Quote:
Originally Posted by Dodger
Cholesterol level go up after eating; as do blood glucose, insulin and many other body chemicals. How much, when, and what type of foods your have eaten affect the levels. The fasting levels are measured because they are the baseline 'stable' levels that should be within certain limits. Everyones average cholesterol levels are higher than the fasting levels that are measured, just as your average blood pressure is higher than the resting level that is measured.
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Yes, all this I understood. My point may have been missed. Yes, fasting levels are relatively stable, so measurement of them tells you something about the metabolism, perhaps more than non-fasting levels without a lot of special considerations, such as exactly what was eaten and when and other factors. But consider this:
Suppose that eating carbs elevates cholesterol, above the baseline, more than eating, say, fat. Someone may have an elevated fasting level and have not much more cholesterol in the blood when not fasting, and someone else, perhaps with elevated glucose levels from carbs, has much more cholesterol. Freshly synthesized cholesterol also may differ in density from baseline cholesterol.
My point is that people are being treated for hypercholesterolemia based on fasting levels, when they may not have truly elevated levels; the baseline is higher than "normal," but the average may actually be lower than "normal." Depending on their diet, as well as on other metabolic factors.
Blood pressure was mentioned as an example. Resting blood pressure is an indication, but more definitive is the elevation of blood pressure level with sustained exertion, as in a stress test.
Fasting cholesterol is used, I suspect, not because it is the best measurement, but because it is much easier (and cheaper) to determine. And a multibillion dollar statin industry may be hinging on defective testing....
To do more sophisticated testing would cost more, to be sure. However, statins are
expensive. And, of course, the real problem: we really don't understand the risks of higher cholesterol levels; the cholesterol hypothesis is probably oversimplified at best and may be just plain wrong.
Bottom line: I would not consider cholesterol tests to be good predictors of heart disease risk, there are apparently better ways: CRP levels, Cardiac CAT scans, stress tests, etc. I've got cholesterol levels high enough that most doctors would be prescribing Lipitor, but I have very low CRP, an Agatston score of 25 on a Cardiac CAT Scan, my HDL/LDL ratio is good, my triglycerides are low, I don't smoke, I'm not overweight, and there are a host of reasons to think I'm low risk. And still most doctors would be saying "Lipitor." It's insane.