Kidneys and women's health: key challenges and considerations

Systematic Review of Women Leading and Participating in Nephrology Randomized Clinical Trials

Introduction

Women are underrepresented in the leadership of and participation in randomized controlled trials (RCTs). We conducted a bibliometric review of nephrology RCTs to examine trial leadership by women and participation of women in nephrology RCTs.

Methods

A bibliometric review of RCTs published in top medical, surgical, or nephrology journals was conducted using MEDLINE and EMBASE from January 2011 to December 2021. Leadership by women as corresponding authors, women trial participation, and trial characteristics were examined with duplicate independent data extraction. Logistic regression was used to examine associations between trial characteristics and women leadership and trial participation.

Results

A total of 1770 studies were screened and 395 RCTs met eligibility criteria. The number (%) of women in corresponding, first, and last authorship positions were as follows: 89 (22%), 109 (28%), and 74 (19%), respectively, without change over time (P = 0.94). The median percentage (interquartile range [IQR]) of women trial participants was 39.0% (13.5%) with no difference between women or men lead authors (P = 0.15). Men lead authors were statistically less likely to enroll women in RCTs. Women lead authors were less likely to be funded by industry (odds ratio [OR]: 0.30; 95% confidence interval [CI]: 0.14-0.63; P = 0.002) or lead international trials (OR: 0.11; 95% CI: 0.01-0.83; P = 0.03). Trials with sex-specific eligibility criteria were more likely to have women leaders (OR: 2.56; 95% CI: 1.19-5.49; P = 0.02) than those without.

Discussion

Gender inequalities in RCT leadership and RCT participation exist in nephrology and did not improve over time. Strategies to improve inequalities need to be implemented and evaluated.

Microchimerism as Post-Transplant Marker of a Chronic Rejection Process

The risk of losing a transplanted organ is high, and non-invasive markers to warn of this phenomenon are still being sought. We investigated the impact of post-transplant microchimerism on the function of the transplanted kidney. The study included 100 kidney transplant recipients, mostly women. All transplanted organs were from opposite-sex deceased donors. Microchimerism was assessed using multiplex PCR. Male DNA was detected in all urine samples from female recipients and in 13/56 blood samples from female kidney recipients. Female DNA was found in 31/44 urine samples from male recipients, but in none of the blood samples. Microchimerism in the urine of female recipients correlated positively with blood urea (Rs = 0.45; p = 5.84 × 10^-4) and K⁺ ions (Rs = 0.29; p = 0.03), while microchimerism in the blood of female recipients also correlated positively with blood urea (Rs = 0. 28; p = 0.04), cystatin C (Rs = 0.31; p = 0.02) and the number of incompatible HLA alleles (Rs = 0.42; p = 0.01). A history of DGF was associated with higher urinary donor DNA concentrations in female recipients.: Post-transplant microchimerism may serve as a potential marker of chronic kidney rejection.

Pregnancy and postpartum experiences of women undergoing hemodialysis: a qualitative study

INTRODUCTION

There are particularities of chronic kidney disease (CKD) in women and their treatment. The biology of women exposes them to greater risk factors for CKD and both pregnancy and the postpartum period place an additional burden on renal health. Pregnancy complications may cause or worsen CKD.

OBJECTIVE

To explore the experiences of women with CKD undergoing hemodialysis in relation to their reproductive history.

METHODS

This study consisted of clinical-qualitative design with semi-structured individual interviews and open-ended questions. The sample selection was intentional and according to the theoretical saturation criterion. The data analysis was carried out based on the seven steps of the clinical-qualitative content analysis and validated by Nvivo11. This study was conducted in a public hemodialysis clinic of the Brazilian National Health System.

RESULTS

Twelve women undergoing hemodialysis were interviewed. The results from the analysis revealed three categories: 1) Association of pregnancy with CKD; 2) Nebulosity in relation to diagnosis and reproductive history 3) Being a woman undergoing hemodialysis.

CONCLUSION

Our study showed the importance of considering the specificities of CKD in women, suggesting that these issues are important for diagnosis and treatment adherence. Consideration of reproductive life history allows the health of women undergoing hemodialysis to be promoted holistically, including aspects of mental health.

