Hypertension and Kidney Function After Living Kidney Donation

Importance

Recent guidelines call for better evidence on health outcomes after living kidney donation.

Objective

To determine the risk of hypertension in normotensive adults who donated a kidney compared with nondonors of similar baseline health. Their rates of estimated glomerular filtration rate (eGFR) decline and risk of albuminuria were also compared.

Design, Setting, and Participants

Prospective cohort study of 924 standard-criteria living kidney donors enrolled before surgery and a concurrent sample of 396 nondonors. Recruitment occurred from 2004 to 2014 from 17 transplant centers (12 in Canada and 5 in Australia); follow-up occurred until November 2021. Donors and nondonors had the same annual schedule of follow-up assessments. Inverse probability of treatment weighting on a propensity score was used to balance donors and nondonors on baseline characteristics.

Exposure

Living kidney donation.

Main Outcomes and Measures

Hypertension (systolic blood pressure [SBP] ≥140 mm Hg, diastolic blood pressure [DBP] ≥90 mm Hg, or antihypertensive medication), annualized change in eGFR (starting 12 months after donation/simulated donation date in nondonors), and albuminuria (albumin to creatinine ratio ≥3 mg/mmol [≥30 mg/g]).

Results

Among the 924 donors, 66% were female; they had a mean age of 47 years and a mean eGFR of 100 mL/min/1.73 m2. Donors were more likely than nondonors to have a family history of kidney failure (464/922 [50%] vs 89/394 [23%], respectively). After statistical weighting, the sample of nondonors increased to 928 and baseline characteristics were similar between the 2 groups. During a median follow-up of 7.3 years (IQR, 6.0-9.0), in weighted analysis, hypertension occurred in 161 of 924 donors (17%) and 158 of 928 nondonors (17%) (weighted hazard ratio, 1.11 [95% CI, 0.75-1.66]). The longitudinal change in mean blood pressure was similar in donors and nondonors. After the initial drop in donors' eGFR after nephrectomy (mean, 32 mL/min/1.73 m2), donors had a 1.4-mL/min/1.73 m2 (95% CI, 1.2-1.5) per year lesser decline in eGFR than nondonors. However, more donors than nondonors had an eGFR between 30 and 60 mL/min/1.73 m2 at least once in follow-up (438/924 [47%] vs 49/928 [5%]). Albuminuria occurred in 132 of 905 donors (15%) and 95 of 904 nondonors (11%) (weighted hazard ratio, 1.46 [95% CI, 0.97-2.21]); the weighted between-group difference in the albumin to creatinine ratio was 1.02 (95% CI, 0.88-1.19).

Conclusions and Relevance

In this cohort study of living kidney donors and nondonors with the same follow-up schedule, the risks of hypertension and albuminuria were not significantly different. After the initial drop in eGFR from nephrectomy, donors had a slower mean rate of eGFR decline than nondonors but were more likely to have an eGFR between 30 and 60 mL/min/1.73 m2 at least once in follow-up.

Trial Registration

ClinicalTrials.gov Identifier: NCT00936078.

Decreased patient discharges on weekends part 3: what do the leaders tell us?

BACKGROUND

Emergency department (ED) crowding is a significant challenge to providing safe and quality care to patients. We know that hospital and ED crowding is exacerbated on Mondays because fewer in-patients are discharged on the weekend. We evaluated barriers and potential solutions to improve in-patient flow and diminished weekend discharges, in hopes of decreasing the severe ED crowding observed on Mondays.

METHODS

In this observational study, we conducted interviews of (a) leaders at The Ottawa Hospital, a major academic health sciences centre (nursing, allied health, physicians), and (b) leaders of community facilities (long-term care and chronic hospital) that receive patients from the hospital, and (c) home care. Each interview was conducted individually and addressed perceived barriers to the discharge of hospital in-patients on weekends as well as potential solutions. An inductive thematic analysis was conducted whereby themes were organized into a summary table of barriers and solutions.

RESULTS

We interviewed 40 leaders including 30 nursing, physician, and allied health leaders from the hospital as well as 10 senior personnel from community facilities and home care. Many barriers to weekend discharges were identified, highlighting that this problem is complex with many interdependent internal and external factors. Fortunately, many specific potential solutions were suggested, in immediate, short-term and long-term time horizons. While many solutions require additional resources, others require a culture change whereby hospital and community stakeholders recognize that services must be provided consistently, seven days a week.

INTERPRETATION

We have identified the complex and interdependent barriers to weekend discharges of in-patients. There are numerous specific opportunities for hospital staff and services, physicians, and community facilities to provide the same patient care on weekends as on weekdays. This will lead to improved patient flow and safety, and to decreased ED crowding on Mondays.

Sex-Related Disparities in Cardiovascular Outcomes Among Older Adults With Late-Onset Hypertension

BACKGROUND

It is unclear whether sex-based differences in cardiovascular outcomes exist in late-onset hypertension.

METHODS

This is a population-based cohort study in Ontario, Canada of 266 273 adults, aged ≥66 years with newly diagnosed hypertension. We determined the incidence of the primary composite cardiovascular outcome (myocardial infarction, stroke, and congestive heart failure), all-cause mortality, and cardiovascular death by sex using Cox proportional hazard models adjusted for demographic factors and comorbidities.

