Prescription Pattern of Cation Exchange Resins and Their Efficacy in Treating Chronic Hyperkalemia Among Patients With Chronic Kidney Diseases: Findings From a Population-Based Analysis in British Columbia, Canada.

Background: Little was known about how chronic hyperkalemia (cHK) in patients with chronic kidney disease (CKD) is managed in British Columbia, Canada. Objective: To investigate the trend in sodium polystyrene sulfonate (SPS) and calcium polystyrene sulfonate (CPS) utilization and their efficacy in treating cHK in CKD patients from British Columbia, Canada. Study Design: Retrospective cohort. Setting & Patients: CKD patients aged ≥18 years, followed in Kidney Care Clinic (KCC), who had at least 2 potassium values ≥5.0 mmol/L separated by no more than 91 days during the period of June 1, 2015, to July 31, 2021, were included. Index date was the first date of the 2 potassium values ≥5.0 mmol/L. Patients who received SPS or CPS within 90 days before index date were excluded. Patients who were on dialysis or received kidney transplantation on or before index date were also excluded. Exposure: Continuous exposure to SPS and CPS. Outcome: SPS/CPS prescription utilization trend was described by the proportion of patients ever treated with SPS/CPS, median time in days between cHK diagnosis and initiating treatment with SPS/CPS, total and median number of SPS/CPS prescriptions dispensed. Change in mean serum potassium concentration before and after a 90-day continuous treatment with SPS/CPS was estimated. Analytical Approach: Descriptive. Results: This study included 10 495 patients with cHK (median age 74 years, 60% were male). Median follow-up time was 625 days. Only 2864 (27%) patients were dispensed at least 1 prescription of either SPS or CPS. A total 7300 prescriptions were dispensed; median prescriptions dispensed per patients were 2 (interquartile range [IQR]: 1-3). Median time from index date to the first prescription dispensing date was 154 days (IQR: 36-455). Continuous 90-day treatment with SPS/CPS decreased the mean serum potassium concentration by 0.60 mmol/L, from 5.58 to 4.98 mmol/L. Limitations: Descriptive observational study without control group. Conclusions: In British Columbia, only 1 in 4 CKD patients with cHK were dispensed with SPS/CPS, mostly with higher degrees of hyperkalemia. These medications appeared to be moderately effective in reducing the serum potassium concentration. Future research is necessary to evaluate the comparative effectiveness of newer generation medications.

Contexte: On savait peu de choses sur la façon dont l'hyperkaliémie chronique (HKc) est prise en charge chez les patients atteints d'insuffisance rénale chronique (IRC) de la Colombie-Britannique (C.-B.), au Canada. Objectif: Étudier les tendances d'utilisation du sulfonate de polystyrène sodique (SPS) et du sulfonate de polystyrène calcique (SPC), ainsi que l'efficacité de ces agents dans le traitement de l'HKc chez les patients britanno-colombiens atteints d'IRC. Type d'étude: étude de cohorte rétrospective. Sujets et cadre de l'étude: Ont été inclus des adultes atteints d'IRC suivis en clinique de soins rénaux qui avaient au moins 2 valeurs de potassium ≥ 5,0 mmol/L mesurées à moins de 91 jours d'intervalle entre le 1er juin 2015 et le 31 juillet 2021. La date de la première des deux valeurs de potassium ≥ 5,0 mmol/L constitue la date indice. Les patients qui avaient reçu du SPS ou du SPC dans les 90 jours précédant la date indice ont été exclus. Les patients sous dialyse ou ayant reçu une greffe rénale avant ou à la date indice ont également été exclus. Exposition: Exposition continue au SPS et au SPC. Résultats: La tendance d'utilisation de SPS/SPC a été décrite par la proportion de patients ayant déjà été traités par SPS/SPC, par le temps médian en jours entre le diagnostic d'hyperkaliémie chronique et le début du traitement par SPS/SPC, et par le nombre total et médian de prescriptions de SPS/SPC délivrées. La variation de la concentration moyenne de potassium sérique avant et après un traitement continu de 90 jours avec SPS/SPC a été estimée. Approche analytique: Descriptive. Résultats: L'étude porte sur 10 495 patients atteints d'hyperkaliémie chronique (60 % d'hommes; âge médian: 74 ans). Le temps médian de suivi était de 625 jours. Seulement 2 864 (27 %) patients avaient reçu au moins une prescription de SPS ou de SPC. Au total, 7 300 ordonnances ont été délivrées; la moyenne d'ordonnances délivrées par patient était de 2 (IIQ: 1, 3). Le délai médian entre la date indice et la date de la première ordonnance était de 154 jours (IIQ: 36, 455). Un traitement continu de 90 jours avec SPS/SPC a abaissé la concentration moyenne de potassium sérique de 0,60 mmol/L, la faisant passer de 5,58 à 4,98 mmol/L. Limites: Étude observationnelle descriptive sans groupe témoin. Conclusion: En C.-B., seul un patient sur quatre atteint d'IRC avec HKc avait reçu une prescription de SPS/SPC, la plupart présentaient des degrés plus élevés d'hyperkaliémie. Ces médicaments se sont avérés modérément efficaces pour réduire la concentration sérique en potassium. Des recherches supplémentaires sont nécessaires pour évaluer l'efficacité comparative des médicaments de nouvelle génération.

Nutritional Status, Nutritional Phenotypes, and Oral Nutritional Supplement Prescription Patterns Among Patients With Non-Dialysis Chronic Kidney Disease in British Columbia.

