Adherence to a Healthy Plant-Based Diet and Cardiovascular-Kidney-Metabolic Risk Factors in Patients with Moderate to Advanced Chronic Kidney Disease

OBJECTIVE

The confluence of cardiovascular-kidney-metabolic (CKM) risk factors and chronic kidney disease (CKD) elevates the risk for adverse cardiovascular and kidney outcomes. Mounting evidence has emerged on the benefits of plant-based diets for CKD management. However, whether the benefits are mediated by improved CKM health are unclear. In addition, there remain concerns about the risk of malnutrition and hyperkalemia associated with plant-based diets. The objective of this study was to assess the relationship between adherence to healthy plant-based diets and CKM syndrome, nutritional status, and serum potassium levels in patients with nondialysis CKD stages 3-5.

METHOD

A total of 147 patients (median age 66 years) with CKD (median eGFR 23.1 mL/min/1.73 m2) were included. Responses to a food frequency questionnaire developed for the Asian population with CKD were used to calculate a healthy plant-based diet score (HPDS), which reflects higher consumption of plant foods and reduced intake of animal products and sugar. CKM risk factors included overweight/obesity, central obesity, high blood pressure, high triglycerides, and high blood glucose. Nutritional status was assessed using serum albumin and dietary energy and protein intake.

RESULTS

In logistic regression analyses, a higher HPDS was significantly associated with lower odds of all CKM risk factors and malnutrition. After adjusting for age, sex, comorbidities, lifestyle factors, and medications, a higher HPDS remained significantly linked to lower odds of overweight/obesity and central obesity, as well as higher odds of having a normal serum albumin level (≥ 3.8 g/dL), dietary protein intake (≥ 0.6 g/kg/day), and dietary energy intake (≥ 25 g/kg/day). No significant association was observed between HPDS and hyperkalemia.

CONCLUSIONS

In patients with moderate to advanced CKD, healthy plant-based diets were associated with a lower risk of CKM syndrome. Adherence to a healthy plant-based diet was more likely to achieve a better nutritional status and was not associated with risk of hyperkalemia.

Dietary Guidelines Post Kidney Transplant: Is This the Missing Link in Recovery and Graft Survival?

The physiology of a transplanted kidney is affected from the moment it is separated from the donor. The risk of complications arising from surgery are highly associated with ischemic-reperfusion injury (IRI) due to the effects of hypoxia and oxidative stress during the procurement, preservation and reperfusion procedures. Hypoxia promotes the formation of reactive oxygen species (ROS) and it seems apparent that finding ways of optimising the metabolic milieu for the transplanted kidney would improve recovery and graft survival. Studies have demonstrated the benefits of nutrition and antioxidant compounds in mitigating the disturbance of energy supply to cells post-transplant and at improving long-term graft survival. Particularly in patients who may be nutritionally deficient following long-term dialysis. Despite the high incidence of allograft failure, a search of the literature and grey literature reveals no medical nutriti on therapy guidelines on beneficial nutrient intake to aid transplant recovery and survival. This narrative review aims to summarise current knowledge of specific macro and micronutrients and their effect on allograft recovery and survival in the perioperative period, up to 1-year post transplant, to optimise the metabolic environment and mitigate risk to graft injury.

Agreement between methods to assess potassium intake in patients with chronic kidney disease

BACKGROUND & AIMS

In the general population, 24-h urine potassium excretion is considered the reference standard for estimating potassium intake. However, its agreement with food records and spot urine collections in adults living with chronic kidney disease (CKD) is not well-established. Given the risk of hyperkalemia related to changes in renal potassium handling, understanding if this reference standard is appropriate for the CKD population is important. This study aimed to compare agreement between methods for estimating potassium intake, using food records, 24-h urine measures, and spot urine samples.

METHODS

A cross-sectional study was conducted among adults recruited from a kidney care clinic. Participants were instructed to complete a detailed food record and a 24-h urine collection, both performed on the same day. The following day, participants provided a spot urine sample from the second void, at the research site. Potassium excretion was estimated from the spot urine sample using Tanaka's and Kawasaki's equations. Agreement between methods was assessed using the highest p-value for paired t-test and the lowest Bland-Altman bias combined with the narrowest upper and lower limits of agreements (LoA).

RESULTS

60 adults with Stage 3 and 4 CKD completed the study (48 % male, 62.9 ± 14.6 years; eGFR = 34.9 ± 12.7 mL/min). The food records showed the highest agreement with 24-h urine potassium (1823.9 ± 746.7 vs 1918.2 ± 809.3, p = 0.584). This was followed by Kawasaki's equation for spot urine (1994.8 ± 441.9, p = 0.231) and Tanaka's equation (1630.0 ± 325.9, p = 0.174). Food records and Kawasaki's equation had slightly higher mean values compared to 24-h urine with mean differences <100-200 mg/day (bias; 95%CI: bias = -94.4 mg/day; -438.3 to 249.6 mg/day and -170.9 mg/day; -454.1 to 112.2 mg/day, respectively). Tanaka's equation had a lower mean value compared to 24-h urine with a mean difference of 193.9 mg/day; -88.5 to 476.3 mg/day). The limits of agreement were as follows: in the Kawasaki's equation from -2082.2 to 1740.3 mg/day, in the Tanaka's equation from -1712.2 to 2100.0 mg/day and in the food records from -2416.1 to 2227.4 mg/day.

CONCLUSION

Mean potassium intake estimates were similar across methods. Food records demonstrated the highest agreement with 24-h urine potassium, followed by Kawasaki's equation. The Tanaka's equation showed the highest bias compared to 24-h urine and was significantly different from food records. Combining food records with potassium excretion estimated using the Kawasaki's equation from spot urine samples may be a clinically useful tool for assessing potassium intake in adults with CKD.

Nutritional Intake and Diet Quality in Hemodialysis Patients: Scope for Improvement

OBJECTIVE

Hemodialysis (HD) patients face challenges in upholding dietary compliance. This study aimed to compare dietary intake against disease-specific guidelines. Secondary, to assess the overall diet quality and to explore the association between dietary potassium intake and serum potassium concentrations.

METHODS

In this cross-sectional multicenter study, nutrient intake of Dutch adult HD patients was assessed using food frequency questionnaires and diet quality with the Dutch Healthy Diet 15-index. Intake and diet quality were compared to disease-specific dietary recommendations or Dutch Dietary Guidelines. Insufficient intake was defined as <90% of the requirement, sufficient as 90-100%, and excessive as >110%. The association between serum potassium concentration and dietary potassium intake was modeled with linear regression analysis.

RESULTS

The study population consisted of 248 participants (60% male) from 21 dialysis centers. Energy intake (1789 [872] kcal/day) was insufficient for 45% of the participants, while protein intake (1 [0.5] g/kg/d) was insufficient for 50%. Despite 67% of participants managing to align their energy intake below 110% of the recommended level, a high prevalence of overweight (61%) was observed in this cohort. Saturated fat intake was excessive for 87% of participants, while only 15% met the recommended fiber intake. Overall diet quality was low (74 [20] maximum score of 150). No association was observed between serum potassium and dietary potassium intake after adjusting for relevant confounders (r = 0.163, P = .261).

CONCLUSIONS

A considerable proportion of Dutch HD patients were unable to meet disease-specific dietary guidelines. Diet quality was shown to be poor.

Dietary Needs, Barriers, and Facilitators Among Patients on Hemodialysis and Their Caregivers: The GoodRENal Project in Spain

OBJECTIVE

Dietary restrictions are common in patients undergoing hemodialysis (HD). These restrictions result in a complex diet that becomes difficult for patients to understand and to follow. Therefore, we aimed to identify dietary needs, barriers, and facilitators that influence the adherence to dietary recommendations as perceived by patients on HD and their caregivers.

METHODS

Seventy-two Spanish patients on HD and 57 caregivers participated in this explorative study by replying a questionnaire consisting of 20 and 10 questions respectively. The responses were assessed using a Likert scale varying from 1 to 5 (strongly agree, agree, neither disagree or disagree, disagree, strongly disagree, respectively) to evaluate the perception of patients and caregivers regarding dietary needs, barriers, and facilitators to adhere to the recommended diet. For analysis purposes, the responses were grouped in 3 categories (agree, neither agree or disagree, disagree).

