Plasma and Urine TMAO Formation and Changes to Oxidized LDL After Ingestion of Different Amounts of Egg

July 20, 2013 updated by: Steven Zeisel, University of North Carolina, Chapel Hill

Determining Whether or Not Egg Ingestion Increases Concentrations of Trimethylamine N-oxide (TMAO) in Plasma and Urine and Activates LDL Oxidation in Humans

Eggs contain an essential nutrient called choline and adequate levels of choline are required for good health. Studies in mice have demonstrated that high levels of choline may increase risk of heart disease through a process that involves the breakdown of choline by gut bacteria. Previous research did not show that human consumption of eggs increases risk of heart disease. This study is designed to investigate whether the number of eggs in the diet affects blood and urine markers for heart disease.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Diets low in choline have adverse health consequences, while observations in humans and experiments in mouse models suggest that a diet containing too much choline or phosphatidylcholine may activate inflammatory pathways and increase cardiovascular disease risk through bacterial conversion of choline to trimethylamine (TMA) and its subsequent oxidation to trimethylamine N-oxide (TMAO) in the liver. What is unclear is whether choline and phosphatidylcholine in eggs is a source of TMAO formation, and if so how many eggs must be eaten before enough TMAO is generated to cause increased oxidized LDL (a biomarker for atherosclerosis mechanisms). We hypothesize that TMAO will only be formed from eggs when very large quantities are ingested and that TMAO formation will vary greatly between individuals for any given dietary exposure. This variability will be determined by 1) the dose at which dietary choline or phosphatidylcholine exceeds the absorptive capacity of the volunteer's small intestine and therefore spills into large intestine where gut bacteria have access to it and 2) the bacterial populations that constitute the volunteer's microbiome.

Study Type

Interventional

Enrollment (Actual)

6

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • North Carolina
      • Kannapolis, North Carolina, United States, 28081
        • University of North Carolina at Chapel Hill Nutrition Research Institute

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 75 years (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Healthy
  • non-smoker
  • Body mass index between 20 to 39 kg/m²

Exclusion Criteria:

  • History of chronic system disease/s (e.g., hepatic, renal, cardiovascular, intestinal)
  • Diabetes controlled by insulin
  • Alcohol or illegal drug misuse/abuse
  • Use of antibiotics or choline-containing supplements within three months of study
  • Allergies to soy, eggs, wheat or other food
  • Use of drugs or medications known to alter liver metabolism, cardiovascular and/or kidney function
  • Abnormal physical examination or abnormal clinical laboratory values
  • Pregnancy
  • Unusual dietary habits

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Allocation: NA
  • Interventional Model: SINGLE_GROUP
  • Masking: TRIPLE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
EXPERIMENTAL: Egg Dose
Other: Egg Dose
Different quantities of eggs

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Area under the plasma concentration versus time curve (AUC) of TMAO
Time Frame: TMAO concentrations in plasma collected prior to and 1, 2, 6, 8, and 24 hours after egg ingestion.
TMAO concentrations in plasma collected prior to and 1, 2, 6, 8, and 24 hours after egg ingestion.

Secondary Outcome Measures

Outcome Measure
Time Frame
Concentration of TMAO in urine
Time Frame: Concentration of TMAO will be measured in 24 hour urine collections that start the morning of the egg dose
Concentration of TMAO will be measured in 24 hour urine collections that start the morning of the egg dose

Other Outcome Measures

Outcome Measure
Time Frame
Changes to plasma oxidized LDL
Time Frame: Oxidized LDL will be measured in plasma collected prior to and 24 hours after ingestion of each egg dose
Oxidized LDL will be measured in plasma collected prior to and 24 hours after ingestion of each egg dose

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of North Carolina, Chapel Hill

Collaborators

American Egg Board

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

October 1, 2012

Primary Completion (ACTUAL)

January 1, 2013

Study Completion (ACTUAL)

July 1, 2013

Study Registration Dates

First Submitted

July 16, 2013

First Submitted That Met QC Criteria

July 20, 2013

First Posted (ESTIMATE)

July 24, 2013

Study Record Updates

Last Update Posted (ESTIMATE)

July 24, 2013

Last Update Submitted That Met QC Criteria

July 20, 2013

Last Verified

July 1, 2013

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • A12-1066-001

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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