Effects of secular trends in obesity on coronary risk factors in children: the Bogalusa Heart Study.

OBJECTIVE

To determine whether a secular trend toward increased weight gain was present in children examined 11 years apart in the Bogalusa Heart Study and, if present, the association of this trend with the cardiovascular risk status of the children.

STUDY DESIGN

Two biracial cohorts (approximately 65% white, 35% black) were identified. One cohort was examined first in 1973 at 7 to 9 years of age and was reexamined in 1981 (n = 417). The second was examined first in 1984 at the same age and reexamined in 1992 (n = 235). Measurements made at each assessment included age, gender, race, height, weight, blood pressure, and lipoproteins. The two cohorts were then compared.

RESULTS

The two cohorts were comparable at their first assessment. However, at follow-up 8 years later the more recent cohort was 5 to 7 kg heavier without any difference in linear growth; this increased ponderosity was associated with adverse changes in lipids and lipoproteins: the high-density lipoprotein-cholesterol concentration was 0.15 to 0.35 mmol/L (6 to 13 mg/dl) lower, triglyceride values were 0.09 to 0.40 mmol/L (8 to 36 mg/dl) higher, and there were small increases in total cholesterol and low-density lipoprotein-cholesterol concentrations in white girls. Multivariate analyses showed that in the more recent cohort these changes were related more to a change in ponderosity than to ponderosity. Although blood pressure was generally lower in the recent cohort, increasing ponderosity was associated with higher blood pressure.

CONCLUSIONS

There is a secular trend toward increased ponderosity in children examined in the Bogalusa Heart Study. This trend is associated with worsening cardiovascular risk, particularly with regard to lipoproteins.