Lipoprotein metabolism and inflammation in healthy young subjects - exploring the postprandial and postabsorptive phases following intake of a standardized meal.
In healthy young adults, lipoprotein subclasses and IL-6 levels significantly change after a meal, with IL-6 increasing by 325% at 10 hours post-meal.
Where it sits
this study against the rest of the elamipretide corpusSummary and findings
This study evaluated the impact of time since last meal on lipoprotein particles and inflammatory biomarkers in 34 normal-weighted young adults aged 20-30 years. Participants underwent fasting followed by a standardized breakfast, with blood samples taken at baseline and 13 additional times over 24 hours. The study found significant increases in various lipoprotein subclasses and IL-6 levels postprandially.
Abstract
<h4>Background and aims</h4>Commonly measured cardiometabolic biomarkers have not been systematically characterized across the long-term continuum of the postprandial and postabsorptive phases. The aim of the present study was to evaluate how the exact time since last meal impacts test results for lipoprotein particles and inflammatory biomarkers.<h4>Methods</h4>We used data from a trial where 34 normal-weighted males and females aged 20-30 y were included. Subjects fasted 12 h, had blood sampled at baseline, then consumed a standardized, habitual breakfast meal, and had blood sampled 13 more times over the next 24 h. 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.<h4>Results</h4>Six VLDL subclasses increased by 11-429% within 2-4 h postprandially before returning to baseline levels, followed by another increase 8-10 h after intake of the breakfast meal. IDL and three LDL subclasses increased around 10-12% over 24 h. Four HDL subclasses showed an inverse association with VLDL subclasses, reaching their lowest levels about 1 h after the meal and peaking after 8-10 h with a 5-15% increase from baseline. Participants had an average increase of 325% in IL-6 10 h 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.<h4>Conclusions</h4>Baseline levels and time of return to baseline varied between individuals, with some sex-specific differences in responses. TG-rich lipoproteins and VLDL increased postprandially and normalized by 12-24 h, whereas IDL and LDL showed minor early changes but increased by 24 h. IL-6 increased markedly during the first 10 h and returned to baseline by 12-24 h, while other inflammatory markers changed little.
Background
This study addresses the variability in cardiometabolic biomarkers during the postprandial and postabsorptive phases, which has not been systematically characterized. Previous research has shown that lipoprotein metabolism and inflammation can fluctuate based on meal timing, but detailed insights into the exact timing and magnitude of these changes are limited. Understanding these dynamics is crucial for interpreting metabolic health and disease risk.
Methods
The study utilized a trial design involving 34 normal-weighted males and females aged 20-30 years. Participants fasted for 12 hours prior to consuming a standardized breakfast meal, followed by blood sampling at baseline and 13 additional times over the next 24 hours. NMR metabolomics quantified lipoprotein subclasses, while ELISA was used to analyze inflammatory biomarkers such as VCAM-1, ICAM-1, E-selectin, and IL-6.
Results
The primary endpoint showed that six VLDL subclasses increased by 11-429% within 2-4 hours postprandially. IL-6 levels increased by 325% at 10 hours post-meal, while IDL and three LDL subclasses increased around 10-12% over 24 hours. HDL subclasses peaked after 8-10 hours with a 5-15% increase from baseline.
Interpretation
The findings indicate significant postprandial increases in specific lipoprotein subclasses and IL-6, suggesting a dynamic response to meal intake. While these results are statistically significant, the clinical relevance of such changes, particularly the small increases in IDL and LDL, may be limited. The small sample size and lack of long-term follow-up restrict the generalizability of the findings.
Key findings
- Six VLDL subclasses increased by 11-429% within 2-4 h postprandially, returning to baseline levels later.
- IL-6 increased by 325% 10 h after breakfast, with other inflammatory biomarkers showing little change.
- IDL and three LDL subclasses increased around 10-12% over 24 h.
- Four HDL subclasses peaked after 8-10 h with a 5-15% increase from baseline.
- Males generally exhibited higher baseline concentrations of biomarkers compared to females.
Limitations
- small n=34
- short follow-up of 24 hours
- no long-term outcome data
- limited to young adults aged 20-30
- no diverse population representation