Serum cholesterol in early childhood. Familial and nutritional influences and the emergence of tracking.

Abstract

The influence of familial and nutritional factors on serum total cholesterol (TC), and the age at which evidence of tracking appeared, was investigated in the first 2 years. The level of association between the parents' and children's TC levels increased to age two (r 0.25 p < 0.001), being slightly greater for the boys than for the girls. This was paralleled tin the results for low density lipoprotein cholesterol (LDL), but weak association only occurred for high density lipoprotein cholesterol (HDL). Comparing the relative influence on the children's TC of nutritional and familial factors, the parents' TC levels and a family history of early coronary heart disease were found to be important correlates of the children's TC. Low correlations occurred for nutritional factors. The degree of tracking of cholesterol (the extent to which the level maintains its relative position in the distribution curve through time) as measured by the correlation coefficient of the level at time one on the level at time two, increased through infancy to r 0.40 from one to two years. The association between the TC level in cord blood and later levels increased to two years (r 0.32). The results are interpreted as showing either familial influences on a child's TC level become increasingly important from the end of the first year, or that the effect of these influences is obscured during infancy by other, presumably nutritional, factors which themselves are elusive because of the inherently inadequate methodological techniques of dietary studies.