Many people regularly get tested for cholesterol, and the test usually includes other markers and is known as a lipid panel. There’s a lot of confusion about which of these markers are important, so let’s look at the most important lipid panel marker as documented by biomedical science.
What’s a lipid panel?
Lipids are fats, and a lipid panel measures levels of different types of fat in the blood.
More specifically, it measures lipoproteins, which are proteins that transport lipids in the blood.
A lipid panel includes:
- total cholesterol
- LDL cholesterol
- HDL cholesterol
Up until a few years ago, doctors focused most on total cholesterol.
Now, the focus is more on LDL, the so-called “bad” cholesterol. (A dumb name, but there it is.)
Why the focus on LDL? Most doctors and scientists believe high LDL causes atherosclerosis, which leads to heart attacks.
More importantly, they focus on LDL because there are drugs that lower LDL, and patients must take them for a lifetime. Statins. The pharmaceutical companies coach doctors at conferences, and buy influence via medical journals, to convince medical gatekeepers that they must prescribe statins. “In 2011, US doctors wrote nearly 250 million prescriptions for cholesterol-lowering drugs, creating a US$18.5-billion market”.
However, LDL really doesn’t correlate very well with cardiovascular risk compared to other tests.
First, LDL, the one doctors focus on the most.
In a large cohort of people hospitalized for cardiovascular disease, a total of 136,905 hospitalizations, “almost half have admission LDL levels <100 mg/dL”. Their LDL was normal, yet they had heart disease.
If you have low HDL, however, watch out.
The triglyceride/HDL ratio appears to be the most powerful marker for heart disease risk. The lower the better.
Those in the top quartile (fourth) of the ratio of triglycerides to HDL had 16 times the risk of heart attack as those in the lowest quartile.
Pretty much explains cardiovascular risk.
This relationship has been found in other studies too.
A high ratio of triglycerides to HDL predicts extensive coronary artery disease. Of all the lipid markers, “only TG/HDL-c and HDL-c were useful for detecting extensive coronary disease, with the former more strongly associated with disease.”
Let me repeat, of all lipid markers, only the triglyceride/HDL ratio and HDL were associated with coronary disease, and the ratio was a stronger marker. No significant relationship was found between total cholesterol or LDL.
“Men with conventional risk factors for IHD have a low risk of IHD if they have low TG–high HDL-C levels.”
The following chart, taken from this paper, shows that men with a low triglycerides/HDL ratio had a low risk of heart disease even when LDL levels were high.
These are of course markers, and not necessarily causative. Raising HDL artifically with drugs has been shown to be ineffective against CVD.
What are good numbers for the triglyceride/HDL ratio?
Last time I checked, mine was 0.5, and it’s hard to get lower than that. Dr. Stephen Sinatra suggests that below 2.0 is ideal.
What does all this mean?
The old model of atherosclerosis and heart disease suggested that arteries were like pipes, and cholesterol clogged them.
In reality, atherosclerosis is an inflammatory disease.
Triglycerides and HDL are markers of insulin resistance, which raises inflammation.
Is there a simple way to identify insulin-resistant individuals at high risk for cardiovascular disease? Yes, a triglyceride/HDL ratio of >3.5 identifies them.
Risk factors for heart disease also raise insulin resistance and inflammation:
- lack of exercise
- poor diet of processed foods containing sugar and seed oils.
The ratio of triglycerides to HDL is the most important blood lipid marker.
It predicts cardiovascular risk much better than other markers, such as total or LDL cholesterol.