Lipid Challenge in Adults
Condition: Cardiovascular Diseases
MeSH terms: Cardiovascular Diseases
Study type: Interventional

Summary: 
      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      Participants will have 20 mL blood withdrawn at six successive time points over an 8-hour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.
    

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).
    

Intervention name(s): Lipid Challenge
Intervention type(s): Dietary Supplement
Intervention description(s): 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 intervention name(s): Calogen
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Basic Science