HDL cholesterol is considered a significant negative risk faktor in the development of atherosclerosis. It Plays a crucial role in the reverse cholesterol transport and studies of the HDL subpopulation make it Possible, as aPParent in adults at risk, to assess the Prognosis of subjects with the risk of early atherosclerosis. In the majority of child groups these studies were not made. In the submitted work authors tried to elucidate the development of the HDL cholesterol subpopulation and esterification rate of cholesterol (FERxnL) in 221 children (108 boys and 113 girls) aged 4 months to 20 years in relation to age and sex. The authors estimated total cholesterol (TC), HDL cholesterol (HDL-C), LDL cholesterol (LDL-C) and triglycerides (TG) and assessed also the rado of the HDL subpopulation HDLzb (protective) and HDL3b,~ (atherogenic). In the TC, LDL-C and TG levels there were no differences in relation to age and sex, but HDL cholesterol increased with age. Adolescent girls had a higher concentration of HDLzb as compared with boys (30.4% and 17.2% resp.) while girls had fewer HDL3b,~ Particles (8.7% and 16.5% resp.). Esterification of HDL cholesterol correlated inversely with HDLzb and Positively with HDL3b,~ and was significantly higher in adolescent boys than in girls (16.5%/h and 12.5%/h resp.). The results indicate the development of the HDL cholesterol level in childhood in relation to age and indicate also the determination of the risk of male sex already in adolescent boys. Because esterification of HDL cholesterol correlated highly positively with the distribution of HDL Particles it will be possible to use this relatively simPle method as another biochemcckl marker in children who are at risk of developing early atherosclerosis.

        Key words: HDL subpopulation, esterification of cholesterol, children, risk of atherosclerosis