RESULTS

Seventy percent of the patients agreed that knowing the food sources of potassium, protein and phosphate was a need for them to know to be able to adhere to the dietary recommendations. Moreover, patients stated that not being able to eat what they liked, and feeling thirsty, were important barriers. For caregivers, the support of a renal dietitian was mentioned as an important facilitator to assist those they cared for to adhere to the diet.

CONCLUSIONS

Knowing food sources of potassium, phosphate, and protein, exploring foods patients like to eat and adjusting fluid intake to avoid feeling thirsty were identified as important by the patients. These findings can be used to develop strategies and educational material to improve the dietary adherence in patients undergoing HD. Moreover, the presence of a renal dietitian was identified as an important resource by the caregivers.

Plant-Dominant Low-Protein Diets: A Promising Dietary Strategy for Mitigating Disease Progression in People with Chronic Kidney Disease-A Comprehensive Review

Chronic kidney disease (CKD) is a global health crisis affecting over 10% of the population, with mortality rates increasing significantly. Current management strategies, including expensive medications and renal replacement therapies, highlight the need for cost-effective, conservative approaches. This review examines the evidence for plant-dominant low-protein diets (PLADO) in managing non-dialysis-dependent CKD. Existing guidelines for protein restriction in CKD vary considerably, with inconsistencies and a lack of personalization noted in the KDOQI and KDIGO recommendations. While traditional low-protein diet trials show limited success due to poor adherence and marginal benefits, PLADO offers a potentially more sustainable alternative. PLADO's advantages include improved nutrient density, reduced dietary acid load, anti-inflammatory effects, and beneficial modulation of the gut microbiome, potentially reducing uremic toxins and improving cardiovascular health. However, challenges remain, including adherence issues, potential nutrient deficiencies, and potassium management. Although observational studies show promise, further large-scale randomized controlled trials are necessary to validate PLADO's efficacy and establish optimal dietary composition. A personalized, multidisciplinary approach is essential for successful implementation and monitoring to maximize PLADO's benefits in improving outcomes for individuals with NDD-CKD.

Barriers and Facilitators to Adherence to a Healthy Diet Across the Spectrum of Chronic Kidney Disease

Purpose

A healthy diet plays an important role for chronic kidney disease (CKD) treatment, but adherence to nutritional recommendations is frequently low. The aim of the present study was to describe barriers and facilitators to adherence to a healthy diet in people with CKD.

Patients and Methods

Cross-sectional study; 80 predialysis (n=20), hemodialysis (n=20), peritoneal dialysis (n=20) and transplant (n=20) patients matched by age and sex, were included. Nutritional evaluation included subjective global assessment, anthropometry, quality of food consumption (Mini-ECCA v.2), self-perception about diet and willingness to change. Barriers and facilitators were evaluated with a qualitative approach (semi-structured interviews). Concepts were converted into "in vivo" and "theoretical" codes, then, grouped into categories. A second analysis was performed with the ATLAS.ti software.

Results

Frequency of malnutrition was 50% in people receiving dialysis. Quality of food consumption was healthier on people with CKD stages 3b-5 (40%) and people with kidney transplant (65%) compared to peritoneal dialysis (25%) and hemodialysis (0%). The main themes influencing adherence to a healthy diet were: need for nutritional guidance, economy, dietary restrictions, willingness to change, relationship with consequences in disease control and health status, aversion for healthy foods, bad and good self-perception, family support, feelings and emotions, environment, eating habits and CKD itself. Lack of time, work, economy, food preferences and cravings were the main barriers in people with CKD stage 3b-5 and transplant, while low willingness to eat healthy foods and dietary restrictions were the main barriers in people receiving dialysis.

Conclusion

Personal, environmental, health professional-related, CKD related as well as feelings and emotions aspects that people with CKD face in a daily basis, act as barriers or facilitators when trying to follow a healthy diet. Individualizing nutritional treatment taking into account people with CKD perspectives and situations is of utmost importance to improve adherence to nutritional treatment.

Seasonal variation of serum potassium in hemodialysis patients: myth or reality? A narrative review of literature

Research has shown that patients undergoing hemodialysis experience seasonal variations in their serum potassium levels. There was inconsistent seasonal fluctuation in serum potassium levels among the hemodialysis population across different locations. In the form of narrative review for the first time, the article discusses the seasonal changes of serum potassium in this population and its potential reasons, this article demonstrates that it is primarily attributable to seasonal dietary potassium intake. However, existing studies have not quantified seasonal dietary potassium intake, so the results are still speculative. Furthermore, future research ought to further expound upon the clinical implications of seasonal variations in serum potassium levels among dialysis patients, as well as other influencing mechanisms such as the pathophysiological causes of these seasonal changes, particularly those pertaining to dietary, geographical, and regional factors. These findings contribute to a more thorough interpretation of laboratory results in hemodialysis patients and provide important guidance for their individualized dietary management.

Dietary nutrient intake and nutritional status in maintenance hemodialysis patients: a multicenter cross-sectional survey

PURPOSE

To investigate the dietary nutrient intake of Maintenance hemodialysis (MHD) patients, identify influencing factors, and explore the correlation between dietary nutrient intake and nutritional and disease control indicators.

METHODS

This was a multicenter cross-sectional study. A dietary survey was conducted using a three-day dietary record method, and a self-designed diet management software was utilized to calculate the daily intake of dietary nutrients. The nutritional status and disease control indicators were assessed using subjective global assessment, handgrip strength, blood test indexes, and dialysis adequacy.

RESULTS

A total of 382 MHD patients were included in this study. Among them, 225 (58.9%) and 233 (61.0%) patients' protein and energy intake did not meet the recommendations outlined in the National Kidney Foundation's Kidney Disease Outcomes Quality Initiative Clinical Practice Guideline for Nutrition in Chronic Kidney Disease (2020 update). The average protein and energy intake for these patients were 0.99 ± 0.32 g/kg/d and 29.06 ± 7.79 kcal/kg/d, respectively. Multiple linear regression analysis showed that comorbidity-diabetes had a negative influence on normalized daily energy intake (nDEI = DEI / ideal body weight) (B = -2.880, p = 0.001) and normalized daily protein intake (nDPI = DPI / ideal body weight) (B = -0.109, p = 0.001). Pearson correlation analysis revealed that dietary DPI (r = -0.109, p < 0.05), DEI (r = -0.226, p < 0.05) and phosphorus (r = -0.195, p < 0.001) intake were statistically correlated to Kt/V; dietary nDPI (r = 0.101, p < 0.05) and sodium (r = -0.144, p < 0.001) intake were statistically correlated to serum urea nitrogen; dietary DPI (r = 0.200, p < 0.001), DEI (r = 0.241, p < 0.001), potassium (r = 0.129, p < 0.05), phosphorus (r = 0.199, p < 0.001), and fiber (r = 0.157, p < 0.001) intake were statistically correlated to serum creatinine; dietary phosphorus (r = 0.117, p < 0.05) and fiber (r = 0.142, p < 0.001) intake were statistically correlated to serum phosphorus; dietary nDPI (r = 0.125, p < 0.05), DPI (r = 0.135, p < 0.05), nDEI (r = 0.116, p < 0.05), DEI (r = 0.125, p < 0.05), potassium (r = 0.148, p < 0.001), and phosphorus (r = 0.156, p < 0.001) intake were statistically correlated to subjective global assessment scores; dietary nDPI (r = 0.215, p < 0.001), DPI (r = 0.341, p < 0.001), nDEI (r = 0.142, p < 0.05), DEI (r = 0.241, p < 0.001), potassium (r = 0.166, p < 0.05), phosphorus (r = 0.258, p < 0.001), and fiber (r = 0.252, p < 0.001) intake were statistically correlated to handgrip strength in males; dietary fiber (r = 0.190, p < 0.05) intake was statistically correlated to handgrip strength in females.

CONCLUSIONS

The dietary nutrient intake of MHD patients need improvement. Inadequate dietary nutrient intake among MHD patients could have a detrimental effect on their blood test indexes and overall nutritional status. It is crucial to address and optimize the dietary intake of nutrients in this patient population to enhance their health outcomes and well-being.

Associations Between Dietary Potassium Intake From Different Food Sources and Hyperkalemia in Patients With Chronic Kidney Disease

OBJECTIVE

Previous studies reported mixed results on associations between dietary potassium intake and hyperkalemia in patients with chronic kidney disease (CKD). This study investigated the association between potassium intake from different food sources and hyperkalemia in patients with non-dialysis-dependent CKD.

