Peter Attia MD240 ‒ The confusion around HDL and its link to cardiovascular disease | Dan Rader, M.D.
At a glance
WHAT IT’S REALLY ABOUT
Why HDL Cholesterol Isn't Protective: Function, CETP Failures, and Brain Links
- Rader and Attia walk through how HDL forms and matures, from free apoA-I acquiring lipid via ABCA1 to LCAT creating the cholesterol ester core, and show how rare genetic disorders reveal each step.
- Failed CETP inhibitor trials, the niacin trials, and SR-B1 deficiency support Rader's conclusion that HDL cholesterol itself is not directly and causally protective, so a high HDL is never a reason to withhold treatment otherwise indicated.
- Rader describes HDL cholesterol as an integrator, like HbA1c, of postprandial triglyceride metabolism and insulin resistance, which explains why low HDL tracks with risk without causing it.
- A cholesterol efflux capacity assay measures HDL function and predicted cardiovascular events better than HDL cholesterol, and the CSL112 infusion trial will be the closest test yet of whether boosting efflux reduces risk.
- Rader raises emerging links between apoA-I, ApoE, ABCA1 and ABCA7 and Alzheimer's disease, and says brain lipid metabolism is a promising frontier.
IDEAS WORTH REMEMBERING
5 ideasHDL cholesterol is not directly and causally protective
Rader says repeated CETP inhibitor failures, plus the Mendelian randomization findings Attia cites, make this conclusion rock solid, though he notes nuances remain.
A high HDL should never talk you out of treatment
Rader advises that high HDL is never a reason to skip a statin or other therapy someone would otherwise merit, while a low HDL can modestly tilt a borderline case toward treating.
Very high HDL can signal a clogged system, not protection
People lacking SR-B1 can't unload cholesterol from HDL at the liver, so they have very high HDL cholesterol yet increased heart disease risk.
HDL cholesterol works like an HbA1c for cardiovascular risk factors
Rader explains that it integrates chronic postprandial triglyceride handling, insulin resistance and inflammation, so low HDL flags risk without being the cause.
HDL function matters more than HDL quantity
The ex vivo cholesterol efflux capacity assay predicted coronary disease and incident events better than HDL cholesterol, even after adjusting for it, though causality remains unproven.
WORDS WORTH SAVING
5 quoteshigh HDL is never a reason not to treat someone who would've otherwise merited treatment.
— Dr. Dan Rader
HDL cholesterol, while not causally related to disease, is sort of like an HbA1c for cardiovascular risk factors. It's an integrator of information related to insulin resistance, related to triglycerides, related to inflammation, that in one number, in most people when it's low, it's telling you something about cardiovascular risk, even though itself it isn't directly impacting on risk.
— Dr. Dan Rader
HDL as a molecule, as a lipoprotein, I think of as a platform. It's a platform for all sorts of proteins and lipids that get transported by HDL in the blood and then transfer off HDL to other things
— Dr. Dan Rader
If you see a lot of people in a room, it might be tempting to conclude that there's something awesome going on in that room. But what you don't know, if you can't measure all the ins and outs, is it might be that those people are all stuck in the room because the door is locked.
— Peter Attia
I don't think HDL per se is the next frontier, but I do think lipid metabolism in the brain is one of the next frontiers. I really do.
— Dr. Dan Rader
High quality AI-generated summary created from speaker-labeled transcript.
