Hypothalamic-pituitary-adrenal axis function and the cellular immune response in former preterm children

Abstract

Context: Animal data suggest that adverse early experiences may affect endocrine and immune functioning in later life. Objective: Our objective was to assess the impact of preterm delivery on hypothalamus-pituitary-adrenal axis functioning, heart rate responses, and immune function. Participants: Former preterm children [aged 8-14 yr (n = 18)], sex and age-matched full-term born control children (n = 18), data on birth weight, gestational age, birth weight for gestational age (in SD units), actual body weight, height, and body mass index were assessed. Design and Outcome Measures: Subjects were exposed to a standardized laboratory stressor ("Trier Social Stress Test for Children"). Cortisol in saliva was determined in 10-min intervals before and after the stress test; heart rates were obtained continuously during the stress test. Additional assessment of saliva cortisol was performed: 1) on 3 consecutive days after awakening and at +10, +20, and +30 min (morning cortisol); and 2) at 0800, 1400, 1600, and 1900 h (short diurnal profile). Measurement of the delayed type hypersensitivity reaction to seven recall antigens [Multitest cellular mediated immunity (Multitest-Immignost, Biosyn, Fellbach, Germany)]. Results: Exposure to the Trier Social Stress Test for Children yielded significantly increased cortisol levels [F (8, 232) = 19.86; P < 0.001] and heart rates [F (38, 988) = 10.46; P < 0.001], however, no difference between former preterms and full-terms could be observed. No between-group differences were found in the short diurnal cortisol profile. Former preterms showed significantly higher cortisol levels after awakening [F (3, 102) = 3.14; P < 0.05]. In addition, a significantly suppressed delayed type hypersensitivity response [reduced number of positive antigens (t = -2.64, P < 0.05); induration (t = -2.4, P < 0.05)] was found in former preterms. Conclusion: The data suggest that preterm delivery may be associated with altered endocrine and immune functions well into late childhood. Copyright © 2007 by The Endocrine Society.