Pathways for Diagnosing and Treating CKD-Associated Pruritus: A Narrative Review

Purpose of Review

Chronic kidney disease (CKD)-associated pruritus is a common, persistent, and distressing itch experienced by patients across the CKD spectrum. Although the disorder is associated with adverse outcomes and poor health-related quality of life, it remains underdiagnosed and undertreated. The purpose of this narrative review is to offer health care providers guidance on how to effectively identify, assess, and treat patients with CKD-associated pruritus, with the goal of reducing symptom burden and improving patient-important outcomes, such as quality of life (QoL).

Sources of Information

A panel of nephrologists and researchers from across Canada and the United States was assembled to develop this narrative review based on the best available data, current treatment guidelines, and their clinical experiences.

Methods

A panel of nephrologists who actively care for patients with pruritus receiving dialysis from across Canada was assembled. Two researchers from the United States were also included based on their expertise in the diagnosis and management of CKD-associated pruritus. Throughout Spring 2023, the panel met to discuss key topics in the identification, assessment, and management of CKD-associated pruritus. Panel members subsequently developed summaries of the pertinent information based on the best available data, current treatment guidelines, and added information on their own clinical experiences. In all cases, approval of the article was sought and achieved through discussion.

Key Findings

This narrative review provides pragmatic guidance addressing: (1) methods for screening CKD-associated pruritus, (2) assessing severity, (3) management of CKD-associated pruritus, and (4) suggested areas for future research. The panel developed a 3-pillar framework for proactive assessment and severity scoring in CKD-aP: systematic screening for CKD-associated pruritus (pillar 1), assessment of pruritus intensity (pillar 2), and understanding the impact of CKD-associated pruritus on the patient's QoL (pillar 3). Management of CKD-associated pruritus can include ensuring optimization of dialysis adequacy, achieving mineral metabolism targets (ie, calcium, phosphate, and parathyroid hormone). However, treatment of CKD-associated pruritus usually requires additional interventions. Patients, regardless of CKD-associated pruritus severity, should be counseled on adequate skin hydration and other non-pharmacological strategies to reduce pruritus. Antihistamines should be avoided in favor of evidence-based treatments, such as difelikefalin and gabapentin.

Limitations

A formal systematic review (SR) of the literature was not undertaken, although published SRs were reviewed. The possibility for bias based on the experts' own clinical experiences may have occurred. Key takeaways are based on the current available evidence, of which head-to-head clinical trials are lacking.

Funding

This work was funded by an arm's length grant from Otsuka Canada Pharmaceutical Inc. (the importer and distributer of difelikefalin in Canada). LiV Medical Education Agency Inc. provided logistical and editorial support.

Association between Serum Estradiol and Cardiovascular Health among Transgender Adults Using Gender-Affirming Estrogen Therapy

INTRODUCTION

Gender-affirming estrogen therapy (GAET) is commonly used for feminization in transgender and non-binary (TNB) individuals, yet the optimal rate of change (ROC) in estradiol levels for cardiovascular health is unclear. We examined the association between serum estradiol levels and cardiovascular-related mortality, adverse events, and risk factors in TNB adults using GAET.

METHODS

Cochrane Central Register of Controlled Trials, EMBASE, MEDLINE and Web of Science were systematically searched (inception-April 2023) for original articles reporting serum estradiol levels and cardiovascular-related mortality, adverse events, and risk factors in TNB adults using GAET. Data extraction was completed in duplicate following PRISMA guidelines. Stratified random effects meta-analyses using serum estradiol ROC (serum estradiolbaseline-serum estradiolfollow-up/study duration) was used to assess longitudinal studies (Low:0

RESULTS

Thirty-five studies (13 cross-sectional, 19 cohort, 3 trials) were included. Two studies collectively reported 50 cardiovascular-related deaths, and four collectively reported 23 adverse cardiovascular events. Nineteen studies reporting cardiovascular risk factors were meta-analyzed by ROC stratum (Low=5; Moderate=6; High=8), demonstrating an association between moderate (0.40, 95%CI: 0.22, 0.59kg/m2, I2=28.2%) and high (0.46, 95%CI:0.15, 0.78kg/m2; I2=0.0%,) serum estradiol ROC and increased body mass index. High (-6.67, 95%CI:-10.65, -2.68mg/dL; I2=0.0%) serum estradiol ROC were associated with decreased low-density lipoproteins. Low (-7.05, 95%CI:-10.40, -3.70mmHg; I2=0.0%) and moderate (-3.69, 95%CI:-4.93, -2.45mmHg; I2=0.0%) serum estradiol ROC were associated with decreases in systolic blood pressure.

CONCLUSION

In TNB adults using GAET, serum estradiol ROC may influence cardiovascular risk factors, which may have implications for clinical cardiovascular outcomes.

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Key Words

• cardiovascular
• gender-affirming estrogen therapy
• rate of change
• serum estradiol
• transgender women

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Global trends in chronic kidney disease-related mortality: a systematic review protocol

INTRODUCTION

In recent decades, all-cause mortality has increased among individuals with chronic kidney disease (CKD), influenced by factors such as aetiology, standards of care and access to kidney replacement therapies (dialysis and transplantation). The recent COVID-19 pandemic also affected mortality over the past few years. Here, we outline the protocol for a systematic review to investigate global temporal trends in all-cause mortality among patients with CKD at any stage from 1990 to current. We also aim to assess temporal trends in the mortality rate associated with the COVID-19 pandemic.

METHODS AND ANALYSIS

We will conduct a systematic review of studies reporting mortality for patients with CKD following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We will search electronic databases, national and multiregional kidney registries and grey literature to identify observational studies that reported on mortality associated with any cause for patients with CKD of all ages with any stage of the disease. We will collect data between April and August 2023 to include all studies published from 1990 to August 2023. There will be no language restriction, and clinical trials will be excluded. Primary outcome will be temporal trends in CKD-related mortality. Secondary outcomes include assessing mortality differences before and during the COVID-19 pandemic, exploring causes of death and examining trends across CKD stages, country classifications, income levels and demographics.

ETHICS AND DISSEMINATION

A systematic review will analyse existing data from previously published studies and have no direct involvement with patient data. Thus, ethical approval is not required. Our findings will be published in an open-access peer-reviewed journal and presented at scientific conferences.

PROSPERO REGISTRATION NUMBER

CRD42023416084.

Impact of a Medical Fitness Model on Incident Major Adverse Cardiovascular Events: A Prospective Cohort Study of 11 000 Members

BACKGROUND

Cardiovascular disease remains the leading cause of disease burden and death in the world. The medical fitness model may be an alternative public health strategy to address cardiovascular risk factors with medical integrated programming.

METHODS AND RESULTS

We performed a retrospective cohort study between January 1, 2005, and December 31, 2015. Adults (aged ≥18 years) who did not have a prior major adverse cardiovascular event were included. Controls were assigned a pseudo-index date at random on the basis of the frequency distribution of start dates in the medical fitness facility group. Multivariate Cox proportional hazards regression models were adjusted for age, sex, socioeconomic status, comorbidities, and year of index date. We stratified the medical fitness facility group into low-frequency attenders (≤1 weekly visit) and regular-frequency attenders (>1 weekly visit). Our primary outcome was a hospitalization for nonfatal myocardial infarction and stroke, heart failure, or cardiovascular death. We included 11 319 medical fitness facility members and 507 400 controls in our study. Compared with controls, members had a lower hazard risk of a major adverse cardiovascular event-plus (hazard ratio [HR], 0.88 [95% CI, 0.81-0.96]). Higher weekly attendance was associated with a lower hazard risk of a major adverse cardiovascular event-plus compared with controls, but the effect was not significant for lower weekly attendance (low-frequency attenders: HR, 0.94 [95% CI, 0.85-1.04]; regular-frequency attenders: HR, 0.77 [95% CI, 0.67-0.89]).

CONCLUSIONS

Medical fitness facility membership and attendance at least once per week may lower the risk of a major adverse cardiovascular event-plus. The medical fitness model should be considered as a public health intervention, especially for individuals at risk for cardiovascular disease.

The Association Between Intradialytic Symptom Clusters and Recovery Time in Patients Undergoing Maintenance Hemodialysis: An Exploratory Analysis

Background

Individuals receiving hemodialysis often experience concurrent symptoms during treatment and frequently report feeling unwell after dialysis. The degree to which intradialytic symptoms are related, and which specific symptoms may impair health-related quality of life (HRQoL) is uncertain.

Objectives

To explore intradialytic symptoms clusters, and the relationship between intradialytic symptom clusters with dialysis treatment recovery time and HRQoL.

Design/setting

We conducted a post hoc analysis of a prospective cohort study of 118 prevalent patients receiving hemodialysis in two centers in Calgary, Alberta and Hamilton, Ontario, Canada.

Participants

Adults receiving hemodialysis treatment for at least 3 months, not scheduled for a modality change within 6 weeks of study commencement, who could provide informed consent and were able to complete English questionnaires independently or with assistance.

