Lipid Challenge in Adults

Measurements of Lipoproteins, Apolipoproteins and Lipids - Determination of Pre-analytical Variables for Analysis of Blood Collected From Fasting and Post-prandial Subjects

Participants in this study will have one visit to the Emory University Hospital Clinical Research Unit. Participants will consume, over 5 minutes, a single standardized fat challenge (100 grams), using a commercially available liquid high-energy long chain triglyceride fat emulsion (Calogen), which provides 50 grams of long chain triglycerides per 100 mL. Participants will have 20 mL blood withdrawn at six successive time points over an 8-hour period, where the first time point after fasting (baseline) is followed by 5 time-points after fat consumption. Blood will be analyzed for a wide panel of blood lipids.

Study Overview

• Status: Completed
• Conditions: Cardiovascular Diseases
• Intervention / Treatment: Dietary supplement: Lipid Challenge

Detailed Description

Cardiovascular disease (CVD) is the leading killer of Americans, accounting more than 800,000 deaths each year. A vital step in reducing the number of heart disease-related deaths in the U.S. is to identify those at probable risk. The Clinical Chemistry Branch (CCB) in the Division of Laboratory Sciences (DLS) at the Centers for Disease Control and Prevention (CDC) has developed advanced analytical methods for assessing the risk for lipid metabolism related diseases, including CVD. CCB of the CDC has developed a comprehensive analytical method to measure levels of protein and lipid constituents of lipoprotein size/density classes (e.g. high-density lipoprotein (HDL), low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) in blood. CCB plans to eventually apply this method in future investigations of cohorts with different CVD states. The measurement of this wide array of CVD-linked biomarkers has the potential to improve the assessment of CVD risk over current clinical methods based on lipoprotein classes.

However, limited information is available about how the advanced tests developed by CCB are affected by blood collection conditions, such as fasting/non-fasting state of the subjects. The purpose of this study is to determine the relative significance of these pre-analytical variables and determine optimal conditions for future cohort studies.

This study will recruit up to 32 healthy individuals, with and without obesity, to participate. The study involves one visit to the Emory University Hospital Clinical Research Unit where participants will consume, over 5 minutes, a single standardized fat challenge (100 grams), using a commercially available liquid high-energy long chain triglyceride fat emulsion (Calogen; http://www.nutricia.ie/calogen#), which provides 50 grams of long chain triglycerides per 100 mL. Participants will have 20 mL blood withdrawn at six successive time points over an 8-hour period, where the first time point after fasting is followed by 5 time-points after fat (Calogen) consumption. Blood will be analyzed at the CCB for a wide panel of blood lipids and potential biomarkers for CVD.

Specific expected outcomes of the study include the following: 1) Determination of typical intra-individual differences between fasting and post-prandial states; and 2) Changes in the levels of the various analytes after fat consumption will be indicative of inter-individual differences in the rate of triglyceride depletion, and the rate of accumulation/depletion of HDL or LDL of different particle size range and composition. The results will allow the assessment of significant differences in lipid metabolism between individuals with a normal BMI (20 to 25 kg/m^2) versus those with a BMI in the obese range (30-35 kg/m^2).

• Study Type: Interventional
• Enrollment (Actual): 32
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Georgia
    • Atlanta, Georgia, United States, 30322
      • Emory University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 50 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• functionally ambulatory
• BMI between >20 to 40 kg/m^2
• available for an 8 hour visit to the Emory University Hospital Clinical Research Center

Exclusion Criteria:

• has taken any diabetic or lipid lowering prescription medications within the past 12 months
• history of chronic diseases
• hospitalized within the last year
• currently pregnant
• current active malignant neoplasm or history of malignancy (other than localized basal cell cancer of the skin) during the previous 5 years
• current chronic autoimmune or pro-inflammatory disease
• history of tuberculosis, HIV, or other chronic infection
• previous diagnosis of type 1 or type 2 diabetes with active treatment with insulin or other glucose lowering medication
• advanced (>= stage 3) renal disease
• recreational or prescription drug or alcohol abuse
• any history of gastrointestinal diseases, including malabsorption
• any history of intolerance to dietary fat
• inability to provide informed consent

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Lipid Challenge Intervention; Participants of all weights will receive the lipid challenge intervention.

