Saliva cortisol diurnal variation and stress responses in term and preterm infants. Issue 5 (7th March 2022)

• Record Type: Journal Article
• Authors: Stoye, David Q; Boardman, James P; Osmond, Clive; Sullivan, Gemma; Lamb, Gillian; Black, Gill S; Homer, Natalie Z M; Nelson, Nina; Theodorsson, Elvar; Mörelius, Evalotte; Reynolds, Rebecca M
• Is Part Of: Archives of disease in childhood. Volume 107:Issue 5(2022)
• Page Start: 558
• Page End: 564
• Publication Date: 2022-03-07
• Subjects: neonatology -- endocrinology -- infant development; Infants -- Diseases -- Periodicals; Newborn infants -- Diseases -- Periodicals; Fetus -- Diseases -- Periodicals; 618.920105
• DOI: 10.1136/archdischild-2021-321593
• Languages: English
• ISSNs: 1359-2998

Abstract

Abstract : Objective: To determine if preterm birth is associated with adaptation of the hypothalamic–pituitary–adrenal (HPA) axis and whether HPA axis programming relates to the degree of prematurity (defined as extremely preterm birth at <28 weeks or very preterm birth at 28–32 weeks gestation). Design: This study reports findings from a prospective birth cohort. Saliva cortisol concentrations were measured prevaccination and postvaccination, and in the morning and evening, at 4 months chronological age. Setting: Infants born at a single Scottish hospital. Participants: 45 term-born, 42 very preterm and 16 extremely preterm infants. Outcomes: Cortisol stress response to vaccination (postvaccination minus prevaccination cortisol concentrations), diurnal slope (log-transformed morning minus log-transformed evening cortisol values) and mean log-transformed daily cortisol. Results: Compared with infants born at term, infants born extremely preterm had a blunted cortisol response to vaccination (5.8 nmol/L vs 13.1 nmol/L, difference in means: −7.3 nmol/L, 95% CI −14.0 to −0.6) and a flattened diurnal slope (difference in geometric means: −72.9%, 95% CI −87.1 to −42.8). In contrast, the cortisol response to vaccination (difference in means −2.7 nmol/L, 95% CI −7.4 to 2.0) and diurnal slope at 4 months (difference in geometric means: −33.6%, 95% CI −62.0 to 16.0) did not differ significantly in infants born very preterm compared with infants born at term. Conclusions: Infants born extremely preterm have blunted cortisol reactivity and a flattened diurnal slope. These patterns of HPA axis regulation are commonly seen after childhood adversity and could contribute to later metabolic and neurodevelopmental phenotypes observed in this population. Abstract : Results from salivary cortisol concentrations of infants at 4 months of age suggests that extremely preterm birth disrupts the normative development of the HPA axis in infancy, with patterns of cortisol secretion resembling those seen after childhood adversity.