LAUSR

BACKGROUND AND AIMS Familial hypercholesterolaemia (FH) is underdiagnosed in children. In addition to lipid concentrations, lipoprotein particle quantity and quality could influence cardiovascular risk. We aimed to perform a comprehensive plasma lipid study, including lipoprotein particle number and size assessment by two-dimensional nuclear magnetic resonance (2D-1H-NMR), in children with FH compared to non-affected children and to evaluate the clinical value of these factors as subclinical atherosclerosis biomarkers. METHODS One hundred eighty-three children participating in the broad "Hypercholesterolemia Early Detection Programme" (Decopin Project) were recruited. They were categorized as FH, if they had either a positive genetic test or clinical certainty, or as control children (CCh). Medical history, anthropometry and clinical variables were recorded. Standard biochemical measurements were performed. The lipoprotein profile was studied by 2D-1H-NMR. Carotid intima-media thickness (cIMT) was assessed by sonography in 177 children. RESULTS FH children had a significant 36% increase in LDL particles. The small LDL fraction was increased by 33% compared to CCh. The relative relationship between large, medium and small LDL and the mean LDL particle size was similar between FH children and CCh. The total and small LDL particle numbers were directly associated with and contributed to the determination of the mean cIMT according to bivariate and multivariate analyses in FH children. CONCLUSIONS The higher cholesterol levels of FH children are due to an overall increased number of all LDL particle subclasses, including a notable 33% increase in small LDL. Total and small LDL particle number shows a good correlation with cIMT in FH children.