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Answer · biomarkers
What is LDL particle number (LDL-P)?
Short answer
LDL-P quantifies the absolute number of LDL particles by NMR spectroscopy. When LDL-P and LDL-C diverge, particle number better predicts cardiovascular risk.
Reviewed by Dr. Laura PurdyMay 29, 2026
Full answer
LDL particle number directly counts atherogenic particles rather than measuring the cholesterol mass they carry. Discordance between LDL-P and LDL-C is common — many insulin-resistant patients show elevated LDL-P despite average LDL-C, hiding cardiovascular risk on a standard panel. LDL-P correlates strongly with ApoB; ApoB is more standardized but LDL-P remains widely used in advanced workups. Within oMeds review, LDL-P is interpreted alongside ApoB, sdLDL, triglycerides, and the broader metabolic picture.
Educational. Not a substitute for individualized provider review.
References & sources
- LDL Particle Number — Primary source · oMeds
- Reviewed by Dr. Laura Purdy, MD, MBA · Clinical Director, oMeds · Last reviewed 2026-05-29
Related answers
What is sdLDL?
sdLDL measures cholesterol carried by small, dense LDL particles — the LDL subfraction most strongly tied to atherogenesis and metabolic syndrome.
LDL-P vs ApoB?
Both count atherogenic particles and correlate strongly. ApoB is more standardized and accessible; LDL-P (NMR) provides additional subfraction detail.
Primary source
LDL Particle Number