Episode Summary
Executive Summary: This final Week of Tom episode synthesizes advanced lipidology: LP(a), remnants, oxidized LDL, LPPLA2, ADMA/SDMA, ApoC3, omega-3s, and the role of inflammation/endothelial dysfunction in atherosclerosis. The core message is that particle number, apo-protein biology, and individualized biomarker interpretation matter more than simplistic cholesterol metrics, and that emerging therapies may finally target previously untreatable residual risk.
Main Topics: LP(a) biology, measurement, and treatment (Priority: 5/5): The discussion explains why LP(a) mass is a flawed metric, why particle count is preferable, why statins don’t meaningfully lower LP(a), and why PCSK9 inhibitors and future apo(a)-targeting antisense drugs may be more relevant. Inflammation and oxidative biomarkers (Priority: 5/5): The speakers review inflammatory and oxidative markers such as CRP, fibrinogen, oxidized LDL, myeloperoxidase, and F2-isoprostanes, emphasizing that these are mechanistically interesting but often less actionable than ApoB reduction. LPPLA2 and endothelial dysfunction markers (Priority: 4/5): LPPLA2 is discussed as a macrophage-derived enzyme linked to oxidized phospholipids, but with weak outcome data and limited clinical utility. ADMA and SDMA are presented as more biologically plausible markers of endothelial dysfunction and nitric oxide impairment. Remnants, ApoC3, and triglyceride-rich lipoproteins (Priority: 5/5): The episode clarifies what remnants are, why they are heterogeneous, and why ApoC3 is a key determinant of delayed clearance and risk. It also connects ApoC3 to longevity and to potential future antisense therapies. Omega-3 fatty acids and formulation issues (Priority: 4/5): The conversation challenges simplistic views of omega-3s, distinguishing pharmacologic EPA/DHA from supplements, discussing red blood cell omega-3 testing, and noting that DHA may lower ApoC3 while EPA has outcome-trial momentum. Red blood cells, cholesterol, and atherosclerosis (Priority: 3/5): Red blood cells contain substantial cholesterol but are not the main atherogenic vehicle because they do not typically enter the arterial wall and undergo the same oxidative processes as ApoB particles. Personal story and clinical motivation (Priority: 4/5): Tom Dayspring recounts a tragic friend who likely had familial hypercholesterolemia and died young after avoiding care, illustrating how preventable cardiovascular disease drives his passion for lipidology.
Key Arguments: LP(a) mass is a poor metric because it measures the weight of heterogeneous particles rather than particle number; LP(a)-P is more informative when available. Statins lower LDL particles but do not meaningfully lower LP(a) because LP(a) production is driven more by apo(a) synthesis than by clearance. PCSK9 inhibitors may lower LP(a) modestly, but outcome benefit specifically from LP(a) lowering is unproven because LDL/ApoB lowering confounds interpretation. Oxidized LDL in plasma is not the same as arterial-wall oxidized LDL; plasma assays mostly detect minimally oxidized ApoB particles. LPPLA2 is biologically linked to oxidized phospholipids, but Mendelian randomization and inhibitor trials have not shown outcome benefit. ADMA and SDMA are promising because they map onto nitric oxide biology and endothelial dysfunction, especially in the context of homocysteine and renal impairment. ApoC3 is a major determinant of triglyceride-rich lipoprotein clearance and may be a more meaningful biomarker than triglycerides alone. Remnants are not a single entity; they are heterogeneous smaller versions of VLDL/chylomicron/LDL-class particles, and their risk depends on ApoE, ApoC3, and particle burden. Omega-3 evidence is often misread because many trials use non-pharmacologic doses or do not measure baseline omega-3 status; formulation and dose matter. The most actionable strategy remains lowering ApoB/LDL particle burden while using specialized biomarkers to identify residual risk and personalize therapy.
Data Points: LP(a) lowering with niacin: ~20% - Tom describes niacin as a weak LP(a)-lowering option. LP(a) lowering with PCSK9 inhibitors: ~30–50% - Estimated range discussed for PCSK9 inhibitor effects on LP(a), varying by individual response. Oxidized LDL fraction: ~5% of total particles - Tom notes only a small fraction of circulating LDL is minimally oxidized in plasma. HDL particle count assay: NMR cannot assay LP(a) particles - Because NMR measures lipid content, not protein content, it cannot directly count LP(a) particles. LPPLA2 inhibitor trials: 2 mega trials - Two large inhibitor trials lowered LPPLA2 activity/mass but did not reduce outcomes. IL-1 inhibitor cost: $30,000 - Referenced as a barrier to broad clinical use of anti-inflammatory therapy. Omega-3 outcome dose: 3–4 grams - Prescription-strength EPA dose discussed in the pending outcome trial. Red blood cell omega-3 testing window: 30–90 days - RBC omega-3s are described as a longer-term marker than plasma fatty acids. ApoC3 effect on statin benefit: No event reduction in high-triglyceride/ApoC3-enriched subgroup - Post hoc CARE trial discussion suggested pravastatin benefit depended on ApoC3-related biology. ApoB particle count example: 1600 nmol/L total LDL-P with 600 nmol/L LP(a)-P - Illustrative case showing mixed LDL particle burden and LP(a) contribution.
Pivotal Quotes: "“The astute listener realizes it's our good friend LP little a.”" — Peter Atiyah: Introduces the discussion of LP(a) as the missing lipoprotein linking niacin, statins, and PCSK9 inhibitors. "“The only way you can do that now is to maybe try niacin… or a PCSK9 inhibitor.”" — Tom Dayspring: Summarizes current limited options for lowering LP(a) before apo(a)-targeting antisense therapies arrive. "“The only particle I really care about is an ApoB particle that can wind up in your artery wall.”" — Tom Dayspring: Captures the central particle-number framework for atherosclerosis risk.
Implications: Listeners should focus on ApoB/particle burden first, then use specialized biomarkers to identify residual risk. The field is moving toward targeted therapies for LP(a), ApoC3, and inflammation, but interpretation must remain mechanistic and individualized.
About Peter Attia Drive
Expert insight on health, performance, longevity, critical thinking, and pursuing excellence. Dr. Peter Attia (Stanford/Hopkins/NIH-trained MD) talks with leaders in their fields.