METHODS

A total of 285 patients were recruited at a university hospital and 2 city hospitals in Tokyo. Dietary potassium intake was estimated by a validated diet history questionnaire. Associations of potassium intake from all foods and individual food groups with serum potassium were examined by multivariable linear regression among potassium binder nonusers. An association between tertile groups of potassium intake and hyperkalemia, defined as serum potassium ≥5.0 mEq/L, was evaluated by multivariable logistic regression.

RESULTS

Among 245 potassium binder nonusers, total potassium intake was weakly associated with serum potassium (regression coefficient = 0.147, 95% confidence interval (CI): 0.018-0.277), while an association with hyperkalemia was not observed (first vs third tertile: adjusted odds ratio = 0.98, 95% CI: 0.29-3.26). As for food groups, potassium intakes from potatoes, pulses, and green/yellow vegetables were positively associated with serum potassium. Patients in the highest tertile of potassium intake from potatoes had higher odds of hyperkalemia as compared to those in the lowest tertile (adjusted odds ratio = 4.12, 95% CI: 1.19-14.34).

CONCLUSION

Total potassium intake was weakly associated with serum potassium, but not with hyperkalemia. Potassium intake from potatoes was associated with hyperkalemia. These findings highlight the importance of considering food sources of potassium in the management of hyperkalemia in CKD.

Real-World Application of a Quantitative Systems Pharmacology (QSP) Model to Predict Potassium Concentrations from Electronic Health Records: A Pilot Case towards Prescribing Monitoring of Spironolactone

Quantitative systems pharmacology (QSP) models are rarely applied prospectively for decision-making in clinical practice. We therefore aimed to operationalize a QSP model for potas-sium homeostasis to predict potassium trajectories based on spironolactone administrations. For this purpose, we proposed a general workflow that was applied to electronic health records (EHR) from patients treated in a German tertiary care hospital. The workflow steps included model exploration, local and global sensitivity analyses (SA), identifiability analysis (IA) of model parameters, and specification of their inter-individual variability (IIV). Patient covariates, selected parameters, and IIV then defined prior information for the Bayesian a posteriori prediction of individual potassium trajectories of the following day. Following these steps, the successfully operationalized QSP model was interactively explored via a Shiny app. SA and IA yielded five influential and estimable parameters (extracellular fluid volume, hyperaldosteronism, mineral corticoid receptor abundance, potassium intake, sodium intake) for Bayesian prediction. The operationalized model was validated in nine pilot patients and showed satisfactory performance based on the (absolute) average fold error. This provides proof-of-principle for a Prescribing Monitoring of potassium concentrations in a hospital system, which could suggest preemptive clinical measures and therefore potentially avoid dangerous hyperkalemia or hypokalemia.

Real-world management of chronic and postprandial hyperkalemia in CKD patients treated with patiromer: a single-center retrospective study

INTRODUCTION

Hyperkalemia, one of the most important electrolyte abnormalities of chronic kidney disease (CKD), often limits the use of renin-angiotensin-aldosterone system inhibitors and can increase in the postprandial period. In this study we report a real-world experience with the new non-adsorbed potassium binder patiromer in stage 3b-4 CKD patients. Moreover, we performed a cross-sectional analysis to evaluate, for the first time, the efficacy of patiromer in the control of postprandial potassium concentrations.

METHODS

We retrospectively collected data of 40 patients at the time of patiromer initiation (T0), and after 2 (T2), 6 (T6) and 12 (T12) months of treatment. For cross sectional analysis, a blood sample was collected 2 h after the main meal for the evaluation of postprandial potassium concentrations.

RESULTS

Eighty-two point five percent of patients (33/40) reached normal potassium concentrations at T2. Serum potassium significantly decreased at T2 compared to T0 (5.13 ± 0.48 vs 5.77 ± 0.41 mmol/L, respectively; p < 0.001) and the reduction remained significant during the follow-up (5.06 ± 0.36 at T6 and 5.77 ± 0.41 at T12; p < 0.001 vs T0). Renin-angiotensin-aldosterone system inhibitors were continued by 93% of patients (27/29). Adverse events were reported in 27.5% of patients and were all mild-to-moderate. Postprandial potassium concentrations did not significantly change compared to fasting state potassium measured at T12 (4.53 ± 0.33 vs 5.06 ± 0.36 mmol/L; p = 0.15).

CONCLUSIONS

In a real-world setting of advanced CKD patients, patiromer is a useful treatment for hyperkalemia, since it significantly reduces serum potassium levels over the long term and is able to maintain potassium concentrations in the normal range even in the post-prandial period.

Hyperkalemia Recurrence and Its Association With Race and Ethnicity in United States Veterans: A Retrospective Cohort Study

INTRODUCTION

Information on whether race and ethnicity are associated with a greater risk of recurrent hyperkalemia is limited. The aim of this study was to examine the association between race or ethnicity and recurrent hyperkalemia in a population of US veterans.

METHODS

This retrospective study used the US Veterans Affairs database to identify adults (aged ≥18 years) with at least one serum potassium measurement during the study period who ever experienced hyperkalemia (serum potassium > 5.0 mmol/L). The proportion of patients with hyperkalemia recurrence (≥1 subsequent event) within one year was determined for different race and ethnicity groups. The association between patient race and ethnicity and the risk of hyperkalemia recurrence within one year after the index hyperkalemia event was analyzed using competing risk regression.

RESULTS

Among a total of 1,493,539 veterans with incident hyperkalemia (median age (interquartile range): 61.0 years (54.0, 71.0)), recurrence within one year occurred in 19.1% of Black, 16.0% of Native Hawaiian/other Pacific Islander, 15.1% of White, 14.9% of American Indian/Alaska Native, and 13.1% of Asian patient groups. Recurrent hyperkalemia occurred in 18.1% of Hispanic and 15.6% of non-Hispanic patient groups. In a fully-adjusted regression model, recurrent hyperkalemia risk was significantly higher in Black versus White patient groups (subhazard ratio (sHR), 1.17; 95% confidence interval (CI), 1.16-1.19; p< 0.0001) and in Hispanic versus non-Hispanic patient groups (sHR, 1.30; 95% CI, 1.28-1.33; p< 0.0001).

DISCUSSION/CONCLUSION

Among US veterans with incident hyperkalemia, the risk of recurrent hyperkalemia was higher in Black and Hispanic patient groups. This information may be useful for health system screenings to risk stratify patient groups and both guide the frequency of serum potassium monitoring and better understand the root causes of group differences.

Potassium-Enriched Salt Substitutes: A Review of Recommendations in Clinical Management Guidelines

Excess dietary sodium intake and insufficient dietary potassium intake are both well-established risk factors for hypertension. Despite some successful initiatives, efforts to control hypertension by improving dietary intake have largely failed because the changes required are mostly too hard to implement. Consistent recent data from randomized controlled trials show that potassium-enriched, sodium-reduced salt substitutes are an effective option for improving consumption levels and reducing blood pressure and the rates of cardiovascular events and deaths. Yet, salt substitutes are inconsistently recommended and rarely used. We sought to define the extent to which evidence about the likely benefits and harms of potassium-enriched salt substitutes has been incorporated into clinical management by systematically searching guidelines for the management of hypertension or chronic kidney disease. We found incomplete and inconsistent recommendations about the use of potassium-enriched salt substitutes in the 32 hypertension and 14 kidney guidelines that we reviewed. Discussion among the authors identified the possibility of updating clinical guidelines to provide consistent advice about the use of potassium-enriched salt for hypertension control. Draft wording was chosen to commence debate and progress consensus building: strong recommendation for patients with hypertension-potassium-enriched salt with a composition of 75% sodium chloride and 25% potassium chloride should be recommended to all patients with hypertension, unless they have advanced kidney disease, are using a potassium supplement, are using a potassium-sparing diuretic, or have another contraindication. We strongly encourage clinical guideline bodies to review their recommendations about the use of potassium-enriched salt substitutes at the earliest opportunity.

Importance of the Vegetable and Fruit Intake for Health Based on the Relationship between Urinary Potassium Excretion and Cerebro-cardiovascular-renal Events or All-cause Mortality

Since it is widely accepted that there is a positive correlation between the salt intake and hypertension or cerebro-cardiovascular-renal events, salt intake restriction is currently widely recommended, especially in patients with hypertension. However, salt intake restriction does not always have beneficial effects. Indeed, an excessively low salt intake has been reported to be harmful to health. While a reasonable vegetable and fruit intake reportedly decreases blood pressure, whether or not vegetable and fruit intake truly leads to reductions in cerebro-cardiovascular-renal events or all-cause mortality remains unclear. We reviewed the importance of vegetable and fruit intake for health, focusing on the relationship between urinary potassium excretion, a marker of vegetable and fruit intake, and cerebro-cardiovascular-renal events or all-cause mortality. In conclusion, vegetable and fruit intake may be essential for reducing cerebro-cardiovascular-renal events and all-cause mortality.

