unknown hampering clinical translation. Here, we examined the molecular basis of caloric restriction-mediated protection to elucidate the principles of kidney stress resistance. Analysis of an RNAseq dataset after caloric restriction identified Cyp4a12a, a cytochrome exclusively expressed in male mice, to be strongly downregulated after caloric restriction. Kidney ischemia reperfusion injury robustly induced acute kidney injury in male mice and this damage could be markedly attenuated by pretreatment with caloric restriction. In females, damage was significantly less pronounced and preconditioning with caloric restriction had only little effect. Tissue concentrations of the metabolic product of Cyp4a12a, 20-hydroxyeicosatetraenoic acid (20-HETE), were found to be significantly reduced by caloric restriction. Conversely, intraperitoneal supplementation of 20-HETE in preconditioned males partly abrogated the protective potential of caloric restriction. Interestingly, this effect was accompanied by a partial reversal of caloric restriction-induced changes in protein but not RNA expression pointing towards inflammation, endoplasmic reticulum stress and lipid metabolism. Thus, our findings provide an insight into the mechanisms underlying kidney protection by caloric restriction. Hence, understanding the mediators of preconditioning is an important pre-requisite for moving towards translation to the clinical setting.

Estradiol Ameliorates Acute Kidney Ischemia-Reperfusion Injury by Inhibiting the TGF-βRI-SMAD Pathway

Renal ischemia–reperfusion injury (IRI) is less extensive in females than males in both animals and humans; however, this protection diminishes after menopause, suggesting that estrogen plays a pivotal role in IRI, but the underlying mechanism remains largely unknown. Our study found that 45 min of warm ischemia was sufficient to induce significant pathological changes without causing death in model animals. Compared with male rats, female rats exhibited less extensive apoptosis, kidney injury, and fibrosis; these effects were worsened in ovariectomized (OVX) rats and ameliorated upon estradiol (E₂) supplementation. Furthermore, the levels of TGF-βRI, but not TGF-βRII or TGF-β1, were significantly increased in OVX rats, accompanied by phosphorylated SMAD2/3 activation. Interestingly, the alteration trend of the nuclear ERα level was opposite that of TGF-βRI. Furthermore, dual luciferase reporter and chromatin immunoprecipitation assays showed that ERα could bind to the promoter region of TGF-βRI and negatively regulate its mRNA expression. Moreover, an in vitro study using NRK-52E cells showed that ERα knockdown blocked E₂-mediated protection, while TGF-βRI knockdown protected cells against hypoxic insult. The findings of this study suggest that renal IRI is closely related to the TGF-βRI-SMAD pathway in females and that E₂ exert its protective effect via the ERα-mediated transcriptional inhibition of TGF-βRI expression.

Polymyxin B-Associated Nephrotoxicity and Its Predictors: A Retrospective Study in Carbapenem-Resistant Gram-Negative Bacterial Infections

Polymyxin B (PMB), a kind of polymyxin, was widely used in carbapenem-resistant Gram-negative bacterial (CR-GNB) infections. However, adverse reactions such as nephrotoxicity and neurotoxicity limit its use in clinical practice. The aim of this study was to explore PMB associated with nephrotoxicity and its predictors. Patients who received PMB intravenous drip for more than 72 h were eligible for the study. Characteristics of patients, concomitant nephrotoxic agents, underlying disease, and antimicrobial susceptibility were submitted for descriptive analysis. Univariate analysis and binary logistic regression were used to assess the factors leading to acute kidney injury (AKI). AKI was assessed with serum creatinine variations according to the classification of risk (stage R), injury (stage I), failure (stage F), loss, and end-stage of kidney disease. Among 234 patients with CR-GNB infections who used PMB in our study, 67 (28.63%) patients developed AKI, including 31 (14.25%) patients in stage R, 15 (6.41%) patients in stage I, and 21 (8.97%) patients in stage F. The incident rate of PMB-related nephrotoxicity in patients with normal renal function was 32.82% (43/131). The higher risk factors of AKI include males [odds ratio (OR) = 3.237; 95% confidence interval (95%CI) = 1.426–7.350], digestive system diseases [OR = 2.481 (1.127–5.463)], using furosemide (&gt;20 mg/day) [OR = 2.473 (1.102–5.551)], and baseline serum creatinine [OR = 0.994 (0.990–0.999)]. Nonparametric tests of K-independent samples showed that baseline serum creatinine and the PMB maintenance dose were associated with the severity of nephrotoxicity (both p &lt; 0.05). Male, digestive system diseases, using furosemide (&gt;20 mg/day), and high baseline serum creatinine were the independent risk factors of PMB-associated AKI development. The maintenance dose of PMB may be related to the severity of AKI. These risk factors should be taken into consideration when initiating PMB-based therapy. The serum creatinine value should be closely monitored when using PMB.

