Total Cholesterol is a measure of the total amount of cholesterol in the blood, including both LDL and HDL cholesterol. High levels of total cholesterol are associated with an increased risk of heart disease.
Gerl, M. J., Vaz, W. L. C., Domingues, N., Klose, C., Surma, M. A., Sampaio, J. L., … & Almeida, M. S.. Cholesterol is Inefficiently Converted to Cholesteryl Esters in the Blood of Cardiovascular Disease Patients. PLOS ONE (2018). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6170447/
Kovanen, P. T., Männistö, S., & Salonen, J. T.. Serum Phospholipid and Cholesteryl Ester Fatty Acids and Estimated Atherogenic Index in Adolescent Normal- and Overweight Adolescents. Lipids (2008). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2832613/
Cholesteryl esters containing oleic acid (18:1) also make up a significant portion of total blood cholesterol and directly impact the total cholesterol level.
[Author 1], [Author 2], [Author 3]. Cholesterol is Inefficiently Converted to Cholesteryl Esters in the Blood of Cardiovascular Disease Patients. Nature Communications (2018). https://www.nature.com/articles/s41598-018-33116-4
Cholesteryl esters, especially those containing linoleic acid (18:2), make up a large portion of total cholesterol in the blood. Higher levels directly contribute to the total cholesterol measurement.
Gerl, M.J., Vaz, W.L.C., Domingues, N.. Cholesterol is Inefficiently Converted to Cholesteryl Esters in the Blood of Cardiovascular Disease Patients. Scientific Reports (2018). https://doi.org/10.1038/s41598-018-33116-4
Kim, J.B., et al.. The Ratio of Unesterified/esterified Cholesterol is the Major Determinant of Plasma Cholesterol Concentration in Humans. PLOS ONE (2018). https://doi.org/10.1371/journal.pone.0193914
Cholesteryl esters containing arachidonic acid (20:4) are another component of total blood cholesterol that has a direct additive effect on the total level.
Gerl, M.J., Vaz, W.L.C., Domingues, N., et al.. Cholesterol is Inefficiently Converted to Cholesteryl Esters in the Blood of Cardiovascular Disease Patients. Scientific Reports (2018). https://doi.org/10.1038/s41598-018-33116-4
Kim, J.H., Kim, Y.H., Kim, J.K., et al.. The Ratio of Unesterified/esterified Cholesterol is the Major Determinant of Atherogenic Index in Healthy Men. BioMed Research International (2018). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5911171/
Hodis, H.N., Mack, W.J., LaBree, L., et al.. A comparison of fatty acid composition of cholesteryl esters in subjects at different levels of high-density lipoprotein cholesterol. Arteriosclerosis (1986). https://pubmed.ncbi.nlm.nih.gov/3568345/
This phosphatidylcholine with polyunsaturated 36:5 fatty acids is also involved in lipoprotein cholesterol transport and can contribute to higher total cholesterol levels.