RESULTS

The mean age of the total cohort was 74 years, and 135 531 (51%) were female. Over a median follow-up of 6.6 (4.7-9.0) years, females experienced a lower crude incidence rate (per 1000 person-years) than males for the primary composite cardiovascular outcome (287.3 versus 311.7), death (238.4 versus 251.4), and cardiovascular death (395.7 versus 439.6), P<0.001. The risk of primary composite cardiovascular outcome was lower among females (adjusted hazard ratio, 0.75 [95% CI, 0.73-0.76]; P<0.001) than in males. This was consistent after adjusting for the competing risk of all-cause death with a subdistributional hazard ratio, 0.88 ([95% CI, 0.86-0.91]; P<0.001).

CONCLUSIONS

Females had a lower risk of cardiovascular outcomes compared with males within a population characterized by advanced age and new hypertension. Our results highlight that the severity of outcomes is influenced by sex in relation to the age at which hypertension is diagnosed. Further studies are required to identify sex-specific variations in the diagnosis and management of late-onset hypertension due to its high incidence in this group.

The Second International Consensus Guidelines on the Management of BK Polyomavirus in Kidney Transplantation

BK polyomavirus (BKPyV) remains a significant challenge after kidney transplantation. International experts reviewed current evidence and updated recommendations according to Grading of Recommendations, Assessment, Development, and Evaluations (GRADE). Risk factors for BKPyV-DNAemia and biopsy-proven BKPyV-nephropathy include recipient older age, male sex, donor BKPyV-viruria, BKPyV-seropositive donor/-seronegative recipient, tacrolimus, acute rejection, and higher steroid exposure. To facilitate early intervention with limited allograft damage, all kidney transplant recipients should be screened monthly for plasma BKPyV-DNAemia loads until month 9, then every 3 mo until 2 y posttransplant (3 y for children). In resource-limited settings, urine cytology screening at similar time points can exclude BKPyV-nephropathy, and testing for plasma BKPyV-DNAemia when decoy cells are detectable. For patients with BKPyV-DNAemia loads persisting >1000 copies/mL, or exceeding 10 000 copies/mL (or equivalent), or with biopsy-proven BKPyV-nephropathy, immunosuppression should be reduced according to predefined steps targeting antiproliferative drugs, calcineurin inhibitors, or both. In adults without graft dysfunction, kidney allograft biopsy is not required unless the immunological risk is high. For children with persisting BKPyV-DNAemia, allograft biopsy may be considered even without graft dysfunction. Allograft biopsies should be interpreted in the context of all clinical and laboratory findings, including plasma BKPyV-DNAemia. Immunohistochemistry is preferred for diagnosing biopsy-proven BKPyV-nephropathy. Routine screening using the proposed strategies is cost-effective, improves clinical outcomes and quality of life. Kidney retransplantation subsequent to BKPyV-nephropathy is feasible in otherwise eligible recipients if BKPyV-DNAemia is undetectable; routine graft nephrectomy is not recommended. Current studies do not support the usage of leflunomide, cidofovir, quinolones, or IVIGs. Patients considered for experimental treatments (antivirals, vaccines, neutralizing antibodies, and adoptive T cells) should be enrolled in clinical trials.

Stroke Subtype Among Individuals With Chronic Kidney Disease

Background

It is widely accepted that there is a stepwise increase in the risk of acute ischemic stroke with chronic kidney disease (CKD). However, whether the risk of specific ischemic stroke subtypes varies with CKD remains unclear.

Objective

To assess the association between ischemic stroke subtypes (cardioembolic, arterial, lacunar, and other) classified using the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) and CKD stage.

Design

retrospective cohort study.

Setting

Ontario, Canada.

Patients

A total of 17 434 adults with an acute ischemic stroke in Ontario, Canada between April 1, 2002 and March 31, 2013, with an estimated glomerular filtration rate (eGFR) measurement or receipt of maintenance dialysis captured in a stroke registry were included.

Measurements

Kidney function categorized as an eGFR of ≥60, 30-59, <30 mL/min/1.73 m2, or maintenance dialysis. Ischemic stroke classified by TOAST included arterial, cardioembolic, lacunar, and other (dissection, prothrombotic state, cortical vein/sinus thrombosis, and vasculitis) types of strokes.

Methods

Adjusted regression models.

Results

In our cohort, 58.9% had an eGFR of ≥60, 34.7% an eGFR of 30-59, 6.0% an eGFR of <30 and 0.5% were on maintenance dialysis (mean age of 73 years; 48% women). Cardioembolic stroke was more common in patients with non-dialysis-dependant CKD (eGFR 30-59: 50.4%, adjusted odds ratio [OR] 1.20, 95% confidence interval [CI]: 1.02, 1.44; eGFR<30: 50.6%, OR 1.21, 95% CI: 1.02, 1.44), whereas lacunar stroke was less common (eGFR 30-59: 22.7% OR 0.85, 95% CI: 0.77, 0.93; eGFR <30: 0.73, 95% CI: 0.61, 0.88) compared with those with an eGFR ≥60. In stratified analyses by age and CKD, lacunar strokes were more frequent in those aged less than 65 years, whereas cardioembolic was higher in those aged 65 years and above.

Limitations

TOAST classification was not captured for all patients.

Conclusion

Non-dialysis CKD was associated with a higher risk of cardioembolic stroke, whereas an eGFR ≥60 mL/min/1.73 m2 was associated with a higher risk of lacunar stroke. Detailed stroke subtyping in CKD may therefore provide mechanistic insights and refocus treatment strategies in this high-risk population.

Estimated glomerular filtration rate from the renal hypothermia trial: clinical implications

OBJECTIVE

To assess if estimated glomerular filtration rate (eGFR) can replace measured GFR (mGFR) in partial nephrectomy (PN) trials, using data from a randomised clinical trial.

