By playing, you agree to uListen's Terms and Privacy Policy and YouTube's Terms of Service.
Peter Attia MD#03 – Ron Krauss, M.D.: a deep dive into heart disease
Summaries, chapters, transcripts, and FAQs on this page are made by uListen, not YouTube.
CHAPTERS
- 0:04 – 6:23
Episode Preview and the Case That Prompted the Conversation
Peter Attia introduces Dr. Ron Krauss, his background, and the topics ahead, including particle size versus number, statins, inflammation, niacin, the HDL paradox and PCSK9 inhibitors. He then explains how a difficult patient case led to this recorded conversation.
- •Krauss is a lipidologist and director of atherosclerosis research at Children's Hospital in Oakland
- •Attia frames statins as tools whose value depends on knowing when and how to use them
- •Preview topics include niacin, the HDL paradox, inflammation and PCSK9 inhibitors
- •The episode grew out of a phone call about a patient with a high calcium score who hesitated to treat
- 6:23 – 12:00
How Atherosclerosis Develops: From Fatty Streak to Plaque Rupture
Krauss explains atherosclerosis as a process that begins in childhood with fatty streaks and becomes dangerous when oxidized lipoproteins trigger inflammation. Plaque rupture and clot formation cause most heart attacks and strokes.
- •Fatty streaks are common in young people and not hazardous unless they progress
- •Oxidation and stickier lipoproteins trigger inflammation in the artery wall
- •Inflammation weakens the fibrous cap, which can rupture and form a clot
- •Krauss estimates sudden death is the first sign of disease in roughly 30% of cases, a rough figure
- 12:00 – 15:23
Age, Exposure, and Early Lesions
The two discuss autopsy data showing advanced lesions in young people and why age is the greatest risk factor. Attia describes it as cumulative exposure, an area under the curve, and Krauss notes that genetic disorders accelerate the process.
- •Autopsies of young people show lesions beyond fatty streaks, linked to smoking, diabetes, hypertension and dyslipidemia
- •Age is the biggest risk factor because of cumulative exposure
- •Genetic cholesterol disorders can cause disease in the teens
- •Attia cites actuarial data in which atherosclerosis was the only disease whose risk rose with every decade
- 15:23 – 28:27
Lipoproteins, LDL-C, LDL-P and ApoB Explained
Krauss and Attia define lipoproteins, LDL cholesterol, LDL particle number and ApoB. They explain why cholesterol content and particle count can be discordant and why particle number tracks risk.
- •Lipoproteins package hydrophobic cholesterol for transport in blood
- •LDL-C measures cholesterol on LDL particles, while ApoB, one per LDL particle, is a surrogate for particle number
- •Smaller, cholesterol-depleted particles can make LDL-C understate particle number
- •Discordance is common in metabolic syndrome, linked to the triad of high triglycerides, low HDL and small LDL
- 28:27 – 30:47
Metabolic Syndrome, Framingham, and the NIH Lipid Era
The conversation turns to metabolic syndrome and atherogenic dyslipidemia, and to Attia's recounting of the early Framingham finding about HDL and triglycerides. Krauss recalls his NIH training during the LDL-focused trial era, and Attia flags niacin as a topic for later.
- •Atherogenic dyslipidemia is high triglycerides, low HDL and predominantly small LDL
- •Visceral abdominal fat is the most prevalent underlying factor in metabolic syndrome
- •Attia says early Framingham data found low HDL plus high triglycerides more predictive than LDL-C
- •Attia argues the LDL focus delayed attention to insulin resistance
- •Attia sets up niacin as a puzzle to revisit
- 30:47 – 35:56
Does LDL Cause Heart Disease? The European Consensus Statement
Krauss describes the consensus statement he co-authored on LDL causality, a response to claims that LDL is merely associated with disease. He adds the caveat that lowering LDL cholesterol is not always beneficial, and that particles rather than cholesterol are the causal agents.
- •The paper assembled evidence from epidemiology, trials and genetics that LDL is causal
- •A second paper on LDL's role in pathophysiology is still in progress
- •Krauss cautions that LDL lowering does not always reduce risk, which doesn't disprove causality
- •Particles, not LDL cholesterol, are the causal agents
- 35:56 – 42:13
Genetic Evidence for Causality: FH, PCSK9, and Mendelian Randomization
Krauss and Attia walk through genetic evidence, including familial hypercholesterolemia, PCSK9 gain- and loss-of-function variants, and Mendelian randomization. They also discuss how LDL clearance and residence time shape risk.
- •Severe genetic LDL elevation, as in FH, causes disease early and is unequivocal evidence of causality
- •The liver makes and clears most circulating lipoproteins, with LDL receptors binding ApoB
- •Risk depends on how long atherogenic particles circulate
- •PCSK9 loss-of-function carriers have very low LDL and, as discussed, no heart disease or evident other consequences
- •Mendelian randomization reflects lifelong exposure and predicts larger risk changes than short trials
- 42:13 – 52:14
Remnants, Fredrickson Typing, and Krauss's Career Path
Prompted by Attia's question about VLDL remnants, Krauss recounts the five New England Journal articles that shaped him and his NIH training with Fredrickson, Levy and Lees. He explains type III disease and remnants as highly pathologic particles.
