Lower cortisol levels in children with asthma exposed to recurrent maternal distress from birth

Background: Existing evidence supports associations between exposure to maternal distress and the development of childhood asthma, between exposure to maternal distress and an increased cortisol response in children, and between childhood asthma and an attenuated cortisol response. Objective: To investigate the association between children's cortisol levels and the combined predictors of exposure to maternal distress and childhood asthma. Methods: Serum cortisol levels were examined at age 7 to 10 years in relation to asthma status and exposure to maternal distress in a representative sample of children (n = 503) born in 1995. Data from health care and prescription databases were linked with additional data collected in this longitudinal study. Maternal distress was defined as a physician diagnosis of a depressive or anxiety disorder or a prescription history of related medications as reported in the mothers' health care records. Children's asthma status was determined via examination by 2 pediatric allergists. Results: A multiple linear regression analysis revealed that exposure to maternal distress restricted to the first year of life predicted elevated cortisol levels in children, regardless of asthma status (>40% increase). A significant interaction was discovered in the group of children exposed to maternal distress extending beyond the postnatal period such that no asthma predicted a 25.9% increase in cortisol and a diagnosis of asthma predicted a 5.2% decrease in cortisol. Cortisol levels were further lowered in atopic and bronchial hyperresponsive asthma. Conclusion: Among children exposed to recurrent maternal distress, an elevation in cortisol levels occurs in response to an acute stressor when there is no-accompanying diagnosis of asthma, whereas, in comparison, children with asthma tend to exhibit lower cortisol levels. (J Allergy Clin Immunol 2010;125:116-22.)