Methods

Participants self-reported the presence (1 = none to 5 = very much) of 10 symptoms during each dialysis treatment, the time it took to recover from each treatment, and weekly Kidney Disease Quality of Life 36-Item-Short Form (KDQoL-36) assessments. Principal component analysis identified clusters of intradialytic symptoms. Mixed-effects, ordinal and linear regression examined the association between symptom clusters and recovery time (categorized as 0, >0 to 2, >2 to 6, or >6 hours), and the physical component and mental component scores (PCS and MCS) of the KDQoL-36.

Results

One hundred sixteen participants completed 901 intradialytic symptom questionnaires. The most common symptom was lack of energy (56% of treatments). Two intradialytic symptom clusters explained 39% of the total variance of available symptom data. The first cluster included bone or joint pain, muscle cramps, muscle soreness, feeling nervous, and lack of energy. The second cluster included nausea/vomiting, diarrhea and chest pain, and headache. The first cluster (median score: -0.56, 25th to 75th percentile: -1.18 to 0.55) was independently associated with longer recovery time (odds ratio [OR] 1.62 per unit difference in score, 95% confidence interval [CI]: 1.23-2.12) and decreased PCS (-0.72 per unit difference in score, 95% CI: -1.29 to -0.15) and MCS scores (-0.82 per unit difference in score, 95% CI: -1.48 to -0.16), whereas the second cluster was not (OR 1.24, 95% CI: 0.97-1.58; PCS 0.19, 95% CI -0.46 to 0.83; MCS -0.72, 95% CI: -1.50 to 0.06).

Limitations

This was an exploratory analysis of a small data set from 2 centers. Further work is needed to externally validate these findings to confirm intradialytic symptom clusters and the generalizability of our findings.

Conclusions

Intradialytic symptoms are correlated. The presence of select intradialytic symptoms may prolong the time it takes for a patient to recover from a dialysis treatment and impair HRQoL.

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

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

Sodium-glucose co-transporter-2 inhibitors are associated with kidney benefits at all degrees of albuminuria: A retrospective cohort study of adults with diabetes

AIM

To estimate the real-world effectiveness of sodium-glucose co-transporter-2 inhibitors (SGLT2is) versus dipeptidyl peptidase-4 inhibitors (DPP4is) at reducing loss of kidney function and adverse kidney events in adults with varying levels of albuminuria.

MATERIALS AND METHODS

In this retrospective cohort study using administrative data, we matched new SGLT2i users 1:2 to DPP4i users on diabetes therapy, chronic kidney disease (CKD) stage, albuminuria and time-conditional propensity score. Albuminuria was defined by spot urine albumin or equivalent as mild, moderate or severe. Linear regression was used to model the estimated glomerular filtration rate (eGFR), and Poisson regression for a composite kidney outcome (> 40% loss of eGFR, kidney replacement therapy or death from kidney causes) and all-cause mortality.

RESULTS

SGLT2i users (n = 19 238, median age 57.9 years, female 40.9%) had mostly nil/mild albuminuria (70.7%). SGLT2is were associated with a 1.36 (95% CI 0.98-1.74) mL/min/1.73m2 (P < .001) acute (≤ 60 days) decline in eGFR, relative to DPP4is. Thereafter, SGLT2is were associated with 1.04 (95% CI 0.93-1.15) mL/min/1.73m2 (P < .001) less annual eGFR loss. SGLT2i users had fewer adverse kidney outcomes (incidence rate ratio [IRR] 0.58 [0.47-0.71]; P < .001), but not all-cause mortality (IRR 0.82 [0.66-1.01]; P = .06). Outcomes were similar considering only those with nil/mild albuminuria.

CONCLUSIONS

SGLT2is may prevent eGFR decline and reduce the risk of adverse kidney events in adults with diabetes and nil or non-severe albuminuria.

Sexual and gender minority relevant policies in Canadian and United States organ and tissue donation and transplantation systems: An opportunity to improve equity and safety

Current policies in organ and tissue donation and transplantation (OTDT) systems in Canada and the United States unnecessarily restrict access to donation for sexual and gender minorities (SGMs) and pose safety risks to transplant recipients. We compare SGM-relevant policies between the Canadian and United States systems. Policy domains include the risk assessment of living and deceased organ and tissue donors, physical examination considerations, viral testing recommendations, and informed consent and communication. Identified gaps between current evidence and existing OTDT policies along with differences in SGM-relevant policies between systems, represent an opportunity for improvement. Specific recommendations for OTDT system policy revisions to achieve these goals include the development of behavior-based, gender-neutral risk assessment criteria, a reduction in current SGM no-sexual contact period requirements pending development of inclusive criteria, and destigmatization of sexual contact with people living with human immunodeficiency virus. OTDT systems should avoid rectal examinations to screen for evidence of receptive anal sex without consent and mandate routine nucleic acid amplification test screening for all donors. Transplant recipients must receive enhanced risk-to-benefit discussions regarding decisions to accept or decline an offer of an organ classified as increased risk. These recommendations will expand the donor pool, enhance equity for SGM people, and improve safety and outcomes for transplant recipients.

Precision Medicine in Diabetic Kidney Disease: A Narrative Review Framed by Lived Experience

Purpose of review

Diabetic kidney disease (DKD) is a leading cause of chronic kidney disease (CKD) for which many treatments exist that have been shown to prevent CKD progression and kidney failure. However, DKD is a complex and heterogeneous etiology of CKD with a spectrum of phenotypes and disease trajectories. In this narrative review, we discuss precision medicine approaches to DKD, including genomics, metabolomics, proteomics, and their potential role in the management of diabetes mellitus and DKD. A patient and caregivers of patients with lived experience with CKD were involved in this review.

Sources of information

Original research articles were identified from MEDLINE and Google Scholar using the search terms "diabetes," "diabetic kidney disease," "diabetic nephropathy," "chronic kidney disease," "kidney failure," "dialysis," "nephrology," "genomics," "metabolomics," and "proteomics."

Methods

A focused review and critical appraisal of existing literature regarding the precision medicine approaches to the diagnosis, prognosis, and treatment of diabetes and DKD framed by a patient partner's/caregiver's lived experience.

Key findings

Distinguishing diabetic nephropathy from CKD due to other types of DKD and non-DKD is challenging and typically requires a kidney biopsy for a diagnosis. Biomarkers have been identified to assist with the prediction of the onset and progression of DKD, but they have yet to be incorporated and evaluated relative to clinical standard of care CKD and kidney failure risk prediction tools. Genomics has identified multiple causal genetic variants for neonatal diabetes mellitus and monogenic diabetes of the young that can be used for diagnostic purposes and to specify antiglycemic therapy. Genome-wide-associated studies have identified genes implicated in DKD pathophysiology in the setting of type 1 and 2 diabetes but their translational benefits are lagging beyond polygenetic risk scores. Metabolomics and proteomics have been shown to improve diagnostic accuracy in DKD, have been used to identify novel pathways involved in DKD pathogenesis, and can be used to improve the prediction of CKD progression and kidney failure as well as predict response to DKD therapy.

Limitations

There are a limited number of large, high-quality prospective observational studies and no randomized controlled trials that support the use of precision medicine based approaches to improve clinical outcomes in adults with or at risk of diabetes and DKD. It is unclear which patients may benefit from the clinical use of genomics, metabolomics and proteomics along the spectrum of DKD trajectory.

Implications

Additional research is needed to evaluate the role of the use of precision medicine for DKD management, including diagnosis, differentiation of diabetic nephropathy from other etiologies of DKD and CKD, short-term and long-term risk prognostication kidney outcomes, and the prediction of response to and safety of disease-modifying therapies.

Reducing Dietary Acid With Fruit and Vegetables Versus Oral Alkali in People With Chronic Kidney Disease (ReDACKD): A Clinical Research Protocol

Background

Individuals with chronic kidney disease (CKD) can develop metabolic acidosis which, in turn, is associated with faster progression of CKD and an increased need for dialysis. Oral sodium bicarbonate (the current standard of care therapy for metabolic acidosis) is poorly tolerated leading to low adherence. Base-producing or alkalizing Fruit and vegetables have potential as an alternative treatment for metabolic acidosis as they have been shown to reduce acid load arising from the diet.

Objective

This trial will evaluate the feasibility of providing base-producing fruit and vegetables as a dietary treatment for metabolic acidosis, compared with oral sodium bicarbonate.

Design

A 2-arm, open-label, dual-center, randomized controlled feasibility trial.

Setting

Two Canadian sites: a nephrology clinic in Winnipeg, Manitoba, and a nephrology clinic in Halifax, Nova Scotia.

Participants

Adult participants with G3-G5 CKD and metabolic acidosis.

Measurements

Participants will undergo baseline measurements and attend 5 study visits over 12 months at which they will have a measurement of feasibility criteria as well as blood pressure, blood and urine biochemistry, 5-repetition chair stand test (STS5), and questionnaires to assess quality of life and symptoms. Furthermore, participants fill out Automated Self-Administered 24-hour recalls (ASA-24) in the beginning, middle, and end of trial.

Methods

A total of 40 eligible participants will be randomized 1:1 to either base-producing fruit and vegetables (experimental) group or sodium bicarbonate (control) group, beginning from a daily dose of 1500 mg.

