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Dietary Potassium Liberalization in Pre-Dialysis Patients

Not Applicable
Recruiting
Conditions
Hyperkalemia
Chronic Kidney Disease
Interventions
Dietary Supplement: Liberalized dietary potassium via fruits and vegetables
Dietary Supplement: Standard dietary potassium restriction
Registration Number
NCT05090865
Lead Sponsor
University of Manitoba
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.

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
30
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 <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 > 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

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
Liberalized dietary potassium and then restricted potassium via fruit and vegetablesLiberalized dietary potassium via fruits and vegetablesParticipants 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.
Liberalized dietary potassium and then restricted potassium via fruit and vegetablesStandard dietary potassium restrictionParticipants 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.
Restricted dietary potassium and then liberalized potassium via fruit and vegetablesLiberalized dietary potassium via fruits and vegetablesParticipants 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
Restricted dietary potassium and then liberalized potassium via fruit and vegetablesStandard dietary potassium restrictionParticipants 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
Primary Outcome Measures
NameTimeMethod
Change in serum potassium concentrations between treatmentsbetween endpoints of each experimental period (week 8 to week 16)

Serum potassium at the end of the liberalize dietary potassium period compared to the end of restricted dietary potassium period

Secondary Outcome Measures
NameTimeMethod
Urinary phosphatebetween endpoints of each experimental period (week 8 to week 16)

Measured in mmol/L

Systolic blood pressurebetween endpoints of each experimental period (week 8 to week 16)

Blood pressure will be measured in triplicate using a validated blood pressure monitor following Kidney Disease: Improving Global Outcomes (KDIGO) 2021 measurement guidelines, the average of the 2nd and 3rd measurements will be recorded.

Five repetition chair stand timebetween endpoints of each experimental period (week 8 to week 16)

Assessing physical functionality by asking participant to sit with arms folded in a chair and then stand up and sit down 5 times as fast as they can, time to complete is recorded.

Urinary albumin to creatinine Ratiobetween endpoints of each experimental period (week 8 to week 16)

calculated by dividing urinary albumin concentration in milligrams by urinary creatinine concentration in grams

Urinary ureabetween endpoints of each experimental period (week 8 to week 16)

Measured in mmol/L

Hemoglobin A1cbetween endpoints of each experimental period (week 8 to week 16)

Measure of glycosylated hemoglobin, hemoglobin A1c, expressed as a percentage

Change in physical function related quality of life between treatmentsbetween endpoints of each experimental period (week 8 to week 16)

Participants will complete the SF-12 physical component score of the Kidney Disease Quality of Life Short Form (KDQOL-SF) questionnaire.

Change in urinary potassium between treatmentsbetween endpoints of each experimental period (week 8 to week 16)

total potassium concentration in mmol/L

Change in urinary sodium between treatmentsbetween endpoints of each experimental period (week 8 to week 16)

Total sodium concentration in mmol/L

Diastolic blood pressurebetween endpoints of each experimental period (week 8 to week 16)

Blood pressure will be measured in triplicate using a validated blood pressure monitor following KDIGO 2021 measurement guidelines, the average of the 2nd and 3rd measurements will be recorded.

Dietary Intakebetween endpoints of each experimental period (week 8 to week 16)

Dietary intake will be captured via triplicate dietary recall surveys using the Automated Self-Administered 24 hours Canada (ASA24, NCI, Rockville, Maryland, USA; http:// asa24. ca/)

Trial Locations

Locations (2)

Seven Oaks General Hospital Chronic Disease Innovation Centre

🇨🇦

Winnipeg, Manitoba, Canada

Health Sciences Centre

🇨🇦

Winnipeg, Manitoba, Canada

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