Identifying Longitudinal CD4:CD8 Ratio Trajectories Indicative of Chronic Renal Disease Risk among People Living with HIV: An Application of Growth Mixture Models

The incidence of chronic kidney disease (CKD) is increasing among people living with HIV (PLWH). Routine monitoring of indicators such as CD4:CD8 ratio might improve the early detection of CKD. Our objective was to identify clinically relevant CD4:CD8 ratio trajectories indicative of CKD risk. Participants were ≥ 18 years old, initiated antiretroviral therapy between 2000 and 2016, and were followed for ≥6 months until 31 March 2017 or last contact date. Outcome was incidence of CKD. Growth mixture models (GMMs) and decay models were used to compare CD4:CD8 ratio trajectories. Following GMM, 4547 (93.5%) participants were classified in Class 1 with 5.4% developing CKD, and 316 (6.5%) participants were classified in Class 2 with 20.9% developing CKD. The final model suggested that participants in Class 2 had 8.72 times the incidence rate of developing CKD than those in Class 1. Exponential decay models indicated a significant CD4:CD8 ratio decline among Class 2 participants who developed CKD. Among those who developed CKD in Class 2, starting at 5.5 years of follow-up, the slope of their ratio trajectory curve changed significantly, and the rate of decline increased dramatically. Routine monitored CD4:CD8 ratios can be an effective strategy to identify early CKD risk among PLWH.

Experiências de gravidez e puerpério de mulheres em hemodiálise: um estudo qualitativo

Resumo Introdução: Existem particularidades da doença renal crônica (DRC) em mulheres e seu tratamento. A biologia das mulheres as expõe a fatores de risco mais elevados para DRC e tanto a gravidez quanto o puerpério implicam um ônus adicional à saúde renal. Complicações na gestação podem causar ou piorar a DRC. Objetivo: Explorar as experiências de mulheres com DRC submetidas à hemodiálise em relação ao seu histórico reprodutivo. Métodos: Este estudo consistiu em desenho clínico-qualitativo com entrevistas individuais semiestruturadas e questões abertas. A seleção da amostra foi intencional e de acordo com o critério de saturação teórica. A análise de dados foi realizada com base nos sete passos da análise clínico-qualitativa de conteúdo e validada pelo Nvivo11. Este estudo foi realizado em uma clínica pública de hemodiálise do Sistema Único de Saúde brasileiro. Resultados: Foram entrevistadas 12 mulheres em hemodiálise. Os resultados da análise revelaram três categorias: 1) Associação da gravidez com DRC; 2) Nebulosidade em relação ao diagnóstico e à história reprodutiva; 3) Ser mulher e fazer hemodiálise. Conclusões: Nosso estudo mostrou a importância de considerar as especificidades da DRC em mulheres, sugerindo que estas questões são importantes para o diagnóstico e a adesão ao tratamento. A consideração do histórico de vida reprodutiva permite promover de forma holística a saúde das mulheres submetidas à hemodiálise, incluindo aspectos de saúde mental.

Sex differences in clinical outcomes in Japanese incident dialysis patients: a prospective observational multicenter study

BACKGROUND

A Dialysis Outcomes and Practice Patterns Study (DOPPS) has shown a one-to-one male-to-female mortality ratio, notwithstanding the statistically longer life expectancy of women in the general population. This finding contrasts with the recent report that Japanese women on dialysis treatment have a more favorable longevity. Accordingly, we further investigated the clinical procedures and outcomes to clarify the sex differences in Japanese patients undergoing dialysis treatment.

METHODS

Subjects were incident dialysis patients who participated in a multicenter prospective cohort study from October 2011 to September 2013. The all-cause mortality was analyzed by a Cox proportional hazard regression model and studied separately in women and men with or without cardiovascular disease (CVD) at baseline.

RESULTS

Overall, 492 (32.3%) of the 1520 test subjects were women. All-cause mortality was higher in men (28.6%) than in women (19.9%, p < 0.001). Female sex (hazard ratio [HR]: 0.70, 95% confidence interval [CI]: 0.54-0.90) and history of CVD (HR: 1.51, 95% CI: 1.18-1.95) were independent predictors of all-cause mortality. In patients without CVD, female gender was strong independent contributor (HR = 0.46, 95% CI: 0.30-0.70, p < 0.001). In contrast, patients with CVD showed no difference in survival between the sexes (HR: 0.92, 95% CI: 0.67-1.24, p = 0.597).