PATIENTS AND METHODS

We conducted a post hoc analysis of the renal hypothermia trial. Patients underwent mGFR with diethylenetriaminepentaacetic acid (DTPA) plasma clearance preoperatively and 1 year after PN. The eGFR was calculated using the 2009 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) creatinine equations incorporating age and sex, with and without race: 2009 eGFRcr(ASR) and 2009 eGFRcr(AS), and the 2021 equation that only incorporates age and sex: 2021 eGFRcr(AS). Performance was evaluated by determining the median bias, precision (interquartile range [IQR] of median bias), and accuracy (percentage of eGFR within 30% of mGFR).

RESULTS

Overall, 183 patients were included. Pre- and postoperative median bias and precision were similar between the 2009 eGFRcr(ASR) (-0.2 mL/min/1.73 m2 , 95% confidence interval [CI] -2.2 to 1.7, IQR 18.8; and -2.9, 95% CI -5.1 to -1.5, IQR 15, respectively) and 2009 eGFRcr(AS) (-0.3 mL/min/1.73 m2 , 95% CI -2.4 to 1.5, IQR 18.8; and -3.0, 95% CI -5.7 to -1.7, IQR 15.0, respectively). Bias and precision were worse for the 2021 eGFRcr(AS) (-8.8 mL/min/1.73 m2 , 95% CI -10.9 to -6.3, IQR 24.7; and -12.0, 95% CI -15.8 to -8.9, IQR 23.5, respectively). Similarly, pre- and postoperative accuracy was >90% for the 2009 eGFRcr(ASR) and 2009 eGFRcr(AS) equations. Accuracy was 78.6% preoperatively and 66.5% postoperatively for 2021 eGFRcr(AS).

CONCLUSION

The 2009 eGFRcr(AS) can accurately estimate GFR in PN trials and could be used instead of mGFR to reduce cost and patient burden.

Screening for Primary Aldosteronism Among Hypertensive Adults with Obstructive Sleep Apnea: A Retrospective Population-Based Study

BACKGROUND

Hypertension plus obstructive sleep apnea (OSA) is recommended in some guidelines as an indication to screen for primary aldosteronism (PA), yet prior data has brought the validity of this recommendation into question. Given this context, it remains unknown whether this screening recommendation is being implemented into clinical practice.

METHODS

We conducted a population-based retrospective cohort study of all adult Ontario (Canada) residents with hypertension plus OSA from 2009 to 2020 with follow-up through 2021 utilizing provincial health administrative data. We measured the proportion of individuals who underwent PA screening via the aldosterone-to-renin ratio by year. We further examined screening rates among patients with hypertension plus OSA by the presence of concurrent hypokalemia and resistant hypertension. Clinical predictors associated with screening were assessed via Cox regression modeling.

RESULTS

The study cohort included 53,130 adults with both hypertension and OSA, of which only 634 (1.2%) underwent PA screening. Among patients with hypertension, OSA, and hypokalemia, the proportion of eligible patients screened increased to 2.8%. Among patients ≥65 years with hypertension, OSA, and prescription of ≥4 antihypertensive medications, the proportion of eligible patients screened was 1.8%. Older age was associated with a decreased likelihood of screening while hypokalemia and subspecialty care with internal medicine, cardiology, endocrinology, or nephrology were associated with an increased likelihood of screening. No associations with screening were identified with sex, rural residence, cardiovascular disease, diabetes, or respirology subspecialty care.

CONCLUSIONS

The population-level uptake of the guideline recommendation to screen all patients with hypertension plus OSA for PA is exceedingly low.

Management and Outcome of COVID-19 Infection Using Nirmatrelvir/Ritonavir in Kidney Transplant Patients

BACKGROUND

Nirmatrelvir/ritonavir has been shown to reduce the risk of COVID-19 related complications in patients at high risk for severe COVID-19. However, clinical experience of nirmatrelvir/ritonavir in the transplant recipient population is scattered due to the complex management of drug-drug interactions with calcineurin inhibitors. We describe the clinical experience with nirmatrelvir/ritonavir at The Ottawa Hospital kidney transplant program.

METHODS

Patients who received nirmatrelvir/ritonavir between April and June 2022 were included and followed up 30 days after completion of treatment. Tacrolimus was withheld for 24 hours and resumed 72 hours after the last dose of nirmatrelvir/ritonavir (on Day 8) based on drug level the day before. The first 30 patients had their dose adjusted according to drug levels performed twice in the first week and as needed thereafter. Subsequently, a simplified algorithm with less frequent calcineurin inhibitor level monitoring was implemented. Outcomes including tacrolimus level changes, serum creatinine and acute kidney injury (AKI, defined as serum creatinine increase by 30%) and clinical outcomes were described globally and compared between algorithms.

RESULTS

Fifty-one patients received nirmatrelvir/ritonavir. Tacrolimus levels drawn at the first timepoint, 7 days after withholding of calcineurin inhibitor and 2 days after discontinuing nirmatrelvir/ritonavir were within the therapeutic target in 17/44 (39%), subtherapeutic in 21/44(48%) and supratherapeutic in 6/44 (14%). Two weeks after, 55% were within the therapeutic range, 23% were below, and 23% were above it. The standard and simplified algorithms provided similar tacrolimus level (median 5.2 ug/L [4.0, 6.2] versus 4.8 ug/L [4.3, 5.7] p=0.70). There were no acute rejections or other complications.

CONCLUSIONS

Withholding tacrolimus starting the day before initiation of nirmatrelvir/ritonavir with resumption 3 days after completion of therapy resulted in a low incidence of supratherapeutic levels but a short period of subtherapeutic levels for many patients. AKI was infrequent. The data are limited by the small sample size and short follow-up.

