Emergency Department Use Among Adults Receiving Dialysis.

Importance: People with kidney failure receiving maintenance dialysis visit the emergency department (ED) 3 times per year on average, which is 3- to 8-fold more often than the general population. Little is known about the factors that contribute to potentially preventable ED use in this population. Objective: To identify the clinical and sociodemographic factors associated with potentially preventable ED use among patients receiving maintenance dialysis. Design, Setting, and Participants: This cohort study used linked administrative health data within the Alberta Kidney Disease Network to identify adults aged 18 years or older receiving maintenance dialysis (ie, hemodialysis or peritoneal dialysis) between April 1, 2010, and March 31, 2019. Patients who had been receiving dialysis for more than 90 days were followed up from cohort entry (defined as dialysis start date plus 90 days) until death, outmigration from the province, receipt of a kidney transplant, or end of study follow-up. The Andersen behavioral model of health services was used as a conceptual framework to identify variables related to health care need, predisposing factors, and enabling factors. Data were analyzed in March 2024. Main Outcomes and Measures: Rates of all-cause ED encounters and potentially preventable ED use associated with 4 kidney disease-specific ambulatory care-sensitive conditions (hyperkalemia, heart failure, volume overload, and malignant hypertension) were calculated. Multivariable negative binomial regression models were used to examine the association between clinical and sociodemographic factors and rates of potentially preventable ED use. Results: The cohort included 4925 adults (mean [SD] age, 60.8 [15.5] years; 3071 males [62.4%]) with kidney failure receiving maintenance hemodialysis (3183 patients) or peritoneal dialysis (1742 patients) who were followed up for a mean (SD) of 2.5 (2.0) years. In all, 3877 patients had 34 029 all-cause ED encounters (3100 [95% CI, 2996-3206] encounters per 1000 person-years). Of these, 755 patients (19.5%) had 1351 potentially preventable ED encounters (114 [95% CI, 105-124] encounters per 1000 person-years). Compared with patients with a nonpreventable ED encounter, patients with a potentially preventable ED encounter were more likely to be in the lowest income quintile (38.8% vs 30.9%; P < .001); to experience heart failure (46.8% vs 39.9%; P = .001), depression (36.6% vs 32.5%; P = .03), and chronic pain (60.1% vs 54.9%; P = .01); and to have a longer duration of dialysis (3.6 vs 2.6 years; P < .001). In multivariable regression analyses, potentially preventable ED use was higher for younger adults (incidence rate ratio [IRR], 1.69 [95% CI, 1.33-2.15] for those aged 18 to 44 years) and patients with chronic pain (IRR, 1.35 [95% CI, 1.14-1.61]), greater material deprivation (IRR, 1.57 [95% CI, 1.16-2.12]), a history of hyperkalemia (IRR, 1.31 [95% CI, 1.09-1.58]), and historically high ED use (ie, ≥3 ED encounters in the prior year; IRR, 1.46 [95% CI, 1.23-1.73). Conclusions and Relevance: In this study of adults receiving maintenance dialysis in Alberta, Canada, among those with ED use, 1 in 5 had a potentially preventable ED encounter; reasons for such encounters were associated with both psychosocial and medical factors. The findings underscore the need for strategies that address social determinants of health to avert potentially preventable ED use in this population.

Impaired Renal Function and Major Cardiovascular Events in Young Adults.

