Dietary Potassium Liberalization in Pre-Dialysis Patients

NCT ID: NCT05090865

Last Updated: 2026-01-16

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 30 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2024-01-15
• Study Completion Date: 2026-05-31

Brief Summary

The study will look at the impact of the potassium content in fruits and vegetables, on serum potassium concentrations in people with Chronic Kidney Disease (CKD) using a randomized crossover design. Participants will receive home delivery of fruit and vegetables with either higher or lower potassium content in a random order. Clinical chemistry markers from blood and urine samples, blood pressure, physical functioning and health related quality of life will be assessed throughout the duration of the trial. This study will also measure their physical functioning, using a chair stand test. The results of this study could change the dietary recommendations for people with CKD related to potassium.

Detailed Description

The kidney is a primary site of potassium regulation in the body. Hyperkalemia, elevated serum potassium, occurs in approximately 10% of patients with chronic kidney disease (CKD) and is associated with elevated all-cause mortality. To minimize the risk of hyperkalemia, individuals with CKD are told to restrict dietary potassium. This recommendation is based on very-low quality evidence. Dietary potassium restrictions can negatively impact quality of life, and may put participants at risk of nutritional deficiencies so they should be based on good quality evidence. There is a need for high quality randomized controlled trials investigating the impact of dietary potassium modification on serum potassium concentrations in people with CKD.

This trial will evaluate the impact and safety of dietary potassium liberalization using fruit and vegetables on serum potassium concentrations in people with CKD. In this 16-week study, the investigators will test if changing the amount of potassium people with CKD are eating with fruits and vegetables changes the amount of potassium in their blood. The investigators will do this by providing people with fruits and vegetables that are either high or low in potassium for a period of 6 weeks. Then these same participants will be provided with fruits and vegetables that they didn't receive in the first 6 weeks, for an additional 6 weeks in what is called a randomized crossover design. In a randomized crossover design everyone gets both treatments, but the order they get them in is chosen at random, like a coin toss. Thirty participants will be recruited to this study. The investigators will measure blood potassium during the study and see if it changes due to the change in potassium in the fruit and vegetables provided. The investigators think that changing the amount of potassium that participants eat through fruit and vegetables will not lead to a different level of potassium in the participants blood, and that having higher potassium fruit and vegetables in the diet may lead to an increase in the participants quality of life. This study's results could change the dietary recommendation given to people living CKD and potentially allow them to eat a greater variety of food.

Conditions

Chronic Kidney Disease; Hyperkalemia

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

Liberalized dietary potassium and then restricted potassium via fruit and vegetables

Participants will receive weekly supplementation of higher potassium fruit and vegetables via grocery home delivery during the liberalized dietary potassium 2-week run-in and liberalized potassium treatment period, then cross-over to the restricted potassium treatment period following a 2-week washout period. Participants will receive a 30-60 minute dietary counseling session in the first week of each treatment period from a registered dietitian (RD), either in person or via videoconference, depending on regional Coronavirus disease (COVID)-19 restrictions and participant preference, which will outline the concepts of the dietary intervention. The RD will also recommend the best ways to prepare and include the fruit and vegetables into the participant's current diet.

Group Type: OTHER

Liberalized dietary potassium via fruits and vegetables

Intervention Type: DIETARY_SUPPLEMENT

On the liberalized dietary potassium intervention, participants will receive groceries delivered to their houses that contain potassium rich fruit and vegetables, that contain more than 250 mg of potassium per typical serving. Participants will be instructed to incorporate the fruit and vegetables into their diet targeting a daily intake of 2000 mg of potassium a day from delivered fruit and vegetables, and a daily dietary potassium intake of 3500 mg.

Standard dietary potassium restriction

Intervention Type: DIETARY_SUPPLEMENT

Participants will receive weekly supplementation of lower potassium fruit and vegetables, that deliver less than 200 mg of potassium per typical serving. Participants will be instructed to incorporate the fruit and vegetables into their diet targeting a daily intake of 500 mg of K a day from the box, and a daily dietary K intake \< 2000 mg. Participants will receive counselling from a registered dietician (RD) to reinforce the potassium restriction.

Restricted dietary potassium and then liberalized potassium via fruit and vegetables

Participants will receive weekly supplementation of higher potassium fruit and vegetables via grocery home delivery during the liberalized dietary potassium 2 week run-in and then start receiving a restricted potassium treatment period, then cross-over to the liberalized potassium treatment period following a 2-week washout period. Participants will receive a 30-60 minute dietary counseling session in the first week of each treatment period from a registered dietitian (RD), either in person or via videoconference, depending on regional COVID-19 restrictions and participant preference, which will outline the concepts of the dietary intervention. The RD will also recommend the best ways to prepare and include the fruit and vegetables into the participant's current diet

Group Type: OTHER

Liberalized dietary potassium via fruits and vegetables

Intervention Type: DIETARY_SUPPLEMENT

On the liberalized dietary potassium intervention, participants will receive groceries delivered to their houses that contain potassium rich fruit and vegetables, that contain more than 250 mg of potassium per typical serving. Participants will be instructed to incorporate the fruit and vegetables into their diet targeting a daily intake of 2000 mg of potassium a day from delivered fruit and vegetables, and a daily dietary potassium intake of 3500 mg.