A Therapeutic Approach in the Management of Chronic Kidney Disease: Plant-Based Dietary Models and Associated Parameters

PURPOSE OF REVIEW

Chronic kidney disease is one of the leading causes of death worldwide today. Nutrition and nutrition-related factors have a very important role in both the prevention and management of the disease. Plant-based dietary practices are one of the promising approaches to chronic kidney disease. This review aims to examine the potential benefits and risks of plant-based diet models on symptoms and indices used in diet quality in chronic kidney disease.

RECENT FINDINGS

Recently, a growing body of evidence has shown that, unlike animal-based diets, diets rich in plant-based nutrients may play an active role in the incidence of chronic kidney disease in many ways and the management of common symptoms, such as metabolic acidosis, uremic toxicity, and hyperphosphatemia. Implementation of existing plant-based dietary patterns in patients with chronic kidney disease may increase the efficacy of the diet and improve patients' quality of life by expanding their food choices. While there are concerns about creatine deficiency, dietary adequacy, and accessibility regarding plant-based diets, available information is limited.

Re-Thinking Hyperkalaemia Management in Chronic Kidney Disease-Beyond Food Tables and Nutrition Myths: An Evidence-Based Practice Review

Potassium dysregulation can be life-threatening. Dietary potassium modification is a management strategy for hyperkalaemia. However, a 2017 review for clinical guidelines found no trials evaluating dietary restriction for managing hyperkalaemia in chronic kidney disease (CKD). Evidence regarding dietary hyperkalaemia management was reviewed and practice recommendations disseminated. A literature search using terms for potassium, hyperkalaemia, and CKD was undertaken from 2018 to October 2022. Researchers extracted data, discussed findings, and formulated practice recommendations. A consumer resource, a clinician education webinar, and workplace education sessions were developed. Eighteen studies were included. Observational studies found no association between dietary and serum potassium in CKD populations. In two studies, 40-60 mmol increases in dietary/supplemental potassium increased serum potassium by 0.2-0.4 mmol/L. No studies examined lowering dietary potassium as a therapeutic treatment for hyperkalaemia. Healthy dietary patterns were associated with improved outcomes and may predict lower serum potassium, as dietary co-factors may support potassium shifts intracellularly, and increase excretion through the bowel. The resource recommended limiting potassium additives, large servings of meat and milk, and including high-fibre foods: wholegrains, fruits, and vegetables. In seven months, the resource received > 3300 views and the webinar > 290 views. This review highlights the need for prompt review of consumer resources, hospital diets, and health professionals' knowledge.

Overview of research progress on the association of dietary potassium intake with serum potassium and survival in hemodialysis patients, does dietary potassium restriction really benefit hemodialysis patients?

For the general population, increasing potassium intake can reduce the incidence of cardiovascular and cerebrovascular diseases. However, since hyperkalemia is a common and life-threatening complication in maintenance hemodialysis patients, which can increase the risk of malignant arrhythmia and sudden death, the current mainstream of management for hemodialysis patients is dietary potassium restriction in order to prevent hyperkalemia. Hemodialysis patients are usually advised to reduce dietary potassium intake and limit potassium-rich fruits and vegetables, but there is limited evidence to support this approach can reduce mortality and improve quality of life. There is still no consistent conclusion on the association between dietary potassium intake and serum potassium and survival in hemodialysis patients. According to the current small observational studies, there was little or even no association between dietary potassium intake and serum potassium in hemodialysis patients when assurance of adequate dialysis and specific dietary patterns (such as the plant-based diet mentioned in the article) are being followed, and excessive dietary potassium restriction may not benefit the survival of hemodialysis patients. Additionally, when assessing the effect of diet on serum potassium, researchers should not only focus on the potassium content of foods, but also consider the type of food and the content of other nutrients. However, more large-scale, multi-center clinical trials are required to provide high-quality evidence support. Besides, further research is also needed to determine the optimal daily potassium intake and beneficial dietary patterns for hemodialysis patients.

Association of serum potassium level with dietary potassium intake in Chinese older adults: a multicentre, cross-sectional survey

OBJECTIVES

Evidence linking dietary potassium and serum potassium is virtually scarce and inconclusive. The aim of the study was to investigate the association between serum potassium level and potassium intake measured by 24-hour urine. We also explored whether the association differed across health conditions.

DESIGN

A cross-sectional study conducted from September 2017 to March 2018.

SETTING

48 residential elderly care facilities in northern China.

PARTICIPANTS

Participants aged 55 years and older and with both serum potassium and 24-hour urinary potassium measured were classified as having a low (apparently healthy), moderate (with ≥1 health condition but normal renal function) and high (with ≥1 health condition and abnormal renal function) risk of hyperkalaemia.

EXPOSURE

Potassium intake is measured by 24-hour urinary potassium.

OUTCOMES

Serum potassium in association with potassium intake after adjustment for age, sex, region and accounting for the cluster effect.

RESULTS

Of 962 eligible participants (mean age 69.1 years, 86.8% men), 17.3% were at low risk, 48.4% at moderate risk and 34.3% at high risk of hyperkalaemia. Serum potassium was weakly associated with 24-hour urinary potassium among individuals with moderate (adjusted β=0.0040/L; p=0.017) and high (adjusted β=0.0078/L; p=0.003) but not low (adjusted β=0.0018/L; p=0.311) risk of hyperkalaemia.

CONCLUSIONS

A weak association between dietary potassium intake and serum potassium level existed only among individuals with impaired renal function or other health conditions but not among apparently healthy individuals. The results imply that increasing dietary potassium intake may slightly increase the risk of hyperkalaemia but may also decrease the risk of hypokalaemia in unhealthy individuals, both of which have important health concerns.

TRIAL REGISTRATION NUMBER

NCT03290716; Post-results.

Planetary Health, Nutrition, and Chronic Kidney Disease: Connecting the Dots for a Sustainable Future

The increasing consumption of ultra-processed food (UPF) and the global chain of food production have a negative impact on human health and planetary health. These foods have been replacing the consumption of nonprocessed healthy foods. This shift has not only worsened human health by increasing the risk of the development of noncommunicable diseases, but also resulted in environmental perturbations. This review aims to bring awareness of the problems caused by the industrialized food production chain, addressing the negative effects it has on the environment and human health, with special reference to chronic kidney disease (CKD). We discuss possible solutions focusing on the benefits of adopting plant-based diets with low UPF content to promote a sustainable and healthy food production and diet for patients with CKD. For a sustainable future we need to "connect the dots" of planetary health, food production, and nutrition in the context of CKD.

Hyperkalemia and Plant-Based Diets in Chronic Kidney Disease

Traditional dietary guidelines for patients with kidney disease recommend restriction of plant foods due to concerns about hyperkalemia and associated adverse events. Studies conducted over several decades have shown that the basis for these guidelines does not match the evidence. Serum potassium levels can be elevated in patients with reduced kidney function after consumption of foods with potassium-based additives or with highly concentrated potassium content such as juices, dried fruit, or purees. However, plant foods may have certain qualities that may blunt potassium retention including their alkalinizing effects, the lack of bioavailable potassium, and the impact of dietary fiber in organic plant foods on colonic potassium excretion. Furthermore, there are many benefits of plant foods that patients with kidney disease may be missing by excluding them from their diets by recommending the historical low-potassium "renal diet." Revised dietary recommendations for kidney health may encourage patient-centered kidney recipes that revolve around plant foods and do not restrict them.

New Insights Into Dietary Approaches to Potassium Management in Chronic Kidney Disease

Potassium disorders are one of the most common electrolyte abnormalities in patients with chronic kidney disease (CKD), contributing to poor clinical outcomes. Maintaining serum potassium levels within the physiologically normal range is critically important in these patients. Dietary potassium restriction has long been considered a core strategy for the management of chronic hyperkalemia in patients with CKD. However, this has been challenged by recent evidence suggesting a paradigm shift toward fostering more liberalized, plant-based dietary patterns. The advent of novel potassium binders and an improved understanding of gastrointestinal processes involved in potassium homeostasis (e.g., gastrointestinal potassium wasting) may facilitate a paradigm shift and incorporation of heart-healthy potassium-enriched food sources. Nevertheless, uncertainty regarding the risk-benefit of plant-based diets in the context of potassium management in CKD remains, requiring well-designed clinical trials to determine the efficacy of dietary potassium manipulation toward improvement of clinical outcomes in patients with CKD.

