Choline and Cardiometabolic Health

Virginia Polytechnic Institute and State University14 enrolled

Overview

Trimethylamine-N-oxide (TMAO), a metabolite produced by gut microbial metabolism of dietary choline, has recently been causally linked to atherosclerosis in animal models and has been shown to be predictive of cardiovascular disease (CVD) risk in some but not all cohort studies. The relevance of observations in animals to humans is unclear and little information is available on the mechanisms linking TMAO to increased CVD risk. Vascular dysfunction plays a critical role in the initiation and progression of atherothrombotic disease. Whether TMAO impairs vascular function in humans is not known. The purpose of this study is to determine if short term supplementation of dietary choline, which increases TMAO, affects CVD risk factors, such as glucose homeostasis and vascular function.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

DOUBLE

Enrollment

Conditions

Cardiovascular Risk Factor

Interventions

Eligibility

Sex: ALLMin age: 18 YearsMax age: 79 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Age 18-79 years * Weight stable for previous 6 months (+2.0kg) * Sedentary to recreationally active (\<30 min aerobic exercise \<2x/wk) * No plans to gain/lose weight or change physical activity level * Verbal and written informed consent * Willing to be randomized to treatment order * Fully vaccinated against COVID-19 Exclusion Criteria: * BMI \> 35 kg/m2 * Smoking * Pregnant or plans of becoming pregnant * Vegetarian or Vegan * Changed dietary patterns within the last month * Diabetes (or use of diabetes medications) or unstable heart disease * Untreated high blood pressure or high cholesterol * Health problems that mide it unsafe to participate * Taking medications, vitamins or supplements that could affect study outcomes (including but not limited to aspirin, antibiotics, prebiotics, and probiotics) * Known allergy, hypersensitivity, intolerance to choline supplement or its ingredients * Trimethylaminuria or "fish odor" syndrome

Outcomes

Primary Outcomes

Change From Baseline in Insulin Sensitivity at 4 Weeks

Participants will complete a 2-hour glucose tolerance test at baseline, immediately following the first intervention, after a 2-week washout, and immediately following the second intervention. A catheter will be placed in one of the participant's arms. After a baseline blood draw to measure fasting levels of glucose, insulin, cholesterol and other factors, participants will drink a glucose beverage (75 g). Blood will be collected in small amounts (less than one half teaspoon) at eight timepoints over a 2-hour period. Insulin sensitivity will be calculated using Matsuda's index (a ratio with no units). This test will be conducted two times separated by about 4 weeks for each intervention (choline, placebo).

Time frame: Calculated difference between the baseline and 4-week testing session for each intervention

Secondary Outcomes

Change in 24-hour Area Under the Curve for Glucose Levels After Supplementation

Glucose will be monitored by a Continuous Glucose Monitor (CGM) sensor (Enlite Sensor; Medtronic, Inc. or FreeStyle Libre Pro; Abbott) and this will be placed on the participant's abdomen or back of the upper arm in order to measure glucose continuously. The measured glucose levels will be assessed by an iPro2 Professional CGM; Medtronic, Inc. or FreeStyle Libre Pro reader; Abbott; and the CGM will be worn for 4 consecutive days. This test will be conducted two times separated by about 4 weeks for each intervention (choline, placebo).

Time frame: Difference in 24-hour glucose levels during free living at baseline and 4 weeks