Urinary Tetrahydrocortisol/Tetrahydrocortisone Ratio at Early Postnatal Period Predict Steroid Dependency and Neonatal Condition in Preterm Infant

Abstract

Insufficient adrenal function in preterm infants affects poor neonatal outcome, owing to the immaturity of their adrenal enzyme. While 11β-hydroxysteroid dehydrogenase (11βHSD) type 1 and type2 act as gatekeepers for cell steroid action. This study aimed to investigate the effects of early postnatal urinary tetrahydrocortisol/tetrahydrocortisone (F/E) ratio, used as an alternative indicator of 11βHSDs activity, in preterm infants on their subsequent clinical course. In 80 preterm infants of ≤ 34 weeks gestational age admitted to our hospital, urinary F/E ratio was measured within 24 hours of birth. Furthermore, the relationship between this ratio and neonatal outcomes was estimated. Univariate analysis revealed that the high F/E ratio group had significantly higher morbidity in terms of duration of ventilatory support for more than 14 days, hypotension requiring inotropes and hydrocortisone, and symptomatic patent ductus arteriosus. On multivariate analysis, the incidence of hypotension requiring hydrocortisone was higher in the high F/E group, despite the absence of elevated dehydroepiandrosterone, a precursor of cortisol.Conclusion: The urinary F/E ratio in the early postnatal period in preterm infants may contribute to the understanding of the pathogenesis of infant condition after birth by estimating the amount of local steroid action in the organs.