Sex and race differences in cardiovascular disease risk factor changes in schoolchildren, 1975-1990: The Princeton School Study

Objectives. This study was done to assess changes in obesity and risk factors for cardiovascular disease (CVD) in Black and White children from 1975 through 1990. Methods. A cross-sectional study of body composition and CVD risk factors conducted in a school district as part of the Lipid Research Clinics (LRC) Program Prevalence Study(1973-1975) was compared with a later study (1989-1990) conducted in the same school district, which remained demographically stable. The studies included 1456 third- and fifth-grade students and 300 LRC subjects within the same age ranges. Results. Students in the 1989-1990 study had a significantly higher mean body mass index (BMI), total blood cholesterol concentration, and systolic and diastolic blood pressures and marginally higher resting heart rates than those in the earlier study. The prevalence of obesity increased from 12.5% to 25.3%, and of hypercholesterolemia from 8.0% to 14.8%. Black females had the largest increase in BMI and resting heart rate and the highest prevalence of elevated total cholesterol in the 1989-1990 study. Conclusions. The results of this study suggest a secular trend toward increased obesity in children and portend the potential development of a public health problem that could reverse the recent decline in morbidity from CVD.