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A prospective longitudinal study to estimate the "adjusted cortisol percentile" in preterm infants
Pak C Ng1, Sam P S Wong, Iris H S Chan
1Department of Pediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, New Territories, Hong Kong. pakcheungng@cuhk.edu.hk
Insights
This study established a model to estimate adjusted cortisol percentiles in preterm infants, accounting for various perinatal factors. This tool aids neonatologists in interpreting serum cortisol levels more accurately in clinical practice.
Area of Science:
- Neonatal Medicine
- Endocrinology
- Pediatric Research
Background:
- Normal serum cortisol ranges in preterm infants are not well-defined.
- Accurate interpretation of cortisol levels is crucial for clinical decision-making in neonates.
- Perinatal factors significantly influence circulating cortisol concentrations.
Purpose of the Study:
- To evaluate the impact of perinatal factors on serum cortisol levels in preterm infants.
- To develop a quantitative model for estimating an "adjusted cortisol percentile."
Main Methods:
- Serial serum cortisol concentrations were measured in 209 preterm infants (≤ 32 weeks gestation) on days 1, 4, 7, 14, and 21.
- Seven identified perinatal factors were analyzed for their effect on cortisol levels.
- A mathematical equation was derived to calculate the adjusted cortisol percentile.
Main Results:
- Cortisol levels varied significantly over the first 21 days of life.
- Higher cortisol levels were associated with nasal continuous positive airway pressure, need for vasopressors, intraventricular hemorrhage, histologic chorioamnionitis, severe lung disease, and lower gestational age.
- A predictive model for adjusted cortisol percentile was developed.
Conclusions:
- The study provides a novel tool for interpreting serum cortisol levels in preterm infants.
- The "adjusted cortisol percentile" model helps standardize interpretation across diverse clinical scenarios.
- This quantitative approach can enhance clinical management and understanding of endocrine function in vulnerable neonates.
Abstract:
The normal range of serum cortisol concentrations and the appropriate levels of circulating cortisol in different clinical situations in preterm infants are not well defined. This study aimed to evaluate the impact of perinatal factors on circulating cortisol levels in preterm infants and to create a quantitative model that could estimate the "adjusted cortisol percentile." Serial serum cortisol concentrations were measured in 209 infants ≤ 32 wk gestation on d 1, 4, 7, 14, and 21 of life. Seven perinatal factors or conditions that could affect circulating cortisol level were identified. Serum cortisol levels were higher on d 4 (p = 0.007) and d 7 (p = 0.007) but lower on d 21 (p = 0.001) compared with d 1. Serum cortisol was also higher in infants on nasal continuous positive airway pressure (p = 0.003); requiring a second vasopressor (p < 0.001); with intraventricular hemorrhage (≥ grade 3; p < 0.001); with histologic chorioamnionitis (p = 0.007); with severe lung disease (p = 0.046); and with decreasing GA (p < 0.001). A mathematical equation was proposed based on factors derived in this preliminary study for estimating the adjusted cortisol percentile. Frontline neonatologists could now access the equation on our Web site (http://www.sta.cuhk.edu.hk/pswong/ACortP.html) to calculate the adjusted cortisol percentile, which could potentially improve the interpretation of circulating cortisol in different clinical situations.
