Gender and ethnicity in children's cardiovascular reactivity: 7 years of study.

A total of 295 children (127 White boys, 15 Black boys, 133 White girls, and 20 Black girls) participated in reactivity examinations in 1987 (all were in 3rd grade; age, M = 9.1 years), 1988, 1989, 1991, 1992 and 1993 (all were in 9th grade; age, M = 15.1 years). An analysis of residualized reactivity change values indicated consistent and significant ethnicity effects (Blacks greater than Whites) for systolic and diastolic blood pressure and for heart rate. Gender effects were also apparent for both systolic and diastolic blood pressure (boys greater than girls). These data suggest that the transition from childhood to adolescence is associated with a significant pattern of ethnic differences in reactivity, although the association of this pattern with the development of cardiovascular risk and disease remains to be ascertained.