Effects of Neonatal Dexamethasone Treatment on the Cardiovascular Stress Response of Children at School Age

Abstract

The goal was to investigate cardiovascular responses to a psychosocial stressor in school-aged, formerly premature boys and girls who had been treated neonatally with dexamethasone or hydrocortisone because of chronic lung disease. We compared corticosteroid-treated, formerly preterm infants with formerly preterm infants who had not been treated neonatally with corticosteroids (reference group). Children performed the Trier Social Stress Test for Children, which includes a public speaking task and a mental arithmetic task. Blood pressure was recorded continuously before, during, and after the stress test. Plasma norepinephrine levels were determined before the test, directly after the stress task, and after recovery. Overall, in response to stress, girls had significantly larger changes in systolic blood pressure and mean arterial pressure and in stroke volume and cardiac output, compared with boys. Boys exhibited larger total peripheral resistance responses, compared with girls. The hydrocortisone group did not differ significantly from the reference group in any of the outcome measures. However, dexamethasone-treated children had smaller stress-induced increases in systolic and mean arterial blood pressure than did hydrocortisone-treated children. In addition, the dexamethasone group showed smaller increases in stroke volume and blunted norepinephrine responses to stress, compared with children in the reference group. Correction for gender did not affect these results. The differences in cardiovascular stress responses between girls and boys are consistent with known gender differences in adult cardiovascular stress responses. Our data demonstrate that neonatal treatment with dexamethasone has long-term consequences for the cardiovascular and noradrenergic stress responses; at school age, the cardiovascular stress response was blunted in dexamethasone-treated children. Hydrocortisone-treated children did not differ from the reference group, which suggests that hydrocortisone might be a safe alternative to dexamethasone for treating chronic lung disease of prematurity.