LDL Particle Concentration NMR, Plasma
Method Description Describes how the test is performed and provides a method-specific reference
LDL particle concentrations are measured using an automated nuclear magnetic resonance (NMR) spectrometer. Lipoproteins are analyzed by the NMR according to the spectral signals produced by the terminal methyl groups contained within the lipid particles. The number of methyl groups present on triglycerides, cholesterol, cholesteryl esters, and phospholipids is consistent for particles at a given size, allowing for translation into particle concentration. Individual subclasses are derived using the measured amplitude of the NMR signal along with a deconvolution algorithm. The total LDL-P concentration is the sum of all LDL particle subfractions/sizes and is inclusive of IDL and Lp(a). NMR lipoprotein analyses have been evaluated against other existing methods of lipoprotein subclass methodologies; however, there are no standardization programs targeted towards these analytes.(Otvos JD: Measurement of lipoprotein subclass profiles by nuclear magnetic resonance spectroscopy. Clin Lab 2002;48:171-180; Jeyarajah EJ, Cromwell WC, Otvos JD: Lipoprotein particle analysis by nuclear magnetic resonance spectroscopy. Clin Lab Med 2006;26:847-870; Freedman DS, Otvos JD, Jeyarajah EJ, et al: Sex and age differences in lipoprotein subclasses measured by nuclear magnetic resonance spectroscopy: the Framingham Study. Clin Chem 2004;50:1189-1200)
PDF Report Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday; Continuous