Dietary Potassium and Clinical Outcomes among Patients on Peritoneal Dialysis

BACKGROUND

The association between dietary potassium and clinical prognosis is unclear in patients with chronic kidney disease (CKD). Here, we explored the association between dietary potassium intake and all-cause and cardiovascular (CV) mortality in peritoneal dialysis (PD) patients.

METHODS

Here, we present a retrospective analysis of a prospective study. Patients that began incident PD in our center between 1 October 2002 and 31 August 2014 were screened. We recorded all demographic and clinical data at baseline. Repeated measurements were recorded at regular intervals to calculate time-averaged values. Spline regression analysis and Cox proportional regression models were used to evaluate the relationship between dietary potassium and mortality.

RESULTS

We followed 881 PD patients for 45.0 (21.5, 80.0) months; 467 patients died, of which 189 (40.5%) died of CV death and 93 were still on PD treatment. Compared with those who had baseline dietary potassium ≥1200 mg/d, the majority of patients with lower dietary potassium were female, older, or poorly educated. They were prone to have poorer nutritional status, CV disease, and diabetes mellitus (p < 0.05). In the unadjusted analysis, both baseline and time-averaged dietary potassium <1200 mg/d predicted higher all-cause and CV mortality (p < 0.001~0.01). After adjusting for demographic and laboratory data, the association between potassium intake and all-cause and CV mortality weakened, which even disappeared after additional adjustment for dietary fiber, protein, and energy intake.

CONCLUSIONS

Dietary potassium in PD patients was not independently associated with all-cause and CV mortality.

Moderate stepwise restriction of potassium intake to reduce risk of hyperkalemia in chronic kidney disease: A literature review

A potassium-rich diet has several cardiovascular and renal health benefits; however, it is not recommended for patients with advanced chronic kidney disease or end-stage kidney disease because of the risk of life-threatening hyperkalemia. To assess the strength of evidence supporting potassium intake restriction in chronic kidney disease, the medical literature was searched looking for the current recommended approach and for evidence in support for such an approach. There is a lack of strong evidence supporting intense restriction of dietary potassium intake. There are several ways to reduce potassium intake without depriving the patient from fruits and vegetables, such as identifying hidden sources of potassium (processed food and preservatives) and soaking or boiling food to remove potassium. An individualized and gradual reduction of dietary potassium intake in people at risk of hyperkalemia is recommended. The current potassium dietary advice in chronic kidney disease needs to be reevaluated, individualized, and gradually introduced.

The Role of Plant-Based Diets in Preventing and Mitigating Chronic Kidney Disease: More Light than Shadows

Chronic kidney disease (CKD) is a non-communicable disease that affects >10% of the general population worldwide; the number of patients affected by CKD is increasing due in part to the rise in risk factors such as obesity, hypertension, and diabetes mellitus. As many studies show, diet can be an important tool for preventing and mitigating the onset of non-communicable diseases. Plant-based diets (PBDs) are those that emphasize the consumption of plant foods and may or may not include small or moderate amounts of animal foods. Recently, these diets have received increasing interest because they have been associated with favourable effects on health and also appear to protect against the development and progression of CKD. PBDs, which are associated with protein restrictions, seem to offer adjunctive advantages in patients with chronic kidney disease, as compared to conventional low-protein diets that include animal proteins. The principal aims of this review are to provide a comprehensive overview of the existing literature regarding the role of plant-based diets and low-protein, plant-based diets in the context of chronic kidney disease. Moreover, we try to clarify the definition of plant-based diets, and then we analyse possible concerns about the use of PBDs in patients with chronic kidney disease (nutritional deficiency and hyperkalaemia risk). Finally, we offer some strategies to increase the nutritional value of plant-based low-protein diets. In the Materials and Methods section, many studies about plant-based diets and low-protein plant-based diets (e.g., the very-low-protein diet and vegan low-protein diet, LPD) in chronic kidney disease were considered. In the Results and Conclusion section, current data, most from observational studies, agree upon the protective effect of plant-based diets on kidney function. Moreover, in patients with advanced CKD, low-protein plant-based options, especially a very-low-protein diet supplemented with heteroanalogues (VLPDs), compared to a conventional LPD appear to offer adjunctive advances in terms of delaying dialysis and mitigating metabolic disturbances. However, further studies are necessary to better investigate the possible metabolic and cardiovascular advantages of plant-based LPDs versus conventional LPDs.

Serum Potassium and Risk of Death or Kidney Replacement Therapy in Older People With CKD Stages 4-5: Eight-Year Follow-up

RATIONALE & OBJECTIVE

Hypokalemia may accelerate kidney function decline. Both hypo- and hyperkalemia can cause sudden cardiac death. However, little is known about the relationship between serum potassium and death or the occurrence of kidney failure requiring replacement therapy (KRT). We investigated this relationship in older people with chronic kidney disease (CKD) stage 4-5.

STUDY DESIGN

Prospective observational cohort study.

SETTING & PARTICIPANTS

We followed 1,714 patients (≥65 years old) from the European Quality (EQUAL) study for 8 years from their first estimated glomerular filtration rate (eGFR)<20mL/min/1.73m2 measurement.

EXPOSURE

Serum potassium was measured every 3 to 6 months and categorized as≤3.5,>3.5-≤4.0,>4.0-≤4.5,>4.5-≤5.0 (reference),>5.0-≤5.5, >5.5-≤6.0, and>6.0mmol/L.

OUTCOME

The combined outcome death before KRT or start of KRT.

ANALYTICAL APPROACH

The association between categorical and continuous time-varying potassium and death or KRT start was examined using Cox proportional hazards and restricted cubic spline analyses, adjusted for age, sex, diabetes, cardiovascular disease, renin-angiotensin-aldosterone system (RAAS) inhibition, eGFR, and subjective global assessment (SGA).

RESULTS

At baseline, 66% of participants were men, 42% had diabetes, 47% cardiovascular disease, and 54% used RAAS inhibitors. Their mean age was 76±7 (SD) years, mean eGFR was 17±5 (SD) mL/min/1.73m2, and mean SGA was 6.0±1.0 (SD). Over 8 years, 414 (24%) died before starting KRT, and 595 (35%) started KRT. Adjusted hazard ratios for death or KRT according to the potassium categories were 1.6 (95% CI, 1.1-2.3), 1.4 (95% CI, 1.1-1.7), 1.1 (95% CI, 1.0-1.4), 1 (reference), 1.1 (95% CI, 0.9-1.4), 1.8 (95% CI, 1.4-2.3), and 2.2 (95% CI, 1.5-3.3). Hazard ratios were lowest at a potassium of about 4.9mmol/L.

LIMITATIONS

Shorter intervals between potassium measurements would have allowed for more precise estimations.

CONCLUSIONS

We observed a U-shaped relationship between serum potassium and death or KRT start among patients with incident CKD 4-5, with a nadir risk at a potassium level of 4.9mmol/L. These findings underscore the potential importance of preventing both high and low potassium in patients with CKD 4-5.

PLAIN-LANGUAGE SUMMARY

Abnormal potassium blood levels may increase the risk of death or kidney function decline, especially in older people with chronic kidney disease (CKD). We studied 1,714 patients aged≥65 years with advanced CKD from the European Quality (EQUAL) study and followed them for 8 years. We found that both low and high levels of potassium were associated with an increased risk of death or start of kidney replacement therapy, with the lowest risk observed at a potassium level of 4.9 mmol/L. In patients with CKD, the focus is often on preventing high blood potassium. However, this relatively high optimum potassium level stresses the potential importance of also preventing low potassium levels in older patients with advanced CKD.

Factors associated with kalemia in renal disease

BACKGROUND

International recommendations promote a strict potassium diet in order to avoid hyperkalemia in chronic kidney disease (CKD) patients. However, the efficiency of such a dietary recommendation has never been demonstrated. The objectives of this study were to define the relationship between kalemia, dietary potassium intake estimated by kaliuresis and renal function, and to define the factors associated with kalemia in patients using artificial intelligence.