Limitations

Using self-administered dietary assessments, lack of supervision over the consumption of study treatments and the possible disappointment of the control group for not receiving fruit and vegetables would be considered as limitations for this study. However, we are planning to undertake proper practices to overcome the possible limitations. These practices are discussed throughout the article in detail.

Conclusions

This study will generate data on base-producing fruit and vegetables consumption as a dietary treatment for metabolic acidosis in CKD. The data will be used to design a future multi-center trial looking at slowing CKD progression in people with metabolic acidosis.

Trial Registration

This study is registered on clinicaltrials.gov with the identifier NCT05113641.

AACC/NKF Guidance Document on Improving Equity in Chronic Kidney Disease Care

BACKGROUND

Kidney disease (KD) is an important health equity issue with Black, Hispanic, and socioeconomically disadvantaged individuals experiencing a disproportionate disease burden. Prior to 2021, the commonly used estimated glomerular filtration rate (eGFR) equations incorporated coefficients for Black race that conferred higher GFR estimates for Black individuals compared to non-Black individuals of the same sex, age, and blood creatinine concentration. With a recognition that race does not delineate distinct biological categories, a joint task force of the National Kidney Foundation and the American Society of Nephrology recommended the adoption of the CKD-EPI 2021 race-agnostic equations.

CONTENT

This document provides guidance on implementation of the CKD-EPI 2021 equations. It describes recommendations for KD biomarker testing, and opportunities for collaboration between clinical laboratories and providers to improve KD detection in high-risk populations. Further, the document provides guidance on the use of cystatin C, and eGFR reporting and interpretation in gender-diverse populations.

SUMMARY

Implementation of the CKD-EPI 2021 eGFR equations represents progress toward health equity in the management of KD. Ongoing efforts by multidisciplinary teams, including clinical laboratorians, should focus on improved disease detection in clinically and socially high-risk populations. Routine use of cystatin C is recommended to improve the accuracy of eGFR, particularly in patients whose blood creatinine concentrations are confounded by processes other than glomerular filtration. When managing gender-diverse individuals, eGFR should be calculated and reported with both male and female coefficients. Gender-diverse individuals can benefit from a more holistic management approach, particularly at important clinical decision points.

Management of antineutrophil cytoplasmic antibody-associated vasculitis: a changing tide

PURPOSE OF REVIEW

Antineutrophil cytoplasmic antibody associated vasculitis (AAV) is a group of autoimmune disorders of small blood vessels. While outcomes in AAV have improved with the use of glucocorticoids (GC) and other immunosuppressants, these treatments are associated with significant toxicities. Infections are the major cause of mortality within the first year of treatment. There is a move towards newer treatments with better safety profiles. This review reflects on recent advances in the treatment of AAV.

RECENT FINDINGS

The role of plasma exchange (PLEX) in AAV with kidney involvement has been clarified with new BMJ guideline recommendations following the publication of PEXIVAS and an updated meta-analysis. Lower dose GC regimens are now standard of care. Avacopan (C5a receptor antagonist) was noninferior to a regimen of GC therapy and is a potential steroid-sparing agent. Lastly, rituximab-based regimens were noninferior to cyclophosphamide in two trials for induction of remission and superior to azathioprine in one trial of maintenance of remission.

SUMMARY

AAV treatments have changed tremendously over the past decade with a drive towards targeted PLEX use, increased rituximab use and lower GC dosing. Striking a crucial balance between morbidity from relapses and toxicities from immunosuppression remains a challenging path to navigate.

Magnitude of the Potential Screening Gap for Fabry Disease in Manitoba: A Population-Based Retrospective Cohort Study

Background:

Fabry disease is a rare disorder caused by the deficient activity of α-galactosidase A (GLA) that often leads to organ damage. Fabry disease can be treated with enzyme replacement or pharmacological therapy, but due to its rarity and nonspecific manifestations, it often goes undiagnosed. Mass screening for Fabry disease is impractical; however, a targeted screening program for high-risk individuals may uncover previously unknown cases.

Objective:

Our objective was to use population-level administrative health databases to identify patients at high risk of Fabry disease.

Design:

Retrospective cohort study.

Setting:

Population-level health administrative databases housed at the Manitoba Centre for Health Policy.

Patients:

All residents of Manitoba, Canada, between 1998 and 2018.

Measurements:

We ascertained the evidence of GLA testing in a cohort of patients at high risk of Fabry disease.

Methods:

Individuals without a hospitalization or prescription indicative of Fabry disease were included if they had evidence of 1 of 4 high-risk conditions for Fabry disease: (1) ischemic stroke <45 years of age, (2) idiopathic hypertrophic cardiomyopathy, (3) proteinuric chronic kidney disease or kidney failure of unknown cause, or (4) peripheral neuropathy. Patients were excluded if they had known contributing factors to these high-risk conditions. Those who remained and had no prior GLA testing were assigned a 0% to 4.2% probability of having Fabry disease depending on their high-risk condition and sex.

Results:

After applying exclusion criteria, 1386 individuals were identified as having at least 1 high-risk clinical condition for Fabry disease in Manitoba. There were 416 GLA tests conducted during the study period, and of those, 22 were conducted in individuals with at least 1 high-risk condition. This leaves a screening gap of 1364 individuals with a high-risk clinical condition for Fabry disease in Manitoba who have not been tested. At the end of the study period, 932 of those individuals were still alive and residing in Manitoba, and if screened today, we expect between 3 and 18 would test positive for Fabry disease.

Limitations:

The algorithms we used to identify our patients have not been validated elsewhere. Diagnoses of Fabry disease, idiopathic hypertrophic cardiomyopathy, and peripheral neuropathy were only available via hospitalizations and not physician claims. We were only able to capture GLA testing processed through public laboratories. Patients identified to be at high risk of Fabry disease by the algorithm did not undergo GLA testing due to a clinical rationale that we were unable to capture.

Conclusions:

Administrative health databases may be a useful tool to identify patients at higher risk of Fabry disease or other rare conditions. Further directions include designing a program to screen high-risk individuals for Fabry disease as identified by our administrative data algorithms.

Inequities in organ and tissue donation and transplantation for sexual orientation and gender identity diverse people: A scoping review

Sexual orientation and gender identity (SOGI) diverse populations experience discrimination in organ and tissue donation and transplantation (OTDT) systems globally. We assembled a multidisciplinary group of clinical experts as well as SOGI-diverse patient and public partners and conducted a scoping review including citations on the experiences of SOGI-diverse persons in OTDT systems globally to identify and explore the inequities that exist with regards to living and deceased OTDT. Using scoping review methods, we conducted a systematic literature search of relevant electronic databases from 1970-2021 including a grey literature search. We identified and screened 2402 references and included 87 unique publications. Two researchers independently coded data in included publications in duplicate. We conducted a best-fit framework synthesis paired with an inductive thematic analysis to identify synthesized benefits, harms, inequities, justification of inequities, recommendations to mitigate inequities, laws and regulations, as well as knowledge and implementation gaps regarding SOGI-diverse identities in OTDT systems. We identified numerous harms and inequities for SOGI-diverse populations in OTDT systems. There were no published benefits of SOGI-diverse identities in OTDT systems. We summarized recommendations for the promotion of equity for SOGI-diverse populations and identified gaps that can serve as targets for action moving forward.

Improving the inclusion of transgender and nonbinary individuals in the planning, completion, and mobilization of cardiovascular research

Cardiovascular disease is the leading cause of morbidity and mortality globally. Transgender and nonbinary (TNB) individuals face unclear but potentially significant cardiovascular health inequities, yet no TNB-specific evidence-based interventions for cardiovascular risk reduction currently exist. To address this gap, we propose a road map to improve the inclusion of TNB individuals in the planning, completion, and mobilization of cardiovascular research. In doing so, the adoption of inclusive practices would optimize cardiovascular health surveillance and care for TNB communities.

Plasma Exchange for ANCA-Associated Vasculitis: An International Survey of Patient Preferences

Rationale & Objective

We sought to elicit patient preferences regarding the use of plasma exchange in antineutrophil cytoplasmic antibody-associated vasculitis (AAV) and its tradeoffs of risk of kidney failure and risk of serious infection.

Study Design

Patient survey.

Setting & Participants

The online survey was circulated to adults with AAV via kidney and vasculitis networks in Canada, the United Kingdom, and the United States.

Outcomes

Respondents reviewed the estimated 1-year risks of kidney failure and serious infection in AAV with and without plasma exchange across 5 serum creatinine categories (150, 250, 350, 450, and 600 μmol/L). For each scenario, participants indicated whether or not they would choose plasma exchange.

Analytical Approach

Responses were assessed with multilevel multivariable logistic regression models to identify predictors of respondent choice regarding treatment with plasma exchange.

