Potassium Intake in Patients With Chronic Kidney Disease

NCT ID: NCT00949585

Last Updated: 2012-09-19

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 29 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2009-07-31
• Study Completion Date: 2011-06-30

Brief 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

Detailed 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.

Conditions

Chronic Kidney Disease; Hypertension

Keywords

randomized, controlled feeding study; crossover design; potassium intake

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: TREATMENT
• Blinding Strategy: QUADRUPLE

Study Groups

Dietary potassium intake: 100 mmol/day

Participants will be given one of two diets: one contains 100 mmol of potassium per day, and the other contains 40 mmol of potassium per day

Group Type: OTHER

Dietary intake of potassium

Intervention Type: OTHER

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

Dietary potassium intake: 40 mmol/day

Diet containing 40 mmol/day of potassium

Group Type: OTHER

Dietary intake of potassium

Intervention Type: OTHER

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

Interventions

Dietary intake of potassium

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

Intervention Type: OTHER

Eligibility Criteria

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

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

Sponsors

American Heart Association

OTHER

Sponsor Role: collaborator

Johns Hopkins University

OTHER

Sponsor Role: lead

Responsible Party

Sharon Turban

Assistant Professor of Medicine, Division of Nephrology

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Sharon Turban, MD, MHS

Role: PRINCIPAL_INVESTIGATOR

Johns Hopkins University

Locations

Johns Hopkins University Pro Health Clinical Research Facility

Baltimore, Maryland, United States

Countries

United States

Other Identifiers

AHA 0835162N

Identifier Type: -

Identifier Source: org_study_id