Standard dietary potassium restriction

Intervention Type: DIETARY_SUPPLEMENT

Participants will receive weekly supplementation of lower potassium fruit and vegetables, that deliver less than 200 mg of potassium per typical serving. Participants will be instructed to incorporate the fruit and vegetables into their diet targeting a daily intake of 500 mg of K a day from the box, and a daily dietary K intake \< 2000 mg. Participants will receive counselling from a registered dietician (RD) to reinforce the potassium restriction.

Interventions

Liberalized dietary potassium via fruits and vegetables

On the liberalized dietary potassium intervention, participants will receive groceries delivered to their houses that contain potassium rich fruit and vegetables, that contain more than 250 mg of potassium per typical serving. Participants will be instructed to incorporate the fruit and vegetables into their diet targeting a daily intake of 2000 mg of potassium a day from delivered fruit and vegetables, and a daily dietary potassium intake of 3500 mg.

Intervention Type: DIETARY_SUPPLEMENT

Standard dietary potassium restriction

Participants will receive weekly supplementation of lower potassium fruit and vegetables, that deliver less than 200 mg of potassium per typical serving. Participants will be instructed to incorporate the fruit and vegetables into their diet targeting a daily intake of 500 mg of K a day from the box, and a daily dietary K intake \< 2000 mg. Participants will receive counselling from a registered dietician (RD) to reinforce the potassium restriction.

Intervention Type: DIETARY_SUPPLEMENT

Eligibility Criteria

Inclusion Criteria

• Male or female, aged 18 years or above
• Participants who have an estimated glomerular filtration rate between 15 and 45 ml/min/1.73m2
• Serum potassium concentration between 4.5 and 5.5 milliequivalent (mEq)/L
• Hemoglobin A1c ≤ 11%
• Systolic and diastolic blood pressure &lt;160/100 mmHg
• Are registered in the multidisciplinary nephrology clinic in Winnipeg
• Able to communicate in English and provide written informed consent

Exclusion Criteria

• Serum potassium concentration &gt; 5.6 mEq/L, anuria, dialysis, or acute kidney injury failure in the 6 months prior to screening
• Chronic obstructive pulmonary disease that requires the participant to be on oxygen
• New York Heart Association Class 3-4 Heart symptoms or heart, liver or renal transplant
• A myocardial infarction or stroke within the last 6 months
• Unable to consume study treatments or control, such as swallowing or gastro-intestinal issues
• Currently on potassium binding therapy
• In the opinion of the investigator any medical condition, uncontrolled systemic disease or concurrent illness that would decrease the study compliance or jeopardize the safety of the participant
• Female participant who is pregnant or lactating

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University of Manitoba

OTHER

Sponsor Role: lead

Dalhousie University

OTHER

Sponsor Role: collaborator

Responsible Party

Dylan MacKay

Assistant Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Dylan Mackay, PhD

Role: PRINCIPAL_INVESTIGATOR

University of Manitoba

Locations

Seven Oaks General Hospital Chronic Disease Innovation Centre

Winnipeg, Manitoba, Canada

Site Status: RECRUITING

Health Sciences Centre

Winnipeg, Manitoba, Canada

Site Status: RECRUITING

Countries

Canada

Central Contacts

Dylan Mackay, PhD

Role: CONTACT

dylan.mackay@umanitoba.ca

2042723119

Rebecca Mollard, PhD

Role: CONTACT

rmollard@sogh.mb.ca

Facility Contacts

Rebecca Mollard, PhD

Role: primary

rmollard@sogh.mb.ca

Jay Hingwala, MD

Role: primary

jhingwala@hsc.mb.ca

204-787-3863

References

Iman Y, Balshaw R, Alexiuk M, Hingwala J, Cahill L, Mollard R, Tangri N, Mackay D. Dietary potassium liberalization with fruit and vegetables versus potassium restriction in people with chronic kidney disease (DK-Lib CKD): a clinical trial protocol. BMC Nephrol. 2023 Oct 13;24(1):301. doi: 10.1186/s12882-023-03354-4.

Reference Type: DERIVED

PMID: 37833679 (View on PubMed)

Other Identifiers

HS25191 (B2021:104)

Identifier Type: -

Identifier Source: org_study_id