Results

The 470 respondents from the 13 countries (United States 61.7%, United Kingdom 20.0%, Canada 13.8%, and other countries 4.5%) had a mean age of 58.6 (SD 14.3) years, 70.2% women. Respondents were more likely to choose plasma exchange in scenarios at high risk of kidney failure and serious infection (creatinine level of 350 or 450 μmol/L) compared with lower risk scenarios or the highest risk scenario. However, 145 (30.9%) chose plasma exchange across all scenarios, whereas 80 (17.0%) declined plasma exchange across all scenarios. Respondents from the United Kingdom (OR, 2.61; 95% CI, 1.09-6.22) who received previous dialysis (OR, 2.70; 95% CI, 1.12-6.52) or received previous plasma exchange (OR, 5.62; 95% CI, 2.72-11.61) were more likely to choose plasma exchange, whereas older respondents (OR, 0.98; 95% CI, 0.96-0.99 per 1 year increase) were less likely.

Limitations

Unclear generalizability to non-English-speaking, older, and less health literate adults, possible responder bias, survivor bias, lack of individualized risk assessments for kidney failure, and serious infection.

Conclusions

Patients with AAV do not express a consistent choice for plasma exchange, which highlights the need for shared decision making.

Sex and Gender in Randomized Controlled Trials of Adults Receiving Maintenance Dialysis: A Meta-epidemiologic Study

RATIONALE & OBJECTIVE

How sex and gender concepts are incorporated into randomized controlled trials (RCTs) in adults with kidney failure receiving maintenance dialysis is largely unknown. We describe these practices in published journal articles as well as investigate the proportion of women and female participants in these studies.

STUDY DESIGN

Meta-epidemiologic study.

SETTING & STUDY POPULATIONS

RCTs in maintenance dialysis.

SELECTION CRITERIA FOR STUDIES

Trials published in high-impact journals in 2000-2020.

DATA EXTRACTION

Implemented in duplicate with conflicts resolved by a third reviewer.

ANALYTICAL APPROACH

Meta-regression was performed to identify trial characteristics independently associated with the proportion of women and female participants.

RESULTS

Among 561 included RCTs, 69.7% were parallel and 28.0% were crossover in design; 80.6% were conducted in the hemodialysis population; and 25% of trials compared the treatment of interest with a placebo arm, 25% with a usual care treatment arm, and 50% with an active alternative therapy arm. Of the RCTS, 37.6% were masked. The median size was 60 (IQR, 26-151) participants, and the median follow-up period was 154 (IQR, 42-365) days. The mean proportion of women or female participants was 0.40±0.13 (SD): 39.0% of trials reported sex, and 26.6% reported the gender of the participants. Also, 56.2% referred to participants as females, 25.3% referred to participants as women, and 15.5% referred to both females and women. No trial characteristic other than region (β of 0.062 [95% CI, 0.007-0.117] for Asia) was associated with the proportion of women or female participants. Considering trial design and conduct, 2.7% of trials used sex and/or gender as an inclusion criterion, 26.6% as an exclusion criterion, 4.5% for randomization, 4.8% for subgroup analyses, and 15.7% for covariate adjustment.

LIMITATIONS

Only high-impact journal articles were studied; and the included studies lacked pediatric trials, those addressing chronic kidney disease or kidney transplantation, any trials from Africa and underrepresentation of other regions, and missing data.

CONCLUSIONS

RCTs in dialysis are representative of the general dialysis population with regard to sex and gender but they uncommonly report both and often do not include either in their reporting or analysis.

Metabolic acidosis is undertreated and underdiagnosed: a retrospective cohort study

Background

Guidelines recommend treatment of metabolic acidosis (MA) in patients with chronic kidney disease (CKD), but diagnosis and treatment rates in real-world settings are unknown. We investigated the frequency of MA treatment and diagnosis in patients with CKD.

Methods

In this retrospective cohort study, we examined administrative health data from 2 US databases (Optum's de-identified Integrated Claims + Clinical Electronic Health Record Database (US EMR cohort; January 1, 2007 to June 30, 2019) and Symphony Health Solutions IDV® (US Claims cohort; May 1, 2016 to April 30, 2019)) and population-level databases from Manitoba, Canada (April 1, 2006 to March 31, 2018). Patients who met laboratory criteria indicative of CKD and chronic MA were included: 2 consecutive estimated glomerular filtration (eGFR) results &lt;60 mL/min/1.73 m2 and 2 serum bicarbonate results 12 to &lt;22 mEq/L over 28–365 days. Outcomes included treatment of MA (defined as a prescription for oral sodium bicarbonate) and a diagnosis of MA (defined using administrative records). Outcomes were assessed over a 3-year period (1 year pre-index, 2 years post-index).

Results

A total of 96 184 patients were included: US EMR, 6179; Manitoba 3223; US Claims, 86 782. Sodium bicarbonate treatment was prescribed for 17.6%, 8.7%, and 15.3% of patients, and a diagnosis was found for 44.7%, 20.9%, and 20.9% of patients, for the US EMR, Manitoba and US Claims cohorts, respectively.

Conclusions

This analysis of 96 184 patients with laboratory-confirmed MA from 3 independent cohorts of patients with CKD and MA highlights an important diagnosis and treatment gap for this disease-modifying complication.

Gender-affirming estrogen therapy route of administration and cardiovascular risk: a systematic review and narrative synthesis

Transgender women (individuals assigned male sex at birth who identify as women) and nonbinary and gender-diverse individuals receiving gender-affirming estrogen therapy (GAET) are at increased cardiovascular risk. Nonoral (i.e., patch, injectable) compared with oral estrogen exposure in cisgender women (individuals assigned female sex at birth who identify as women) may be associated with lower cardiovascular risk, though whether this applies to transgender women and/or gender-diverse individuals is unknown. We sought to determine the association between the route of estrogen exposure (nonoral compared with oral) and cardiovascular risk in transgender women and gender diverse individuals. Bibliographic databases (MEDLINE, Embase, PsycINFO) and supporting relevant literature were searched from inception to January 2022. Randomized controlled trials and observational studies reporting cardiovascular outcomes, such as all-cause and cardiovascular mortality, adverse cardiovascular events, and cardiovascular risk factors in individuals using nonoral compared with oral gender-affirming estrogen therapy were included. The search strategy identified 3,113 studies, 5 of which met inclusion criteria (3 prospective cohort studies, 1 retrospective cohort study, and 1 cross-sectional study; n = 259 participants, range of duration of exposure of 2 to 60 mo). One out of five studies reported on all-cause and cardiovascular mortality or adverse cardiovascular events. All five studies reported lipid levels [low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides (TG), and total cholesterol (TC)], whereas only two studies reported systolic blood pressure (SBP) and diastolic blood pressure (DBP). Limited studies have examined the effect of the route of GAET on all-cause cardiovascular mortality, morbidity, and risk factors. In addition, there is significant heterogeneity in studies examining the cardiovascular effects of GAET.NEW & NOTEWORTHY This study is the first to summarize the potential effect of nonoral versus oral gender-affirming estrogen therapy use on cardiovascular risk factors in transgender women or nonbinary or gender-diverse individuals. Heterogeneity of studies in reporting gender-affirming estrogen therapy formulation, dose, and duration of exposure limits quantification of the effect of gender-affirming estrogen therapy on all-cause and cardiovascular mortality, adverse cardiovascular events, and cardiovascular risk factors. This systematic review highlights the needs for large prospective cohort studies with appropriate stratification of gender-affirming estrogen therapy by dose, formulation, administration route, and sufficient follow-up and analyses to limit selection bias to optimize the cardiovascular care of transgender, nonbinary, and gender-diverse individuals.

Patient Navigators for CKD and Kidney Failure: A Systematic Review

Rationale & Objective

To what degree and how patient navigators improve clinical outcomes for patients with chronic kidney disease (CKD) and kidney failure is uncertain. We performed a systematic review to summarize patient navigator program design, evidence, and implementation in kidney disease.

Study Design

A search strategy was developed for randomized controlled trials and observational studies that evaluated the impact of navigators on outcomes in the setting of CKD and kidney failure. Articles were identified from various databases. Two reviewers independently screened the articles and identified those meeting the inclusion criteria.

Setting & Participants

Patients with CKD or kidney failure (in-center hemodialysis, peritoneal dialysis, home hemodialysis, or kidney transplantation).

Selection Criteria for Studies

Studies that compared patient navigators with a control, without limits on size, duration, setting, or language. Studies focusing solely on patient education were excluded.

Data Extraction

Data were abstracted from full texts and risk of bias was assessed.

Analytical Approach

No meta-analysis was performed.

Results

Of 3,371 citations, 17 articles met the inclusion criteria including 14 original studies. Navigators came from various healthcare backgrounds including nursing (n=6), social worker (n=2), medical interpreter (n=1), research (n=1), and also included kidney transplant recipients (n=2) and non-medical individuals (n=2). Navigators focused mostly on education (n=9) and support (n = 6). Navigators were used for patients with CKD (n=5), peritoneal dialysis (n=2), in-center hemodialysis (n=4), kidney transplantation (n=2), but not home hemodialysis. Navigators improved transplant workup and listing, peritoneal dialysis utilization, and patient knowledge.

Limitations

Many studies did not show benefits across other outcomes, were at a high risk of bias, and none reported cost-effectiveness or patient-reported experience measures.

Conclusions

Navigators improve some health outcomes for CKD but there was heterogeneity in their structure and function. High-quality randomized controlled trials are needed to evaluate navigator program efficacy and cost-effectiveness.

