Although conventional wisdom is that obesity causes high cholesterol, results of a study in the September issue of the American Journal of Clinical Nutrition suggest that, at least for girls, high cholesterol can be a marker of obesity developing later in childhood. "It is not clear how hypercholesterolemia is linked to high adiposity," write Andrew M. Tershakovec, from the Children’s Hospital of Philadelphia, Pennsylvania, and colleagues. "It seems more likely that hypercholesterolemia acts as a marker of altered metabolism, which results in excessive adiposity."
This spin-off from the Bogalusa Heart study compared 58 hypercholesterolemic children (low-density lipoprotein [LDL] levels greater than 75th percentile) with 215 children who had normal cholesterol levels (LDL less than 60th percentile). Subjects were age 5 to 6 years at study enrollment, and none were obese. There were equal numbers of girls and boys, and 41% of the children were black. Although the nonhypercholesterolemic children were taller than the hypercholesterolemic children, there were no other significant differences between the two groups.
At three- and six-year follow-up, body mass index (BMI) in the hypercholesterolemic girls increased at a greater rate than in the normocholesterolemic girls. By age 11 to 12 years, 45.2% of the hypercholesterolemic girls were overweight or obese, as were 21.6% of the girls with normal cholesterol. This effect was not observed in boys, and it was independent of race in girls.
Associations between BMI and cardiovascular risk factors including blood pressure, insulin, and blood lipids were stronger with increasing age, and in some cases were stronger in hypercholesterolemic children and girls.
"Hypercholesterolemia is associated with increased relative weight in girls," the authors write. "The increased relative weight, even at an early age, is associated with a deleterious effect on blood lipids and other cardiovascular disease risk factors in hypercholesterolemic children, although the strength of these associations is sex dependent." Am J Clin Nutr. 2002;76:730-735