Sexual Maturation Affects Diet-Blood Total Cholesterol Association in Children. Project HeartBeat!

Background: Cardiovascular disease (CVD) does not become clinically manifest until adulthood. However, children and young adults have evidence of atheromatous lesions and fatty streaks in their aortas and coronary vessels. Most longitudinal studies in children are not designed to evaluate the dynamics of change in CVD risk factors. There is a need to describe the trajectory of CVD risk factors as growth processes, to better understand their relationships. This study assesses the associations between dietary variables and blood total cholesterol concentration (BTCC) among children and adolescents aged 8-18 years after adjustment for sexual maturation. Methods: There were 678 boys and girls aged 8, 11, and 14 years at baseline who were followed for up to 4 years, allowing the creation of a synthetic cohort analytically, from ages 8-18 years. Multilevel modeling was used to longitudinally assess BTCC, dietary intake, Tanner stage, and BMI. Results: For every 1-mg/day increase in dietary cholesterol, BTCC increased by 0.012 mg/dL. However, no associations were evident between BTCC and dietary total fat, saturated fatty acids, polyunsaturated fatty acids, or monounsaturated fatty acids. In girls, none of the dietary variables was significantly associated with BTCC after controlling for Tanner stage for breast. In boys, with the exception of dietary cholesterol, no other dietary variable was significantly associated with BTCC after controlling for Tanner stage for genitalia. Conclusions: Sexual maturation exerts a strong influence on BTCC in children and adolescents aged 8-18 years, obscuring most associations between diet and BTCC. The inclusion of sexual maturity stage is important in studies of blood lipids among children and adolescents.