The Effect of Gender-Affirming Hormone Therapy on Measures of Kidney Function: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

Gender-affirming hormone therapy modifies body composition and lean muscle mass in transgender persons. We sought to characterize the change in serum creatinine, other kidney function biomarkers, and GFR in transgender persons initiating masculinizing and feminizing gender-affirming hormone therapy.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We searched PubMed, EMBASE, the Cochrane Library, and ClinicalTrials.gov from inception to September 16, 2020 for randomized controlled trials, observational studies, and case series that evaluated the change in serum creatinine, other kidney function biomarkers, and GFR before and after the initiation of gender-affirming hormone therapy in adult transgender persons. Two reviewers independently screened and abstracted data, and disagreements were resolved by a third reviewer. A random effects meta-analysis was performed to determine the change in outcomes over follow-up of 3, 6, and 12 months.

RESULTS

Of the 4758 eligible studies, 26 met the inclusion criteria, including nine studies that recruited 488 transgender men and 593 women in which data were meta-analyzed. There was heterogeneity in study design, populations, gender-affirming hormone therapy routes, and dosing. At 12 months after initiating gender-affirming hormone therapy, serum creatinine increased by 0.15 mg/dl (95% confidence interval, 0.00 to 0.29) in 370 transgender men and decreased by -0.05 mg/dl (95% confidence interval, -0.16 to 0.05) in 361 transgender women. No study reported the effect of gender-affirming hormone therapy on albuminuria, proteinuria, cystatin C, or measured GFR.

CONCLUSIONS

Gender-affirming hormone therapy increases serum creatinine in transgender men and does not affect serum creatinine in transgender women. The effect on gender-affirming hormone therapy on other kidney function biomarkers and measured GFR is unknown.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Change in Kidney Function Biomarkers in Transgender Persons on Gender Affirmation Hormone Therapy-A Systematic Review and Meta-Analysis, CRD42020214248.

Hyperkalemia-Related Discontinuation of Renin-Angiotensin-Aldosterone System Inhibitors and Clinical Outcomes in CKD: A Population-Based Cohort Study

RATIONALE & OBJECTIVE

Renin-angiotensin-aldosterone system (RAAS) inhibitors are evidence-based therapies that slow the progression of chronic kidney disease (CKD) but can cause hyperkalemia. We aimed to evaluate the association of discontinuing RAAS inhibitors after an episode of hyperkalemia and clinical outcomes in patients with CKD.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Adults in Manitoba (7,200) and Ontario (n = 71,290), Canada, with an episode of de novo RAAS inhibitor-related hyperkalemia (serum potassium ≥ 5.5 mmol/L) and CKD.

EXPOSURE

RAAS inhibitor prescription.

OUTCOME

The primary outcome was all-cause mortality. Secondary outcomes were cardiovascular (CV) mortality, fatal and nonfatal CV events, dialysis initiation, and a negative control outcome (cataract surgery).

ANALYTICAL APPROACH

Cox proportional hazards models examined the association of RAAS inhibitor continuation (vs discontinuation) and outcomes using intention to treat approach. Sensitivity analyses included time-dependent, dose-dependent, and propensity-matched analyses.

RESULTS

The mean potassium and mean estimated glomerular filtration rate were 5.8 mEq/L and 41 mL/min/1.73 m², respectively, in Manitoba; and 5.7 mEq/L and 41 mL/min/1.73 m², respectively, in Ontario. RAAS inhibitor discontinuation was associated with a higher risk of all-cause mortality (Manitoba: HR, 1.32 [95% CI, 1.22-1.41]; Ontario: HR, 1.47 [95% CI, 1.41-1.52]) and CV mortality (Manitoba: HR, 1.28 [95% CI, 1.13-1.44]; and Ontario: HR, 1.32 [95% CI, 1.25-1.39]). RAAS inhibitor discontinuation was associated with an increased risk of dialysis initiation in both cohorts (Manitoba: HR, 1.65 [95% CI, 1.41-1.85]; Ontario: HR, 1.11 [95% CI, 1.08-1.16]).

LIMITATIONS

Retrospective study and residual confounding.

CONCLUSIONS

RAAS inhibitor discontinuation is associated with higher mortality and CV events compared with continuation among patients with hyperkalemia and CKD. Strategies to maintain RAAS inhibitor treatment after an episode of hyperkalemia may improve clinical outcomes in the CKD population.

Patient views regarding cannabis use in chronic kidney disease and kidney failure: a survey study

BACKGROUND

Cannabis is frequently used recreationally and medicinally including for symptom management in patients with kidney disease.

METHODS

We elicited the views of Canadian adults with kidney disease regarding their cannabis use. Participants were asked whether they would try cannabis for anxiety, depression, restless legs, itchiness, fatigue, chronic pain, decreased appetite, nausea/vomiting, sleep, cramps and other symptoms. The degree to which respondents considered cannabis for each symptom was assessed with a modified Likert scale ranging from 1-5 (anchored at 1 'definitely would not' and 5 being 'definitely would'). Multilevel multivariable linear regression was used to identify respondent characteristics associated with considering cannabis for symptom control.

RESULTS

Of 320 respondents, 290 (90.6%) were from in-person recruitment (27.3% response rate) and 30 (9.4%) responses were from online recruitment. 160/320 respondents (50.2%) had previously used cannabis including smoking (140, 87.5%), oils (69, 43.1%) and edibles (92, 57.5%). The most common reasons for previous cannabis use were recreation (84/160, 52.5%), pain alleviation (63/160, 39.4%) and sleep enhancement (56/160, 35.0%). Only 33.8% of previous cannabis users thought their physicians were aware of their cannabis use. >50% of respondents probably would or definitely would try cannabis for symptom control for all 10 symptoms. Characteristics independently associated with interest in trying cannabis for symptom control included symptom type (pain, sleep, restless legs), online respondent (ß 0.7, 95% CI 0.1-1.4) and previous cannabis use (ß 1.2, 95% CI 0.9, 1.5).

CONCLUSIONS

Many patients with kidney disease use cannabis and there is interest in trying cannabis for symptom control.

Metabolic Acidosis is Associated With Acute Kidney Injury in Patients With CKD

Introduction

Metabolic acidosis in patients with chronic kidney disease (CKD) results from a loss of kidney function. It has been associated with CKD progression, all-cause mortality, and other adverse outcomes. We aimed to determine whether metabolic acidosis is associated with a higher risk of acute kidney injury (AKI).

Methods

This was a retrospective cohort study. Using electronic health records and administrative data, we enrolled 2 North American cohorts of patients with CKD Stages G3-G5 as follows: (i) 136,067 patients in the US electronic medical record (EMR) based cohort; and (ii) 34,957 patients in the Manitoba claims-based cohort. The primary exposure was metabolic acidosis (serum bicarbonate between 12 mEq/l and <22 mEq/l). The primary outcome was the development of AKI (defined using ICD-9 and 10 codes at hospital admission or a laboratory-based definition based on Kidney Disease: Improving Global Outcomes guidelines). We applied Cox proportional hazards regression models adjusting for relevant demographic and clinical characteristics.

Results

In both cohorts, metabolic acidosis was associated with AKI: hazard ratio (HR) 1.57 (95% confidence interval [CI] 1.52-1.61) in the US EMR cohort, and HR 1.65 (95% CI 1.58-1.73) in the Manitoba claims cohort. The association was consistent when serum bicarbonate was treated as a continuous variable, and in multiple subgroups, and sensitivity analyses including those adjusting for albuminuria.

Conclusion

Metabolic acidosis is associated with a higher risk of AKI in patients with CKD. AKI should be considered as an outcome in studies of treatments for patients with metabolic acidosis.

Impact of quality improvement initiatives to improve CKD referral patterns: a systematic review protocol

INTRODUCTION

Chronic kidney disease (CKD) is a global-health problem. A significant proportion of referrals to nephrologists for CKD management are early and guideline-discordant, which may lead to an excess number of referrals and increased wait-times. Various initiatives have been tested to increase the proportion of guideline-concordant referrals and decrease wait times. This paper describes the protocol for a systematic review to study the impacts of quality improvement initiatives aimed at decreasing the number of non-guideline concordant referrals, increasing the number of guideline-concordant referrals and decreasing wait times for patients to access a nephrologist.

METHODS AND ANALYSIS

We developed this protocol by using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Protocols (2015). We will search the following empirical electronic databases: MEDLINE, Embase, Cochrane Library, CINAHL, Web of Science, PsycINFO and grey literature for studies designed to improve guideline-concordant referrals or to reduce unnecessary referrals of patients with CKD from primary care to nephrology. Our search will include all studies published from database inception to April 2021 with no language restrictions. The studies will be limited to referrals for adult patients to nephrologists. Referrals of patients with CKD from non-nephrology specialists (eg, general internal medicine) will be excluded.

ETHICS AND DISSEMINATION

Ethics approval will not be required, as we will analyse data from studies that have already been published and are publicly accessible. We will share our findings using traditional approaches, including scientific presentations, open access peer-reviewed platforms, and appropriate government and public health agencies.