- •Remnant particles can cause severe disease even when ApoB and LDL-C look normal
- •Krauss read five articles on lipid disorders as a medical student, which inspired him to train at NIH
- •Fredrickson typing described genetic lipoprotein disorders such as type III, caused by an apoprotein E variant
- •Krauss describes remnants as likely the most pathologic particles and recommends his 2016 history review
- 52:14 – 1:02:32
LDL Particle Size Versus Number and the Sortilin Variant
Attia asks about the argument that size doesn't matter once particle number is accounted for. Krauss explains his view that small LDL is likely more atherogenic, notes large LDL is also harmful with long residence time, and describes a genetic variant tied to very small LDL.
- •Krauss says he has never claimed particle size is independent of the broader metabolic syndrome
- •The population distribution of LDL size is bimodal, marking a metabolic trait
- •Large LDL can be atherogenic through long residence time, as in LDL receptor defects
- •A sortilin-related variant is linked to small and very small LDL and to cardiovascular risk
- •Krauss is testing whether very small LDL is secreted directly rather than through VLDL
- 1:02:32 – 1:16:43
Can LDL Be Too Low? Cholesterol Synthesis and Statin Off-Target Effects
Attia asks whether pharmacologic LDL lowering has a downside. Krauss points to genetic low-LDL syndromes as reassuring but notes limits, then discusses statin disposition, muscle effects, and an increased diabetes risk.
- •Genetic low-LDL conditions suggest very low LDL is generally safe, but this may not extrapolate to all drugs
- •Attia worries about suppressing cholesterol synthesis and brain cholesterol, citing a desmosterol and dementia paper
- •Statin disposition varies with genes and the specific statin, affecting tissues beyond the liver
- •Krauss cites about a 10% average rise in diabetes risk, possibly higher in women
- •Pitavastatin appears less linked to diabetes and atorvastatin more, per Krauss's observations
- 1:16:43 – 1:24:15
Statin Myalgias, CoQ10, and Long-Term Unknowns
The discussion covers practical monitoring and tradeoffs on statins, including Attia's use of PCSK9 inhibitors to reduce statin dose. Krauss describes hypotheses for muscle symptoms, including mitochondrial effects, and the CoQ10 question.
- •Attia describes short-term monitoring for muscle and liver effects, and says he sees more LFT bumps with ezetimibe
- •Both agree decisions here often rely on judgment beyond the evidence
- •Krauss notes that millions are on lifelong statins with unknown downstream effects
- •No single mechanism explains myalgias, and a mitochondrial hypothesis is under study
- •CoQ10 benefit is uncertain, with absorption differences between formulations discussed
- 1:24:15 – 1:33:44
Statins, Inflammation, and Primary Prevention Evidence
The two examine whether statin benefit comes from LDL lowering or anti-inflammatory effects, referencing CRP and Ridker's work and the IL-1 trial. They then cover why statins shouldn't be replaced by PCSK9 inhibitors without need, and the strength of primary prevention evidence in men and women.
- •Krauss says LDL is causal, so statin benefit operates at least partly through LDL lowering, though not only that
- •CRP and LDL targets together gave the greatest benefit in Ridker's analyses
- •PCSK9 inhibitors lack the same anti-inflammatory and nitric oxide effects, an argument for not abandoning statins when tolerated
- •Secondary prevention efficacy is not disputed, while primary prevention evidence is for events more than mortality
- •Attia notes that 10-year risk models and short trials limit conclusions about lifetime benefit
- 1:33:44 – 1:40:45
Statins in Older Age, Cognition, and the ATP Guidelines
Krauss discusses unresolved questions on cognition, ApoE4, and possible muscle wasting with long statin exposure, and why evidence is thin beyond age 75. He then explains why he left the ATP IV panel after its scope narrowed to LDL-lowering evidence.
- •Data on statins and cognition are not compelling in either direction
- •Attia is more careful with statins in ApoE4 carriers
- •Krauss speculates about mitochondrial effects and muscle loss over decades in older patients
- •Guidelines stop at age 75 because evidence stops there
- •Krauss left the ATP panel when its questions shrank to three on LDL lowering
- 1:40:45 – 1:53:36
Niacin, the HDL Paradox, and Who Still Benefits
Attia raises why niacin fell out of favor despite improving lipid numbers. Krauss explains that the AIM-HIGH and HPS2 trials tested HDL raising on top of intensive LDL lowering and showed HDL raising isn't protective, but he still sees niacin as useful for patients with small LDL and elevated Lp(a).
- •The trials show HDL raising by niacin or CETP inhibitors was not protective
- •HATS analysis linked niacin's lowering of small and very small LDL to vascular benefit
- •Niacin can lower Lp(a) by up to about 25% and preferentially lowers small LDL
- •Statins and PCSK9 inhibitors lower larger LDL more than small particles
- •Krauss prefers PCSK9 inhibitors when affordable, using niacin for complementary effects and as a low-cost option
- 1:53:36 – 1:56:13
Closing Remarks and Future Topics
Attia thanks Krauss and says there are many topics left, including saturated fat, fructose and ApoE. Krauss agrees to return, and Attia closes with show notes and a disclaimer.
- •Attia credits Krauss as a mentor and friend
- •Remaining topics include saturated fat, fructose and ApoE
- •They plan a follow-up conversation
- •Show notes and links are at peterattiamd.com/podcast
