Why do we keep ignoring sex in kidney disease?

Throughout the history of nephrology, little attention has been paid to the sex and gender differences in kidney disease. This lack of awareness prevents optimal diagnosis and management of kidney disease. In today's world of precision medicine, it is imperative to appreciate the differential factors regarding gender and kidney disease. This editorial summarizes the up-to-date literature regarding sex and gender differences in kidney disease and considers areas where knowledge is incomplete and where further research is needed. We address sex-specific effects on chronic kidney disease epidemiology; risks of dialysis underdosing and medication overdosing in women; unexplained loss of female sex advantage in life expectancy during dialysis, and impact of sex on diagnosis and management of genetic kidney disease. We also aim to highlight the impact of gender on kidney health and raise awareness of disparities that may be faced by women, and transgender and gender-diverse persons when a male-model approach is used by healthcare systems. By understanding the link between sex and kidney disease, kidney specialists can improve the care and outcomes of their patients. In addition, research on this topic can inform the development of targeted prevention and intervention strategies that address the specific needs and risk factors of different populations.

Health inequities in dialysis care: A scoping review

MAIN PROBLEM

We aim to look at potential gaps in current dialysis literature on inequities and explore future research that could contribute to more equitable care.

METHODS

Following guidelines from the Joanna Briggs Institute (JBI) and the Preferred Reporting Items for Systematic reviews and Meta Analyses extension for Scoping Reviews (PRISMA-ScR), we conducted a scoping review of health inequities in dialysis. PubMed and Ovid Embase were searched in July 2022 for articles published between 2016 and 2022 that examined at least one of the following NIH defined health inequities: race/ethnicity, sex/gender, LGBTQ+ identity, underserved rural populations, education level, income, and occupation status. Frequencies of each health inequity as well as trends over time of the four most examined inequities were analyzed.

RESULTS

In our sample of 69 included studies, gaps were identified in LGBTQ+ identity and patient education. Inequities pertaining to race/ethnicity, sex/gender, underserved rural populations, and income were sufficiently reported. No trends between inequities investigated over time were identified.

CONCLUSIONS

Our scoping review examined current literature on health inequities pertaining to dialysis and found gaps concerning LGBTQ+ and patients with lower levels of education. To help fill these gaps, and possibly alleviate additional burden to these patients, we recommend cultural competency training for providers and dialysis center staff as well as community-based educational programs to improve dialysis patients' health literacy.

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.

Demography and Outcomes of Arteriovenous Fistula: Challenges and Future Directions

The incidence and prevalence rates of treated end-stage kidney disease (ESKD) patients are on the rise worldwide. Hemodialysis remains the main modality of providing renal replacement therapy for the ESKD patients, and the preferred vascular access is an arteriovenous fistula (AVF). The objective is to assess the patency rates and primary failures of the AVF. All patients who attended the Royal Hospital in Muscat, Oman, from January 2010 to December 2014 for AVF creation were included in this study. Data were extracted from the hospital's electronic medical record system where data are entered prospectively. During the period of study from 2010 to 2014, 465 primary fistulae were created in 427 patients. The mean age of the patient was 58 years. Only 6% needed general anesthesia, while the rest were done under regional or local anesthesia. Fifty-one percent of the patients were diabetic. Preemptive AVF was constructed in only 12% of patients. Most cases (47%) had left brachiocephalic (BC) fistulae. The left radiocephalic (RC) fistulae constituted 25.7% and the left brachiobasilic fistulae 9.9%. The remaining were constructed in the right upper limb. The total patency was achieved in 80% of fistulae and the failure rate was 20% at 6 months. Whereas, at 12 months, the total patency rate was 71% and the failure rate was 29%. Thus, we can conclude that more than 50% of patients, half of them being females, were diabetics. This resulted in more fistulae being constructed in the arm, namely left BC fistulae and left RC fistulae. Furthermore, it is important to note that only a very small percentage of patients had an established preemptive AVF. These factors may be responsible for a failure rate of 20% and 29% of the AVFs at 6 months and 12 months, respectively.

