Tracking of serum cholesterol levels in a multiracial sample of preschool children.

The relation of an initial measurement of serum total cholesterol to subsequent levels over a (mean) 13-month interval was examined in a multiracial (white, Hispanic, American Indian, and black) sample of 1680 one- to four-year-olds. Although the relation of the initial level to the final measurement (r = .54) did not vary by race, sex, relative weight, or changes in relative weight, the association increased with age at the time of the initial measurement (eg, r = .64 among 4-year-olds). Based on the initial and final total cholesterol determinations, the within-person standard deviation was 21 mg/dL and the coefficient of variation was 13%. Although the final total cholesterol level was within 5 mg/dL of the initial level for 18% of the children, the two determinations differed by greater than or equal to 25 mg/dL for about 35% of the children and by greater than or equal to 50 mg/dL for about 8%. Of the 149 children who had an initial cholesterol level greater than or equal to 200 mg/dL, 34% (about five times the expected number) had a follow-up level that was similarly elevated whereas 25% had a subsequent measurement below 170 mg/dL. The results indicate that although an initial cholesterol level in early life is moderately predictive of subsequent levels, it may be difficult to interpret a single total cholesterol determination because of substantial within-person variability.