BACKGROUND: Cardiovascular (CV) disease in young adults (aged 18-39 years) is on the rise. Whether subclinical reductions in kidney function (ie, estimated glomerular filtration rate [eGFR] above the current threshold for chronic kidney disease but below age-expected values) are associated with elevated CV risk is unknown. OBJECTIVES: The goal of this study was to examine age-specific associations of subclinical eGFR reductions in young adults with major adverse cardiovascular events (MACEs) and MACE plus heart failure (MACE+). METHODS: A retrospective cohort study of 8.7 million individuals (3.6 million aged 18-39 years) was constructed using linked provincial health care data sets from Ontario, Canada (January 2008-March 2021). Cox models were used to examine the association of categorized eGFR (50-120 mL/min/1.73 m2) with MACE (first of CV mortality, acute coronary syndrome, and ischemic stroke) and MACE+, stratified according to age (18-39, 40-49, and 50-65 years). RESULTS: In the study cohort (mean age 41.3 years; mean eGFR 104.2 mL/min/1.73 m2; median follow-up 9.2 years), a stepwise increase in the relative risk of MACE and MACE+ was observed as early as eGFR <80 mL/min/1.73 m2 in young adults (eg, for MACE, at eGFR 70-79 mL/min/1.73 m2, ages 18-30 years: 2.37 events per 1,000 person years [HR: 1.31; 95% CI: 1.27-1.40]; ages 40-49 years: 6.26 events per 1,000 person years [HR: 1.09; 95% CI: 1.06-1.12]; ages 50-65 years: 14.9 events per 1,000 person years [HR: 1.07; 95% CI: 1.05-1.08]). Results persisted for each MACE component and in additional analyses (stratifying according to past CV disease, accounting for albuminuria at index, and using repeated eGFR measures). CONCLUSIONS: In young adults, eGFR below age-expected values were associated with an elevated risk for MACE and MACE+, warranting age-appropriate risk stratification, proactive monitoring, and timely intervention.

"You need a team": perspectives on interdisciplinary symptom management using patient-reported outcome measures in hemodialysis care-a qualitative study.

BACKGROUND: Patient-reported outcome measures (PROMs) are standardized instruments used for assessing patients' perspectives on their health status at a point in time, including their health-related quality of life, symptoms, functionality, and physical, mental, and social wellbeing. For people with kidney failure receiving hemodialysis, addressing high symptom burden and complexity relies on care team members integrating their expertise to achieve common management goals. In the context of a program-wide initiative integrating PROMs into routine hemodialysis care, we aimed to explore patients' and clinicians' perspectives on the role of PROMs in supporting interdisciplinary symptom management. METHODS: We employed a qualitative descriptive approach using semi-structured interviews and observations. Eligible participants included adult patients receiving intermittent, outpatient hemodialysis for > 3 months, their informal caregivers, and hemodialysis clinicians (i.e., nurses, nephrologists, and allied health professionals) in Southern Alberta, Canada. Guided by thematic analysis, team members coded transcripts in duplicate and developed themes iteratively through review, refinement, and discussion. RESULTS: Thirty-three clinicians (22 nurses, 6 nephrologists, 5 allied health professionals), 20 patients, and one caregiver participated in this study. Clinicians described using PROMs to coordinate care across provider types using the resources available in their units, whereas patients tended to focus on the perceived impact of this concerted care on symptom trajectory and care experience. We identified 3 overarching themes with subthemes related to the role of PROMs in interdisciplinary symptom management in this setting: (1) Integrating care for interrelated symptoms ("You need a team", conducive setting, role clarity and collaboration); (2) Streamlining information sharing and access (symptom data repository, common language for coordinated care); (3) Reshaping expectations (expectations for follow-up, managing symptom persistence). CONCLUSIONS: We found that use of PROMs in routine hemodialysis care highlighted symptom interrelatedness and complexity and helped to streamline involvement of the interdisciplinary care team. Issues such as role flexibility and resource constraints may influence sustainability of routine PROM use in the outpatient hemodialysis setting.

People with kidney failure receiving hemodialysis are faced with complex symptoms that impact their day-to-day functioning and quality of life. Patient-reported outcome measures (PROMs) are tools used by patients to directly communicate symptoms to their care team and guide symptom-focused care. Little is known about how PROMs could be integrated into the team-based care models of outpatient hemodialysis centres. In this study, we conducted interviews with people receiving hemodialysis and their clinicians about their perspectives on how PROMs could support interdisciplinary symptom management (i.e., integration of expertise to achieve common management goals). Participants described how the interrelatedness of symptoms was well suited to an integrated care approach and how PROMs enhanced communication and access to information across team members. In cases where symptoms persisted despite appropriate treatment, patients and clinicians explained how PROMs served as a tool to set realistic goals and reshape illness perception. Findings from this study suggest that access to resources, role flexibility, and established relationships within hemodialysis centres are important for sustaining PROM use in this setting.