Is there sex disparity in vascular access at dialysis initiation in France? A mediation analysis using the data of the REIN registry

Background

This study was conducted to estimate the direct effect of sex on the proportion of hemodialysis catheters at dialysis initiation and to investigate whether predialysis care or socioeconomic status acted as a mediator of the sex effect.

Methods

Patients who started dialysis between 01–01-2017 and 30–06-2018 in France were included using the data of the REIN registry. Logistic regression was performed to study the association between sex and the proportion of HD catheters. A mediation analysis with a counterfactual approach was carried out to evaluate whether there was an indirect effect of gender through the proxies of predialysis care (hemoglobin, albumin levels, glomerular filtration rate (GFR) at dialysis initiation) and socioeconomic status. Due to the identification of an interaction between gender and social deprivation, a subgroup analysis was performed among deprived and nondeprived patients.

Results

There were 16 032 patients included, and the sex ratio (M/F) was 10 405/5627. In the multivariable analysis, women were associated with a greater risk of starting dialysis with a catheter (OR 1.32 [95% CI: 1.23–1.42]). There was an indirect effect of sex on the proportion of HD catheters through proxies for predialysis care (albuminemia < 30 g/L (OR 1.08 [95% CI: 1.05–1.10]), hemoglobin < 11 g/dL (OR 1.03 [95% CI: 1.02–1.04]), GFR < 7 ml/min (OR 1.05 [95% CI: 1.04–1.07])). Among deprived patients, there was no direct effect of sex on the catheter proportion.

Conclusions

Women were associated with a higher risk of starting dialysis through an HD catheter. The effect of sex was mediated by predialysis care, particularly for deprived patients.

Gender Disparities in Vascular Access and One-Year Mortality among Incident Hemodialysis Patients: An Epidemiological Study in Lazio Region, Italy

(1) Background: Interest in gender disparities in epidemiology, clinical features, prognosis and health care in chronic kidney disease patients is increasing. Aims of the study were to evaluate the association between gender and vascular access (arteriovenous fistula (AVF) or central venous catheter (CVC)) used at the start of hemodialysis (HD) and to investigate the association between gender and 1-year mortality. (2) Methods: The study includes 9068 adult chronic HD patients (64.7% males) registered in the Lazio Regional Dialysis Register (January 2008–December 2018). Multivariable logistic regression models were used to investigate the associations between gender and type of vascular access (AVF vs. CVC) and between gender and 1-year mortality. Interactions between gender and socio-demographic and clinical variables were tested adding the interaction terms in the final model. (3) Results: Females were older, had lower educational level and lower rate of self-sufficiency compared to males. Overall, CVC was used in 51.2% of patients. Females were less likely to use AVF for HD initiation than males. 1354 out of 8215 (16.5%) individuals died at the end of the follow-up period. Interaction term between gender and vascular access was significant in the adjusted model. From stratified analyses by vascular access, OR female vs. male (AVF) = 0.65; 95% CI 0.48–0.87 and OR female vs. male (CVC) = 0.88; 95% CI 0.75–1.04 were found. (4) Conclusions: This prospective population-based cohort study in a large Italian Region showed that in females starting chronic HD AVF was less common respect to men. The better 1-year survival of females is more evident among those women with AVF. Reducing gender disparity in access to AVF represents a key point in the management of HD patients.

Sex and gender differences in anesthesia: Relevant also for perioperative safety?

Sex (a biological determination) and gender (a social construct) are not interchangeable terms and both impact perioperative management and patient safety. Sex and gender differences in clinical phenotypes of chronic illnesses and risk factors for perioperative morbidity and mortality are relevant for preoperative evaluation and optimization. Sex-related differences in physiology, as well as in pharmacokinetics and pharmacodynamics of anesthetic drugs may influence the anesthesia plan, the management of pain, postoperative recovery, adverse effects, patient satisfaction, and outcomes. Further studies are needed to characterize outcome differences between men and women in non-cardiac, cardiac, and transplantation surgery in order to individualize perioperative management and improve patient safety. Transgender patients represent a vulnerable population who need special perioperative care. Gender balance increases team performance and may improve perioperative outcomes.

