Apolipoprotein B (Apo B) is a protein found in LDL cholesterol and is used to estimate the total number of LDL particles in the blood. High levels of Apo B are associated with an increased risk of heart disease.
Cholesteryl esters, especially those containing linoleic acid (18:2), are major components of LDL particles, which contain Apo B as their primary apolipoprotein. Higher cholesteryl ester levels correlate with increased LDL and Apo B.
Phosphatidylcholines are key phospholipids in LDL particles. PC aa C36:2 likely reflects LDL particle concentration and therefore correlates with Apo B levels, since each LDL particle contains one Apo B molecule.
References
A. M. J. H. van der Velde, R. J. van Wijngaarden, M. J. C. E. Trip, and J. W. Jukema. Regulation of apolipoprotein B secretion by biliary lipids in CaCo-2 cells. Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids (2021). https://www.sciencedirect.com/science/article/pii/S0022227520391719
This phosphatidylcholine species containing arachidonic acid (20:4) is associated with LDL particles and Apo B levels, although the relationship is not as strong as some other PCs.
References
Tukiainen T, Laine J, Aalto S, et al.. Genetics Meets Metabolomics: A Genome-Wide Association Study of Plasma Lipids in 3271 Finns. PLoS Genet (2008). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2581785/Liu X, Zhang Y, Li S, et al.. Percutaneous Closure of Left Atrial Appendage significantly affects Plasma Phosphatidylcholine and Apolipoprotein B Levels in Patients with Non-Valvular Atrial Fibrillation. Frontiers in Physiology (2018). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5897373/Carlsson ER, Allin KH, Madsbad S, et al.. Phosphatidylcholine and its relation to apolipoproteins A-1 and B changes after Roux-en-Y gastric bypass: a cohort study. Lipids in Health and Disease (2019). https://lipidworld.biomedcentral.com/articles/10.1186/s12944-019-1111-7Mapstone M, Wang Y, Liang WS, et al.. Predictive metabolic networks reveal sex- and APOE genotype-specific effects on the Alzheimer’s disease lipidome. Alzheimer’s & Dementia (2022). https://alz-journals.onlinelibrary.wiley.com/doi/pdf/10.1002/alz.12675
Sphingomyelins are sphingolipids present in LDL particles. SM C16:0 levels tend to correlate positively with LDL concentration and Apo B.
References
Hammad SM, Lopes-Virella MF. Circulating Sphingolipids in Insulin Resistance, Diabetes and Associated Complications. International Journal of Molecular Sciences (2023). https://doi.org/10.3390/ijms241814015Chatterjee S, Tavori H, Cohen JR. The Complex Tail of Circulating Sphingolipids in Atherosclerosis. Frontiers in Cardiovascular Medicine (2021). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8473959/Ng TWK, Ooi EMM, Watts GF, Chan DC, Meikle PJ, Barrett PHR. Association of Plasma Ceramides and Sphingomyelin With VLDL apoB-100 Fractional Catabolic Rate Before and After Rosuvastatin Treatment. The Journal of Clinical Endocrinology & Metabolism (2015). https://doi.org/10.1210/jc.2014-4348
Triacylglycerides with palmitic acid (16:0) and 34:2 fatty acids are found in VLDL particles, which are metabolic precursors of LDL. Higher VLDL levels can drive increased LDL and Apo B production.