Changes in and stability of cardiovascular responses to behavioral stress: results from a four-year longitudinal study of children.

This study examined the changes in and stability of cardiovascular responses to behavioral stress among 132 children in a 4-year longitudinal study. Children's heart rate and blood pressure were measured at rest and while performing 3 tasks: serial subtraction, mirror image tracing, and isometric exercise. This procedure was followed at study entry when children were in grades 2-12 (ages 6-18 years) and at follow-up when children were in grades 6 through post-high school (ages 11-21 years). Results showed that blood pressure and heart rate responses during the tasks were reliable across time for all measures except heart rate responses during isometric exercise. Systolic blood pressure responses to all tasks increased with age for boys, but not for girls. These results support the notion that cardiovascular responses to behavioral stress are a stable individual difference variable.