OBJECTIVES: Management of protein-energy wasting and undernutrition with oral nutritional supplements (ONS) has not been systematically studied in the non-dialysis chronic kidney disease (CKD-ND) population. We aimed to describe nutritional status, identify phenotypes of patients prescribed ONS, and evaluate ONS prescription patterns among CKD-ND patients in British Columbia. DESIGN AND METHODS: This observational study assessed adult CKD-ND patients who entered multidisciplinary CKD clinics during 2013-2018 in British Columbia. Descriptive statistics were used to describe baseline nutrition and inflammation parameters among patients prescribed ONS versus patients not prescribed ONS within 1 year of clinic entry. Hierarchical clustering method with consensus clustering was applied to identify phenotypes of patients prescribed ONS. Multivariable logistic regression was used to assess the associations between ONS prescription and health region/dietitian full-time equivalents per 1,000 CKD patients. RESULTS: Of 15,859 CKD-ND patients, 9% of patients entering CKD clinics were prescribed ONS within 1 year of clinic entry, and these patients demonstrated lower baseline estimated glomerular filtration rate, body mass index (BMI), serum albumin, bicarbonate, as well as greater age, serum phosphate, and neutrophil-to-lymphocyte ratio compared with those not receiving ONS. Cluster analysis revealed 5 phenotypes of ONS users: cluster 1 had the highest mean neutrophil-to-lymphocyte ratio; cluster 2 had the lowest mean albumin; cluster 3 had the lowest mean BMI; cluster 4 had the highest mean BMI; and cluster 5 had the lowest mean bicarbonate. There was regional variability in ONS prescription, and an odds ratio for ONS prescription of 1.32 (95% confidence interval 1.16-1.50) for every 1-unit increase in dietitian full-time equivalents per 1,000 patients. Over 3 years of follow-up, overall ONS use among CKD-ND patients remained stable. CONCLUSIONS: This study demonstrates appropriate prescribing of ONS to patients with suboptimal nutritional status, although regional variation exists. Patients receiving ONS represent a heterogenous group with phenotypes reflecting several clinical and biochemical features of the protein-energy wasting syndrome. These findings will assist with updating ONS policy, planning quality improvement initiatives, and informing dietitian resource allocation.

Serum Biomarkers of Iron Stores Are Associated with Increased Risk of All-Cause Mortality and Cardiovascular Events in Nondialysis CKD Patients, with or without Anemia.

BACKGROUND: Approximately 30%-45% of patients with nondialysis CKD have iron deficiency. Iron therapy in CKD has focused primarily on supporting erythropoiesis. In patients with or without anemia, there has not been a comprehensive approach to estimating the association between serum biomarkers of iron stores, and mortality and cardiovascular event risks. METHODS: The study included 5145 patients from Brazil, France, the United States, and Germany enrolled in the Chronic Kidney Disease Outcomes and Practice Patterns Study, with first available transferrin saturation (TSAT) and ferritin levels as exposure variables. We used Cox models to estimate hazard ratios (HRs) for all-cause mortality and major adverse cardiovascular events (MACE), with progressive adjustment for potentially confounding variables. We also used linear spline models to further evaluate functional forms of the exposure-outcome associations. RESULTS: Compared with patients with a TSAT of 26%-35%, those with a TSAT ≤15% had the highest adjusted risks for all-cause mortality and MACE. Spline analysis found the lowest risk at TSAT 40% for all-cause mortality and MACE. Risk of all-cause mortality, but not MACE, was also elevated at TSAT ≥46%. Effect estimates were similar after adjustment for hemoglobin. For ferritin, no directional associations were apparent, except for elevated all-cause mortality at ferritin ≥300 ng/ml. CONCLUSIONS: Iron deficiency, as captured by TSAT, is associated with higher risk of all-cause mortality and MACE in patients with nondialysis CKD, with or without anemia. Interventional studies evaluating the effect on clinical outcomes of iron supplementation and therapies for alternative targets are needed to better inform strategies for administering exogenous iron.

Anemia and iron deficiency among chronic kidney disease Stages 3-5ND patients in the Chronic Kidney Disease Outcomes and Practice Patterns Study: often unmeasured, variably treated.

BACKGROUND: International variation in anemia assessment and management practices in chronic kidney disease (CKD) is poorly understood. METHODS: We performed a cross-sectional analysis of anemia laboratory monitoring, prevalence and management in the prospective Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps). A total of 6766 participants with CKD Stages 3a-5ND from nephrology clinics in Brazil, France, Germany and the USA were included. RESULTS: Among patients with anemia (hemoglobin <12 g/dL), 36-58% in Brazil, the USA and Germany had repeat hemoglobin measured and 40-61% had iron indices measured within 3 months of the index hemoglobin measurement. Anemia was more common in the USA and Brazil than in France and Germany across CKD stages. Higher ferritin and lower iron saturation (TSAT) levels were observed with lower hemoglobin levels, and higher ferritin with more advanced CKD. The proportion of anemic patients with ferritin <100 ng/mL or TSAT <20% ranged from 42% in Brazil to 53% in France and Germany, and of these patients, over 40% in Brazil, Germany and the USA, compared with 27% in France, were treated with oral or intravenous iron within 3 months after hemoglobin measurement. The proportion of patients with hemoglobin <10 g/dL treated with erythropoiesis-stimulating agents ranged from 28% in the USA to 57% in Germany. CONCLUSIONS: Hemoglobin and iron stores are measured less frequently than per guidelines. Among all regions, there was a substantial proportion of anemic patients with iron deficiency who were not treated with iron, highlighting an area for practice improvement in CKD care.