METHODS

To this extent, data from patients followed in a nephrology unit, included in the UniverSel study and whose kalemia (measured on the day of urine collection; n = 367) were analyzed.

RESULTS

The patients included had a wide range of estimated glomerular filtration rate (eGFR), but few had stage 5 CKD. Kalemia was negatively and linearly correlated to eGFR (P < .001) but was not correlated to kaliuresis (P = .55). Kaliuresis was not correlated to eGFR (P = .08). Factors associated with kalemia were analyzed using a Bayesian network. The five variables most associated with kalemia were, in descending order, eGFR, original nephropathy, age, diabetes and plasma bicarbonate level.

CONCLUSION

The results of this study do not support a strict dietary potassium control to regulate kalemia in stage 1-4 CKD patients.

Managing Hyperkalemia in the Modern Era: A Case-Based Approach

The last decade has seen tremendous advances in the prevention and treatment of recurrent hyperkalemia. In this narrative review, we aim to highlight contemporary data on key areas in the epidemiology and management of hyperkalemia. Focusing on drug-induced hyperkalemia (the implications of renin-angiotensin-aldosterone system inhibitors [RAASi] discontinuation and the role of mineralocorticoid receptor antagonists), newer concurrent therapies that modify potassium handling (sodium-glucose transporter 2 inhibitors [SGLT2i]), the introduction of new treatment agents (oral potassium binding agents), and the controversial role of dietary potassium restriction, we apply recent research findings and review the evidence in a case-based format.

RAASi Therapy Attenuates the Association between 24-h Urinary Potassium Excretion and Dietary Potassium Intake in CKD Patients

The aim of this study was to evaluate urinary potassium (K) excretion as a reliable marker of dietary K intake, in a cohort of CKD patients with or without Renin-Angiotensin-Aldosterone System (RAAS) inhibitor therapy. One hundred and thirty-eight consecutive out-patients (51 f and 87 m) aged 60 ± 13 years and affected by CKD stage 3-4, who were metabolically and nutritionally stable, entered the study between November 2021 and October 2022. No difference was observed between patients with (n = 85) or without (n = 53) RAAS inhibitor therapy, regarding dietary intakes, blood biochemistry, and 24-h urine excretion parameters. Considering all patients, urinary K showed a weak relationship with eGFR (r = 0.243, p < 0.01), and with dietary K intake (r = 0.184, p < 0.05). Serum K was not associated with dietary K intake, but an inverse relationship was observed with eGFR (r = -0.269, p < 0.01). When patients were examined depending on whether they were receiving RAAS inhibitor therapy, the weak inverse relationship between serum K and eGFR was maintained in both groups. Conversely, urinary K excretion remained positively associated with dietary K intake only in the no RAAS inhibitor group. In conclusion, 24-h urine K excretion may be used as a surrogate of K intake, but RAAS inhibitor therapy reduces the association between 24-h urine K excretion and dietary K intake in CKD patients.

Diagnosis and Management of Malnutrition in Patients with Heart Failure

Heart failure is a disease with an increasingly greater prevalence due to the aging population, the development of new drugs, and the organization of healthcare processes. Malnutrition has been identified as a poor prognostic factor in these patients, very often linked to frailty or to other comorbidities, meaning that early diagnosis and treatment are essential. This paper reviews some important aspects of the pathophysiology, detection, and management of malnutrition in patients with heart failure.

Association Between Dietary Potassium Intake Estimated From Multiple 24-Hour Urine Collections and Serum Potassium in Patients With CKD

Introduction

Limited and inconclusive evidence for the association of dietary potassium intake with serum potassium in chronic kidney disease (CKD) patients have been shown, though restricting dietary potassium has been recommended for CKD patients to prevent hyperkalemia. Multiple 24-hour urine collections are necessary to adequately assess potassium intake. We investigated associations of 24-hour urinary potassium excretion (UKV) with serum potassium in CKD outpatients based on multiple 24-hour urine collections.

Methods

This retrospective cohort study was based on outpatients with CKD stages G3 to G5, median age of 72.0 years; and median follow-up of 3.9 months and 8.9 months, respectively, for analyses using 3-time measurement (N = 290 and 870 observations) and 7-time measurements (N = 220 and 1540 observations). The outcome was serum potassium.

Results

Multivariable-adjusted mean difference in serum potassium (mEq/l) and odds ratio of hyperkalemia per 10 mEq/d increase in UKV were, respectively, 0.12 (95% confidence interval [CI]: 0.09-0.15) and 2.15 (1.70-2.73) in generalized estimating equations (GEEs) with 3-time measurements. The mean difference became more pronounced as CKD stages progressed: 0.08 (0.05-0.12), 0.12 (0.08-0.16), and 0.16 (0.12-0.20) for CKD G3, G4, and G5. Similar results were obtained from analyses using 7-time measurements and hierarchical Bayesian measurement error models treating measurement error of UKV adequately.

Conclusion

We suggest significant but weak associations (R²: 0.08, 0.14, and 0.18 for CKD G3, G4, and G5) between serum potassium and dietary potassium intake estimated by multiple 24-hour urine collections in CKD patients. Further studies are needed to validate nutritional and clinical aspects of the associations.

Development and Validation of a Food Frequency Questionnaire to Assess Potassium Intake of Patients on Hemodialysis

OBJECTIVE

To develop and to validate a food frequency questionnaire (FFQ) to assess potassium intake of patients on hemodialysis.

METHODS

This is a cross-sectional study that included 41 patients in the FFQ development step and 53 patients in the FFQ validation step. In the FFQ development step, the patients completed a 3-day food record (used as a reference method). Total potassium intake and potassium from each food item were calculated. Food items that contributed up to 90% of the total potassium intake were considered to be included in the FFQ food list. Then the FFQ was applied in person through the google-forms platform. The result of potassium intake obtained by the FFQ was compared with that obtained by the 3-day food record.

RESULTS

A total of 94 patients were included: 53.2% women; age 55.7 ± 15.0 years; 47.9% had diabetes; body mass index 25.0 ± 4.5 kg/m²; and dialysis vintage 34.5 (17.0-68.2) months. Demographic, clinical, and laboratory parameters did not differ between the development and validation groups. From the 255 registered food items, 85 comprised the FFQ. The standardized Cronbach's alpha obtained was 0.71. No difference was found between the potassium intake obtained by the FFQ and by the 3-day food record (1,438.5 ± 659.4 mg/d vs. 1,464.8 ± 529.4 mg/d; P = .753, respectively) with an intraclass correlation coefficient of 0.66 (P = .001). No systematic bias or proportionality bias between the methods was observed in the Bland-Altman graphical analysis.

CONCLUSION

The quantitative FFQ presented strong relative validity and may constitute a practical tool in the analysis of potassium intake of patients on hemodialysis.

The impact of protein source on serum potassium and phosphate levels in adults living with advanced kidney disease

BACKGROUND AND AIMS

Plant proteins may be restricted on low potassium/phosphorus diets. The primary objective was to investigate the impact of protein source on serum potassium and phosphate levels in adults with stage 4-5 chronic kidney disease (CKD), including hemodialysis (HD).

METHODS AND RESULTS

Using a cross-sectional design, 24-h recalls or food frequency questionnaires were used to assess dietary intake. Serum values were obtained from medical records. Quartiles (Q1-4) of plant:animal protein serving ratios was considered to investigate outcomes, with Q1 having high animal and low plant serving intake and those in Q4 having high plant and low animal servings. 216 participants were enrolled, 135 on HD and 81 stage 4/5 CKD. For both HD and CKD, there was no difference in either serum potassium or phosphate levels between those in Q4 consuming high plant:animal vs Q1 low plant:animal (for HD: potassium 4.6 mmol/L vs 4.6 mmol/L; phosphate 1.8 mmol/L vs 1.6 mmol/L, respectively; for CKD: potassium 4.7 mmol/L vs 4.6 mmol/L; phosphate 1.4 mmol/L vs 1.4 mmol/L; all p > 0.05). Those in Q4 consuming high plant:animal consumed 7.5 g (62%) more fibre than those in Q1 (low plant:animal). For diet quality, Q4 (high plant:animal) had a 12.8 point (24%) higher healthy eating index score than Q1 (low plant:animal). There was no relationship between plant:animal and serum albumin or hospital admissions (all p > 0.05).