Dietary supplement: Lipid Challenge; After fasting for 10 hours, all participants will undergo a lipid challenge with Calogen. Calogen is a commercially available liquid high-energy long chain triglyceride fat emulsion used to fortify foods. Calogen provides 50 grams of long chain triglycerides per 100 mL. Participants must avoid physical activity during the 6 hour study period to avoid changes in metabolism that could affect the results of the study.; Other Names: Calogen

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in high-density lipoprotein (HDL) Size	HDL concentration size profiles for each time-point will be compared between participants with normal BMI and participants with obese range BMI. HDL is considered to be anti-atherogenic because of its ability deplete excess cholesterol accumulating necrotic cores and repair arterial lesions.	Hours 0, 0.5, 1, 2, 4, and 6
Change in low-density lipoprotein (LDL) Size	LDL concentration size profiles for each time-point will be compared between participants with normal BMI and participants with obese range BMI. LDL is considered to be atherogenic because it is likely to be trapped inside the intima of blood vessels and arteries and initiate inflammatory response, foam-cell formation, and smooth muscle cell proliferation, leading to development necrotic cores, lesions, plaques and their eventual rupture. Elevated LDL has been thought to contribute to atherosclerotic events, however, research has also observed coronary events occurring in individuals with LDL levels in the acceptable range.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Total Cholesterol	Total cholesterol profiles for each time-point will be compared between participants with normal BMI and participants with obese range BMI. Elevated total cholesterol has been thought to contribute to atherosclerotic events, however, research has also observed coronary events occurring in individuals with total cholesterol levels in the acceptable range.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Free Cholesterol	Free cholesterol concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI. Free cholesterol is unesterified cholesterol that is circulating in the blood stream.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Cholesterol Ester	Cholesterol ester concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI. Lipoproteins contain cholesterol ester, and cholesterol ester is associated with atherosclerosis.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Triglycerides	Triglyceride concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI. Triglycerides peak in serum 2 to 4 hours after a meal and return to a pre-meal state in 6 to 8 hours.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Phosphatidylinositol	Phosphatidylinositol concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Phosphatidylethanolamine	Phosphatidylethanolamine concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Phosphatidylcholine	Phosphatidylcholine concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Sphingomyelin	Sphingomyelin concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Lysophosphatidylcholine	Lysophosphatidylcholine concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Apolipoprotein AI	Apolipoprotein AI concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Apolipoprotein AII	Apolipoprotein AII concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Apolipoprotein AIV	Apolipoprotein AIV concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Apolipoprotein B	Apolipoprotein B concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Apolipoprotein CI	Apolipoprotein CI concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Apolipoprotein CII	Apolipoprotein CII concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Apolipoprotein CIII	Apolipoprotein CIII concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Apolipoprotein E	Apolipoprotein E concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Lecithin-Cholesterol Acyltransferase	Lecithin-cholesterol acyltransferase concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Cholesterol Ester Transfer Protein	Cholesterol ester transfer protein concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Lipoprotein (a)	Lipoprotein (a) concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Phospholipid Transfer Protein	Phospholipid transfer protein concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Serum Paraoxonase/arylesterase 1	Serum paraoxonase/arylesterase 1 concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Serum Amyloid A1	Serum amyloid A1 concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI.	Hours 0, 0.5, 1, 2, 4, and 6
Change in Serum Amyloid A4	Serum amyloid A4 concentration for each time-point will be compared between participants with normal BMI and participants with obese range BMI.	Hours 0, 0.5, 1, 2, 4, and 6

Collaborators and Investigators

• Sponsor: Emory University
• Collaborators: Centers for Disease Control and Prevention

Study record dates

Study Major Dates

• Study Start (Actual): August 29, 2019
• Primary Completion (Actual): September 9, 2021
• Study Completion (Actual): September 9, 2021

Study Registration Dates

• First Submitted: May 10, 2019
• First Submitted That Met QC Criteria: May 10, 2019
• First Posted (Actual): May 13, 2019

Study Record Updates

• Last Update Posted (Actual): May 1, 2023
• Last Update Submitted That Met QC Criteria: April 27, 2023
• Last Verified: April 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiovascular Diseases
• Other Study ID Numbers: IRB00107183

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No