Plasma Lipids-Dependent Vitamin E Metabolism During Dynamic Hyperlipidemia

November 2, 2026 updated by: National Heart, Lung, and Blood Institute (NHLBI)

Plasma Lipids-dependent Vitamin E Metabolism During Dynamic Hyperlipidemia

Background:

Obesity is known to lead to diseases such as diabetes and high cholesterol (or fats) in the blood (hyperlipidemia). But no one knows why. Researchers think that high levels of fat in the blood may block important nutrients, such as vitamin E, from reaching places they are needed in the body.

Objective:

To learn how high-fat meals affect levels of vitamin E in the blood.

Eligibility:

People aged 18 to 65 with high blood fat levels. Healthy volunteers are also needed.

Design:

Participants will have 3 or 4 clinic visits in 3 months. The last visit will require them to stay in the clinic for 2 nights.

Participants will be screened. They will have a physical exam and blood tests.

After this visit, all participants must stop taking any dietary supplements.

Those who use them must also stop taking any drugs to lower their blood sugar and blood fats. These participants will have an extra visit for blood tests after 60 days.

The next visit will include 2 imaging scans:

Magnetic resonance imaging (MRI) of the abdomen. This scan will check for fat in the liver.

Dual-energy X-ray absorptiometry (DEXA). This scan measures the levels of body fat.

On day 1 of the clinic stay, participants will have 2 set meals, with nothing but water after 10 pm.

On day 2, they will drink high-fat shakes at 9am, 1pm, and 5pm. They will have blood draws every 30 minutes for the first hour, every hour the next 16 hours, and then every 2 hours until 7 am. The blood will be taken from a tube inserted into a vein and left in place for the day.

On day 3, they will go home.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Study Description:

A controlled interventional study of effects of postprandial hypertriglyceridemia from three consecutive high-fat vitamin E-stripped meals on the dynamics of plasma vitamin E concentrations in subjects with baseline normo- and hyperlipidemia, to explore the concept of vitamin E sequestration by fats in plasma.

Objectives:

Primary Objective: Compare effects of postprandial hypertriglyceridemia (PHTG) on plasma/lipoprotein vitamin E dynamics in subjects between baseline normo- and hyperlipidemia.

Secondary Objectives: Compare effects of postprandial hypertriglyceridemia (PHTG) on other fat-soluble vitamins (gamma-tocopherol, phylloquinone [K1]; menaquinone [K2]; 25-OH vitamin D; retinol [A]) and related vitamers (beta-carotene, lycopene lutein/zeaxanthin) between subjects with baseline normo- and hyperlipidemia.

Tertiary/Exploratory Objectives:

  1. Compare effects of individual high-fat meals on the dynamics of vitamin E, gamma-tocopherol, phylloquinone [K1], menaquinone [K2], 25-OH vitamin D, retinol [A], and other carotenoids between subjects with baseline normo- and hyperlipidemia.

  2. Compare effects of postprandial hypertriglyceridemia (PHTG) and resultant vitamin E dynamics on: red blood cell (RBC) membrane

    deformability, fluidity, and oxygen exchange capacity (pO2, p50); RBC vitamin E, plasma vitamin C, plasma dehydroascorbic acid;

    fasting glucose and insulin; oxidized LDL, coenzyme Q10, and plasma cytokine/adipokine profile between subjects with baseline normo- and hyperlipidemia;

  3. Explore effects of postprandial hypertriglyceridemia on small RNAs including microRNAs, tRNAs, and PIWI-interacting RNAs.

  4. Explore the influence of genetic variance on the metabolism of vitamin E and other fat-soluble vitamins and related vitamers in subjects with baseline normo- and hyperlipidemia.

Endpoints:

Primary Endpoint: AUC (Area Under the Curve) of vitamin E plasma from hour 1 to hour 23, by cohort.

Secondary Endpoints: AUC of gamma-tocopherol, phylloquinone [K1], menaquinone [K2], 25-OH vitamin D and retinol [A] from hour 1 to hour 23, by cohort.

Tertiary/Exploratory Endpoints:

  1. Between the timepoints that reflect consuming 3 high-fat meals, AUC of vitamin E, gamma-tocopherol, phylloquinone [K1], menaquinone [K2], 25-OH vitamin D, retinol [A], and other carotenoids will be separately calculated for each participant.
  2. Over the course of inpatient visit, RBC membrane deformability/fluidity, pO2, p50, RBC vitamin E, plasma vitamin C, plasma dehydroascorbic acid, blood glucose, insulin, c-peptide, oxidized LDL, coenzyme Q10 and serum cytokine/adipokine profiles in each subject.
  3. Over the course of inpatient visit, small RNAs including microRNAs, tRNAs, and PIWI-interacting RNAs.
  4. Genetic variance (single nucleotide polymorphisms, SNPs)- dependent change in lipid-soluble vitamin dynamics over the course of inpatient visit in each subject.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
48

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Robert D Shamburek, M.D.
  • Phone Number: (301) 496-3460
  • Email: bobs@mail.nih.gov

Study Contact Backup

Study Locations

  • United States
    • Maryland
      • Bethesda, Maryland, United States, 20892
        • National Institutes of Health Clinical Center
        • Contact:
          • NIH Clinical Center Office of Patient Recruitment (OPR)
          • Phone Number: TTY dial 711 (800) 411-1222
          • Email: ccopr@nih.gov
        • Contact:

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

  • INCLUSION CRITERIA:

Cohort 1

  • Males and females aged 18 to 65 years.

  • BMI 18.5 26.9 kg/m^2 .

  • Able to understand the study procedures and provide written consent, and willing to comply with all scheduled follow-up visits and assessments.