Diagnostic accuracy of ancillary tests for death by neurologic criteria: a systematic review and meta-analysis

PURPOSE

Ancillary tests are frequently used in death determination by neurologic criteria (DNC), particularly when the clinical neurologic examination is unreliable. Nevertheless, their diagnostic accuracy has not been extensively studied. Our objective was to synthesize the sensitivity and specificity of commonly used ancillary tests for DNC.

SOURCE

We performed a systematic review and meta-analysis by searching MEDLINE, EMBASE, Cochrane databases, and CINAHL Ebsco from their inception to 4 February 2022. We selected cohort and case-control studies including patients with 1) clinically diagnosed death by neurologic criteria or 2) clinically suspected death by neurologic criteria who underwent ancillary testing for DNC. We excluded studies without a priori diagnostic criteria and studies conducted solely on pediatric patients. Accepted reference standards were clinical examination, four-vessel conventional angiography, and radionuclide imaging. Data were directly extracted from published reports. We assessed the methodological quality of studies with the QUADAS-2 tool and estimated ancillary test sensitivities and specificities using hierarchical Bayesian models with diffuse priors.

PRINCIPAL FINDINGS

Overall, 137 records met the selection criteria. One study (0.7%) had a low risk of bias in all QUADAS-2 domains. Among clinically diagnosed death by neurologic criteria patients (n = 8,891), ancillary tests had similar pooled sensitivities (range, 0.82-0.93). Sensitivity heterogeneity was greater within (σ = 0.10-0.15) than between (σ = 0.04) ancillary test types. Among clinically suspected death by neurologic criteria patients (n = 2,732), pooled ancillary test sensitivities ranged between 0.81 and 1.00 and specificities between 0.87 and 1.00. Most estimates had high statistical uncertainty.

CONCLUSION

Studies assessing ancillary test diagnostic accuracy have an unclear or high risk of bias. High-quality studies are required to thoroughly validate ancillary tests for DNC.

STUDY REGISTRATION

PROSPERO (CRD42013005907); registered 7 October 2013.

Health System-Level Barriers to Living Donor Kidney Transplantation: Protocol for a Comparative Case Study Analysis

BACKGROUND

Living donor kidney transplantation (LDKT) is the best treatment option for patients with kidney failure and offers significant medical and economic advantages for both patients and health systems. Despite this, rates of LDKT in Canada have stagnated and vary significantly across Canadian provinces, the reasons for which are not well understood. Our prior work has suggested that system-level factors may be contributing to these differences. Identifying these factors can help inform system-level interventions to increase LDKT.

OBJECTIVE

Our objective is to generate a systemic interpretation of LDKT delivery across provincial health systems with variable performance. We aim to identify the attributes and processes that facilitate the delivery of LDKT to patients, and those that create barriers and compare these across systems with variable performance. These objectives are contextualized within our broader goal of increasing rates of LDKT in Canada, particularly in lower-performing provinces.

METHODS

This research takes the form of a qualitative comparative case study analysis of 3 provincial health systems in Canada that have high, moderate, and low rates of LDKT performance (the percentage of LDKT to all kidney transplantations performed). Our approach is underpinned by an understanding of health systems as complex adaptive systems that are multilevel and interconnected, and involve nonlinear interactions between people and organizations, operating within a loosely bounded network. Data collection will comprise semistructured interviews, document reviews, and focus groups. Individual case studies will be conducted and analyzed using inductive thematic analysis. Following this, our comparative analysis will operationalize resource-based theory to compare case study data and generate explanations for our research question.

RESULTS

This project was funded from 2020 to 2023. Individual case studies were carried out between November 2020 and August 2022. The comparative case analysis will begin in December 2022 and is expected to conclude in April 2023. Submission of the publication is projected for June 2023.

CONCLUSIONS

By investigating health systems as complex adaptive systems and making comparisons across provinces, this study will identify how health systems can improve the delivery of LDKT to patients with kidney failure. Our resource-based theory framework will provide a granular analysis of the attributes and processes that facilitate or create barriers to LDKT delivery across multiple organizations and levels of practice. Our findings will have practice and policy implications and help inform transferrable competencies and system-level interventions conducive to increasing LDKT.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/44172.

Health System–Level Barriers to Living Donor Kidney Transplantation: Protocol for a Comparative Case Study Analysis (Preprint).. [DOI: 10.2196/preprints.44172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

BACKGROUND

Living donor kidney transplantation (LDKT) is the best treatment option for patients with kidney failure and offers significant medical and economic advantages for both patients and health systems. Despite this, rates of LDKT in Canada have stagnated and vary significantly across Canadian provinces, the reasons for which are not well understood. Our prior work has suggested that system-level factors may be contributing to these differences. Identifying these factors can help inform system-level interventions to increase LDKT.

OBJECTIVE

Our objective is to generate a systemic interpretation of LDKT delivery across provincial health systems with variable performance. We aim to identify the attributes and processes that facilitate the delivery of LDKT to patients, and those that create barriers and compare these across systems with variable performance. These objectives are contextualized within our broader goal of increasing rates of LDKT in Canada, particularly in lower-performing provinces.

METHODS

This research takes the form of a qualitative comparative case study analysis of 3 provincial health systems in Canada that have high, moderate, and low rates of LDKT performance (the percentage of LDKT to all kidney transplantations performed). Our approach is underpinned by an understanding of health systems as complex adaptive systems that are multilevel and interconnected, and involve nonlinear interactions between people and organizations, operating within a loosely bounded network. Data collection will comprise semistructured interviews, document reviews, and focus groups. Individual case studies will be conducted and analyzed using inductive thematic analysis. Following this, our comparative analysis will operationalize resource-based theory to compare case study data and generate explanations for our research question.

