{"id":"large-hdl-p","name":"Large HDL Particle Number","shortName":"Large HDL-P","aliases":["HDL Large","Large HDL-P","Large HDL Particles","Large HDL","HDL Large (Cardio IQ)","HDL LARGE","Large HDL Particle Concentration","Large HDL Particle Count","Large HDL-P (NMR)"],"abbreviations":["Large HDL-P"],"loinc":[{"code":"43729-3","primary":true}],"specimen":"serum-or-plasma","units":[{"ucum":"umol/L","display":"µmol/L"},{"ucum":"nmol/L","display":"nmol/L"}],"referenceRanges":[{"population":"Adults","low":4.8,"high":null,"unit":"umol/L","unitDisplay":"µmol/L","note":"Labcorp prints 'greater than or equal to 4.8 µmol/L' on its NMR LipoProfile with insulin resistance markers. 4.8 is the 50th percentile (median) of Labcorp's reference group of 4,588 adults without known heart disease or diabetes and not on lipid medication, so about half of that group falls below it (25th percentile 3.1, 75th percentile 7.3 µmol/L). It is a cutoff on a risk scale, not the central 95% of healthy people. Quest's ion mobility test also reports large HDL, but its ranges are printed only on the Quest report, so none are encoded.","sources":[{"title":"NMR LipoProfile+IR+Graph, sample patient report (test 123497)","url":"https://files.labcorp.com/testmenu-d8/sample_reports/123497.pdf","publisher":"Labcorp","year":2024},{"title":"NMR LipoProfile With Insulin Resistance Markers, Without Lipids (With Graph) (test 123497)","url":"https://www.labcorp.com/tests/123497/nmr-lipoprofile-with-insulin-resistance-markers-without-lipids-with-graph","publisher":"Labcorp"}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"The number of large HDL particles in your blood. Labs mainly use it as one input to an insulin-resistance score, not as a stand-alone heart test.","url":"https://bloodtesttracker.com/markers/large-hdl-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."}