David, in the case study you mentioned that by knowing the TG/HDL ratio you can assume an estimate of the LDL particle size and particle number per volume of blood without actually having to do that test - if I understood your comment correctly. Can you speak to that more? Thanks!

It is called the Trig:HDL ratio, LDL size - Larger, less dense LDL particle size is associated with reduced risk of cardiovascular disease. Small, dense LDL particles are related to increased risk. This test, along with the other cholesterol particle size and number tests are much more accurate at determining heart disease risk than the usual LDL/HDL tests. Because these tests are more expensive, they are often not done or covered by insurance. A simple way to roughly determine your LDL size and risk is looking at the ratio of triglcyerides to HDL cholesterol (Trig:HDL ratio). If your triglycerides are 120 mg/dL and your HDL-C is 60 mg/dL, your Trig:HDL ratio is 120/60 or 2.0. If your triglycerides are 260 mg/dL and your HDL-C is 40 mg/dL your Trig:HDL ratio is 260/40 or 6.5. The higher the Trig/HDL number indicates that the person has more of the small/dense particle size. This shows greater insulin resistance and risk of CVD.

Interesting! I learned from Dr Hyman and Dr Peter Attia about the importance of LDL particle size and number but didn't know about its correlation with TG:HDL. That's helpful because e.g. in my home country Hungary, I don't think they really measure LDL particle size at all but they do measure HDL, TG and the other basics. Thanks David