Mainstreaming Genetic Testing for Adult Patients With Autosomal Dominant Polycystic Kidney Disease.

PURPOSE: Genetic testing results are currently obtained approximately 1 year after referral to a medical genetics team for autosomal dominant polycystic kidney disease (ADPKD). We evaluated a mainstream genetic testing (MGT) pathway whereby the nephrology team provided pre-test counseling and selection of patients with suspected ADPKD for genetic testing prior to direct patient interaction by a medical geneticist. SOURCES OF INFORMATION: A multidisciplinary team of nephrologists, genetic counselors, and medical geneticists developed an MGT pathway for ADPKD using current testing criteria for adult patient with suspected ADPKD and literature from MGT in oncology. METHODS: An MGT pathway was assessed using a prospective cohort and compared to a retrospective cohort of 56 patients with ADPKD who received genetic testing using the standard, traditional pathway prior to implementing the MGT for ADPKD. The mainstream pathway was evaluated using time to diagnosis, diagnostic yield, and a patient survey to assess patient perceptions of the MGT pathway. KEY FINDINGS: We assessed 26 patients with ADPKD using the MGT and 18 underwent genetic testing with return of results. Of them, 52 patients had data available for analysis in the traditional control cohort. The time for return of results using our MGT pathway was significantly shorter with a median time to results of 6 months compared to 12 months for the traditional pathway. We identified causative variants in 61% of patients, variants of uncertain significance in 28%, and 10% had negative testing which is in line with expectations from the literature. The patient surveys showed high satisfaction rates with the MGT pathway. LIMITATIONS: This report is an evaluation of a new genetic testing pathway restricted to a single, publicly funded health care center. The MGT pathway involved a prospective collection of a limited number of patients with ADPKD with comparison to a retrospective cohort of patients with ADPKD evaluated by standard testing. IMPLICATIONS: A MGT pathway using clearly defined criteria and commercially available gene panels for ADPKD can be successfully implemented in a publicly funded health care system to reduce the time required to obtain genetic results.

MOTIF: Actuellement, les résultats du dépistage génétique pour la maladie polykystique rénale autosomique dominante (ADPKD) sont obtenus environ un an après l'aiguillage en médecine génique. Nous avons évalué un parcours de dépistage génétique intégré (DGI) où l'équipe de néphrologie fournit des conseils pré-dépistage et sélectionne les patients soupçonnés d'ADPKD pour un test génétique avant l'interaction directe du patient avec un généticien médical. SOURCES: Une équipe multidisciplinaire constituée de néphrologues, de conseillers en génétique et de généticiens médicaux a développé un parcours de DGI à partir des critères existants pour les patients adultes soupçonnés d'ADPKD et de la littérature portant sur le DGI en oncologie. MÉTHODOLOGIE: Le parcours de DGI a été évalué dans une cohorte prospective puis comparé à une cohorte rétrospective de 56 patients atteints d'ADPKD ayant subi un dépistage génétique selon le parcours traditionnel, avant la mise en œuvre d'un parcours de DGI pour l'ADPKD. Le parcours intégré a été évalué en tenant compte du temps requis pour poser le diagnostic, du rendement diagnostique et d'un sondage auprès des patients évaluant leurs perceptions à l'égard du parcours lui-même. PRINCIPAUX RÉSULTATS: Le parcours de DGI a permis d'évaluer 26 patients atteints d'ADPKD, dont 18 ont subi des tests génétiques avec retour des résultats. Dans la cohorte témoin (dépistage traditionnel), 52 patients disposaient de données disponibles pour l'analyse. Le délai médian pour l'obtention des résultats était significativement plus court avec le parcours de DGI qu'avec le parcours traditionnel (6 mois c. 12 mois). Des variantes causales ont été relevées chez 61 % des patients, 28 % des patients présentaient des variantes de signification incertaine et 10 % ont obtenu des résultats négatifs, ce qui est conforme aux attentes posées par les résultats rapportés dans la littérature. Les sondages menés auprès des patients ont montré des taux de satisfaction élevés à l'égard du parcours de DGI. LIMITES: Ce rapport constitue l'évaluation d'un nouveau parcours de dépistage génétique limitée à un seul centre de soins de santé public. Ce parcours de DGI a été évalué dans une cohorte prospective formée d'un nombre limité de patients atteints d'ADPKD par rapport à une cohorte rétrospective de patients atteints d'ADPKD évalués par la méthode traditionnelle. IMPLICATIONS: Un parcours de DGI utilisant des critères clairement définis et des panels génétiques pour l'ADPKD disponible commercialement peut être mis en œuvre avec succès dans un système de santé public et accélérer l'obtention des résultats génétiques.