Postresuscitation care and prognostication after cardiac arrest-Does sex matter?

Background

There are conflicting results concerning sex-specific differences in the post-cardiac arrest period. We investigated the sex distribution of patients after successful cardiopulmonary resuscitation (CPR), differences in treatment, complications, outcome and sex-specific performance of biomarkers for prognostication of neurological outcome.

Methods

Prospective observational study including cardiac-arrest (CA) patients treated with mild therapeutic hypothermia (MTH) at 33 °C for 24 h or normothermia. We investigated common complications including pneumonia and acute kidney injury (AKI) and neuron-specific enolase, secretoneurin and tau protein as biomarkers of neurological outcome, which was assessed with the cerebral performance categories score at hospital discharge.

Results

Out of 134 patients 26% were female. Women were significantly older (73 years, interquartile range (IQR) 56–79 years vs. 62 years, IQR 53–70 years; p = 0.038), whereas men showed a significantly higher rate of pneumonia (29% vs. 6%; p = 0.004) and a trend towards higher rates of AKI (62% vs. 45%; p = 0.091). Frequency of MTH treatment was not significantly different (48% vs. 31%; p = 0.081). Female sex was not associated with neurological outcome in multivariable analysis (p = 0.524). There was no significant interaction of sex with prognostication of neurological outcome at 24, 48 and 72 h after CPR. At the respective time intervals p_interaction for neuron-specific enolase was 0.524, 0.221 and 0.519, for secretoneurin 0.893, 0.573 and 0.545 and for tau protein 0.270, 0.635, and 0.110.

Conclusion

The proportion of female patients was low. Women presented with higher age but had fewer complications during the post-CA period. Female sex was not associated with better neurological outcome. The performance of biomarkers is not affected by sex.

Supplementary Information

The online version of this article (10.1007/s00508-022-02026-x) contains supplementary material, which is available to authorized users.

Emerging Roles for G Protein-Coupled Estrogen Receptor 1 in Cardio-Renal Health: Implications for Aging

Cardiovascular (CV) and renal diseases are increasingly prevalent in the United States and globally. CV-related mortality is the leading cause of death in the United States, while renal-related mortality is the 8th. Despite advanced therapeutics, both diseases persist, warranting continued exploration of disease mechanisms to develop novel therapeutics and advance clinical outcomes for cardio-renal health. CV and renal diseases increase with age, and there are sex differences evident in both the prevalence and progression of CV and renal disease. These age and sex differences seen in cardio-renal health implicate sex hormones as potentially important regulators to be studied. One such regulator is G protein-coupled estrogen receptor 1 (GPER1). GPER1 has been implicated in estrogen signaling and is expressed in a variety of tissues including the heart, vasculature, and kidney. GPER1 has been shown to be protective against CV and renal diseases in different experimental animal models. GPER1 actions involve multiple signaling pathways: interaction with aldosterone and endothelin-1 signaling, stimulation of the release of nitric oxide, and reduction in oxidative stress, inflammation, and immune infiltration. This review will discuss the current literature regarding GPER1 and cardio-renal health, particularly in the context of aging. Improving our understanding of GPER1-evoked mechanisms may reveal novel therapeutics aimed at improving cardio-renal health and clinical outcomes in the elderly.