  • Normotensive and not on antihypertensive medications, blood pressure 90-129/60-84.

  • Not on glucose-lowering or lipid-lowering medications.

  • At screening, laboratory values meet all of the following:

    • HbA1c < 5.7%,

    • Fasting triglycerides < 150 mg/dL

    • LDL < 100 mg/dL

      7. Liver fat < 2%.

Cohort 2

  • Males and females aged 18 to 65 years.

  • BMI > 26.0 to < 36.0 kg/m2.

  • Able to understand the study procedures and provide written informed consent, and willing to comply with all scheduled follow-up visits and assessments.

  • At screening, laboratory values meet all of the following:

    • HbA1c <= 7.5%
    • Fasting triglycerides < 500 mg/dL
    • LDL < 190 mg/dL

  • Willing to discontinue oral glucose-lowering medications (metformin) and oral lipidlowering medications for 4 to 10 weeks prior to the inpatient visit, if applicable.

  • Liver fat < 2%.

EXCLUSION CRITERIA:

  • Women who are pregnant or currently breastfeeding.
  • Subjects younger than 18 years old. This age group has a broad spectrum of hormonal profiles due to development and puberty, which significantly increases the heterogenicity of study subjects.
  • Subjects older than 65 years. This age group has significantly increased risk of cardiovascular diseases. To minimize the risk from temporarily suspending lipid- and glucose-lowering medications and the stress from serial blood draws, these individuals are excluded.
  • Heavy alcohol use within past 12 months (males: >2 drinks per day or >14 drinks per week; females: >1 drink per day or >7 drinks per week).
  • Current smoker, or former smoker who quit smoking less than 15 years ago.
  • Subjects with weight changes greater than 20% of baseline body weight (self-reported or documented within past 12 months) over the past 3 months at outpatient visit 1, or change from outpatient visit 1 during screening.
  • Subjects with lactose intolerance who are unwilling to take lactase.
  • Subjects with type 1 diabetes.
  • Subjects with hemoglobin <11 g/dL or hematocrit <33%.
  • Subjects with clinically significant abnormal liver function test results.
  • Subjects with liver fat >= 2% on abdominal MRI.
  • Subjects with a history of pancreatitis, diabetes ketoacidosis, hyperosmolar hyperglycemic state, advanced atherosclerosis, cardiovascular diseases, kidney diseases, or liver diseases.
  • Subjects with fat malabsorption, including a history of gastrointestinal surgery, pancreatic insufficiency, inflammatory bowel disease, celiac disease, moderate-to-severe irritable bowel syndrome, or pathologic mutations impacting lipoprotein metabolism.
  • Subjects on glucocorticoids for more than 1 week (not including topical glucocorticoids) within past 3 months.
  • Subjects with HIV.
  • Subjects with uncontrolled psychiatric and/or behavioral disorders.
  • Subjects taking diabetes medications other than metformin.
  • Subjects with anticipated surgery during the study period.
  • Subjects with severe medication-resistant claustrophobia.
  • Subjects who are unwilling to stop medications, vitamins, and/or dietary supplements that investigators have requested to be held.
  • Subjects participating in any other clinical study without informing investigators.
  • Any other reason or clinical condition that the investigators judge would interfere with study participation and/or be unsafe for the participant or staff member.

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

  • Primary Purpose: Basic Science
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Healthy subjects

Three consecutive high-fat vitamin E-stripped meals
Dietary supplement: High fat liquid shake

Three consecutive high-fat vitamin E-stripped meals
Experimental: Subjects with hyperlipidemia

Three consecutive high-fat vitamin E-stripped meals
Dietary supplement: High fat liquid shake

Three consecutive high-fat vitamin E-stripped meals

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
AUC (Area Under the Curve) of vitamin E plasma from hour 1 to hour 23 by cohort.
Time Frame: From hour 1 to hour 23

Compare the effects of postprandial hypertriglyceridemia on plasma vitamin E dynamics in subjects between baseline normo- and hyperlipidemia.
From hour 1 to hour 23

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
AUC of gamma-tocopherol, phylloquinone [K1]; menaquinone [K2]; 25-OH vitamin D; retinol [A] from hour 1 to hour 23 by cohort.
Time Frame: From hour 1 to hour 23

Compare the effects of postprandial hypertriglyceridemia on other fat-soluble vitamins (gamma-tocopherol, phylloquinone [K1]; menaquinone [K2]; 25-OH vitamin D; retinol [A]) and related vitamers (beta-carotene, lycopene lutein/zeaxanthin) in subjects between baseline normo- and hyperlipidemia.
From hour 1 to hour 23

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
National Heart, Lung, and Blood Institute (NHLBI)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Robert D Shamburek, M.D., National Heart, Lung, and Blood Institute (NHLBI)

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

Helpful Links

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 (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 8, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
November 30, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 31, 2029

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 18, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 18, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 21, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 3, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 2, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
October 14, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 10002623
  • 002623-H

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified individual participant data underlying results reported in publications may be shared. Depending on the sensitivity of the dataset and risk of re-identification, data may be made available through either an open-access repository or a controlled-access repository, consistent with informed consent, institutional review, and applicable policies.@@@@@@

IPD Sharing Time Frame

Beginning following de-identification and publication of the primary results, or other prespecified time point, and continuing for as long as the repository or access mechanism remains available.

IPD Sharing Access Criteria

Access to de-identified individual participant data will be determined based on the sensitivity of the data and disclosure risk. Data appropriate for broad sharing may be deposited in an open-access repository. Data requiring additional protections may be made available through a controlled-access mechanism subject to review and any applicable agreements.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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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