CONCLUSION

Our study demonstrated that women undergoing chronic dialysis therapy had a lower mortality risk than men. However, complication with CVD canceled out the survival advantage in Japanese women on chronic dialysis. We should reevaluate the risk of women with CVD undergoing dialysis and apply the optimal care for CVD.

An observational claims data analysis on the risk of maternal chronic kidney disease after preterm delivery and preeclampsia

Women with complications of pregnancy such as preeclampsia and preterm birth are at risk for adverse long-term outcomes, including an increased future risk of chronic kidney disease (CKD) and end-stage kidney disease (ESKD). This observational cohort study aimed to examine the risk of CKD after preterm delivery and preeclampsia in a large obstetric cohort in Germany, taking into account preexisting comorbidities, potential confounders, and the severity of CKD. Statutory claims data of the AOK Baden-Wuerttemberg were used to identify women with singleton live births between 2010 and 2017. Women with preexisting conditions including CKD, ESKD, and kidney replacement therapy (KRT) were excluded. Preterm delivery (< 37 gestational weeks) was the main exposure of interest; preeclampsia was investigated as secondary exposure. The main outcome was a newly recorded diagnosis of CKD in the claims database. Data were analyzed using Cox proportional hazard regression models. The time-dependent occurrence of CKD was analyzed for four strata, i.e., births with (i) neither an exposure of preterm delivery nor an exposure of preeclampsia, (ii) no exposure of preterm delivery but exposure of at least one preeclampsia, (iii) an exposure of at least one preterm delivery but no exposure of preeclampsia, or (iv) joint exposure of preterm delivery and preeclampsia. Risk stratification also included different CKD stages. Adjustments were made for confounding factors, such as maternal age, diabetes, obesity, and dyslipidemia. The cohort consisted of 193,152 women with 257,481 singleton live births. Mean observation time was 5.44 years. In total, there were 16,948 preterm deliveries (6.58%) and 14,448 births with at least one prior diagnosis of preeclampsia (5.61%). With a mean age of 30.51 years, 1,821 women developed any form of CKD. Compared to women with no risk exposure, women with a history of at least one preterm delivery (HR = 1.789) and women with a history of at least one preeclampsia (HR = 1.784) had an increased risk for any subsequent CKD. The highest risk for CKD was found for women with a joint exposure of preterm delivery and preeclampsia (HR = 5.227). These effects were the same in magnitude only for the outcome of mild to moderate CKD, but strongly increased for the outcome of severe CKD (HR = 11.90). Preterm delivery and preeclampsia were identified as independent risk factors for all CKD stages. A joint exposure or preterm birth and preeclampsia was associated with an excessive maternal risk burden for CKD in the first decade after pregnancy. Since consequent follow-up policies have not been defined yet, these results will help guide long-term surveillance for early detection and prevention of kidney disease, especially for women affected by both conditions.

Sex and Gender Bias in Kidney Transplantation: 3D Bioprinting as a Challenge to Personalized Medicine

In this article, we explore to what extent sex and gender differences may be reproduced in the 3D bioprinting of kidneys. Sex and gender differences have been observed in kidney function, anatomy, and physiology, and play a role in kidney donation and transplantation through differences in kidney size (sex aspect) and altruism (gender aspect). As a form of personalized medicine, 3D bioprinting might be expected to eliminate sex and gender bias. On the basis of an analysis of recent literature, we conclude that personalized techniques such as 3D bioprinting of kidneys alone do not mean that sex and gender bias does not happen. Therefore, sex and gender considerations should be included into every step of developing and using 3D-bioprinted kidneys: in the choice of design, cells, biomaterials, and X-chromosome-activated cells.

Impending challenges of the burden of end-stage kidney disease in Australia

Sex and age-specific incidence rates of patients with treated end-stage kidney disease (ESKD) in Australia are comparable to those in European countries, but substantially lower compared with those in the United States, Canada and many Asian countries. The incidence rates of treated ESKD in Australia increase with advancing age; however, the incidence of ESKD is likely to be underestimated because a proportion of patients with ESKD (about 50%) remain untreated. Late referral to nephrologists has reduced over the past decade, temporally associated with improved ESKD recognition. However, late referral still occurs in one in five Australians with ESKD. One in two Australians with ESKD has diabetes, with up to 35% of cases directly attributed to diabetes. Mortality rates for patients with ESKD remain substantially higher compared with the age-matched general population, although there has been a significant improvement in survival over time. Cardiovascular disease and cancer are the two most common causes of death in patients with ESKD.

