Chronic Kidney Disease, Hyperkalemia
Conditions
Keywords
Potassium, Nutrition
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.
Interventions
DIETARY_SUPPLEMENTLiberalized 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.
DIETARY_SUPPLEMENTStandard 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.
Sponsors
University of Manitoba
Dalhousie University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in serum potassium concentrations between treatments | between 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
| Measure | Time frame | Description |
|---|---|---|
| Change in physical function related quality of life between treatments | between 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 treatments | between endpoints of each experimental period (week 8 to week 16) | total potassium concentration in mmol/L |
| Change in urinary sodium between treatments | between endpoints of each experimental period (week 8 to week 16) | Total sodium concentration in mmol/L |
| Urinary albumin to creatinine Ratio | between 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 urea | between endpoints of each experimental period (week 8 to week 16) | Measured in mmol/L |
| Urinary phosphate | between endpoints of each experimental period (week 8 to week 16) | Measured in mmol/L |
| Hemoglobin A1c | between endpoints of each experimental period (week 8 to week 16) | Measure of glycosylated hemoglobin, hemoglobin A1c, expressed as a percentage |
| Systolic blood pressure | between 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. |
| Diastolic blood pressure | between 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. |
| Five repetition chair stand time | between 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. |
| Dietary Intake | between 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/) |
Countries
Canada
Contacts
PRINCIPAL_INVESTIGATORDylan Mackay, PhD
University of Manitoba
Outcome results
None listed