The cortisol awakening response in very preterm born adults compared to term born adults.

Very preterm infants are at higher risk of long-term neurodevelopmental and psychiatric impairments, including anxiety. Prematurity is also linked to altered programming of the hypothalamus-pituitary-adrenal (HPA) axis, associated with stress-related diseases. The cortisol awakening response (CAR), marked by a rapid cortisol increase after waking, is a biomarker of HPA reactivity and is linked to psychiatric disorders. This study aimed to evaluate for the first time the CAR in adults born very preterm and to explore its association with anxiety and stress. Twenty-five young adults born very preterm and 24 age- and sex-matched term-born controls collected saliva samples on two consecutive mornings at 0, 30, 45, and 60 min after awakening. Anxiety was measured using the State-Trait Anxiety Inventory, and stress was assessed with the Perceived Stress Scale. The CAR was analyzed using the sample at 0 min (S1), total cortisol output (AUCg), and actual CAR (AUCi). There were no significant differences in AUCi. The preterm group exhibited lower S1 levels and a reduced AUCg. Preterm-born participants reported higher trait anxiety and stress, though no consistent link with the CAR was identified. Findings suggest long-term neuroendocrine changes in adults born very preterm, warranting further research. Clinical Trial Registration: Duetsche Register Klinischer Studien (DRKS): 00020235.