Diet Intervention, End Stage Kidney Disease (ESKD), Hemodialysis, Hyperkalemia, Potassium Bioavailability
Conditions
Keywords
end stage kidney disease, hemodialysis, diet intervention, hyperkalemia, potassium bioavailability
Brief summary
People with end-stage kidney disease who receive hemodialysis are often told to strictly limit foods high in potassium, such as fruits, vegetables, legumes, nuts, and whole grains. This advice is intended to prevent high blood potassium levels (hyperkalemia), which can cause dangerous heart rhythm problems. However, these restrictions can make eating difficult, reduce diet quality, and lower quality of life. New research suggests that not all sources of potassium affect the body in the same way. Potassium added to highly processed foods is more easily absorbed than potassium naturally found in whole foods like fruits and vegetables. Large studies have found little evidence that eating potassium-rich whole foods increases blood potassium levels in people on dialysis. Clinical guidelines are beginning to shift, but no high-quality clinical trial has tested whether a more flexible, food-based approach is safe for people receiving hemodialysis. This study will compare two dietary approaches in 148 adults on hemodialysis: the usual low potassium diet and a "liberalized" potassium diet that encourages minimally processed foods while limiting highly processed foods with potassium additives. Participants will receive dietitian support and grocery assistance for 12 weeks. The investigators will closely monitor blood potassium levels to ensure safety. The investigators will also examine whether the liberalized diet is as safe as standard care, and whether it improves diet quality and quality of life. The investigators will also study factors that influence the participant's ability to follow the diet in real-world settings. If safe, this approach could reduce unnecessary food restrictions, improve diet quality, and enhance quality of life for people receiving hemodialysis, while maintaining patient safety.
Detailed description
Current potassium guidelines are highly restrictive, limit nutritious whole foods, and contribute to poor diet quality and reduced quality of life - yet largely rely on expert consensus rather than robust trial evidence. To our knowledge, LIBERATE K-HD would be the first RCT to evaluate the safety and sustainability of a liberalized potassium diet in patients receiving hemodialysis, directly addressing this critical evidence gap. By shifting the focus from strict potassium restriction to whole, minimally processed foods, this approach has the potential to simplify dietary advice, improve patient satisfaction, and enhance overall nutrition without increasing the risk of hyperkalemia. The results will directly inform clinical practice guidelines and renal dietetic practice, providing patient-centered evidence to support more flexible and equitabledietary recommendations. The behavioural and adherence data generated will further identify key determinants of sustained dietary change, including food literacy, self-efficacy, and dietary burden, offering guidance for behaviour change counselling and responsible implementation of a liberalized potassium approach in routine dialysis care. If effective, it could support more flexible and patient-centered dietary recommendations that improve both health outcomes and patient well-being.
Interventions
For 12 weeks, the liberalized potassium diet group (n=74) will increase their intake of minimally processed foods that are higher in potassium, including fruits, vegetables, nuts, legumes and whole grains, while limiting highly processed foods rich in potassium (\>200 mg/serving) and potassium additives. The liberalized diet will provide \~2600-3000. Participants will also be counselled to use cooking techniques to reduce potassium in root vegetables. The liberalized diet will provide \~2600-3000 mg potassium daily, reflecting the mean potassium intake of Canadian adults. Participants will receive weekly individualized counselling (30-60 min) during the first 4 weeks, followed by sessions (weeks 8 \& 12), reflecting usual care and to reinforce adherence. During weeks 1 to 4, weekly home deliveries of groceries will be provided to support early dietary adoption and adherence. During weeks 5-12, participants will receive weekly grocery gift cards to reduce financial barriers and support.
The control group (n= 74) will limit higher potassium fruits, vegetables, juices, and grains, to achieve a potassium intake of \~2000 mg/day. Participants will also be counselled to use cooking techniques (e.g., double-boiling root vegetables) to reduce potassium. Consistent with standard of care, participants will receive monthly education by a registered dietitian using standardized low potassium education materials that contain lists of foods to 'choose' and 'avoid', and individualized to ensure budget, cooking abilities and patient preferences are addressed, as needed. Participants will receive weekly grocery gift cards for 12 weeks.
Sponsors
Study design
Eligibility
Inclusion criteria
1. Age ≥18 years on maintenance HD \>3 months 2. ≥1 serum potassium concentration \>5.0 mmol/L on routine bloodwork in past 12 months 3. Able to provide consent
Exclusion criteria
1. Treatment with potassium binders within the preceding 7 days 2. Average Urea reduction rate over the past 3 months \<65% 3. \>2 missed scheduled dialysis sessions in the previous month 4. Patients receiving \<3 hemodialysis sessions per week (ex/ incremental dialysis) 5. Average serum potassium concentration \>6.0 mmol/L over the past 3 months 6. Swallowing difficulties or other GI issues preventing adequate intake 7. Residing in an institutional setting (e.g., Long-term care homes) where meals are provided 8. HbA1c \>11% 9. Unable to comply with study procedures due to cognitive impairment, language barrier or for any additional reason specified by the attending clinician
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Time-averaged serum potassium | 12 weeks | Time-averaged serum potassium is calculated as the mean of all weekly serum potassium measurements (mmol/L) for a participant over the defined study period, providing an integrated measure of potassium exposure over time and reducing the influence of isolated or transient fluctuations. Time-averaged serum potassium will be calculated as the area under the serum potassium-time curve divided by the total observation time. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Safety - Severe Hyperkalemia | 12 weeks | Incidence of clinically meaningful, severe hyperkalemia defined as incident non-hemolyzed serum potassium \>6.5 mmol/L at any time point during the study. |
| Dietary Nutrient Intake | 12 weeks | Dietary intake will be assessed using the Automated Self-Administered 24-Hour Dietary Recall (ASA24-Canada-2018). The ASA24-C is a self-administered, web-based recall available in English and French (\~25 minutes) that incorporates Canadian foods and the Canadian Nutrient File for nutrient analysis. From the ASA24-C, we will calculate mean nutrient intakes, including potassium (mg/day). |
| Health-Related Quality of Life | 12 weeks | Health-related quality of life will be assessed using the EQ-5D-5L, a validated, widely used generic indicator of overall health status. It is comprised of five questions assessing the dimension of mobility, self-care, usual activities, pain/discomfort and anxiety/depression. |
| Diet Quality | 12 weeks | From the ASA24-C, diet quality will be assessed using the Healthy Eating Food Index-2019 (HEFI-2019) score (0-80). |
| Ultra-processed food consumption | 12 weeks | From the ASA24-C, ultra-processed food (UPF) consumption will be assessed using the NOVA classification system, which categorizes foods according to the degree of industrial processing. It will be calculated as the proportion of total energy intake from ultra-processed foods (% energy from UPF's, NOVA group 4) |
Countries
Canada
Contacts
Unity Health Toronto
University of Ontario Institute of Technology