PROSPERO REGISTRATION NUMBER

CRD42021247756.

Prescription patterns of Sodium and Calcium Polystyrene Sulfonate in patients with Hyperkalemia and Chronic Kidney Disease receiving RAAS inhibitors

Background

Sodium and calcium polystyrene sulfonate (SPS/CPS) cation-exchange resins have had long-standing clinical use for hyperkalemia in patients with chronic kidney disease (CKD). However, uncertainty exists regarding the real-world usage of SPS/CPS for acute and chronic management of hyperkalemia. We evaluated the prescription patterns of SPS/CPS and their impact on renin–angiotensin–aldosterone system inhibitor (RAASi) treatment in patients with CKD Stages G3–G5 after an episode of de novo hyperkalemia.

Methods

We conducted a retrospective cohort study using population-level administrative databases in Manitoba, Canada, which included adults with CKD and a RAASi prescription who had an episode of de novo hyperkalemia (≥5.5 mmol/L) between January 2007 and December 2017.

Results

A total of 10 009 individuals were included in our study cohort. Among the study population, 4% received an SPS/CPS prescription within 30 days of their hyperkalemia episode. Of those, 22% received a 1-day supply of SPS/CPS and 7% received a prescription for more than 30 days. There were 8145 patients using RAASi at baseline who survived 90 days after their first hyperkalemia episode. Of those, 1447 (18%) discontinued their RAAS inhibitor and 339 (5%) received a prescription of SPS/CPS. Also, the proportion of patients who discontinued their RAASi was similar among those who did and did not receive a prescription of SPS/CPS.

Conclusion

In patients with CKD receiving RAASi therapy, there is a low frequency of SPS/CPS prescription after an episode of hyperkalemia. RAASi discontinuation or downtitration is the most used pharmacologic approach for the management of hyperkalemia, a strategy that deprives patients of the cardiac and renal protective benefits of RAASi. New options for the management of hyperkalemia in this population are needed.

Association of metabolic acidosis with fractures, falls, protein-calorie malnutrition, and failure to thrive in patients with chronic kidney disease

Background

The risk of adverse geriatric outcomes such as falls and fractures is high among patients with chronic kidney disease (CKD). Metabolic acidosis is associated with protein catabolism and bone loss in experimental animal and human studies. We sought to quantify the independent association of metabolic acidosis with adverse muscle, bone, and functional outcomes in a large U.S. community-based cohort.

Methods

The Optum's de-identified Integrated Claims-Clinical dataset of US patients (2007-2017) was used to generate a cohort of patients with non-dialysis-dependent CKD who had eGFR &gt;10 to &lt;60 mL/min/1.73 m2 and 2 serum bicarbonate values 12 to &lt;22 mmol/L or 22-29 mmol/L. The primary outcomes were failure to thrive, protein-calorie malnutrition, and fall or fracture. Cox proportional hazards models were used for the primary outcomes for up to 10 years, while logistic regression models were used at 2 years.

Results

51,558 patients qualified for the study, with a median (IQR) follow-up time of 4.2 (2.5-5.8) years. Over a ≤ 10-year period, for each 1-mmol/L increase in serum bicarbonate, the hazard ratios (adjusted for age, sex, race, eGFR, serum albumin, hemoglobin, diabetes and cardiovascular comorbidities) for failure to thrive, protein-calorie malnutrition, and fall or fracture were 0.91 (95% confidence interval [CI], 0.90-0.92), 0.91 (95% CI, 0.90-0.92), and 0.95 (95% CI, 0.95-0.96), all P &lt; 0.001, respectively.

Conclusions

The presence and severity of metabolic acidosis was a significant, independent risk factor for failure to thrive, protein-calorie malnutrition, and fall or fracture in this large community cohort of patients with stage 3-5 CKD.

Chronic Kidney Disease in the Transgender, Nonbinary, or Gender Diverse Person

Nephrologists are increasingly providing care to transgender, nonbinary, and gender diverse (TNBGD) individuals with chronic kidney disease. This narrative review discusses the care of TNBGD individuals from a nephrology perspective. TNBGD individuals are under-represented in the nephrology literature. TNBGD individuals are at an increased risk of adverse outcomes compared with the cisgender population including mental health, cardiovascular disease, malignancy, sexually transmitted infections, and mortality. Gender-affirming hormone therapy (GAHT) with estradiol in transfeminine individuals potentially increases the risk of venous thromboembolism and cardiovascular disease. GAHT with testosterone in transmasculine individuals potentially increases the risk of erythrocytosis and requires careful monitoring. GAHT modifies body composition and lean muscle mass, which in turn influence creatinine generation and excretion, which may impact the performance of estimated glomerular filtration rate (GFR) equations and the estimation of 24-hour urine values from spot urine albumin/protein to creatinine ratios. There are limited studies regarding TNBGD individuals with chronic kidney disease. Additional research is needed to evaluate the effects of GAHT on GFR and biomarkers of kidney function and the performance of the estimated GFR equation in TNBGD populations.

Plasma exchange and glucocorticoid dosing for patients with ANCA-associated vasculitis: a clinical practice guideline

CLINICAL QUESTIONS

What is the role of plasma exchange and what is the optimal dose of glucocorticoids in the first 6 months of therapy of patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV)? This guideline was triggered by the publication of a new randomised controlled trial.

CURRENT PRACTICE

Existing guideline recommendations vary regarding the use of plasma exchange in AAV and lack explicit recommendations regarding the tapering regimen of glucocorticoids during induction therapy.

RECOMMENDATIONS

The guideline panel makes a weak recommendation against plasma exchange in patients with low or low-moderate risk of developing end stage kidney disease (ESKD), and a weak recommendation in favour of plasma exchange in patients with moderate-high or high risk of developing ESKD. For patients with pulmonary haemorrhage without renal involvement, the panel suggests not using plasma exchange (weak recommendation). The panel made a strong recommendation in favour of a reduced dose rather than standard dose regimen of glucocorticoids, which involves a more rapid taper rate and lower cumulative dose during the first six months of therapy.

HOW THIS GUIDELINE WAS CREATED

A guideline panel including patients, a care giver, clinicians, content experts, and methodologists produced these recommendations using GRADE and in adherence with standards for trustworthy guidelines. The recommendations are based on two linked systematic reviews. The panel took an individual patient perspective in the development of recommendations.

THE EVIDENCE

The systematic review of plasma exchange identified nine randomised controlled trials (RCTs) that enrolled 1060 patients with AAV. Plasma exchange probably has little or no effect on mortality or disease relapse (moderate and low certainty). Plasma exchange probably reduces the one year risk of ESKD (approximately 0.1% reduction in those with low risk, 2.1% reduction in those with low-moderate risk, 4.6% reduction in those with moderate-high risk, and 16.0% reduction in those with high risk or requiring dialysis) but increases the risk of serious infections (approximately 2.7% increase in those with low risk, 4.9% increase in those with low-moderate risk, 8.5% increase in those with moderate-high risk, to 13.5% in high risk group) at 1 year (moderate to high certainty). The guideline panel agreed that most patients with low or low-moderate risk of developing ESKD would consider the harms to outweigh the benefits, while most of those with moderate-high or high risk would consider the benefits to outweigh the harms. For patients with pulmonary haemorrhage without kidney involvement, based on indirect evidence, plasma exchange may have little or no effect on death (very low certainty) but may have an important increase in serious infections at 1 year (approximately 6.8% increase, low certainty). The systematic review of different dose regimens of glucocorticoids identified two RCTs at low risk of bias with 704 and 140 patients respectively. A reduced dose regimen of glucocorticoid probably reduces the risk of serious infections by approximately 5.9% to 12.8% and probably does not increase the risk of ESKD at the follow-up of 6 months to longer than 1 year (moderate certainty for both outcomes).

UNDERSTANDING THE RECOMMENDATION

The recommendations were made with the understanding that patients would place a high value on reduction in ESKD and less value on avoiding serious infections. The panel concluded that most (50-90%) of fully informed patients with AAV and with low or low-moderate risk of developing ESKD with or without pulmonary haemorrhage would decline plasma exchange, whereas most patients with moderate-high or high risk or requiring dialysis with or without pulmonary haemorrhage would choose to receive plasma exchange. The panel also inferred that the majority of fully informed patients with pulmonary haemorrhage without kidney involvement would decline plasma exchange and that all or almost all (≥90%) fully informed patients with AAV would choose a reduced dose regimen of glucocorticoids during the first 6 months of therapy.

The effects of plasma exchange in patients with ANCA-associated vasculitis: an updated systematic review and meta-analysis

OBJECTIVE

To assess the effects of plasma exchange on important outcomes in anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV).

DESIGN

Systematic review and meta-analysis of randomised controlled trials.

ELIGIBILITY CRITERIA

Randomised controlled trials investigating effects of plasma exchange in patients with AAV or pauci-immune rapidly progressive glomerulonephritis and at least 12 months' follow-up.

INFORMATION SOURCES

Prior systematic reviews, updated by searching Medline, Embase, and CENTRAL to July 2020.

RISK OF BIAS

Reviewers independently identified studies, extracted data, and assessed the risk of bias using the Cochrane Risk of Bias tool.

