Lipoprotein metabolism and inflammation in healthy young subjects - exploring the postprandial and postabsorptive phases following intake of a standardized meal

Background and aimsNon-fasting blood sampling is increasingly recommended for routine lipid testing in cardiovascular disease risk assessment. However, these recommendations are mainly based on associations between lipid levels and self-reported time since the last meal in epidemiological studies. The aim of the present study was to explore the time-resolved variation in lipoproteins and inflammatory marker concentrations during the postprandial and postabsorptive period, in males and females ingesting a standard breakfast meal. MethodsWe used data from a trial where 34 normal-weighted subjects aged 20-30 y were included. Subjects fasted 12 hours, had blood sampled at baseline, then consumed a standardized breakfast meal, and had blood sampled 13 more times over the next 24 hours. NMR metabolomics was used to quantify lipoprotein subclasses and various biomarkers, and ELISA to analyze VCAM-1, ICAM-1, E-selectin, and IL-6. We characterized the postprandial and postabsorptive responses using visualizations and non-linear mixed effects models. ResultsSix VLDL subclasses increased by 11-429% within 2-4 hours postprandially before returning to baseline levels, followed by another increase 8-10 hours after intake of the breakfast meal. IDL and three LDL subclasses increased around 10-12% over 24 hours. Four HDL subclasses showed an inverse association with VLDL subclasses, reaching their lowest levels about 1 hour after the meal and peaking after 8-10 hours with a 5-15% increase from baseline. Participants had an average increase of 325% in IL-6 ten hours after breakfast, while other inflammatory biomarkers showed little change over time. For most biomarkers, males generally exhibited higher baseline concentrations compared to females, however the responses over time remained similar. ConclusionsWe observed small-to-moderate changes in plasma concentrations of most biomarkers in the postprandial and postabsorptive phases. Non-fasting lipid testing is likely a viable option for CVD risk assessment, as recommended by recent guidelines and consensus statements.