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NCT07715890

Plasma Lipids-dependent Vitamin E Metabolism During Dynamic Hyperlipidemia

Sponsor: National Heart, Lung, and Blood Institute (NHLBI)

View on ClinicalTrials.gov

Summary

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.

Key Details

Gender

All

Age Range

18 Years - 65 Years

Study Type

INTERVENTIONAL

Enrollment

Start Date

2026-08-01

Completion Date

2029-03-31

Last Updated

2026-07-21

Healthy Volunteers

Conditions

Lipid Metabolism Disorders

Interventions

DIETARY_SUPPLEMENT

High fat liquid shake

Three consecutive high-fat vitamin E-stripped meals

* 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

Locations (1)

National Institutes of Health Clinical Center

Bethesda, Maryland, United States