SYNTHESIS OF RESULTS

Meta-analyses were conducted using random effects models to calculate risk ratios and 95% confidence intervals. Quality of evidence was summarised in accordance with GRADE methods. Outcomes were assessed after at least12 months of follow-up and included all-cause mortality, end stage kidney disease (ESKD), serious infections, disease relapse, serious adverse events, and quality of life.

RESULTS

Nine trials including 1060 participants met eligibility criteria. There were no important effects of plasma exchange on all-cause mortality (relative risk 0.90 (95% CI 0.64 to 1.27), moderate certainty). Data from seven trials including 999 participants that reported ESKD demonstrated that plasma exchange reduced the risk of ESKD at 12 months (relative risk 0.62 (0.39 to 0.98), moderate certainty) with no evidence of subgroup effects. Data from four trials including 908 participants showed that plasma exchange increased the risk of serious infections at 12 months (relative risk 1.27 (1.08 to 1.49), moderate certainty). The effects of plasma exchange on other outcomes were uncertain or considered unimportant to patients.

LIMITATIONS OF EVIDENCE

There is a relative sparsity of events, and treatment effect estimates are therefore imprecise. Subgroup effects at the participant level could not be evaluated.

INTERPRETATION

For the treatment of AAV, plasma exchange has no important effect on mortality, reduces the 12 month risk of ESKD, but increases the risk of serious infections.

FUNDING

No funding was received.

REGISTRATION

This is an update of a previously unregistered systematic review and meta-analysis published in 2014.

Cannabinoids for Symptom Management in Patients with Kidney Failure

People with kidney failure can experience a range of symptoms that lead to suffering and poor quality of life. Available therapies are limited, and evidence for new treatment options is sparse, often resulting in incomplete relief of symptoms. There is growing interest in the potential for cannabinoids, including cannabidiol and tetrahydrocannabinol, to treat symptoms across a wide range of chronic diseases. As legal prohibitions are withdrawn or minimized in many jurisdictions, patients are increasingly able to access these agents. Cannabinoid receptors, CB1 and CB2, are widely expressed in the body, including within the nervous and immune systems, and exogenous cannabinoids can have anxiolytic, anti-emetic, analgesic and anti-inflammatory effects. Considering their known physiological actions and successful studies in other patient populations, cannabinoids may be viewed as potential therapies for a variety of common symptoms affecting those with kidney failure, including pruritus, nausea, insomnia, chronic neuropathic pain, anorexia, and restless legs syndrome. In this review, we summarize the pharmacology and pharmacokinetics of cannabinoids, along with what is known about the use of cannabinoids for symptom relief in those with kidney disease, and the evidence available concerning their role in management of common symptoms. Presently, while these agents show varying efficacy with a reasonable safety profile in other patient populations, evidence-based prescribing of cannabinoids for people with symptomatic kidney failure is not possible. Given the symptom burden experienced by individuals with kidney failure, there is an urgent need to understand the tolerability and safety of these agents in this population, which must ultimately be followed by robust, randomized controlled trials to determine if they are effective for symptom relief.

Metabolic Acidosis and Cardiovascular Disease in CKD

Rationale & Objective

Metabolic acidosis related to chronic kidney disease (CKD) is associated with an accelerated decline in glomerular filtration rate (GFR) and the development of end-stage kidney disease. Whether metabolic acidosis is associated with cardiovascular (CV) events in patients with CKD is unclear.

Study Design

Retrospective cohort study.

Setting & Participants

The Optum De-identified Electronic Health Records Dataset, 2007–2017, was used to generate a cohort of patients with non-dialysis-dependent CKD who had at least 3 estimated GFR < 60 mL/min/1.73 m². Patients with metabolic acidosis (serum bicarbonate 12 to <22 mEq/L) or normal serum bicarbonate (22‒29 mEq/L) at baseline were identified by 2 consecutive measurements 28‒365 days apart.

Predictor

Serum bicarbonate as a continuous variable.

Outcome

Primary outcome was a composite of major adverse cardiovascular events (MACE+). Secondary outcomes included individual components of the composite outcome.

Analytical Approach

Cox proportional hazards models to evaluate the association between 1-mEq/L increments in serum bicarbonate and MACE+.

Results

A total of 51,558 patients were evaluated, 34% had metabolic acidosis. The median follow-up period was 3.9–4.5 years, depending on the outcome assessed. The adjusted hazard ratio (HR) for MACE+ was 0.964 (95% CI, 0.961–0.968). For the individual components of incident heart failure (HF), stroke, myocardial infarction (MI), and CV death, HRs were 0.98 (95% CI, 0.97–0.98), 0.98 (95% CI, 0.97–0.99), 0.96 (95% CI, 0.96–0.97), and 0.94 (95% CI, 0.93–0.94), respectively, for every 1-mEq/L increase in serum bicarbonate.

Limitations

Possible residual confounding.

Conclusions

Metabolic acidosis in CKD is associated with an increased risk of MACE+ as well as the individual components of incident HF, stroke, MI, and CV death. Randomized controlled trials evaluating treatments for the correction of metabolic acidosis in CKD to prevent CV events are needed.

Variability in Cardiac Biomarkers during Hemodialysis: A Prospective Cohort Study

BACKGROUND

The effect of hemodialysis on cardiac biomarkers is unclear. We sought to evaluate the degree and causes of intradialytic variability of high sensitivity troponin I (hs-TnI), galectin-3 (gal-3), and heart-type fatty acid binding protein (hFABP).

METHODS

hs-TnI, gal-3, and hFABP were prospectively measured pre-dialysis and post-dialysis for 1 week every month for 6 months in 178 prevalent adult hemodialysis patients at a single center in Hamilton, Canada. The degree of change from pre-dialysis to post-dialysis for each cardiac biomarker was estimated with multilevel linear regression models.

RESULTS

The median change in the concentration of hs-TnI during hemodialysis was -1 ng/L (interquartile range [IQR] -1 to 2 ng/L) while gal-3 and hFABP changed by -36.3 ng/mL (IQR -27.7 to -46.8 ng/mL) and -19.41 ng/mL (IQR -13.61 to -26.87 ng/mL), respectively. The median (IQR) percentage intradialytic changes for hs-TnI, gal-3, and hFABP were 2.6% (-4.4% to 12.5%), -59.8% (-54.7% to -64.8%) and -35.3% (-28.4% to -42.1%), respectively. Ultrafiltration was associated with an increase in concentration of hs-TnI, gal-3, and hFABP (mean 0.99 ng/L, 1.05 ng/mL, and 1.9 ng/mL per L ultrafiltration, respectively, P < 0.001). Both gal-3 and hFABP concentrations decreased in association with the volume of blood processed (P < 0.001) and with hemodialysis treatment time (P  = 0.02 and P  = 0.04) while hs-TnI concentration decreased only in association with hemodialysis treatment time (P  < 0.001).

CONCLUSIONS

Ultrafiltration volume and hemodialysis treatment time influenced hs-TnI, gal-3, and hFABP concentrations during hemodialysis and should be considered when interpreting their measurement.

Three week compared to seven week run-in period length and the assessment of pre-randomization adherence: A study within a trial

BACKGROUND/AIMS

To examine how measuring adherence at 3 weeks by self-report and pill counts compares to measurements at 7 weeks in a pre-randomization run-in period.

METHODS

Study within a trial of an international parallel group randomized controlled trial (RCT) that compares spironolactone to placebo. Adults receiving dialysis enter an 8-week active run-in period with spironolactone. Adherence was assessed by both self-report and pill counts in a subgroup of participants at both 3 weeks and 7 weeks.

RESULTS

332 participants entered the run-in period of which 166 had complete data. By self-report, 146/166 (94.0%) and 153/166 (92.2%) had at least 80% adherence at 3 and 7 weeks respectively (kappa = 0.27 (95% C.I. 0.16 to 0.38). By pill counts, the mean (SD) adherence was 96.5% (16.1%) and 92.4% (18.2%) at 3 and 7 weeks respectively (r = 0.32) with a mean (SD) difference of 3.1% (17.8%) and a 95% limit of agreement from -31.7% to +37.9%. The proportion of adherent participants by self-report and pill counts at 3 weeks agreed in 87.4% of participants (McNemar's p-value 0.58, kappa 0.11, p = 0.02) and at 7 weeks agreed in 92.2% (McNemar's p-value 0.82, kappa 0.47, p < 0.001).

CONCLUSIONS

Three and seven-week run-in periods and both self-reported and pill count assessments performed similarly.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03020303.

Effect of Aerobic Exercise on Dialysis-Related Symptoms in Individuals Undergoing Maintenance Hemodialysis: A Systematic Review and Meta-Analysis of Clinical Trials

BACKGROUND

Hemodialysis is associated with a high symptom burden that impairs health-related quality of life and functional status. Effective symptom management is a priority for individuals receiving hemodialysis. Aerobic exercise may be an effective, nonpharmacologic treatment for specific hemodialysis-related symptoms. This systematic review investigated the effect of aerobic exercise on hemodialysis-related symptoms in adults with kidney failure undergoing maintenance hemodialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We searched MEDLINE, PubMed, Cochrane CENTRAL, CINAHL, PsycINFO, SPORTDiscus, EMBASE, PEDro, and Scopus databases from 1960 or inception until April 15, 2020 for randomized controlled trials investigating the effect of aerobic exercise on hemodialysis-related symptoms, identified as prespecified primary or secondary outcomes, as compared with controls in adults on maintenance hemodialysis. We identified restless legs syndrome as the primary outcome.

