The Effect of Critical Illness on Acth, Cortisol and Aldosterone in Preterm Infants

Abstract

Objective:To investigate the effect of illness on preterm infant's hypothalamus-putituary-adrenal axis, we measured the concentration of cortisol, aldosterone and ACTH.Methods: Ninety preterm infants were divided into two groups: gestational age (GA) ≥ 34weeks' and GA< 34weeks'. We measured serum cortisol, aldosterone and ACTH within 72 hours after birth, day 7 and day 14. Results:(1) The serum cortisol concentration on severe illness was higher than that on mild illness. GA≥34weeks', the cortisol concentration on severe illness infants was significantly higher than mild ill infants within 72 hours (t=-2.263, P=0.029). GA< 34 weeks', the cortisol concentration on severe illness infants was significantly higher on the day 14 (t=-2.913, P=0.006).(2) The cortisol concentration was significantly decreased on the day 7 and day 14 than that within 72 hours in the GA≥34weeks' (F = 4.679, p = 0.012); (3) The cortisol concentration on death infants was significant higher than that on survivors on the day 14.(4) When the cortisol concentration was above the 75 th , the incidence of mechanical ventilation therapy, glucose metabolism disorder, gastrointestinal hemorrhage, severe periventricular -intraventricular hemorrhage and brain leukomacia, chronic lung disease, and mortality rate were increased strikingly. Conclusions:The preterm infant already has the ability to response stimuli by regulating cortisol secretion. The cortisol concentration is correlated with the severity of the disease, complications and prognosis.