Triglyceride content increases while cholesterol content decreases in HDL and LDL plus IDL fractions following normal meals: The Copenhagen General Population Study of 25,656 individuals

Background and aims: During fat tolerance tests, plasma triglycerides increase while high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and intermediate-density lipoprotein (IDL) cholesterol decrease. However, it is unknown whether triglyceride content increases and cholesterol content decreases in HDL and LDL + IDL fractions following normal meals in the general population. Therefore, we tested the hypothesis that triglyceride content increases while cholesterol content decreases in HDL and LDL + IDL fractions following normal meals.Methods: In this cross-sectional study, we included 25,656 individuals aged 20-100 years, all without lipid lowering therapy at examination and selected for metabolomic profiling from the Copenhagen General Population Study. Triglyceride and cholesterol content of 14 lipoprotein fractions weas measured using nuclear magnetic resonance (NMR) spectroscopy. Time since last meal was recorded by the examiner immediately before blood sampling. Results: Following normal meals in age and sex-adjusted analyses and when compared with fasting levels, plasma triglycerides were higher for up to 5-6 h, and triglyceride content was higher for up to 6-7 h in HDL fractions, for up to 6-7 h in LDL + IDL fractions, and for up to 5-6 h in very-low-density lipoprotein (VLDL) fractions. Further, plasma cholesterol was lower for up to 2-3 h, and cholesterol content was lower for up to 0-1 h in HDL fractions and for up to 4-5 h in LDL + IDL fractions, while cholesterol content was higher for up to 4-5 h in VLDL fractions.Conclusions: Following normal meals, triglyceride content increases while cholesterol content decreases in HDL and LDL + IDL fractions.