Abstract: | Data on the levels of high-density lipoprotein-cholesterol (HDL-C) and subfractions in 102 adolescent twin pairs and their parents are presented. Children with a family history of premature cardiovascular death had lower levels of HDL2-C than did those without such a history. White girls reporting a high level of physical activity had higher levels of HDL-C and HDL2-C than did their more sedentary peers. In general, children of mothers who smoked had lower HDL2-C than did children of nonsmoking mothers. These findings suggest that low levels of HDL2-C in children may identify families in which there is an increased risk of coronary heart disease and that parental smoking may contribute to changes in this risk factor in the children of smokers as well as in the smokers themselves. |