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Purpose

The goal of this clinical trial is to determine if a high potassium intake can counteract the harmful effects of excess sodium on endothelial function in older adults with no history of cardiometabolic disease. The main questions it aims to answer are: 1. Can a high potassium intake attenuate dietary sodium-induced endothelial dysfunction in older adults. 2. Do changes in endothelial function in response to alterations in sodium and potassium intake differ by sex. Participants will participants will consume three controlled diets for 10 days each with a minimum 14-day washout between interventions. The order in which participants consume the diets will be randomized. The study diets will vary in sodium and potassium content. Measures of cardiovascular health (blood pressure, arterial stiffness, endothelial function) will be assessed at the end of each diet.

Condition

Eligibility

Eligible Ages
Between 55 Years and 75 Years
Eligible Sex
All
Accepts Healthy Volunteers
Yes

Inclusion Criteria

  • Adults ages 55-75 years - At least one-year post-menopause (females) - Willing and able to attend laboratory visits

Exclusion Criteria

  • BMI ≥35 kg/m2 - Seated blood pressure >135/85 mmHg - Current diagnosis or history of cardiovascular disease, diabetes, renal disease, cancer, or major cardiovascular event (e.g. heart attack or stroke) - Taking exogenous hormones or hormone replacement therapy - Following a vegan or gluten free diet - Significant weight loss (>10% of body weight) in the last 6 months, or actively trying to lose weight - Current or recent use of a diuretic (within the past 6 months) (e.g. spironolactone, eplerenone) - Current or recent use of a potassium binding medication (within the past 6 months) - Current use of blood pressure lowering medications (e.g. ACE inhibitors, calcium channel blockers, diuretics, vasodilators, beta blockers, AngII receptor blockers) - Current or recent use of the medication trimethoprim - Elevated blood lipids (LDL cholesterol ≥190 mg/dL) - Elevated serum potassium level (>5.1 mmol/L) - Elevated BUN (>22 mg/dL) - Elevated creatinine (>1.2 mg/dL) - Low eGFR (<90 mL/min/1.73 m²) - Current or recent use of tobacco, nicotine, or illicit drugs - Radical hysterectomy or oophorectomy (females)

Study Design

Phase
N/A
Study Type
Interventional
Allocation
Randomized
Intervention Model
Crossover Assignment
Primary Purpose
Prevention
Masking
Triple (Participant, Investigator, Outcomes Assessor)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
low Na/low K, high Na/low K, high Na/high K 		Three 10-day controlled diets in randomized order, each varying in sodium and potassium content. There is a minimum 2-week washout between diets.
  • Other: low sodium/low potassium diet
    On this intervention, participants will be given a diet that provides 2,000 mg Na/day and 2,000 mg K/day
  • Other: high sodium/low potassium diet
    On this intervention, participants will be given a diet that provides 4,700 mg Na/day and 2,000 mg K/day
  • Other: high sodium/high potassium diet
    On this intervention, participants will be given a diet that provides 4,700 mg Na/day and 4,700 mg K/day
Experimental
low Na/low K, high Na/high K, high Na/low K 		Three 10-day controlled diets in randomized order, each varying in sodium and potassium content. There is a minimum 2-week washout between diets.
  • Other: low sodium/low potassium diet
    On this intervention, participants will be given a diet that provides 2,000 mg Na/day and 2,000 mg K/day
  • Other: high sodium/low potassium diet
    On this intervention, participants will be given a diet that provides 4,700 mg Na/day and 2,000 mg K/day
  • Other: high sodium/high potassium diet
    On this intervention, participants will be given a diet that provides 4,700 mg Na/day and 4,700 mg K/day
Experimental
high Na/high K, low Na/low K, high Na/low K 		Three 10-day controlled diets in randomized order, each varying in sodium and potassium content. There is a minimum 2-week washout between diets.
  • Other: low sodium/low potassium diet
    On this intervention, participants will be given a diet that provides 2,000 mg Na/day and 2,000 mg K/day
  • Other: high sodium/low potassium diet
    On this intervention, participants will be given a diet that provides 4,700 mg Na/day and 2,000 mg K/day
  • Other: high sodium/high potassium diet
    On this intervention, participants will be given a diet that provides 4,700 mg Na/day and 4,700 mg K/day
Experimental
high Na/high K, high Na/low K, low Na/low K 		Three 10-day controlled diets in randomized order, each varying in sodium and potassium content. There is a minimum 2-week washout between diets.
  • Other: low sodium/low potassium diet
    On this intervention, participants will be given a diet that provides 2,000 mg Na/day and 2,000 mg K/day
  • Other: high sodium/low potassium diet
    On this intervention, participants will be given a diet that provides 4,700 mg Na/day and 2,000 mg K/day
  • Other: high sodium/high potassium diet
    On this intervention, participants will be given a diet that provides 4,700 mg Na/day and 4,700 mg K/day
Experimental
high Na/low K, low Na/low K, high Na/high K 		Three 10-day controlled diets in randomized order, each varying in sodium and potassium content. There is a minimum 2-week washout between diets.
  • Other: low sodium/low potassium diet
    On this intervention, participants will be given a diet that provides 2,000 mg Na/day and 2,000 mg K/day
  • Other: high sodium/low potassium diet
    On this intervention, participants will be given a diet that provides 4,700 mg Na/day and 2,000 mg K/day
  • Other: high sodium/high potassium diet
    On this intervention, participants will be given a diet that provides 4,700 mg Na/day and 4,700 mg K/day
Experimental
high Na/low K, high Na/high K, low Na/low K 		Three 10-day controlled diets in randomized order, each varying in sodium and potassium content. There is a minimum 2-week washout between diets.
  • Other: low sodium/low potassium diet
    On this intervention, participants will be given a diet that provides 2,000 mg Na/day and 2,000 mg K/day
  • Other: high sodium/low potassium diet
    On this intervention, participants will be given a diet that provides 4,700 mg Na/day and 2,000 mg K/day
  • Other: high sodium/high potassium diet
    On this intervention, participants will be given a diet that provides 4,700 mg Na/day and 4,700 mg K/day

Recruiting Locations

Florida State University
Tallahassee, Florida 32306
Contact:
Andrea Lobene
850-644-1829
alobene@fsu.edu

More Details

Status
Recruiting
Sponsor
Florida State University

Study Contact

Andrea Lobene
850-644-1829
alobene@fsu.edu

Detailed Description

Cardiovascular health declines with age, especially in postmenopausal females. High sodium diets are a major contributor to cardiovascular disease. Unfortunately, reducing sodium intake can be challenging. It is known that increasing potassium intake can improve cardiovascular disease risk factors in young adults, even if sodium intake remains high. The investigators are hoping to show that potassium can improve cardiovascular health in the context of a high sodium diets in older adults. In this study, participants will consume three 10-day controlled diets in a randomized order. The study diets will include: 1) a low sodium (2,000 mg/day)/low potassium (2,000 mg/day) diet; 2) a high sodium (4,700 mg/day)/usual potassium diet; and 3) a high sodium/high potassium (4,700 mg/day). All food will be provided to participants during these periods, and participants will be instructed not to consume any outside food or beverages. Dietary interventions will be separated by a minimum two-week washout period. Measurements of cardiovascular health will be collected at the end of each diet.

Notice

Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.