Preeclampsia and risk of end stage kidney disease: A Swedish nationwide cohort study

BACKGROUND

Preeclampsia has been suggested to increase the risk of end-stage kidney disease (ESKD); however, most studies were unable to adjust for potential confounders including pre-existing comorbidities such as renal disease and cardiovascular disease (CVD). We aimed to examine the association between preeclampsia and the risk of ESKD in healthy women, while taking into account pre-existing comorbidity and potential confounders.

METHODS AND FINDINGS

Using data from the Swedish Medical Birth Register (MBR), women who had singleton live births in Sweden between 1982 and 2012, including those who had preeclampsia, were identified. Women with a diagnosis of chronic kidney disease (CKD), CVD, hypertension, or diabetes prior to the first pregnancy were excluded. The outcome was a diagnosis of ESKD, identified from the Swedish Renal Registry (SRR) from January 1, 1991, onwards along with the specified cause of renal disease. We conducted Cox proportional hazards regression analysis to examine the association between preeclampsia and ESKD adjusting for several potential confounders: maternal age, body mass index (BMI), education, native country, and smoking. This analysis accounts for differential follow-up among women because women had different lengths of follow-up time. We performed subgroup analyses according to preterm preeclampsia, small for gestational age (SGA), and women who had 2 pregnancies with preeclampsia in both. The cohort consisted of 1,366,441 healthy women who had 2,665,320 singleton live births in Sweden between 1982 and 2012. At the first pregnancy, women's mean (SD) age and BMI were 27.8 (5.13) and 23.4 (4.03), respectively, 15.2% were smokers, and 80.7% were native Swedish. The overall median (interquartile range [IQR]) follow-up was 7.4 years (3.2-17.4) and 16.4 years (10.3-22.0) among women with ESKD diagnosis. During the study period, 67,273 (4.9%) women having 74,648 (2.8% of all pregnancies) singleton live births had preeclampsia, and 410 women developed ESKD with an incidence rate of 1.85 per 100,000 person-years. There was an association between preeclampsia and ESKD in the unadjusted analysis (hazard ratio [HR] = 4.99, 95% confidence interval [CI] 3.93-6.33; p < 0.001), which remained in the extensively adjusted (HR = 4.96, 95% CI 3.89-6.32, p < 0.001) models. Women who had preterm preeclampsia (adjusted HR = 9.19; 95% CI 5.16-15.61, p < 0.001) and women who had preeclampsia in 2 pregnancies (adjusted HR = 7.13, 95% CI 3.12-16.31, p < 0.001) had the highest risk of ESKD compared with women with no preeclampsia. Considering this was an observational cohort study, and although we accounted for several potential confounders, residual confounding cannot be ruled out.

CONCLUSIONS

The present findings suggest that women with preeclampsia and no major comorbidities before their first pregnancy are at a 5-fold increased risk of ESKD compared with parous women with no preeclampsia; however, the absolute risk of ESKD among women with preeclampsia remains small. Preeclampsia should be considered as an important risk factor for subsequent ESKD. Whether screening and/or preventive strategies will reduce the risk of ESKD in women with adverse pregnancy outcomes is worthy of further investigation.

A continuous juggle of invisible forces: How fatigued dialysis patients manage daily life

Dialysis patients commonly experience severe fatigue. Fatigue is known as an intrusive symptom strongly affecting perceived quality of life. A total of 23 interviews were conducted to explore how dialysis patients respond to fatigue symptoms and its consequences in daily life. A constructivist grounded theory approach guided data analysis and conceptualization of findings. Patients find themselves within a continuous decision loop, considering ones (physical) abilities and questioning ones normative beliefs and values. This inner process interacts with the outside world, and contains various ambiguities. Improved understanding of this demanding process could help to better address fatigue and positively contribute to the quality of life of dialysis patients.