RESULTS

This project was funded from 2020 to 2023. Individual case studies were carried out between November 2020 and August 2022. The comparative case analysis will begin in December 2022 and is expected to conclude in April 2023. Submission of the publication is projected for June 2023.

CONCLUSIONS

By investigating health systems as complex adaptive systems and making comparisons across provinces, this study will identify how health systems can improve the delivery of LDKT to patients with kidney failure. Our resource-based theory framework will provide a granular analysis of the attributes and processes that facilitate or create barriers to LDKT delivery across multiple organizations and levels of practice. Our findings will have practice and policy implications and help inform transferrable competencies and system-level interventions conducive to increasing LDKT.

INTERNATIONAL REGISTERED REPORT

DERR1-10.2196/44172

Kidney function, cardiovascular outcomes and survival of living kidney donors with hypertension: a systematic review protocol

INTRODUCTION

Hypertension has been considered a contraindication for living kidney donation in the past. Since transplantation from living kidney donors remains the best modality for kidney failure, there is now an increased acceptance of living kidney donors with hypertension. However, the safety of this practice for the cardiovascular and kidney health of the donor is unclear. We will conduct a systematic review to summarise and synthesise the existing literature on this topic.

METHODS AND ANALYSIS

A systematic review of prospective randomised and non-randomised and retrospective studies will be conducted. MEDLINE, EMBASE, Cochrane CENTRAL and EBM reviews published from January 1946 to December 2021 will be reviewed. Primary outcome will be the difference in the survival, major adverse cardiovascular events, estimated glomerular filtration rate of 45 mL/min or less and development of end-stage kidney failure, between living kidney donors with and without hypertension. Study screening, selection, and data extraction will be performed by two independent reviewers. Studies must fulfil all eligibility criteria for inclusion into the systematic review and meta-analysis. The Risk of Bias in Non-Randomised studies tool will be used to assess bias.

ETHICS AND DISSEMINATION

No ethical approval is required for this systematic review. The results of this review will be disseminated in a peer-reviewed, open-access journal to ensure access to all stakeholders in kidney transplantation and to inform clinical guidelines on the evaluation and follow-up care of living kidney donor candidates.

PROSPERO REGISTRATION NUMBER

CRD42022300119.

Analysis of Electrolyte Abnormalities in Adolescents and Adults and Subsequent Diagnosis of an Eating Disorder

IMPORTANCE

Eating disorders lead to increased mortality and reduced quality of life. While the acute presentations of eating disorders frequently involve electrolyte abnormalities, it remains unknown whether electrolyte abnormalities may precede the future diagnosis of an eating disorder.

OBJECTIVE

To determine whether outpatient electrolyte abnormalities are associated with the future diagnosis of an eating disorder.

DESIGN, SETTING, AND PARTICIPANTS

This population-level case-control study used provincial administrative health data for residents of Ontario, Canada aged 13 years or older from 2008 to 2020. Individuals without an eating disorder (controls) were matched 4:1 to individuals diagnosed with an incident eating disorder (cases) based on age and sex. Both groups had outpatient electrolyte measurements between 3 years and 30 days prior to index. Index was defined as the date of an eating disorder diagnosis in any inpatient or outpatient clinical setting for cases. Controls were assigned a pseudo-index date according to the distribution of index dates in the case population. Individuals with any prior eating disorder diagnosis were excluded. The data analyzed was from January 1, 2008, through June 30, 2020.

EXPOSURES

Any electrolyte abnormality, defined as abnormal test results for a composite of hypokalemia, hyperkalemia, hyponatremia, hypernatremia, hypomagnesemia, hypophosphatemia, metabolic acidosis, or metabolic alkalosis.

OUTCOMES AND MEASURES

Eating disorder diagnosis including anorexia nervosa, bulimia nervosa, and eating disorder not otherwise specified.

RESULTS

A total 6970 eligible Ontario residents with an eating disorder (mean [SD] age, 28 (19) years; 6075 [87.2%] female, 895 [12.8%] male) were matched with 27 878 age- and sex-matched residents without an eating disorder diagnosis (mean [SD] age, 28 [19] years; 24 300 [87.2%] female, 3578 [12.8%] male). Overall, 18.4% of individuals with an eating disorder had a preceding electrolyte abnormality vs 7.5% of individuals without an eating disorder (adjusted odds ratio [aOR], 2.12; [95% CI, 1.86-2.41]). The median (IQR) time from the earliest electrolyte abnormality to eating disorder diagnosis was 386 (157-716) days. Specific electrolyte abnormalities associated with a higher risk of an eating disorder were: hypokalemia (aOR, 1.98; 95% CI, 1.70-2.32), hyperkalemia (aOR, 1.97; 95% CI, 1.48-2.62), hyponatremia (aOR, 5.26; 95% CI, 3.32-8.31), hypernatremia (aOR, 3.09; 95% CI, 1.01-9.51), hypophosphatemia (aOR, 2.83; 95% CI, 1.82-4.40), and metabolic alkalosis (aOR, 2.60; 95% CI, 1.63-4.15).

CONCLUSIONS AND RELEVANCE

In this case-control study, individuals with an eating disorder were associated with a preceding outpatient electrolyte abnormality compared with matched controls. Otherwise unexplained electrolyte abnormalities may serve to identify individuals who may benefit from screening for an underlying eating disorder.

Critically important outcomes for infection in trials in kidney transplantation: An international survey of patients, caregivers and health professionals

BACKGROUND

Infections are a common complication following kidney transplantation, but are reported inconsistently in clinical trials. This study aimed to identify the infection outcomes of highest priority for patients/caregivers and health professionals to inform a core outcome set to be reported in all kidney transplant clinical trials.

