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Plasma Lipids-Dependent Vitamin E Metabolism During Dynamic Hyperlipidemia

17 september 2026 bijgewerkt door: 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 8 am, noon, and 4 pm. They will have blood draws every hour for 17 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.

Studie Overzicht

Toestand

Nog niet aan het werven

Conditie

Interventie / Behandeling

Gedetailleerde beschrijving

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 (p50); RBC vitamin E, plasma vitamin C, plasma dehydroascorbic acid; fasting glucose and insulin; oxidized LDL, coenzyme Q10, and plasma 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, p50, RBC vitamin E, plasma vitamin C, plasma dehydroascorbic acid, blood glucose, insulin, c-peptide, oxidized LDL, coenzyme Q10 and serum 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.

Studietype

Ingrijpend

Inschrijving (Geschat)

48

Fase

  • Niet toepasbaar

Contacten en locaties

In dit gedeelte vindt u de contactgegevens van degenen die het onderzoek uitvoeren en informatie over waar dit onderzoek wordt uitgevoerd.

Studiecontact

  • Naam: Robert D Shamburek, M.D.
  • Telefoonnummer: (301) 496-3460
  • E-mail: bobs@mail.nih.gov

Studie Contact Back-up

Studie Locaties

  • Verenigde Staten
    • Maryland
      • Bethesda, Maryland, Verenigde Staten, 20892
        • National Institutes of Health Clinical Center
        • Contact:
          • NIH Clinical Center Office of Patient Recruitment (OPR)
          • Telefoonnummer: TTY dial 711 (800) 411-1222
          • E-mail: ccopr@nih.gov
        • Contact:

Deelname Criteria

Onderzoekers zoeken naar mensen die aan een bepaalde beschrijving voldoen, de zogenaamde geschiktheidscriteria. Enkele voorbeelden van deze criteria zijn iemands algemene gezondheidstoestand of eerdere behandelingen.

Geschiktheidscriteria

Leeftijden die in aanmerking komen voor studie

  • Volwassen
  • Oudere volwassene

Accepteert gezonde vrijwilligers

Nee

Beschrijving

  • INCLUSION CRITERIA

Cohort 1

  1. Males and females between the ages of 18 to 65
  2. BMI 18.5 - 26.9 kg/m^2
  3. Subject understands the protocol and provides written, informed consent in addition to a willingness to comply with specified follow-up instructions and evaluations
  4. Normotensive, not on medications for hypertension
  5. Not on glucose-lowering or lipid-lowing medications
  6. Screening labs with baseline HbA1c <5.7%, baseline fasting triglyceride < 150 mg/dL and LDL <100 mg/dL
  7. Liver fat <2%

Cohort 2

  1. Males and females between the ages of 18 to 65
  2. BMI >26 kg/m^2 and <36 kg/m^2
  3. Subject understands the protocol and provides written, informed consent in addition to a willingness to comply with specified follow-up instructions and evaluations.
  4. Screening labs with baseline HbA1c <= 7.5%, agree to be off or stop oral glucose-lowering medications (metformin), baseline fasting triglyceride < 500 mg/dL and LDL <190 mg/dL, agree to be off or stop oral lipid-lowing medications for 4-10 weeks prior to the inpatient visit.
  5. Liver fat <2%

EXCLUSION CRITERIA

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

Studie plan

Dit gedeelte bevat details van het studieplan, inclusief hoe de studie is opgezet en wat de studie meet.

Hoe is de studie opgezet?

Ontwerpdetails

  • Primair doel: Fundamentele wetenschap
  • Toewijzing: Niet-gerandomiseerd
  • Interventioneel model: Parallelle opdracht
  • Masker: Geen (open label)

Wapens en interventies

Deelnemersgroep / Arm
Interventie / Behandeling
Actieve vergelijker: Healthy subjects
Three consecutive high-fat vitamin E-stripped meals
Voedingssupplement: High fat liquid shake
Three consecutive high-fat vitamin E-stripped meals
Experimenteel: Subjects with hyperlipidemia
Three consecutive high-fat vitamin E-stripped meals
Voedingssupplement: High fat liquid shake
Three consecutive high-fat vitamin E-stripped meals

Wat meet het onderzoek?

Primaire uitkomstmaten

Uitkomstmaat
Maatregel Beschrijving
Tijdsspanne
AUC (Area Under the Curve) of vitamin E plasma from hour 1 to hour 23 by cohort.
Tijdsspanne: 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

Secundaire uitkomstmaten

Uitkomstmaat
Maatregel Beschrijving
Tijdsspanne
AUC of gamma-tocopherol, phylloquinone [K1]; menaquinone [K2]; 25-OH vitamin D; retinol [A] from hour 1 to hour 23 by cohort.
Tijdsspanne: 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

Medewerkers en onderzoekers

Hier vindt u mensen en organisaties die betrokken zijn bij dit onderzoek.

Sponsor

National Heart, Lung, and Blood Institute (NHLBI)

Onderzoekers

  • Hoofdonderzoeker: Robert D Shamburek, M.D., National Heart, Lung, and Blood Institute (NHLBI)

Publicaties en nuttige links

De persoon die verantwoordelijk is voor het invoeren van informatie over het onderzoek stelt deze publicaties vrijwillig ter beschikking. Dit kan gaan over alles wat met het onderzoek te maken heeft.

Algemene publicaties

Nuttige links

Studie record data

Deze datums volgen de voortgang van het onderzoeksdossier en de samenvatting van de ingediende resultaten bij ClinicalTrials.gov. Studieverslagen en gerapporteerde resultaten worden beoordeeld door de National Library of Medicine (NLM) om er zeker van te zijn dat ze voldoen aan specifieke kwaliteitscontrolenormen voordat ze op de openbare website worden geplaatst.

Bestudeer belangrijke data

Studie start (Geschat)

23 september 2026

Primaire voltooiing (Geschat)

30 november 2028

Studie voltooiing (Geschat)

31 maart 2029

Studieregistratiedata

Eerst ingediend

18 juli 2026

Eerst ingediend dat voldeed aan de QC-criteria

18 juli 2026

Eerst geplaatst (Werkelijk)

21 juli 2026

Updates van studierecords

Laatste update geplaatst (Werkelijk)

18 september 2026

Laatste update ingediend die voldeed aan QC-criteria

17 september 2026

Laatst geverifieerd

21 juli 2026

Meer informatie

Termen gerelateerd aan deze studie

Trefwoorden

Aanvullende relevante MeSH-voorwaarden

Andere studie-ID-nummers

  • 10002623
  • 002623-H

Plan Individuele Deelnemersgegevens (IPD)

Bent u van plan om gegevens van individuele deelnemers (IPD) te delen?

JA

Beschrijving IPD-plan

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-tijdsbestek voor delen

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-toegangscriteria voor delen

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 delen Ondersteunend informatietype

  • LEERPROTOCOOL
  • ICF

Informatie over medicijnen en apparaten, studiedocumenten

Bestudeert een door de Amerikaanse FDA gereguleerd geneesmiddel

Nee

Bestudeert een door de Amerikaanse FDA gereguleerd apparaatproduct

Nee

Deze informatie is zonder wijzigingen rechtstreeks van de website clinicaltrials.gov gehaald. Als u verzoeken heeft om uw onderzoeksgegevens te wijzigen, te verwijderen of bij te werken, neem dan contact op met register@clinicaltrials.gov. Zodra er een wijziging wordt doorgevoerd op clinicaltrials.gov, wordt deze ook automatisch bijgewerkt op onze website .

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