Background: Cortisol and GH secretion were studied in preterm newborns to assess the relation between the secretion of these hormones and the development of CLD.

Subjects: 7 male and 6 female preterm newborns. Gestational age ranged from 25 to 32 weeks, postnatal age from 4 to 6 days and birth weight from 699 to 2005 grams. CLD was defined as an oxygen requirement at 28 days of age.

Interventions: In all patients bloodsamples were obtained every 6 hours for 24 hours through a peripheral arterial catheter. Serum cortisol was measured by RIA and serum GH was measured by an IMA.

Results: Cortisol levels (nmol/l) and GH (μg/l) are expressed as means± SD. Table

Table 1
Full size table

Conclusion: The cortisol profiles of children with CLD were lower compared to the controls (p < 0.05) and the GH profiles of children with CLD were higher compared to the controls (p < 0.05). We therefore speculate that preterm newborns who develop a CLD are unable to secrete adequate amounts of cortisol in a setting of increased stress, leaving them vulnerable to continuining lung injury. The disharmonic secretion of cortisol and GH in patients with CLD has to be further investigated.