METHODS

In an international online survey, participants rated the absolute importance of 16 infections and 8 severity dimensions on 9-point Likert Scales, with 7-9 being critically important. Relative importance was determined using a best-worst scale. Means and proportions of the Likert-scale ratings and best-worst preference scores were calculated.

RESULTS

353 healthcare professionals (19 who identified as both patients/caregiver and healthcare professionals) and 220 patients/caregivers (190 patients, 22 caregivers, 8 who identified as both) from 55 countries completed the survey. Both healthcare professionals and patients/caregivers rated bloodstream (mean 8.4 and 8.5 respectively; aggregate 8.5), kidney/bladder (mean 7.9 and 8.4; aggregate 8.1) and BK virus (mean 8.1 and 8.6; aggregate 8.3) as the top 3 most critically important infection outcomes, whilst infectious death (mean 8.8 and 8.6; aggregate 8.7), impaired graft function (mean 8.4 and 8.7; aggregate 8.5) and admission to the intensive care unit (mean 8.2 and 8.3; aggregate 8.2) were the top 3 severity dimensions. Relative importance (best-worst) scores were consistent.

CONCLUSIONS

Healthcare professionals and patients/caregivers consistently identified bloodstream infection, kidney/bladder infections and BK virus as the three most important infection outcomes, and infectious death, admission to intensive care unit and infection impairing graft function as the three most important infection severity outcomes. This article is protected by copyright. All rights reserved.

Immunosuppressant Medication Use in Patients with Kidney Allograft Failure: A Prospective Multi-Center Canadian Cohort Study

Background: Patients with kidney transplant failure have a high risk of hospitalization and death due to infection. The optimal use of immunosuppressants after transplant failure remains uncertain and clinical practice varies widely. Methods: This prospective cohort study enrolled patients within 21 days of starting dialysis after transplant failure in 16 Canadian centers. Immunosuppressant medication use, death, hospitalized infection, rejection of the failed allograft, and panel reactive anti-HLA antibodies (PRA) were determined at 1, 3, 6 , and 12 months and bi-annually until death, repeat transplantation, or loss to follow-up. Results: The 269 study patients were followed for a median of 558 days. There were 33 deaths, 143 patients hospitalized for infection, and 21 rejections. Most patients (65%) continued immunosuppressants, 20% continued prednisone only, while 15% discontinued all immunosuppressants. In multivariable models, patients who continued immunosuppressants had a lower risk of death (HR =0.40, 95% CI, 0.17-0.93) and were not at increased risk of hospitalized infection (HR 1.81; 95% CI 0.82 to 4.0) compared to patients who discontinued all immunosuppressants or continued prednisone only. The mean class I and class II PRA increased from 11% to 27% and 25% to 47%, respectively, but did not differ by immunosuppressant use. Continuation of immunosuppressants was not protective of rejection of the failed allograft (HR 0.81, 95% CI, 0.22-2.94). Conclusions: Prolonged use of immunosuppressants greater than one year after transplant failure was not associated with a higher risk of death or hospitalized infection but was insufficient to prevent higher anti-HLA antibodies or rejection of the failed allograft.

Diet or additional supplement to increase potassium intake: protocol for an adaptive clinical trial

Background

High blood pressure is the leading cause of cardiovascular disease worldwide. The prevalence of high blood pressure is steadily rising as the population grows amongst older adults with the ageing population. Therapeutical treatments are widely available to decrease blood pressures, in addition to many lifestyle options, such as dietary changes and exercise. There is a marked preference amongst patients, as reiterated by Hypertension Canada, for more research into non-therapeutic methods for controlling blood pressure or to reduce the burden of taking many pills to control high blood pressure. Indeed, effective options do exist, especially with diet, specifically decreasing sodium and increasing potassium intake. Current public health outreach primarily focusses on sodium intake, even though potassium intake remains low in the Western world. Excellent data exist in published research that increasing potassium intake, either via dietary modification or supplements, reduces blood pressure and reduces risk of cardiovascular outcomes such as stroke. However, the advice most often provided by medical professionals is to ‘eat more fruits and vegetables’ which has little impact on patient outcomes.

Methods

We propose to do a clinical trial in two stages with an adaptive trial design. In the first stage, participants with high blood pressure and proven low potassium intake (measured on the basis of a 24-h urine collection) will get individually tailored dietary advice, reinforced by weekly supportive phone/email support. At 4 weeks, if there has not been a measured increase in potassium intake, participants will be prescribed an additional potassium supplement. Testing will be conducted again at 8 weeks, to confirm the efficacy of the potassium supplement. Final measurements will be planned at 52 weeks to observe and measure the persistence of the effect of diet or additional supplement. Concurrent measurements of sodium intake, blood pressure, participant satisfaction, and safety measures will also be done.

Discussion

The results of the study will help determine the most effective method of increasing potassium intake, thus reducing blood pressure and need for blood pressure-lowering medicines, and at the same time potentially increasing participant satisfaction. The current guidelines recommend changes in diet, not a potassium supplement, to increase potassium intake; hence, the two-stage design will only add supplements if the most rigorous dietary advice does not work.

