{"id":"ldl-p","name":"LDL Particle Number (LDL-P)","shortName":"LDL-P","aliases":["LDL Particle Number","LDL-P","LDL Particle Count","LDL Particle Concentration","LDL Particles","LDL-P (NMR)","Total LDL Particles","LDL PARTICLE NUMBER","NMR LDL-P","LDL Particle Number (NMR)","LDL Particle Number (Ion Mobility)","Low Density Lipoprotein Particle Number"],"abbreviations":["LDL-P"],"loinc":[{"code":"54434-6","primary":true}],"specimen":"serum-or-plasma","units":[{"ucum":"nmol/L","display":"nmol/L"}],"referenceRanges":[{"population":"Adults","low":null,"high":999.9,"unit":"nmol/L","unitDisplay":"nmol/L","note":"Labcorp and Mayo Clinic Laboratories both print 'below 1,000 nmol/L' for NMR LDL-P (Mayo gives it for ages 18 and up and has no values for younger people). It is stored as 999.9 so a result of exactly 1,000 falls outside it. Labcorp's cutoffs are percentiles of a US reference group of 5,362 adults not on lipid medication (MESA): below 1,000 is below the 20th percentile. It is a risk-based cutoff, not the central 95% of healthy people. Quest's ion mobility test counts particles by a different method and prints its ranges only on the report, so none are encoded here.","sources":[{"title":"NMR LipoProfile+Lipids+Graph, sample patient report (test 123810)","url":"https://files.labcorp.com/testmenu-d8/sample_reports/123810.pdf","publisher":"Labcorp","year":2024},{"title":"Nuclear Magnetic Resonance Lipoprotein Profile, Serum (test NMRLP)","url":"https://www.testcatalog.org/show/NMRLP","publisher":"Mayo Clinic Laboratories (testcatalog.org)"}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"The number of LDL particles in your blood. Some clinicians use it next to LDL cholesterol to see how many cholesterol-carrying particles you have.","url":"https://bloodtesttracker.com/markers/ldl-p","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}