Evaluation of the Cost of a High-Dose Intravenous Iron Protocol in a Regional Hemodialysis Program: Research Letter.

BACKGROUND: Intravenous (IV) iron and erythropoietin stimulating agents (ESAs) are standard treatments for anemia in patients receiving maintenance hemodialysis. These medications are associated with significant costs to hemodialysis programs and patients. Recent trial evidence demonstrated that a high-dose IV iron protocol reduces ESA usage and improves cardiovascular outcomes. The cost of implementing a high-dose iron protocol within the Canadian public healthcare context remains unknown. OBJECTIVE: Our primary aim was to estimate the costs of a high-dose IV iron protocol in a large Canadian hemodialysis program that currently uses a low-dose and reactive IV iron strategy. Our secondary aim was to estimate the reduction in ESA use required to maintain cost neutrality with a high-dose IV iron protocol. DESIGN: In this modeling study of IV iron and ESA utilization from a regional hemodialysis program, changes in medication utilization were calculated based on observed effects from published trial data. Using data from a quality improvement audit of regional anemia management and medication utilization, we estimated potential cost differences under various modeling conditions. SETTING: Four adult hospital-based and 9 community in-center hemodialysis units in the Alberta Kidney Care-South renal program during the observation period of September 1, 2018, to November 30, 2018. PATIENTS: In total, data from 826 patients were included. MEASUREMENTS: Mean monthly IV iron and ESA doses were obtained from routine audit data captured within an electronic medical record. Costs were determined from provincially negotiated medication prices. METHODS: Current IV iron and erythropoietin dosages were aggregated at the hemodialysis unit level. We used the results from the PIVOTAL trial to estimate the expected increase in IV iron dose and reduction in ESA dose with a high-dose IV iron protocol. We assumed the split between various manufactures of IV iron and ESA were maintained in our cost model. Total medication costs were aggregated by hemodialysis unit, and the mean costs in each unit were used to estimate per-patient costs. Sensitivity analyses included models that assumed 100% IV iron sucrose usage, as well as models where community hemodialysis units and hospital-based hemodialysis units were examined separately. Finally, we calculated a break-even point for ESA dose reduction required to maintain cost neutrality. RESULTS: Actual baseline IV iron and ESA dose utilization across 13 adult HD units were 118 mg/patient/month (95% confidence interval [CI]: 102-134 mg) and 20,764 IU/pt./mo. (95% CI: 18,104-23,424 IU), respectively. The mean combined cost of ESA and IV iron was $315/pt./mo. (95% CI: $274-$355). In comparison, using the results of the PIVOTAL trial and assuming a high-dose IV iron scenario, we estimated mean IV iron use of 215 mg/pt./mo. (95% CI: 187-243 mg/pt./mo.) and a reduction in mean ESA use to 15,923 IU/pt./mo. (95% CI: 13,883-17,962 IU/pt./mo.). This resulted in an estimated cost savings of $38/pt./mo. (95% CI: $33-$42/pt./mo.) and a total program savings of $370,000 per year (95% CI: $325,000-$420,000). Sensitivity analyses under various alternate conditions also showed potential cost savings. We estimated that a dose reduction of ESA of 10% would be required for cost neutrality with a high-dose IV iron protocol. LIMITATIONS: Our study is limited in its use of data from a single randomized controlled trial (RCT) to estimate cost savings rather than actualized utilization. Our models do not take into consideration anticipated reductions in transfusions and hospitalizations that could be realized from a high-dose IV iron protocol. CONCLUSIONS: Based on cost modeling, a high-dose IV iron protocol could be integrated in large Canadian regional hemodialysis program in a cost saving manner. Programs implementing such a protocol should monitor IV iron and EPO use prospectively to determine if the trial protocol as applied in a real-world setting translates into cost savings.