RESULTS

Of 3048 studies identified, 15 randomized controlled trials met the eligibility criteria. These studies investigated the effect of aerobic exercise on restless legs syndrome (two studies), sleep disturbance (four studies), anxiety (four studies), depression (nine studies), muscle cramping (one study), and fatigue (one study). Exercise interventions were intradialytic in ten studies and outside of hemodialysis in five studies. Heterogenous interventions and outcomes and moderate to high risk of bias precluded meta-analysis for most symptoms. Aerobic exercise demonstrated improvement in symptoms of restless legs syndrome, muscle cramping, and fatigue, as compared with nonexercise controls. Meta-analysis of depressive symptoms in studies using the Beck Depression Inventory demonstrated a greater reduction in Beck Depression Inventory score with exercise as compared with control (mean difference -7.57; 95% confidence interval, -8.25 to -6.89).

CONCLUSIONS

Our review suggests that in adults on maintenance hemodialysis, aerobic exercise improves several hemodialysis-related symptoms, including restless legs syndrome, symptoms of depression, muscle cramping, and fatigue. However, the use of validated outcome measures with demonstrated reliability and responsiveness in more diverse hemodialysis populations is required to fully characterize the effect of this intervention.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

PROSPERO #CRD42017056658.

Providing Care for Transgender Persons With Kidney Disease: A Narrative Review

Purpose of review

Nephrologists are increasingly providing care to transgender individuals with chronic kidney disease (CKD). However, they may lack familiarity with this patient population that faces unique challenges. The purpose of this review is to discuss the care of transgender persons and what nephrologists should be aware of when providing care to their transgender patients.

Sources of information

Original research articles were identified from MEDLINE and Google Scholar using the search terms "transgender," "gender," "sex," "chronic kidney disease," "end stage kidney disease," "dialysis," "transplant," and "nephrology."

Methods

A focused review and critical appraisal of existing literature regarding the provision of care to transgender men and women with CKD including dialysis and transplant to identify specific issues related to gender-affirming therapy and chronic disease management in transgender persons.

Key findings

Transgender persons are at an increased risk of adverse outcomes compared with the cisgender population including mental health, cardiovascular disease, malignancy, sexually transmitted infections, and mortality. Individuals with CKD have a degree of hypogonadotropic hypogonadism and decreased levels of endogenous sex hormones; therefore, transgender persons with CKD may require reduced exogenous sex hormone dosing. Exogenous estradiol therapy increases the risk of venous thromboembolism and cardiovascular disease which may be further increased in CKD. Exogenous testosterone therapy increases the risk of polycythemia which should be closely monitored. The impact of gender-affirming hormone therapy on glomerular filtration rate (GFR) trajectory in CKD is unclear. Gender-affirming hormone therapy with testosterone, estradiol, and anti-androgen therapies changes body composition and lean body mass which influences creatinine generation and the performance for estimated glomerular filtration rate (eGFR) equations in transgender persons. Confirmation of eGFR with measured GFR is reasonable if an accurate knowledge of GFR is needed for clinical decision-making.

Limitations

There are limited studies regarding the intersection of transgender persons and kidney disease and those that exist are mostly case reports. Randomized controlled trials and observational studies in nephrology do not routinely differentiate between cisgender and transgender participants.

Implications

This review highlights important considerations for providing care to transgender persons with kidney disease. Additional research is needed to evaluate the performance of eGFR equations in transgender persons, the effects of gender-affirming hormone therapy, and the impact of being transgender on outcomes in persons with kidney disease.

Patient reported outcome measures in clinical trials should be initially analyzed as continuous outcomes for statistical significance and responder analyses should be reserved as secondary analyses

OBJECTIVE

To evaluate the power of responder analyses in a randomized controlled trial.

STUDY DESIGN AND SETTING

Simulations were based on the Chronic Kidney Disease Antidepressant Sertraline Trial (CAST), which compared sertraline to placebo for the treatment of depression in kidney disease. Baseline disease severity, placebo response, effect size, and the proportion of responders were varied across 72 scenarios. Power was assessed using a t-test for change scores, and the chi-square test for dichotomized outcomes of the minimal important difference (MID), improvement and remission in 10,000 datasets with a fixed sample size of 193.

RESULTS

The t-test had >80% power except for scenarios with the lowest sertraline effect size. The chi-square test using the MID had <7% power in all scenarios while improvement and remission of achieved >80% power only at higher effect sizes and/or when the proportion of responders was highest at 0.5. The chi-square test for improvement had marginal power increases compared to the t-test (4/72 scenarios = 5.6%) and that for remission did not outperform the t-test in any scenario.

CONCLUSIONS

The t-test outperforms the chi-square test for dichotomized outcomes regardless of baseline disease severity, placebo response, effect size and the proportion of responders to the intervention.

Nephrologist Views Regarding Cannabinoid Use in Advanced Chronic Kidney Disease and Dialysis: A Survey

CONTEXT

The efficacy and safety of cannabinoids to treat symptoms in individuals with kidney disease is uncertain.

OBJECTIVES

We sought to elicit Canadian nephrologists' views regarding the use and study of cannabinoids in patients with kidney disease in an Internet-based survey of Canadian of Society of Nephrology members treating adult patients with kidney disease including dialysis.

METHODS

The degree to which respondents supported the use or study of cannabinoids for symptoms common in kidney disease was assessed using a modified Likert scale ranging from 1 to 7 (anchored at 1-definitely would not and 7-being definitely would). Participants were asked their degree of support for cannabinoid use in clinical practice and for randomized controlled trials examining cannabinoids for anxiety, depression, restless legs syndrome, itchiness, fatigue, chronic pain, decreased appetite, nausea/vomiting, sleep disorder, and others. Multilevel multivariable linear regression was used to identify independent predictors of the degree of support.

RESULTS

There were 151 (43.4%) responses from 348 eligible participants. One hundred twenty-four (82%) previously cared for patients using prescribed cannabinoids by other providers, and 29 (19%) had previously prescribed cannabinoids themselves. One hundred thirty-seven (91%) had previously cared for patients using nonprescription cannabinoids, which were used most commonly recreationally (88.3%), for chronic pain (73.7%) or for anxiety (52.6%). Respondents supported the use of cannabinoids (mean score >5) for each symptom in the setting of refractory symptoms. Similarly, respondents supported enrolling patients for trials for all symptoms (mean scores >5).

CONCLUSION

Nephrologists broadly support the use and study of cannabinoids for symptoms in patients with kidney disease.

Providing Care for Transgender Persons With Kidney Disease: A Narrative Review

Purpose of review:

Nephrologists are increasingly providing care to transgender individuals with chronic kidney disease (CKD). However, they may lack familiarity with this patient population that faces unique challenges. The purpose of this review is to discuss the care of transgender persons and what nephrologists should be aware of when providing care to their transgender patients.

Sources of information:

Original research articles were identified from MEDLINE and Google Scholar using the search terms “transgender,” “gender,” “sex,” “chronic kidney disease,” “end stage kidney disease,” “dialysis,” “transplant,” and “nephrology.”

Methods:

A focused review and critical appraisal of existing literature regarding the provision of care to transgender men and women with CKD including dialysis and transplant to identify specific issues related to gender-affirming therapy and chronic disease management in transgender persons.

Key findings:

Transgender persons are at an increased risk of adverse outcomes compared with the cisgender population including mental health, cardiovascular disease, malignancy, sexually transmitted infections, and mortality. Individuals with CKD have a degree of hypogonadotropic hypogonadism and decreased levels of endogenous sex hormones; therefore, transgender persons with CKD may require reduced exogenous sex hormone dosing. Exogenous estradiol therapy increases the risk of venous thromboembolism and cardiovascular disease which may be further increased in CKD. Exogenous testosterone therapy increases the risk of polycythemia which should be closely monitored. The impact of gender-affirming hormone therapy on glomerular filtration rate (GFR) trajectory in CKD is unclear. Gender-affirming hormone therapy with testosterone, estradiol, and anti-androgen therapies changes body composition and lean body mass which influences creatinine generation and the performance for estimated glomerular filtration rate (eGFR) equations in transgender persons. Confirmation of eGFR with measured GFR is reasonable if an accurate knowledge of GFR is needed for clinical decision-making.

Limitations:

There are limited studies regarding the intersection of transgender persons and kidney disease and those that exist are mostly case reports. Randomized controlled trials and observational studies in nephrology do not routinely differentiate between cisgender and transgender participants.

Implications:

This review highlights important considerations for providing care to transgender persons with kidney disease. Additional research is needed to evaluate the performance of eGFR equations in transgender persons, the effects of gender-affirming hormone therapy, and the impact of being transgender on outcomes in persons with kidney disease.