Salivary cortisol is not associated with dexamethasone response in preterm infants with evolving bronchopulmonary dysplasia

Abstract

Objective: Short-term treatment efficacy of systemic dexamethasone (DEX) in preterm infants with bronchopulmonary dysplasia (BPD) is highly variable. Our objective was to assess if salivary cortisol may serve as a reliable biomarker of steroid response.

Study design: Multi-site prospective observational cohort study. Salivary cortisol was measured before and after DEX treatment. Respiratory Severity Score (RSS) quantified clinical response.

Results: Fifty-four infants with median (inter-quartile range) gestational age of 25.1 (24.1,26.5) weeks initiated DEX at 30 (23,48) days' postnatal age. Median baseline and post-treatment cortisol levels were 0.3 (0.2,0.6) μg/dl; 8.3 (5.5,16.5) nmol/L and 0.2 (0.1,0.3) μg/dl; 5.5 (2.8,8.3) nmol/L, respectively. RSS values decreased by a median of 3.1(1.6,5.0) Change in RSS did not correlate with baseline cortisol or change in cortisol levels.

Conclusion: In this first study to assess salivary cortisol as a biomarker for DEX response in BPD, salivary cortisol did not predict dexamethasone response.