CONTEXTE: Le traitement habituel pour soigner l'anémie chez les patients sous hémodialyse d'entretien consiste en l'administration d'un supplément de fer par voie intraveineuse (IV) et d'agents de stimulation de l'érythropoïétine (ASE); des médicaments coûteux pour les programs d'hémodialyse et les patients. Des études récentes ont démontré qu'un protocole de fer IV à dose élevée réduisait l'utilization des ASE et améliorait les résultats cardiovasculaires. On ignore toutefois les coûts associés à la mise en œuvre d'un tel protocole dans le système public canadien. OBJECTIFS: Notre principal objectif était d'estimer les coûts d'un protocole de fer IV à dose élevée dans un program majeur d'hémodialyse canadien utilisant une stratégie d'administration de fer IV à faible dose et réactive. Nous souhaitions également estimer le taux de réduction de l'utilization des ASE permettant de maintenir la neutralité des coûts avec un protocole de fer IV à dose élevée. CONCEPTION: Dans cette étude de modélisation, où l'administration de fer IV et d'ASE a été examinée dans le cadre d'un program régional d'hémodialyse, les changements dans l'utilization des médicaments ont été calculés en fonction des effets observés à partir des données publiées. Les potentielles différences de coûts ont été estimées dans diverses conditions de modélisation à l'aide des données d'un audit mesurant l'amélioration de la qualité de la gestion de l'anémie et l'utilization des médicaments au niveau régional. CADRE: Quatre unités d'hémodialyse pour adultes en milieu hospitalier et neuf centers d'hémodialyse communautaires du program Alberta Kidney Care ­ South Renal entre le 1er septembre 2018 et le 30 novembre 2018. SUJETS: Les données de 826 patients ont été incluses. MESURES: Les doses moyennes mensuelles de fer IV et d'ASE ont été obtenues avec les données d'un audit courant tirées d'un dossier médical électronique. Les coûts ont été évalués avec les prix négociés par la province pour ces médicaments. MÉTHODOLOGIE: Les posologies actuelles de fer IV et d'érythropoïétine ont été agrégées au niveau de l'unité d'hémodialyse. Les résultats de l'essai PIVOTAL ont servi à estimer l'augmentation prévue de la dose de fer IV et la réduction prévue de la dose d'ASE avec un protocole de fer IV à dose élevée. Nous avons supposé que la division entre les divers fabricants de fer IV et d'ASE était maintenue dans notre modèle de coûts. Les coûts totaux des médicaments ont été agrégés par unité d'hémodialyse, et les coûts moyens pour chaque unité ont été employés pour estimer les coûts par patient. Les analyses de sensibilité ont inclus des modèles qui supposaient une utilization à 100 % du fer saccharose IV et des modèles où les unités d'hémodialyse communautaires et hospitalières ont été examinées séparément. Enfin, nous avons calculé un seuil de rentabilité pour la réduction d'ASE nécessaire au maintien de la neutralité des coûts. RÉSULTATS: L'utilization réelle initiale de fer IV et d'ASE dans les 13 unités d'HD pour adultes était respectivement de 118 mg/patient/mois (IC 95 % : 102 mg à 134 mg) et de 20 764 UI/pt/mois (IC 95 % : 18 104 à 23 424 UI). Le coût combiné moyen du fer IV et des ASE était de 315 $/pt/mois (IC 95 % : 274 à 355 $). En comparaison, en utilisant les résultats de l'essai PIVOTAL et en supposant un scénario de fer IV à dose élevée, nous avons estimé une utilization moyenne de fer IV à 215 mg/pt/mois (IC 95 % : 187 à 243 mg/pt/mois) et une réduction de l'utilization moyenne d'ASE de 15 923 UI/pt/mois (IC 95 % : 13 883 à 17 962 UI/pt/mois); ce qui entraînerait une possible économie de 38 $/pt/mois (IC 95 % : 33 à 42 $/pt/mois) et une économie totale de 370 000 $ par année pour le program (IC 95 % : 325 000 à 420 000 $). Les analyses de sensibilité dans diverses conditions ont également montré des économies potentielles. Nous avons estimé qu'une réduction de 10 % de la dose d'ASE serait nécessaire pour maintenir la neutralité des coûts avec un protocole de fer IV à dose élevée. LIMITES: Notre étude utilize les données d'un seul essai clinique randomisé pour estimer les économies de coûts plutôt que l'utilization actualisée. Nos modèles ne prennent pas en compte les réductions dans les nombres de transfusions et d'hospitalisations qui pourraient découler d'un protocole de fer IV à dose élevée. CONCLUSION: Selon la modélisation des coûts, un protocole de fer IV à dose élevée pourrait être intégré à un program majeur d'hémodialyse régional canadien et réduire les coûts. Les programs qui mettent en œuvre un tel protocole devraient surveiller l'administration de fer IV et d'EPO de façon prospective pour déterminer si le protocole de l'essai, lorsqu'il est appliqué dans un contexte réel, se traduit par une réduction des coûts.

