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

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.