Abstract 17400: Evaluation of Estimated and Directly Measured Remnant Lipoprotein Cholesterol: The Very Large Database of Lipids
Introduction: Remnant lipoproteins (RLP) are triglyceride-rich cholesterol-containing particles and an emerging risk factor for development of cardiovascular disease, but there is no standard method for RLP measurement. Some studies have used very low-density lipoprotein cholesterol (VLDL-C) calculated by the Friedewald equation to estimate RLP cholesterol, while others have measured remnants directly by ultracentrifugation. These methods have not been extensively compared.
Hypothesis: We hypothesized that substantial discordance exists between Friedewald-estimated RLP cholesterol levels compared to levels measured by ultracentrifugation.
Methods: We analyzed data from 1,350,908 U.S. individuals from the Very Large Database of Lipids, comparing estimated RLP cholesterol levels (RLP-Ce = non-HDL cholesterol – Friedewald-estimated LDL cholesterol) to levels measured directly by Vertical Auto Profile ultracentrifugation (RLPd = dense sub-fraction of VLDL-C + intermediate-density lipoprotein cholesterol). We calculated Spearman correlations between RLP-Ce and RLP-Cd along with median relative differences between RLP-Ce and RLP-Cd within quintiles of RLP-Ce.
Results: Our cohort was 48% male and 59±16 yrs-old (mean±SD). RLP-Ce and RLP-Cd were 27.1±16.1 and 26.6±11.5 mg/dL, respectively (median±SD). The overall correlation between RLP-Ce and RLP-Cd was 0.76 and the correlations by increasing RLP-Ce quintiles were weaker: 0.54, 0.23, 0.17, 0.17, and 0.38, respectively. RLP-Ce underestimated RLP-Cd in the 1st and 2nd quintiles of RLP-Ce but overestimated in the highest quintile (Figure).
Conclusions: Friedewald-estimated remnants (RLP-Ce) correlate poorly with remnants measured by ultracentrifugation (RLP-Cd). RLP-Ce significantly overestimates RLP-Cd in the clinically relevant setting of high remnant levels. Our findings emphasize the need to standardize clinical definitions and measurements of remnant lipoproteins.
Author Disclosures: K.F. Faridi: None. R. Quispe: None. A.D. Hendrani: None. P.H. Joshi: None. E.A. Brinton: Speakers Bureau; Modest; Alexion, Amarin, Amgen, AstraZeneca, Genzyme, Janssen, Kowa, Merck, Regeneron, Sanofi-Aventis, Takeda. Honoraria; Modest; Alexion, Amarin, Amgen, AstraZeneca, Genzyme, Janssen, Kowa, Merck, Regeneron, Sanofi-Aventis, Takeda. Expert Witness; Modest; Manso and partners, Kowa. Consultant/Advisory Board; Modest; Alexion, Amarin, Amgen, Aralez, Kowa, Merck, PTS Diagnostics, Regeneron, Sanofi-Aventis. D.E. Cruz: None. M. Banach: Research Grant; Significant; Valeant. Speakers Bureau; Modest; Abbott, Mylan, Abbott Vascular, Actavis, Akcea, Amgen, KRKA, MSD, Sanofi-Aventis. Consultant/Advisory Board; Modest; Abbott Vascular, Amgen, Daiichi Sankyo, Esperion, MSD, Resvelogix, Sanofi-Aventis, Akcea. P.T. Toth: Speakers Bureau; Modest; Kowa, Novartis, Sanofi-Aventis. Consultant/Advisory Board; Modest; Merck, Regeneron, Sanofi-Aventis. Speakers Bureau; Significant; Amarin, Amgen, Merck, Regeneron. Consultant/Advisory Board; Significant; Amgen, Kowa, Regeneron, Merck. K. Kulkarni: Employment; Significant; Atherotech Diagnostics Laboratory. S.S. Martin: Honoraria; Modest; Abbott Nutrition, American College of Cardiology, Pew Research Center, Quest Diagnostics, Sanofi-Regeneron. S.R. Jones: Research Grant; Significant; June and David Trone Family Trust. Consultant/Advisory Board; Modest; UniQure Biopharma.
- © 2016 by American Heart Association, Inc.