Outpatient Interventions for Managing Acute Complications of Chronic Diseases: A Scoping Review and Implications for Patients With CKD.

RATIONALE & OBJECTIVE: Patients with chronic kidney disease (CKD) have high rates of emergency department (ED) use and hospitalization. Outpatient care may provide an alternative to ED and inpatient care in this population. We aimed to explore the scope of outpatient interventions used to manage acute complications of chronic diseases and highlight opportunities to adapt and test interventions in the CKD population. STUDY DESIGN: Scoping review of quantitative and qualitative studies. SETTING & POPULATION: Outpatient interventions for adults experiencing acute complications related to 1 of 5 eligible chronic diseases (ie, CKD, chronic respiratory disease, cardiovascular disease, cancer, and diabetes). SELECTION CRITERIA FOR STUDIES: MEDLINE, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials, grey literature, and conference abstracts were searched to December 2019. DATA EXTRACTION: Intervention and study characteristics were extracted using standardized tools. ANALYTICAL APPROACH: Quantitative data were summarized descriptively; qualitative data were summarized thematically. Our approach observed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) extension for scoping reviews. RESULTS: 77 studies (25 randomized controlled trials, 29 observational, 12 uncontrolled before-after, 5 quasi-experimental, 4 qualitative, and 2 mixed method) describing 57 unique interventions were included. Of identified intervention types (hospital at home [n = 16], observation unit [n = 9], ED-based specialist service [n = 4], ambulatory program [n = 18], and telemonitoring [n = 10]), most were studied in chronic respiratory and cardiovascular disease populations. None targeted the CKD population. Interventions were delivered in the home, ED, hospital, and ambulatory setting by a variety of health care providers. Cost savings were demonstrated for most interventions, although improvements in other outcome domains were not consistently observed. LIMITATIONS: Heterogeneity of included studies; lack of data for outpatient interventions for acute complications related to CKD. CONCLUSIONS: Several interventions for outpatient management of acute complications of chronic disease were identified. Although none was specific to the CKD population, features could be adapted and tested to address the complex acute-care needs of patients with CKD.

Assessment of potential biomarkers of subclinical vitamin K deficiency in patients with end-stage kidney disease.

