Lipid and Lipoprotein Tracking in 108 Children Over a Four-Year Period

This study was designed to assess "tracking" of plasma cholesterol, triglyceride, and high and low density lipoprotein cholesterol (C-HDL, C-LDL), in 108 children followed over a four-year period in the Cincinnati Lipid Research Clinic's Princeton School study. The correlations between initial and subsequent measurements of plasma cholesterol were respectively 0.65, 0.66, and 0.68 for observations one, two, and three years apart, P .001; for plasma triglyceride they were 0.47, 0.37, and 0.39, P .001. Initial and subsequent C-HDL and C-LDL levels were also highly correlated, r = .60, .53 (for C-HDL), r = .67 and .61 (for C-LDL), for observations two and three years apart, P .001. Six of 13 children initially in the top decile for plasma cholesterol remained there over the four-year period. Only three of 11 children initially in the top decile for plasma triglyceride remained there over the four-year period. Plasma C-HDL levels initially in the top decile generally remained there, with 82% and 64% of children initially in the top decile remaining in the top two deciles on follow-up. Plasma C-LDL levels were more dispersed than C-HDL, with three of 11 children initially in the top decile remaining there after four years. A considerable proportion of the decrement in group mean levels of lipids and lipoproteins for children initially in the top deciles could be accounted for by regression toward the mean. Although initial and subsequent measures of lipids and lipoproteins in school children are closely correlated, and there is a moderate degree of tracking for children initially in the top deciles, only small numbers of children after four years of follow-up will retain persistent elevations of cholesterol, triglyceride, and C-LDL. Longitudinal assessment of children with elevated lipid and lipoprotein levels may permit early identification of risk factors which both increase risk to coronary heart disease in adulthood (cholesterol, triglyceride, C-LDL), or decrease it (C-HDL).