The purpose of this study is to assess sample collection conditions for various dietary challenges (fat, sugar, and mixed) and determine the optimal fasting and post-meal sample collection time points for future studies on a larger group of individuals. Study participants will attend three study visits where they take part in lipid, glucose, and mixed meal challenges. At each of the three visits, participants will provide venous blood samples and a urine sample before consuming the test meal and will provide 6 additional venous finger blood samples post-meal.
Cardiovascular disease (CVD) is the leading killer of Americans, accounting for 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. This comprehensive analytical method measures levels of protein and lipid constituents of lipoprotein size and density classes (e.g. high-density lipoprotein (HDL), low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL)) in blood. The analytical method uses asymmetric flow-field flow fractionation (AF4) to separate lipoprotein classes (HDL, LDL, VLDL) in serum or plasma into size fractions, and in each fraction quantifies over 50 CVD-linked biomarkers by isotope dilution tandem mass spectrometry. The CCB plans to apply the measurement of this wide array of biomarkers in future epidemiologic investigations of CVD. These studies have the potential to expand the number of diagnostically relevant CVD risk factors that currently are limited to cholesterol and triglyceride measurements. However, there is limited information about how the CVD-linked biomarkers measured with the CCB's method are affected by blood collection conditions and the fasting/non-fasting state of individuals. Furthermore, lipid metabolism is very dynamic and the absolute levels of biomarkers are strongly affected by each individual's diet, lifestyle, gender, age, and physiology. Thus, assessing biomarkers related to lipid metabolism is most effective in a pre- and post-test comparison (i.e. fasting vs. after a test meal) with controlled lipid and carbohydrate content. The study involves three different meal challenges on three separate days with approximately two weeks in between. The first meal challenge will involve the consumption of a standardized mixture of dietary fats (lipid challenge), the second meal challenge will be a sugar sweetened beverage (glucose challenge) and the third meal challenge will be a nutrition shake (mixed meal challenge). At each of the three visits, each individual will provide both venous and finger-prick blood samples and a urine sample before consuming the test meal (in a fasting state) and 6 additional venous and finger-prick blood samples post-meal at described intervals. Each study visit will last approximately 8 hours.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
PREVENTION
Masking
NONE
Enrollment
11
For the lipid challenge, participants consume 100 grams of a long chain triglyceride emulsion in the form of liquid drink, which is the commercially available brand called Calogen, from Nutricia, Inc.
For the glucose challenge, participants consume 75 grams of glucose in 200 milliliters of water, which is the World Health Organization (WHO) recommended drink for the Oral Glucose Tolerance Test.
For the mixed-meal challenge, participants consume 237 milliliters of the Ensure Enlive nutrition drink , which contains 11 grams of fat, 22 grams of sugar and 20 grams of protein.
Emory University Hospital
Atlanta, Georgia, United States
Change in high-density lipoprotein (HDL) Size
HDL concentration size profiles for each time-point will be determined for each of the three meal challenges. HDL is considered to be anti- atherogenic because of its ability deplete excess cholesterol accumulating necrotic cores and repair arterial lesions.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in low-density lipoprotein (LDL) Size
LDL concentration size profiles for each time-point will be determined for each of the three meal challenges. 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.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Total Cholesterol
Total cholesterol profiles for each time-point will be determined for each of the three meal challenges. 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.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Free Cholesterol
Free cholesterol concentration for each time-point will be determined for each of the three meal challenges. Free cholesterol is unesterified cholesterol that is circulating in the blood stream.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
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Change in Cholesterol Ester
Cholesterol ester concentration for each time-point will be determined for each of the three meal challenges. Lipoproteins contain cholesterol ester, and cholesterol ester is associated with atherosclerosis.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Triglycerides
Triglyceride concentration for each time-point will be determined for each of the three meal challenges. Triglycerides peak in serum 2 to 4 hours after a meal and return to a pre-meal state in 6 to 8 hours.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Phosphatidylinositol
Phosphatidylinositol concentration for each time-point will be determined for each of the three meal challenges.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Phosphatidylethanolamine
Phosphatidylethanolamine concentration for each time-point will be determined for each of the three meal challenges.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Phosphatidylcholine
Phosphatidylcholine concentration for each time-point will be determined for each of the three meal challenges.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Sphingomyelin
Sphingomyelin concentration for each time-point will be determined for each of the three meal challenges.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Lysophosphatidylcholine
Lysophosphatidylcholine concentration for each time-point will be determined for each of the three meal challenges.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Apolipoprotein AI
Apolipoprotein AI concentration for each time-point will be determined for each of the three meal challenges.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Apolipoprotein AII
Apolipoprotein AII concentration for each time-point will be determined for each of the three meal challenges.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Apolipoprotein AIV
Apolipoprotein AIV concentration for each time-point will be determined for each of the three meal challenges.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Apolipoprotein B
Apolipoprotein B concentration for each time-point will be determined for each of the three meal challenges.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Apolipoprotein CI
Apolipoprotein CI concentration for each time-point will be determined for each of the three meal challenges.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Apolipoprotein CII
Apolipoprotein CII concentration for each time-point will be determined for each of the three meal challenges.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Apolipoprotein CIII
Apolipoprotein CIII concentration for each time-point will be determined for each of the three meal challenges.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Apolipoprotein E
Apolipoprotein E concentration for each time-point will be determined for each of the three meal challenges.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Lecithin-Cholesterol Acyltransferase
Lecithin-cholesterol acyltransferase concentration for each time-point will be determined for each of the three meal challenges.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Cholesterol Ester Transfer Protein
Cholesterol ester transfer protein concentration for each time-point will be determined for each of the three meal challenges.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Lipoprotein (a)
Lipoprotein (a) concentration for each time-point will be determined for each of the three meal challenges.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Phospholipid Transfer Protein
Phospholipid transfer protein concentration for each time-point will be determined for each of the three meal challenges.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Serum Paraoxonase/arylesterase 1
Serum paraoxonase/arylesterase 1 concentration for each time-point will be determined for each of the three meal challenges.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Serum Amyloid A1
Serum amyloid A1 concentration for each time-point will be determined for each of the three meal challenges.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)
Change in Serum Amyloid A4
Serum amyloid A4 concentration for each time-point will be determined for each of the three meal challenges.
Time frame: Baseline, Minute 15, Minute 30, Hour 1, Hour 2, Hour 4 and Hour 6 during study visits 1, 2, and 3 (up to 6 weeks)