Links between early adrenal function and respiratory outcome in preterm infants: Airway inflammation and patent ductus arteriosus

Objective. To investigate the relationship of cortisol concentrations durin g the first week of life to patent ductus arteriosus (PDA), markers of lung inflammation, and respiratory outcome in very low birth weight infants. Methods. Newborns <1500 g birth weight were prospectively enrolled at 2 cen ters. Serum cortisol was measured 3 times during days 2 to 7 of life. Trach eal lavage was performed on intubated infants and analyzed for interleukin- 1 beta, -6, and -8, and for total protein, albumin, and alpha-1 protease in hibitor. Infants receiving prenatal glucocorticoids were excluded. Results. We obtained 337 cortisol values from 125 infants. Infants treated for PDA had lower cortisol values after day 2. One hundred thirty-three tra cheal fluid samples were obtained on matching days from 71 intubated infant s. Cortisol correlated inversely with tracheal interleukins and proteins. L ower cortisol values during the second half of the week correlated with lon ger duration of supplemental oxygen therapy and with subsequent development of chronic lung disease at 28 days and at 36 weeks. Conclusion. Infants with lower cortisol values in the first week of life ha d an increased incidence of PDA, increased lung inflammation, and an increa sed incidence of chronic lung disease. These findings suggest that early ad renal insufficiency may underlie the previously observed association of inc reased lung inflammation and PDA with adverse respiratory outcome in this p opulation.