Sex and gender: modifiers of health, disease, and medicine

Clinicians can encounter sex and gender disparities in diagnostic and therapeutic responses. These disparities are noted in epidemiology, pathophysiology, clinical manifestations, disease progression, and response to treatment. This Review discusses the fundamental influences of sex and gender as modifiers of the major causes of death and morbidity. We articulate how the genetic, epigenetic, and hormonal influences of biological sex influence physiology and disease, and how the social constructs of gender affect the behaviour of the community, clinicians, and patients in the health-care system and interact with pathobiology. We aim to guide clinicians and researchers to consider sex and gender in their approach to diagnosis, prevention, and treatment of diseases as a necessary and fundamental step towards precision medicine, which will benefit men's and women's health.

Perspectives in Individualizing Solutions for Dialysis Access

The vascular access is the lifeline for the hemodialysis patient. Previous national vascular access guidelines have emphasized placement of arteriovenous fistulas in most hemodialysis patients. However, the new Kidney Disease Outcomes Quality Initiative guidelines for vascular access, soon to be published, will focus on a patient's end-stage kidney disease "life plan" and take a patient "first" approach. One of the major themes of the new Kidney Disease Outcomes Quality Initiative guidelines is selecting the "right access, for the right patient, at the right time, for the right reason". Given the availability of new advances in biomedical technologies, techniques, and devices in the vascular access field, this shift to a more patient-centered vascular access approach presents unique opportunities to individualize the solutions and care for patients requiring a dialysis vascular access. This review article will address 3 potential areas where there is an unmet need to individualize solutions for dialysis vascular access care: (1) biological approaches to improve vascular access selection and selection of therapies, (2) vascular access care for the post-transplant patient, and (3) vascular access disparities in race, gender, and the elderly patient.

Impact of gender and gender disparities in patients with kidney disease

PURPOSE OF REVIEW

Despite evidence of gender-specific differences in epidemiology and outcomes in all stages of chronic kidney disease (CKD), most studies ignore the issue of gender. This review addresses this knowledge gap by evaluating data on gender disparity in this population.

RECENT FINDINGS

Population-based studies indicate a higher prevalence of CKD in women; however, there are fewer women on renal replacement therapy than men. Men may progress to end-stage kidney disease more rapidly. Gender differences in rates of CKD progression may be influenced by potential antifibrotic and antiapoptotic effects of estrogen or proinflammatory deleterious effects of testosterone. Women are referred later for kidney replacement therapy and receive fewer arteriovenous fistulas than men receive, irrespective of race. Women are also less likely to receive kidney transplants as compared with men but are more likely to donate a kidney.

SUMMARY

Recommendations for medical management of CKD patients are currently made in a gender-blind manner, despite the fact that women have differing underlying physiology. Addressing gender differences and disparities is an important and overlooked area in the care of patients with kidney disease.

Racial and Sex Disparities in Catheter Use and Dialysis Access in the United States Medicare Population

BACKGROUND

Despite efforts to increase arteriovenous fistula and graft use, 80% of patients in the United States start hemodialysis on a central venous catheter (CVC).

METHODS

To better understand in incident hemodialysis patients how sex and race/ethnicity are associated with time on a central venous catheter and transition to an arteriovenous fistula and graft, our observational cohort study analyzed US Renal Data System data for patients with incident ESKD aged ≥66 years who started hemodialysis on a CVC in July 2010 through 2013.

RESULTS

At 1 year, 32.7% of 74,194 patients transitioned to an arteriovenous fistula, 10.8% transitioned to an arteriovenous graft, 32.1% stayed on a CVC, and 24.5% died. Women spent a significantly longer time on a CVC than men. Compared with white patients, patients who were black, Hispanic, or of another racial/ethnicity minority spent significantly more days on a CVC. In competing risk regression, women were significantly less likely than men to transition to a fistula and more likely to transition to a graft. Compared with white patients, blacks were significantly less likely to transition to a fistula but more likely to transition to a graft, Hispanics were significantly more likely to transition to a fistula, and other races/ethnicities were significantly more likely to transition to either a fistula or a graft.

CONCLUSIONS

Female patients spend a longer time on a CVC and are less likely to transition to permanent access. Compared with white patients, minorities also spend longer time on a CVC, but are more likely to eventually transition to permanent access. Strategies to speed transition to permanent access should target groups that currently lag in this area.

