Comparing different assessments of remnant lipoprotein cholesterol: The very large database of lipids

Background Remnant lipoprotein cholesterol (RLP-C) is a risk factor for atherosclerotic cardiovascular disease, but there is no standard method for measurement. Some studies have used very low-density lipoprotein cholesterol estimated by the Friedewald equation to approximate RLP-C using a basic lipid panel, whereas others have attempted to measure RLP-C with ultracentrifugation. Objective The aim of the study was to compare RLP-C levels estimated from basic lipid parameters to those measured by ultracentrifugation. Methods We analyzed 1,350,908 individuals from the Very Large Database of Lipids, comparing one estimate of RLP-C using basic lipid parameters (RLP-Cestimated = non–high-density lipoprotein cholesterol − Friedewald-estimated low-density lipoprotein cholesterol for triglycerides Results Our cohort was 48% male, and median (interquartile range) age was 59 (49–69) years. Median (interquartile range) RLP-Cestimated and RLP-Cmeasured were 23 (16.4–33.2) and 24 (19–32) mg/dL, respectively. The correlation between RLP-Cestimated and RLP-Cmeasured was 0.76. Based on the specified definition of RLP-Cestimated, the correlation between RLP-Cestimated and triglyceride/5 for triglyceride Conclusions A previously used estimate of RLP-C using basic lipid parameters correlates weakly with remnants measured by ultracentrifugation. Our findings emphasize the need to standardize definitions and measurements of RLP-C.