BACKGROUND: A significant proportion of hemodialysis patients have functional, but modifiable, vitamin K deficiency. OBJECTIVE: To determine the correlates of poor vitamin K status in hemodialysis patients. DESIGN: Cross-sectional study. SETTING: Hemodialysis units at Kingston General Hospital and its satellite centres, Ontario, Canada. PATIENTS: Patients undergoing outpatient hemodialysis for end-stage kidney disease. MEASUREMENTS: Serum concentrations of phylloquinone, undercarboxylated prothrombin, also known as protein induced by vitamin K absence or antagonism - factor II (PIVKA-II), and the percentage of undercarboxylated osteocalcin (%ucOC). METHODS: Vitamin K status was determined in fasting blood samples of hemodialysis patients. Bivariate relationships were examined using parametric and non-parametric statistics as appropriate. Multivariable linear regression models were applied to identify predictors of vitamin K status. RESULTS: Among 44 HD patients, criteria for subclinical vitamin K deficiency were met in 13.6% (phylloquinone < 0.4 nmol/L), 51% (%ucOC > 20%) and 90.9% (PIVKA-II > 2.0 nmol/L) of subjects. Phylloquinone levels were positively associated with total cholesterol, triglyceride levels and non-smoking status. Higher %ucOC was associated with increased calcium-phosphate product. Increased PIVKA-II levels were observed with advancing age, reduced dialysis adequacy, lower HDL and a history of coronary artery disease. There were no associations found among the individual biomarkers of vitamin K status. In a multi-variable model, triglycerides were the only significant predictor of phylloquinone levels, while increasing phosphate and decreasing PTH were independent predictors of %ucOC. PIVKA-II levels increased by 0.54 nmol/L for every 10-year increase in age. LIMITATIONS: Observational study; small sample size. CONCLUSIONS: A significant proportion of HD patients met criteria for subclinical vitamin K deficiency. Of the biomarkers measured, PIVKA-II may be superior given its independence of renal function or dyslipidemia, both of which may confound the other vitamin K biomarkers. Studies in patients with ESKD linking biomarkers of vitamin K status to important patient outcomes, including cardiovascular disease, nutritional status and mortality, are required in order to determine the optimal biomarker for evaluating vitamin K status in this particular population.

CONTEXTE: Une proportion considérable de patients traités en hémodialyse ont une carence fonctionnelle, bien que modifiable, en vitamine K. L'objectif de cette étude est de déterminer la corrélation entre une carence en vitamine K chez les patients en hémodialyse. MÉTHODES: Dans le cadre de cette étude d'observation, le statut de la vitamine K était déterminé dans les échantillons sanguins pris à jeun chez 44 patients en hémodialyse, en mesurant les concentrations de phylloquinone, de prothrombine non décarboxylée, aussi connue comme la protéine induite en l'absence de vitamine K ou par antagonisme du facteur II (PIVKA-II), et le pourcentage d'ostéocalcine non décarboxylée (%ucOC). Les relations bivariées ont été examinées à l'aide de statistiques paramétriques et non paramétriques. Des modèles multivariés à régression linéaire ont été appliqués pour déterminer les prédicteurs du statut de la vitamine K. RÉSULTATS: Les critères de carence infraclinique en vitamine K étaient remplis chez 13,6% (phylloquinone < 0,4 nmol/l), 51% (%ucOC > 20%) et 90,9% (PIVKA-II > 2,0 nmol/l) des sujets. Les taux de phylloquinone ont été positivement associés avec les taux de cholestérol total, et de triglycérides, ainsi que le statut de non-fumeur. Un taux élevé de %ucOC a été associé avec une augmentation du produit phosphocalcique. Des taux croissants de PIVKA-II ont été observés avec l'âge, le caractère non adéquat de la dialyse, un faible taux de HDL et des antécédents de coronaropathie. Aucune association n'a été établie parmi les biomarqueurs individuels du statut de la vitamine K. Dans un modèle multivariable, les triglycérides constituaient le seul prédicteur important des taux de phylloquinone, alors qu'un taux croissant de phosphate et un taux décroissant de PTH étaient des prédicteurs indépendants de %ucOC. Les taux de PIVKA-II ont augmenté de 0,54 nmol/l par tranche d'âge de 10 ans. CONCLUSIONS: Une proportion considérable de patients en hémodialyse ont rempli les critères de carence infraclinique en vitamine K. Parmi les biomarqueurs mesurés, PIVKA-II serait le plus fiable, considérant son indépendance par rapport à la fonction rénale ou la dyslipidémie, lesquels peuvent confondre les autres biomarqueurs de la vitamine K. Des études auprès de patients souffrant d'insuffisance rénale terminale permettraient de créer des liens entre les biomarqueurs du statut de la vitamine K et des résultats importants pour le patient, tels que les maladies cardiovasculaires, l'état nutritionnel et le décès, et seraient donc nécessaires afin de déterminer le biomarqueur optimal pour évaluer le statut de la vitamine K dans cette population en particulier.