Abstract 14477: Adolescent Lipoprotein Subclass Profile: Reference Ranges, Comparison to Adult, and Association With Carotid Intima-media Thickness

Abstract

Introduction: Atherosclerosis begins in early life. Assessment of comprehensive lipoprotein subclass profiles in adolescents and their relation to atherosclerosis may enhance our understanding of the development of dyslipidemia in early life and inform early vascular prevention Hypothesis: Lipoprotein subclass profiles in adolescents are distinct from those in adults and associate with carotid intima-media thickness (cIMT). Methods: Content of lipids (cholesterol, free cholesterol, triglycerides, phospholipids) and apolipoproteins (apoB-100, apoA1, apoA2) of 17 lipoprotein subclasses (from least dense to densest: VLDL1-6, IDL, LDL1-6, HDL1-4) was measured in plasma of n=1776 14- to 19-year olds (56.6% female) and of n=3217 adults (51.5% female) by nuclear magnetic resonance. cIMT was ascertained by sonography in adolescents. Results: Adolescents compared to adults featured lower triglycerides, total, LDL, and non-HDL cholesterol, and apoB, and higher HDL cholesterol. They showed 27.2 to 60.5% lower triglyceride content of all lipoprotein subclasses and 21.7 to 50.0% lower VLDL lipid content. Concentrations of LDL-4 and LDL-5 were 40.7 to 47.3% lower, with markedly lower levels also of LDL-6 and LDL-3, but 24.3% higher HDL-1 ApoA1. In adolescents, LDL-3, LDL-4, and LDL-5 subclasses were associated with cIMT (difference in cIMT for a 1-SD higher concentration, 4.76 to 5.93μm), whereas no significant association with cIMT was observed for VLDL or HDL. Conclusions: Adolescents showed a markedly different and more favorable lipoprotein profile compared to adults. Dense LDL subclasses were the only subclasses associated with cIMT, implicating them as the potential preferred therapeutic target for primary prevention of cardiovascular disease in adolescents.