Trial registration

This study has been registered on ClinicalTrials.govNCT03809884. Registered on January 18, 2019

Screening Rates for Primary Aldosteronism Among Individuals With Hypertension Plus Hypokalemia: A Population-Based Retrospective Cohort Study

Primary aldosteronism is a common, yet highly underdiagnosed, cause of hypertension that leads to disproportionately high rates of cardiovascular disease. Hypertension plus hypokalemia is a guideline-recommended indication to screen for primary aldosteronism, yet the uptake of this recommendation at the population level remains unknown. We performed a population-based retrospective cohort study of adults ≥18 years old in Ontario, Canada, with hypertension plus hypokalemia (potassium <3.5 mEq/L) from 2009 to 2015 with follow-up through 2017. We measured the proportion of individuals who underwent primary aldosteronism screening via the aldosterone-to-renin ratio based upon hypokalemia frequency and severity along with concurrent antihypertensive medication use. We assessed clinical predictors associated with screening via Cox regression. The cohort included 26 533 adults of which only 422 (1.6%) underwent primary aldosteronism screening. When assessed by number of instances of hypokalemia over a 2-year time window, the proportion of eligible patients who were screened increased only modestly from 1.0% (158/15 983) with one instance to 4.8% (71/1494) with ≥5 instances. Among individuals with severe hypokalemia (potassium <3.0 mEq/L), only 3.9% (58/1422) were screened. Among older adults prescribed ≥4 antihypertensive medications, only 1.0% were screened. Subspecialty care with endocrinology (hazard ratio [HR], 1.52 [95% CI, 1.10-2.09]), nephrology (HR, 1.43 [95% CI, 1.07-1.91]), and cardiology (HR, 1.39 [95% CI, 1.14-1.70]) were associated with an increased likelihood of screening, whereas age (HR, 0.95 [95% CI, 0.94-0.96]) and diabetes (HR, 0.66 [95% CI, 0.50-0.89]) were inversely associated with screening. In conclusion, population-level uptake of guideline recommendations for primary aldosteronism screening is exceedingly low. Increased education and awareness are critical to bridge this gap.

Proteinuria and venous thromboembolism in pregnancy: a population-based cohort study

Background

Pregnancy-associated venous thromboembolism (VTE) is associated with high morbidity and mortality. Identification of risk factors of VTE may lead to improved maternal and foetal outcomes. Proteinuria confers a pro-thrombotic state, however, its association with VTE in pregnancy remains unknown. We set out to assess the association of proteinuria and VTE during pregnancy.

Methods

We conducted a population-based, retrospective cohort study of all pregnant women (≥16 years of age) with a proteinuria measure within 20 weeks of conception (n = 306 244; mean age 29.8 years) from Ontario, Canada. Proteinuria was defined by any of the following: urine albumin:creatinine ratio ≥3 mg/mmol, urine protein:creatinine ratio ≥5 mg/mmol or urine dipstick proteinuria ≥1. The main outcome measure was a diagnosis of VTE up to 24-weeks post-partum.

Results

A positive proteinuria measurement occurred in 8508 (2.78%) women and was more common with a history of kidney disease, gestational or non-gestational diabetes mellitus and hypertension. VTE events occurred in 625 (0.20%) individuals, with a higher risk among women with positive proteinuria [32 events (0.38%)] compared with women without proteinuria [593 events (0.20%); inverse probability-weighted risk ratio 1.79 (95% confidence interval 1.25-2.57)]. The association was consistent using a more specific VTE definition, in the post-partum period, in high-risk subgroups (hypertension or diabetes) and when the sample was restricted to women with preserved kidney function.

Conclusions

The presence of proteinuria in the first 20 weeks of pregnancy is associated with a significantly higher risk of VTE.

Comparison of Clinical Outcomes and Safety Associated With Chlorthalidone vs Hydrochlorothiazide in Older Adults With Varying Levels of Kidney Function

IMPORTANCE

Thiazide diuretics are commonly prescribed for the treatment of hypertension, a disease highly prevalent among older individuals and in those with chronic kidney disease. How specific thiazide diuretics compare in regard to safety and clinical outcomes in these populations remains unknown.

OBJECTIVE

To compare safety and clinical outcomes associated with chlorthalidone or hydrochlorothiazide use among older adults with varying levels of kidney function.

DESIGN, SETTING, AND PARTICIPANTS

This population-based retrospective cohort study was conducted in Ontario, Canada, from 2007 to 2015. Participants included adults aged 66 years or older who initiated chlorthalidone or hydrochlorothiazide during this period. Data were analyzed from December 2019 through September 2020.

EXPOSURES

New chlorthalidone users were matched 1:4 with new hydrochlorothiazide users by a high-dimensional propensity score. Time-to-event models accounting for competing risks examined the associations between chlorthalidone vs hydrochlorothiazide use and the outcomes of interest overall and within estimated glomerular filtration rate (eGFR) categories (≥60, 45-59, and <45 mL/min/1.73 m2).

MAIN OUTCOMES AND MEASURES

The outcomes of interest were adverse kidney events (ie, eGFR decline ≥30%, dialysis, or kidney transplantation), cardiovascular events (composite of myocardial infarction, coronary revascularization, heart failure, or atrial fibrillation), all-cause mortality, and electrolyte anomalies (ie, sodium or potassium levels outside reference ranges).

