Preterm birth and infant diurnal cortisol regulation

Area of Science:

• Endocrinology
• Developmental Pediatrics
• Human Physiology

Background:

• Early life exposures, such as preterm birth, can influence long-term health via hypothalamic-pituitary-adrenal (HPA) axis adaptation.
• Understanding diurnal cortisol regulation in preterm infants is crucial for identifying potential health risks.

Purpose of the Study:

• To investigate the association between preterm birth and the adaptation of diurnal cortisol regulation throughout infancy.
• To compare cortisol regulation patterns in extremely preterm, very preterm, and term-born infants.

Main Methods:

• Secondary analysis of saliva cortisol data collected monthly (morning, midday, evening) from infants in a Swedish birth cohort.
• Random coefficients regression models were used to compare diurnal cortisol slopes across infancy for different preterm birth groups (extremely preterm, very preterm, term).

Main Results:

• Infants born extremely preterm exhibited a significantly flattened diurnal cortisol slope across infancy compared to term-born infants (-17.2%).
• Infants born very preterm did not show a significant difference in their diurnal cortisol slope compared to term-born infants (1.7%).

Conclusions:

• Extremely preterm birth is associated with a blunted diurnal cortisol rhythm during infancy.
• This altered cortisol regulation pattern may contribute to the metabolic and neurodevelopmental challenges observed in extremely preterm infants.