To provide an overview of our whole room indirect calorimeter (WRIC), demonstrate validity and reliability of our WRIC, and explore a novel application of Bayesian hierarchical modeling to assess responses to small carbohydrate loads.
Seven gas infusion studies were performed using a gas blender and profiles designed to mimic resting and postprandial metabolic events to assess WRIC validity. In a crossover design, 16 participants underwent fasting and postprandial measurements, during which they consumed a 75-kcal drink containing sucrose, dextrose, or fructose. Linear mixed effects models were used to compare resting and postprandial metabolic rate (MR) and carbohydrate oxidation. Bayesian Hierarchical Modeling was also used to model postprandial carbohydrate oxidation trajectories for each participant and condition.
Mean total error in infusions were 1.270.67% and 0.420.70% for VO2 and VCO2 respectively, indicating a high level of validity. Mean resting MR was similar across conditions (=1.050.03 kcal/min, p=0.82, ICC: 0.91). While MR increased similarly among all conditions (~13%, p=0.29), postprandial carbohydrate oxidation parameters were significantly lower for dextrose compared with sucrose or fructose.
Here, we provide evidence of validation of our WRIC and a novel application of statistical methods useful for research using WRIC.
Publisher
University Libraries, Virginia TechCorresponding Author Name
Alexandra G. DiFeliceantonioFiles/Folders in Dataset and Description
Code Read Me.rtf - necessary order for running the code
Folder participant_data - all human subjects data
Folder chamber - all the post-processed chamber data
File 1030-fructose.csv - subject 1030's data from their fructose session
... all files of same name convention
Folder diet - all of the habitual dietary intake data
File 103004.csv - diet information for subject 1030
... all files of same name convention
File table1dat.csv - demographic data including race, ethnicity, age, sex, etc.
Folder Infusion Data - All data from the infusion sessions
Folder rest_profile - all data from the resting infusion profile
File Infusion - RestProfile-2-Infusion-220406.csv - infusion run on April 6, 2022
File Infusion - RestProfile-2-Infusion-220407.csv - infusion run on April 7, 2022
File Infusion - RestProfile-2-Infusion-220509.csv - infusion run on May 9, 2022
File Infusion - RestProfile-2-Infusion-220803.csv - infusion run on August 8, 2022
Folder long_profile - all data from the resting infusion profile
File Flex Profile long 220909.csv - infusion run on September 9, 2022
File Flex Profile long 221004.csv - infusion run on October 4, 2022
File Flex Profile long 221119.csv - infusion run on November 19, 2022
Folder infusion_analysis_code - code to analyze all infusion data
File 0_libraries.R - load in the R packages necessary for these analyses
File 1_infusion_plot.R - create the infusion figure
File 1_infusion_summary_rest.R - create the table which describes one infusion type's errors
File 1_infusion_plot.R - create the table which describes the second infusion type's errors (shown in paper)
Folder human_analysis_code - code to analyze all infusion data
File 0_cleaning_functions.R - load in the R packages necessary for these analyses and functions to clean the data
File 1_data_cleaning.R - compile, clean, and output all data
File 2_frequentist_methods_female_participants.R - all frequentist data analyses and visualizations for female participants only (sensitivity analysis)
File 2_frequentist_methods.R - all frequentist data analyses and visualizations for all participants
File 3_bayesian_methods_female_participants.R - all bayesian data analyses and visualizations for female participants only (sensitivity analysis)
File 3_bayesian_methods.R - all bayesian data analyses and visualizations for all participants
File table1_ICCs_and_figure2.R - all baseline/resting measurement comparisons across conditions
