Children's Activity and Nutrition III was originally part of the Institute-initiated Studies of Children's Activity and Nutrition (SCAN), first funded in 1985. Children's Activity and Nutrition III was renewed in 1992 as a stand-alone project with a focus on assessment of the development of hemodynamic mechanisms responsible for blood pressure (BP) control within the context of ethnicity and family history of early myocardial infarction (MI), defined as having a parent or grandparent with an MI at less than 55 years of age and a family history.
Blacks have a higher mortality rate through middle adulthood than whites from coronary heart disease (CHD), the leading causes of death in the United States. Blacks have been found to exhibit greater cardiovascular (CV) response to stress (i.e., reactivity), a potential risk factor for CHD, as have individuals with a family history. . Although CHD has its pathobiologic origins in childhood, little longitudinal reactivity research has been conducted in youth, especially from childhood through late adolescence.
The study followed a multiethnic sample of 250 13 to 14 year olds for an additional 5 years to determine: 1) whether blood pressure (BP) reactivity during childhood predicted changes in resting BP, left ventricular mass and concentric remodeling, carotid artery wall elasticity and endothelial dependent arterial dilation up to 11 years later after controlling for other expected predictors (i.e., age, gender, ethnicity, resting BP, adiposity, ambulatory BP); 2) the influence of ethnicity, family history and a select group of moderator variables (i.e., environmental stress, anger and John Henryism coping styles, aerobic fitness on youth's cardiovascular (CV) reactivity; and 3) the stability of CV reactivity and a 24- hour ambulatory BP from childhood through late adolescence. The long- term objectives were to provide a better understanding of the development of CV reactivity in youth and its influence upon early pathobiologic markers of coronary heart disease prior to overt manifestation of disease.