CONCLUSIONS

Consumption of higher proportions of plant protein was not associated with higher serum potassium or phosphate levels but was associated with higher fibre and diet quality.

Recent Progresses in Non-Dialysis Chronic Kidney Disease Patients with Hyperkalemia: Outcomes and Therapeutic Strategies

Chronic kidney disease (CKD) affects about 10% of the world's population. Hyperkalemia is a life-threatening complication in patients with CKD, as it is associated with adverse cardiovascular and kidney outcomes. There are still many challenges and questions to address to improve the currently available therapeutic strategies to treat hyperkalemia, such as how to approach the emergency management of hyperkalemia. In recent years, in addition to novel oral potassium binders, great progress has been made in the application of novel kidney protective strategies, such as mineralocorticoid receptor antagonists and sodium-glucose cotransporter 2 inhibitors (SGLT2i) in hyperkalemia therapy. This review will discuss the recent advances from clinical trials in the effective management of hyperkalemia in non-dialysis CKD patients, enhancing the knowledge of physicians and internists concerning these newer agents and providing a helpful reference for clinical practice.

Management of Type 2 Diabetic Kidney Disease in 2022: A Narrative Review for Specialists and Primary Care

Purpose of review

Kidney disease is present in almost half of Canadian patients with type 2 diabetes (T2D), and it is also the most common first cardiorenal manifestation of T2D. Despite clear guidelines for testing, opportunities are being missed to identify kidney diseases, and many Canadians are therefore not receiving the best available treatments. This has become even more important given recent clinical trials demonstrating improvements in both kidney and cardiovascular (CV) endpoints with sodium-glucose cotransporter 2 (SGLT2) inhibitors and a nonsteroidal mineralocorticoid receptor antagonist, finerenone. The goal of this document is to provide a narrative review of the current evidence for the treatment of diabetic kidney disease (DKD) that supports this new standard of care and to provide practice points.

Sources of information

An expert panel of Canadian clinicians was assembled, including 9 nephrologists, an endocrinologist, and a primary care practitioner. The information the authors used for this review consisted of published clinical trials and guidelines, selected by the authors based on their assessment of their relevance to the questions being answered.

Methods

Panelists met virtually to discuss potential questions to be answered in the review and agreed on 10 key questions. Two panel members volunteered as co-leads to write the summaries and practice points for each of the identified questions. Summaries and practice points were distributed to the entire author list by email. Through 2 rounds of online voting, a second virtual meeting, and subsequent email correspondence, the authors reached consensus on the contents of the review, including all the practice points.

Key findings

It is critical that DKD be identified as early as possible in the course of the disease to optimally prevent disease progression and associated complications. Patients with diabetes should be routinely screened for DKD with assessments of both urinary albumin and kidney function. Treatment decisions should be individualized based on the risks and benefits, patients' needs and preferences, medication access and cost, and the degree of glucose lowering needed. Patients with DKD should be treated to achieve targets for A1C and blood pressure. Renin-angiotensin-aldosterone system blockade and treatment with SGLT2 inhibitors are also key components of the standard of care to reduce the risk of kidney and CV events for these patients. Finerenone should also be considered to further reduce the risk of CV events and chronic kidney disease progression. Education of patients with diabetes prescribed SGLT2 inhibitors and/or finerenone is an important component of treatment.

Limitations

No formal guideline process was used. The practice points are not graded and are not intended to be viewed as having the weight of a clinical practice guideline or formal consensus statement. However, most practice points are well aligned with current clinical practice guidelines.

The role of residual renal function on potassium intake and excretion in patients on peritoneal dialysis

BACKGROUND

Patients on chronic dialysis are at increased risk of developing disorders in potassium balance. The preservation of residual renal function (RRF), frequently observed in patients on peritoneal dialysis (PD), may contribute to better control of serum potassium. This study aimed to investigate the role residual renal function on potassium intake and excretion in PD patients.

METHODS

In this cross-sectional study, dietary potassium was evaluated by the 3-day food record. Potassium concentration was determined in serum, 24 h dialysate, stool ample, and 24 h urine of patients with diuresis > 200 mL/day, who were considered non-anuric.

RESULTS

Fifty-two patients, 50% men, 52.6 ± 14.0 years, and PD vintage 19.5 [7.0-44.2] months, were enrolled. Compared to the anuric group (n = 17, 33%), the non-anuric group (n = 35, 67%) had lower dialysate potassium excretion (24.8 ± 5.3 vs 30.9 ± 5.9 mEq/d; p = 0.001), higher total potassium intake (44.5 ± 16.7 vs 35.1 ± 8.1 mEq/d; p = 0.009) and potassium intake from fruit (6.2 [2.4-14.7] vs 2.9 [0.0-6.0]mEq/d; p = 0.018), and no difference in serum potassium (4.8 ± 0.6 vs 4.8 ± 0.9 mEq/L; p = 0.799) and fecal potassium (2.2 ± 0.5 vs 2.1 ± 0.7 mEq/L; p = 0.712). In non-anuric patients, potassium intake correlated directly with urinary potassium (r = 0.40; p = 0.017), but not with serum, dialysate, or fecal potassium. In the anuric group, potassium intake tended to correlate positively with serum potassium (r = 0.48; p = 0.051) and there was no correlation with dialysate or fecal potassium.

CONCLUSION

The presence of residual renal function constitutes an important factor in the excretion of potassium, which may allow the adoption of a less-restrictive diet.

Paradigm shift in lifestyle modification for solitary kidney after donor nephrectomy

PURPOSE OF REVIEW

Living donor kidney transplantation potentially leads to long-term complications including chronic kidney disease, end-stage kidney disease, elevated blood pressure, and pregnancy-associated hypertension. Given living donors generally do not have underlying medical conditions, lifestyle modifications, particularly dietary interventions may prevent those complications and improve their health outcomes.

RECENT FINDINGS

Glomerular hyperfiltration occurs as physiologic adaptation during an initial postdonor nephrectomy period. In the long-term, these adaptations may become pathologic consequences resulting from hyperfiltration-mediated kidney injury and ultimately secondary focal segmental glomerulosclerosis in the solitary kidney. Dietary interventions to slow a decline in kidney function include low protein intake of <0.8 g/kg/day and low sodium consumption of 2-4 g/day as well as certain health dietary patterns. There is no evidence regarding the quantity and quality of protein that can be recommended for living kidney donors and the same for sodium. Plant Dominant (PLADO) diets, Dietary Approaches to Stop Hypertension (DASH), Mediterranean, and vegetarian diets may be favorable for living kidney donors with solitary kidney but the evidence is still lacking.

SUMMARY

Although dietary interventions may provide benefits and kidney health for living kidney donors, further studies including clinical trials are required to incorporate them into clinical practice guidelines.

Higher dietary magnesium and potassium intake are associated with lower body fat in people with impaired glucose tolerance

Introduction

Obesity and diabetes are public health concerns worldwide, but few studies have examined the habitual intake of minerals on body composition in people with prediabetes.

Methods

In this prospective cross-sectional study, 155 Chinese subjects with IGT [median age: 59 (53-62) years, 58% female] had an assessment of body composition including body fat percentage, oral glucose tolerance tests (OGTT), Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) and 3-day food records from nutritional programme analysis.

Results

Dietary intake of minerals was negatively correlated with body fat. People with obesity had the lowest daily consumption of iron median (IQR) 10.3 (6.9-13.3) mg, magnesium 224 (181-282) mg, and potassium 1973 (1563-2,357) mg when compared to overweight [10.5 (8.0-14.5) mg, 273 (221-335) mg, and 2,204 (1720-2,650) mg] and normal weight individuals [13.2 (10.0-18.6) mg, 313 (243-368) mg, and 2,295 (1833-3,037) mg] (p = 0.008, <0.0001, and 0.013 respectively). Amongst targeted minerals, higher dietary magnesium and potassium intake remained significantly associated with lower body fat after the adjustment of age, gender, macronutrients, fibre, and physical activity.

Conclusion

Dietary magnesium and potassium intake may be associated with lower body fat in people with impaired glucose tolerance. Inadequate dietary mineral intake may play contribute to obesity and metabolic disorders independent of macronutrients and fibre consumption.