RESULTS

After propensity score matching, the study cohort included 12 722 adults (mean [SD] age, 74 [7] years; 7063 [56%] women; 5659 [44%] men; mean [SD] eGFR, 69 [19] mL/min/1.73 m2), including 2936 who received chlorthalidone and 9786 who received hydrochlorothiazide. Chlorthalidone use was associated with a higher risk of eGFR decline of 30% or greater (hazard ratio [HR], 1.24 [95% CI, 1.13-1.36]) and cardiovascular events (HR, 1.12 [95% CI, 1.04-1.22]) across all eGFR categories compared with hydrochlorothiazide use. Chlorthalidone use was also associated with a higher risk of hypokalemia compared with hydrochlorothiazide use, which was more pronounced among those with higher eGFR (eGFR ≥60 mL/min/1.73 m2: HR, 1.86 [95% CI, 1.67-2.08]; eGFR 45-59 mL/min/1.73 m2: HR, 1.57 [95% CI, 1.25-1.96]; eGFR <45 mL/min/1.73 m2: HR, 1.10 [95% CI, 0.84-1.45]; P for interaction = .001). No significant differences were observed between chlorthalidone and hydrochlorothiazide for dialysis or kidney transplantation (HR, 1.44 [95% CI, 0.88-2.36]), all-cause mortality (HR, 1.10 [95% CI, 0.93-1.29]), hyperkalemia (HR, 1.05 [95% CI, 0.79-1.39]), or hyponatremia (HR, 1.14 [95% CI, CI 0.98-1.32]).

CONCLUSIONS AND RELEVANCE

This cohort study found that among older adults, chlorthalidone use was associated with a higher risk of eGFR decline, cardiovascular events, and hypokalemia compared with hydrochlorothiazide use. The excess risk of hypokalemia with chlorthalidone was attenuated in participants with reduced kidney function. Placed in context with prior observational studies comparing the safety and clinical outcomes associated with thiazide diuretics, these results suggest that there is no evidence to prefer chlorthalidone over hydrochlorothiazide.

Impact of Perioperative Complications on Living Kidney Donor Health-Related Quality of Life and Mental Health: Results From a Prospective Cohort Study

Background:

Although living kidney donation is safe, some donors experience perioperative complications.

Objective:

This study explored how perioperative complications affected donor-reported health-related quality of life, depression, and anxiety.

Design:

This research was a conducted as a prospective cohort study.

Setting:

Twelve transplant centers across Canada.

Patients:

A total of 912 living kidney donors were included in this study.

Measurements:

Short Form 36 health survey, Beck Depression Inventory and Beck Anxiety Inventory.

Methods:

Living kidney donors were prospectively enrolled predonation between 2009 to 2014. Donor perioperative complications were graded using the Clavien-Dindo classification system. Mental and physical health-related quality of life was assessed with the 3 measurements; measurements were taken predonation and at 3- and 12-months postdonation.

Results:

Seventy-four donors (8%) experienced a perioperative complication; most were minor (n = 67 [91%]), and all minor complications resolved before hospital discharge. The presence (versus absence) of a perioperative complication was associated with lower mental health-related quality of life and higher depression symptoms 3-month postdonation; neither of these differences persisted at 12-month. Perioperative complications were not associated with any changes in physical health-related quality of life or anxiety 3-month postdonation.

Limitations:

Minor complications may have been missed and information on complications postdischarge were not collected. No minimal clinically significant change has been defined for kidney donors across the 3 measurements.

Conclusions:

These findings highlight a potential opportunity to better support the psychosocial needs of donors who experience perioperative complications in the months following donation.

Trial registration:

NCT00319579 and NCT00936078.

Initial and Recurrent Hyperkalemia Events in Patients With CKD in Older Adults: A Population-Based Cohort Study

Background:

The risk of hyperkalemia is elevated in chronic kidney disease (CKD); however, the initial and recurrent risk among older individuals is less clear.

Objectives:

We set out to examine the initial and 1-year recurrent risk of hyperkalemia by level of kidney function (estimated glomerular filtration rate, eGFR) in older adults (≥66 years old).

Design:

Population-based, retrospective cohort study

Settings:

Ontario, Canada

Participants:

905 167 individuals (≥66 years old) from 2008 to 2015.

Measurements:

Serum potassium values

Methods:

Individuals were stratified by eGFR (≥90, 60-89, 30-59, 15-29 mL/min/1.73 m²) and examined for the risk of incident hyperkalemia (K ≥ 5.5 mEq/L) using adjusted Cox proportional hazards models. The 1-year risk of recurrent hyperkalemia was examined using multivariable Andersen-Gill models.

Results:

Among a population of 905 167 individuals (15% eGFR ≥ 90, 58% eGFR 60-89, 25% eGFR 30-59, 3% eGFR 15-29) with a potassium measurement, there were a total of 18 979 (2.1%) individuals with hyperkalemia identified. The event rate (per 1000 person-years) and adjusted hazard ratio (HR) of hyperkalemia was inversely associated with eGFR (mL/min; eGFR >90 mL/min: 8.8, referent, 60-89 mL/min: 11.8 HR 1.41; eGFR 30-59: 39.8, HR 4.37; eGFR 15-29: 133.6, 13.65) and with an increasing urine albumin-to-creatinine ratio (ACR, mg/mmol; ACR< 3: 14, referent, ACR 3-30: 35.1, HR 1.98; ACR >30: 93.7, 4.71). The 1-year event rate and adjusted risk of recurrent hyperkalemia was similarly inversely associated with eGFR (eGFR ≥ 90: 10.1, referent, eGFR 60-89: 14.4, HR 1.47; eGFR 30-59: 54.8, HR 4.90; eGFR 15-29: 208.0, HR 12.98). Among individuals with a baseline eGFR of 30 to 59 and 15 to 29, 0.9 and 3.8% had greater than 2 hyperkalemia events. The relative risk of initial and recurrent hyperkalemia was marginally higher with RAAS blockade. Roughly 1 in 4 individuals with hyperkalemia required hospitalization the day of or within 30 days after their hyperkalemia event.

Limitations:

Limited to individuals aged 66 years and above.

Conclusions:

Patients with low eGFR are at a high risk of initial and recurrent hyperkalemia.

Trial registration:

N/A