What percent of triglycerides come from chylomicrons and VLDL?

[Alex K Chen]

How are TGs calculated, anyways?

Quote

The backbone structural protein is the truncated apolipoprotein B-48, which is the main non-exchangeable protein. However, it does contain other apolipoproteins, including ApoA1, A2, A3, A5 C2, C3, and ApoE. Chylomicrons have a density below 0.94 g/ml and remain at the origin of lipoprotein electrophoresis. Their major lipid is triglycerides, which comprise more than 75% of the particle, and they have the lowest protein content of all lipoproteins of around 2 percent, explaining why they have such low density on ultracentrifugation.

Ok Lustig says it's mostly VLDL when fasting. Both when non-fasting

Edited February 14, 2023 by InquilineKea

[IgorF]

AFAIR the most common way is to measure TGs directly (www.cdc.gov/nchs/data/nhanes/nhanes_05_06/trygly_d_met_triglyceride_h912.pdf) and then derieve LDL with so called Friedwald equation, but this works only if there is no hyperTG state or additional concerns are raised.

There are however techniques to measure all components directly as well as "semi-quantinative" combos like electrophoresis of lipids. There is also NMR.

More precise techniques are usually easy to distinguish - they provide more data and costs in an order of magnitude more.

AFAIR for non-scientists there is no use now for details on different apolipoproteines (except little a and B) yet as well as lab methods available to assess them.

Also it seems a common now that classification based on cargo unit sizes (e.g. LDL, VLDL, IDL chylomicrons) is a bit outdated and is not reflecting the things we want to assess quickly, it was born when the cheap method of assessment was invented but novadays the most useful to know is TG and apoB lp(a).

 

Br,

Igor