Distribution and correlates of high-density lipoprotein subclasses among children and adolescents

Levels of high-density lipoprotein (HDL) cholesterol among children vary by sex and race/ethnicity and are correlated with age, obesity, and other characteristics. Several studies of adults have indicated that atherogenicity of HDL particles may vary by size, but there is little information on the distribution and correlates of HDL subfractions in early life. We used nuclear magnetic resonance (NMR) spectroscopy to determine the mean HDL particle size and levels of 3 HDL subclasses among 10- to 17-year-olds (n = 918). We found the mean HDL particle size to be (1) inversely associated with age among boys, (2) larger among girls than boys, and (3) larger among black children than among white children. These associations with particle size reflected contrasting associations with various HDL subclasses; among boys, for example, levels of large HDL decreased with age, whereas levels of small HDL remained constant (black boys) or tended to increase (white boys). Furthermore, relative weight and levels of both triglycerides and low-density lipoprotein (LDL) cholesterol were associated inversely with levels of large HDL, but positively with levels of small HDL. These contrasting associations suggest that the role of HDLC in coronary heart disease (CHD) may be more complex than previously thought, and that the analysis of HDL subclasses may improve the accuracy of CHD prediction.