Potassium Intake in Patients With Chronic Kidney Disease

Hypertension Clinical Trial

— CKD-K  

Official title:

Potassium Intake in Patients With Chronic Kidney Disease

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00949585
• Other study ID #: AHA 0835162N
• Status: Completed
• Phase: N/A
• First received: July 29, 2009
• Last updated: September 18, 2012
• Start date: July 2009
• Est. completion date: June 2011

Study information

• Verified date: September 2012
• Source: Johns Hopkins University
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical Trial Summary

Chronic kidney disease is associated with high blood pressure, heart disease, and strokes. Potassium lowers blood pressure and may help prevent heart disease and strokes in the general population, but has not been well-studied in people with kidney disease. This study will look at the benefits and safety of two levels of potassium intake in patients with kidney disease. We expect that a higher level of potassium intake safely lowers blood pressure compared to a lower level of potassium intake. We hope that this and other research projects will help us to learn more so that guidelines can be created for potassium intake in patients with chronic kidney disease

Description:

In individuals without chronic kidney disease (CKD), potassium (K) lowers blood pressure (BP) and may help prevent cardiovascular disease (CVD) and stroke. In animal models, K prevented kidney injury and decreased kidney inflammation. CKD patients may especially benefit from higher K intake, due to their high prevalence of hypertension, CVD, and stroke, and the possibility that K may retard CKD progression. Despite these potential benefits, there is great uncertainty about the optimal K intake in CKD patients. K is often restricted in these patients due to concerns about elevating serum K. However, renal K excretion does not appear to be substantially impaired until the glomerular filtration rate (GFR) is severely decreased (< 10-20 mL/min/1.73 m2). In this randomized feeding study with a two-period crossover design, the benefits and safety of 4 weeks of 100 mmol versus 40 mmol K/day in 26 non-diabetic adults with stage 3 CKD (estimated GFR 30-59 mL/min/1.73 m2) will be evaluated. After a one-week run-in period, all participants will be randomized to receive either a diet containing either 40 mmol K/day or 100 mmol K/day (within the current K/DOQI recommendations for K intake for stage 3 CKD) during period 1 (they will receive the other during period 2). The primary outcome variable is 24-hour ambulatory systolic BP. Secondary outcomes are other measures of peripheral BP, central BP, inflammatory markers, and serum K. We hope that this study will lead to a larger trial with sufficient power to examine the effects of increased K intake on clinical outcomes such as CKD progression. The ultimate goal of this effort is to develop the scientific basis for guidelines on K intake in CKD.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 29
• Est. completion date: June 2011
• Est. primary completion date: June 2011
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Stage 3 chronic kidney disease (estimated glomerular filtration rate 30-59 mL/min/1.73 m2 by the 4-variable Modification of Diet in Renal Disease (MDRD) Study Equation

• Systolic blood pressure 120-159 mm Hg and diastolic blood pressure < 100 mm Hg

• Willingness to follow strict dietary rules for 9 weeks and to come to the clinical research unit at least 3 weekdays per week for one meal during the two study periods

Exclusion Criteria:

• Baseline serum potassium of at least 5.5 mEq/L

• Baseline serum potassium of less than 3.5 mEq/L

• Insulin-requiring or uncontrolled (HbA1C > 9 g/dL) diabetes mellitus

• Use of potassium supplements

• Use of digoxin

• Chronic disease(s) that may interfere with trial participation

• Pregnancy or lactation

• > 14 alcoholic drinks/week

• Major food allergies or intolerances

Study Design

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Crossover Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Chronic Kidney Disease
• Hypertension
• Kidney Diseases
• Renal Insufficiency, Chronic

Intervention

Other:
• Dietary intake of potassium
Comparison of two diets: one contains 100 mmol potassium per day, and the other contains 40 mmol potassium per day

Locations

Country	Name	City	State
United States	Johns Hopkins University Pro Health Clinical Research Facility	Baltimore	Maryland

Sponsors (2)

Lead Sponsor	Collaborator
Johns Hopkins University	American Heart Association

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	24-hour ambulatory systolic blood pressure		At screening, and at the end (4th week) of each intervention period	Yes
Secondary	other measures of peripheral blood pressure (other types of ambulatory blood pressure measurements as well as clinic blood pressure)		Ambulatory BP: same as primary outcome. Clinic BP: at screening, run-in, and weekly during intervention	Yes
Secondary	measures of central blood pressure (pulse wave velocity and augmentation index)		at screening and at the end (4th week) of each intervention period	No
Secondary	Serum potassium		At screening, run-in, and at least 3 times during each intervention period	Yes