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Plasma Lipids-Dependent Vitamin E Metabolism During Dynamic Hyperlipidemia

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.

Studieoversigt

Status

Ikke rekrutterer endnu

Betingelser

Intervention / Behandling

Detaljeret beskrivelse

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.

Undersøgelsestype

Interventionel

Tilmelding (Anslået)

48

Fase

  • Ikke anvendelig

Kontakter og lokationer

Dette afsnit indeholder kontaktoplysninger for dem, der udfører undersøgelsen, og oplysninger om, hvor denne undersøgelse udføres.

Studiekontakt

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

Undersøgelse Kontakt Backup

Studiesteder

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

Deltagelseskriterier

Forskere leder efter personer, der passer til en bestemt beskrivelse, kaldet berettigelseskriterier. Nogle eksempler på disse kriterier er en persons generelle helbredstilstand eller tidligere behandlinger.

Berettigelseskriterier

Aldre berettiget til at studere

18 år til 65 år (Voksen, Ældre voksen)

Tager imod sunde frivillige

Ingen

Køn, der er berettiget til at studere

Alle

Beskrivelse

  • 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.

Studieplan

Dette afsnit indeholder detaljer om studieplanen, herunder hvordan undersøgelsen er designet, og hvad undersøgelsen måler.

Hvordan er undersøgelsen tilrettelagt?

Design detaljer

  • Primært formål: Grundvidenskab
  • Tildeling: Ikke-randomiseret
  • Interventionel model: Parallel tildeling
  • Maskning: Ingen (Åben etiket)

Våben og indgreb

Deltagergruppe / Arm
Intervention / Behandling
Aktiv komparator: Healthy subjects

Three consecutive high-fat vitamin E-stripped meals

Three consecutive high-fat vitamin E-stripped meals

Eksperimentel: Subjects with hyperlipidemia

Three consecutive high-fat vitamin E-stripped meals

Three consecutive high-fat vitamin E-stripped meals

Hvad måler undersøgelsen?

Primære resultatmål

Resultatmål
Foranstaltningsbeskrivelse
Tidsramme
AUC (Area Under the Curve) of vitamin E plasma from hour 1 to hour 23 by cohort.
Tidsramme: 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

Sekundære resultatmål

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

Samarbejdspartnere og efterforskere

Det er her, du vil finde personer og organisationer, der er involveret i denne undersøgelse.

Sponsor

Efterforskere

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

Publikationer og nyttige links

Den person, der er ansvarlig for at indtaste oplysninger om undersøgelsen, leverer frivilligt disse publikationer. Disse kan handle om alt relateret til undersøgelsen.

Datoer for undersøgelser

Disse datoer sporer fremskridtene for indsendelser af undersøgelsesrekord og resumeresultater til ClinicalTrials.gov. Studieregistreringer og rapporterede resultater gennemgås af National Library of Medicine (NLM) for at sikre, at de opfylder specifikke kvalitetskontrolstandarder, før de offentliggøres på den offentlige hjemmeside.

Studer store datoer

Studiestart (Anslået)

8. november 2026

Primær færdiggørelse (Anslået)

30. november 2028

Studieafslutning (Anslået)

31. marts 2029

Datoer for studieregistrering

Først indsendt

18. juli 2026

Først indsendt, der opfyldte QC-kriterier

18. juli 2026

Først opslået (Faktiske)

21. juli 2026

Opdateringer af undersøgelsesjournaler

Sidste opdatering sendt (Faktiske)

3. november 2026

Sidste opdatering indsendt, der opfyldte kvalitetskontrolkriterier

2. november 2026

Sidst verificeret

14. oktober 2026

Mere information

Begreber relateret til denne undersøgelse

Andre undersøgelses-id-numre

  • 10002623
  • 002623-H

Plan for individuelle deltagerdata (IPD)

Planlægger du at dele individuelle deltagerdata (IPD)?

JA

IPD-planbeskrivelse

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-delingstidsramme

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-delingsadgangskriterier

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-deling Understøttende informationstype

  • STUDY_PROTOCOL
  • ICF

Lægemiddel- og udstyrsoplysninger, undersøgelsesdokumenter

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Ingen

Studerer et amerikansk FDA-reguleret enhedsprodukt

Ingen

Disse oplysninger blev hentet direkte fra webstedet clinicaltrials.gov uden ændringer. Hvis du har nogen anmodninger om at ændre, fjerne eller opdatere dine undersøgelsesoplysninger, bedes du kontakte register@clinicaltrials.gov. Så snart en ændring er implementeret på clinicaltrials.gov, vil denne også blive opdateret automatisk på vores hjemmeside .