Gender Disparities in Vascular Access Surgical Outcomes in Elderly Hemodialysis Patients

BACKGROUND

Despite national vascular access guidelines promoting the use of arteriovenous fistulas (AVF) over arteriovenous grafts (AVGs) for dialysis, AVF use is substantially lower in females. We assessed clinically relevant AVF and AVG surgical outcomes in elderly male and female patients initiating hemodialysis with a central venous catheter (CVC).

METHODS

Using the United States Renal Data System standard analytic files linked with Medicare claims, we assessed incident hemodialysis patients in the United States, 9,458 elderly patients (≥67 years; 4,927 males and 4,531 females) initiating hemodialysis from July 2010 to June 2011 with a catheter and had an AVF or AVG placed within 6 months. We evaluated vascular access placement, successful use for dialysis, assisted use (requiring an intervention before successful use), abandonment after successful use, and rate of interventions after successful use.

RESULTS

Females were less likely than males to receive an AVF (adjusted likelihood 0.57, 95% CI 0.52-0.63). Among patients receiving an AVF, females had higher adjusted likelihoods of unsuccessful AVF use (hazard ratio [HR] 1.46, 95% CI 1.36-1.56), assisted AVF use (OR 1.34, 95% CI 1.17-1.54), and AVF abandonment (HR 1.28, 95% CI 1.10-1.50), but similar relative rate of AVF interventions after successful use (relative risk [RR] 1.01, 95% CI 0.94-1.08). Among patients receiving an AVG, females had a lower likelihood of unsuccessful AVG use (HR 0.83, 95% CI 0.73-0.94), similar rates of assisted AVG use (OR 1.05, 95% CI 0.78-1.40) and AVG abandonment, and greater relative rate of interventions after successful AVG use (RR 1.16, 95% CI 1.01-1.33).

CONCLUSIONS

While AVFs should be considered the preferred vascular access in most circumstances, clinical AVF surgical outcomes are uniformly worse in females. Clinicians should also consider AVGs as a viable alternative in elderly female patients initiating hemodialysis with a CVC to avoid extended CVC dependence.

Gender and Racial Disparities in Initial Hemodialysis Access and Outcomes in Incident End-Stage Renal Disease Patients

BACKGROUND

Arteriovenous (AV) access confers survival benefits over central venous catheters (CVC) in hemodialysis patients. Although chronic kidney disease disproportionately affects women and racial minorities, disparities in the -utilization of hemodialysis access across Asians, Native Americans, Hispanics, blacks, and whites among males and females after accounting for pre-dialysis health are not well studied.

METHODS

We evaluated 885,699 patients with end-stage renal disease who initiated hemodialysis between January 1, 2004 and December 31, 2014 using the US Renal Data System. Multivariable logistic regression models -adjusted for pre-dialysis health were used to test the associations between gender and race on type of vascular access (AV access vs. CVC, and AV fistula vs. AV graft) at hemodialysis initiation as primary outcome, and on 1-year mortality as a secondary outcome.

RESULTS

Mean age was 65 ± 14 years. Females were less likely to use AV access for hemodialysis initiation than were males (OR 0.85; 95% CI 0.84-0.86). Compared to whites, adjusted odds of AV access for hemodialysis initiation were higher in blacks (OR 1.08; 95% CI 1.07-1.70), Asians (OR 1.11; 95% CI 1.07-1.14); and lower in Hispanics (OR 0.89; 95% CI 0.87-0.90). There was no -significant difference in mortality between males and females. Compared to whites, 1-year adjusted mortality was lower in Asians (OR 0.55; 95% CI 0.53-0.56), blacks (OR 0.67; 95% CI 0.66-0.68), Hispanics (OR 0.62; 95% CI 0.61-0.63), and Native Americans (OR 0.62; 95% CI 0.58-0.66).

CONCLUSION

Females had lower odds of using AV access than do males for hemodialysis initiation. As compared to whites, blacks and Asians were more likely, and Hispanics were less likely to use AV access for first outpatient hemodialysis. Further investigation of biological and process of care factors may help in developing ways to reduce these disparities.