Mediterranean Diet and Chronic Kidney Disease (CKD): A Practical Approach

Chronic kidney disease has become a serious public health issue, as well as others health problems such as hypertension, DM, and obesity. Mediterranean diet (MD) can reduce the risk of cardiovascular disease and cancer and can lead to weight loss in obesity. There are studies that suggest that MD could be the diet of choice for patients with CKD for its influence on endothelial function, inflammation, lipid profile and blood pressure. There are few studies that tell us how to adapt MD to this group of patients. This review aims to offer a practical approach to Mediterranean diet adaptation as nutritional treatment in CKD patients.

A nomogram to predict hyperkalemia in patients with hemodialysis: a retrospective cohort study

BACKGROUND

Hyperkalemia increases the risk of mortality and cardiovascular-related hospitalizations in patients with hemodialysis. Predictors of hyperkalemia are yet to be identified. We aimed at developing a nomogram able to predict hyperkalemia in patients with hemodialysis.

METHODS

We retrospectively screened patients with end-stage renal disease (ESRD) who had regularly received hemodialysis between Jan 1, 2017, and Aug 31, 2021, at Lishui municipal central hospital in China. The outcome for the nomogram was hyperkalemia, defined as serum potassium [K⁺] ≥ 5.5 mmol/L. Data were collected from hemodialysis management system. Least Absolute Shrinkage Selection Operator (LASSO) analysis selected predictors preliminarily. A prediction model was constructed by multivariate logistic regression and presented as a nomogram. The performance of nomogram was measured by the receiver operating characteristic (ROC) curve, calibration diagram, and decision curve analysis (DCA). This model was validated internally by calculating the performance on a validation cohort.

RESULTS

A total of 401 patients were enrolled in this study. 159 (39.65%) patients were hyperkalemia. All participants were divided into development (n = 256) and validation (n = 145) cohorts randomly. Predictors in this nomogram were the number of hemodialysis session, blood urea nitrogen (BUN), serum sodium, serum calcium, serum phosphorus, and diabetes. The ROC curve of the training set was 0.82 (95%CI 0.77, 0.88). Similar ROC curve was achieved at validation set 0.81 (0.74, 0.88). The calibration curve demonstrated that the prediction outcome was correlated with the observed outcome.

CONCLUSION

This nomogram helps clinicians in predicting the risk of PEW and managing serum potassium in the patients with hemodialysis.

Effects of Short-Term Potassium Chloride Supplementation in Patients with CKD

BACKGROUND

Observational studies suggest that adequate dietary potassium intake (90-120 mmol/day) may be renoprotective, but the effects of increasing dietary potassium and the risk of hyperkalemia are unknown.

METHODS

This is a prespecified analysis of the run-in phase of a clinical trial in which 191 patients (age 68±11 years, 74% males, 86% European ancestry, eGFR 31±9 ml/min per 1.73 m2, 83% renin-angiotensin system inhibitors, 38% diabetes) were treated with 40 mmol potassium chloride (KCl) per day for 2 weeks.

RESULTS

KCl supplementation significantly increased urinary potassium excretion (72±24 to 107±29 mmol/day), plasma potassium (4.3±0.5 to 4.7±0.6 mmol/L), and plasma aldosterone (281 [198-431] to 351 [241-494] ng/L), but had no significant effect on urinary sodium excretion, plasma renin, BP, eGFR, or albuminuria. Furthermore, KCl supplementation increased plasma chloride (104±3 to 105±4 mmol/L) and reduced plasma bicarbonate (24.5±3.4 to 23.7±3.5 mmol/L) and urine pH (all P<0.001), but did not change urinary ammonium excretion. In total, 21 participants (11%) developed hyperkalemia (plasma potassium 5.9±0.4 mmol/L). They were older and had higher baseline plasma potassium.

CONCLUSIONS

In patients with CKD stage G3b-4, increasing dietary potassium intake to recommended levels with potassium chloride supplementation raises plasma potassium by 0.4 mmol/L. This may result in hyperkalemia in older patients or those with higher baseline plasma potassium. Longer-term studies should address whether cardiorenal protection outweighs the risk of hyperkalemia.Clinical trial number: NCT03253172.

The "FIFTY SHADOWS" of the RALES Trial: Lessons about the Potential Risk of Dietary Potassium Supplementation in Patients with Chronic Kidney Disease

Hyperkalaemia (HK) is one of the most common electrolyte disorders and a frequent reason for nephrological consultations. High serum potassium (K+) levels are associated with elevated morbidity and mortality, mainly due to life-threatening arrhythmias. In the majority of cases, HK is associated with chronic kidney disease (CKD), or with the use of renin-angiotensin-aldosterone system inhibitors (RAASis) and/or mineral corticoid antagonists (MRAs). These drugs represent the mainstays of treatment in CKD, HF, diabetes, hypertension, and even glomerular diseases, in consideration of their beneficial effect on hard outcomes related to cardiovascular events and CKD progression. However, experiences in relation to the Randomised Aldactone Evaluation Study (RALES) cast a long shadow that extends to the present day, since the increased risk for HK remains a major concern. In this article, we summarise the physiology of K+ homeostasis, and we review the effects of dietary K+ on blood pressure and cardiovascular risk in the general population and in patients with early CKD, who are often not aware of this disease. We conclude with a note of caution regarding the recent publication of the SSaSS trial and the use of salt substitutes, particularly in patients with a limited capacity to increase K+ secretion in response to an exogenous load, particularly in the context of "occult" CKD, HF, and in patients taking RAASis and/or MRAs.

A quantitative systems pharmacology model of plasma potassium regulation by the kidney and aldosterone

Plasma potassium regulation within a narrow range is vital for life. The risk for hyperkalemia increases when kidney function is impaired and with therapeutic interventions such as mineralocorticoid receptor antagonists (MRAs). The kidney maintains potassium homeostasis by matching potassium intake and excretion, in part through the action of aldosterone. A mechanistic mathematical model was developed and used to investigate the effect of renal impairment and MRAs on plasma potassium levels. The model describes renal potassium filtration, reabsorption, and secretion along the nephron; potassium-aldosterone regulatory feedbacks; whole body potassium balance; and the pharmacologic effects of MRAs. The model was calibrated by fitting (1) the plasma potassium and aldosterone response to potassium infusion in humans on high/low potassium diets, and (2) the acute potassium excretion response to spironolactone. The model was validated by predicting steady-state plasma potassium with sustained spironolactone treatment in hyperaldosteronism patients. The model was then used to demonstrate that (1) declining renal function alone has a small effect on plasma potassium for GFR > 30 ml/min, but an increasing effect as GFR approaches end stage renal disease (GFR ~ 15 ml/min) (2) the effect of increasing potassium intake has minimal effect at normal GFRs but increasing effect on plasma potassium as GFR declines, and 3) MRAs have a minor effect on plasma potassium when GFR is normal, but cause larger increases as GFR falls below 60 ml/min. This model provides a quantitative framework for investigating integrated impacts of diseases and therapies in this complex system.

Potassium and fiber: a controversial couple in the nutritional management of children with chronic kidney disease

BACKGROUND

Fruit and vegetable intake is commonly discouraged in children with chronic kidney disease (CKD) to avoid hyperkalemia. However, direct evidence in support of this widespread practice is lacking. Furthermore, the resultant restricted fiber exposure may deprive CKD patients from potential health benefits associated with the latter. Therefore, we investigated associations between dietary potassium intake, fiber intake, and serum potassium levels in pediatric CKD.

METHODS

This study is a longitudinal analysis of a 2-year, prospective, multi-institutional study, following children with CKD at 3-month intervals. At each visit, dietary potassium and fiber intake were assessed, using 24-h recalls and 3-day food records. On the same occasion, serum potassium concentrations were determined. Associations between dietary potassium intake, dietary fiber intake, and serum potassium concentrations were determined using linear mixed models.

RESULTS

Fifty-two CKD patients (7 transplant recipients, none on dialysis) aged 9 [4;14] years with an estimated glomerular filtration rate (eGFR) of 49 [25;68] mL/min/1.73 m² were included. For every g/day decrease in dietary potassium intake, the estimated mean daily fiber intake was 5.1 g lower (95% confidence interval (CI), 4.3-5.9 g/day; p < 0.001). Neither dietary potassium intake (p = 0.40) nor dietary fiber intake (p = 0.43) was associated with circulating potassium in a model adjusted for time point, eGFR, treatment with a renin-angiotensin-aldosterone system blocker, serum bicarbonate concentration, and body surface area.

CONCLUSIONS

Dietary potassium and fiber intake are closely related but were not associated with circulating potassium levels in pediatric CKD. A higher-resolution version of the graphical abstract is available as Supplementary information.