Association of severity and mortality of Covid-19 cases among acute kidney injury and sexual dimorphism

Introduction

The outbreak of coronavirus disease 2019 (Covid-19) severely impacted global health and economic status. The native receptor-ligand interaction of Angiotensin-converting enzyme 2 (ACE2) and S protein induces host cell pathogenesis via immunosuppression.

Material and Methods

The emerging evidence reports the sex disparity in Covid-19 induced mortality rate which affects abundantly men population. Although the biological interaction of Covid-19 with receptor upregulates the viral genome protein interactions and initiates the predictive multiorgan failure followed by acute kidney injury (AKI) in Covid-19 infected male population.

Conclusion

Besides, the knowledge and lessons learned from the study depict that cellular and molecular links may explain the risk and severity of Covid-19 and AKI in the male population and lead to management of Covid-19 induced AKI. Therefore, this review explored the pathways associated with the pathogenesis of two diseased conditions with sex disparity.

Sex Differences in Acute Kidney Injury

Female sex confers renoprotection in chronic progressive kidney disease. It is less well recognized that sexual dimorphism also is evident in the development of ischemic and nephrotoxic acute kidney injury (AKI). Animal studies consistently have shown that female sex protects against the development of renal injury in experimental models of ischemic AKI. However, the consensus opinion is that in human beings, female sex is an independent risk factor for AKI. Based on a systematic review of experimental and clinical literature, we present data to support the conclusion that, contrary to consensus opinion, it is male sex, not female sex, that is associated with the development of AKI.

Sex and Gender Related Differences in Diabetic Kidney Disease

Diversity in sex and gender are important considerations in the pathogenesis, prognostication, research, and management of diabetic kidney disease (DKD). Sex and gender differences in the disease risk, disease-specific mechanisms, and outcomes in DKD may be attributed to biological differences between males and females at the cellular and tissue level, inconsistencies in the diagnostic and assessment tools used in chronic kidney disease and DKD, as well societal differences in the way men, women, and gender-diverse individuals self-manage and interact with health care systems. This review outlines key considerations related to the impact of sex on DKD, specifically elaborating on how they contribute to observed differences in disease epidemiology, pathogenesis, and treatment strategies. We also highlight the effect of gender on DKD progression and care.

Acute kidney injury requiring renal replacement therapy in people with COVID-19 disease in Ontario, Canada: a prospective analysis of risk factors and outcomes

BACKGROUND

Severely ill people with coronavirus disease 2019 (COVID-19) are at risk of acute kidney injury treated with renal replacement therapy (AKI-RRT). The understanding of the risk factors and outcomes for AKI-RRT is incomplete.

METHODS

We prospectively collected data on the incidence, demographics, area of residence, time course, outcomes and associated risk factors for all COVID-19 AKI-RRT cases during the first two waves of the pandemic in Ontario, Canada.

RESULTS

There were 271 people with AKI-RRT, representing 0.1% of all diagnosed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cases. These included 10% of SARS-CoV-2 admissions to intensive care units (ICU). Median age was 65 years, with 11% <50 years, 76% were male, 47% non-White and 48% had diabetes. Overall, 59% resided in the quintile of Ontario neighborhoods with the greatest ethnocultural composition and 51% in the two lowest income quintile neighborhoods. Mortality was 58% at 30 days after RRT initiation, and 64% at 90 days. By 90 days, 20% of survivors remained RRT-dependent and 31% were still hospitalized. On multivariable analysis, people aged >70 years had higher mortality (odds ratio 2.4, 95% confidence interval 1.3, 4.6). Cases from the second versus the first COVID-19 wave were older, had more baseline comorbidity and were more likely to initiate RRT  >2 weeks after SARS-CoV-2 diagnosis (34% versus 14%; P < 0.001).

CONCLUSIONS

AKI-RRT is common in COVID-19 ICU admissions. Residency in areas with high ethnocultural composition and lower socioeconomic status are strong risk factors. Late-onset AKI-RRT was more common in the second wave. Mortality is high and 90-day survivors have persisting high morbidity.