Diurnal Cortisol Patterns and Dexamethasone Suppression Test Responses in Healthy Young Adults Born Preterm at Very Low Birth Weight.
BACKGROUND
Early life stress, such as painful and stressful procedures during neonatal intensive care after preterm birth, can permanently affect physiological, hormonal and neurobiological systems. This may contribute to altered programming of the hypothalamic-pituitary-adrenal axis (HPAA) and provoke changes in HPAA function with long-term health impacts. Previous studies suggest a lower HPAA response to stress in young adults born preterm compared with controls born at term. We assessed whether these differences in HPAA stress responsiveness are reflected in everyday life HPAA functioning, i.e. in diurnal salivary cortisol patterns, and reactivity to a low-dose dexamethasone suppression test (DST), in unimpaired young adults born preterm at very low birth weight (VLBW; <1500 g).


METHODS
The participants were recruited from the Helsinki Study of Very Low Birth Weight Adults cohort study. At mean age 23.3 years (2.1 SD), 49 VLBW and 36 controls born at term participated in the study. For cortisol analyzes, saliva samples were collected on two consecutive days at 0, 15, 30 and 60 min after wake-up, at 12:00 h, 17:00 h and 22:00 h. After the last salivary sample of the first study day the participants were instructed to take a 0.5 mg dexamethasone tablet.


RESULTS
With mixed-effects model no difference was seen in overall diurnal salivary cortisol between VLBW and control groups [13.9% (95% CI: -11.6, 47.0), P = 0.31]. Salivary cortisol increased similarly after awakening in both VLBW and control participants [mean difference -2.9% (29.2, 33.0), P = 0.85]. Also reactivity to the low-dose DST (awakening cortisol ratio day2/day1) was similar between VLBW and control groups [-1.1% (-53.5, 103.8), P = 0.97)].


CONCLUSIONS
Diurnal cortisol patterns and reactivity to a low-dose DST in young adulthood were not associated with preterm birth.
Chronic Disease Prevention Unit, Department of Health, National Institute for Health and Welfare, Helsinki, Finland.
Nina
http://orcid.org/0000-0003-4648-0022
N
Kaseva
Institute of Behavioural Sciences, University of Helsinki, Helsinki, Finland.|Folkhälsan Research Centre, Helsinki, Finland.
Riikka
R
Pyhälä
Institute of Behavioural Sciences, University of Helsinki, Helsinki, Finland.
Anu-Katriina
AK
Pesonen
Institute of Behavioural Sciences, University of Helsinki, Helsinki, Finland.
Katri
K
Räikkönen
Children's Hospital, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland.
Anna-Liisa
AL
Järvenpää
Children's Hospital, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland.
Sture
S
Andersson
Chronic Disease Prevention Unit, Department of Health, National Institute for Health and Welfare, Helsinki, Finland.|Folkhälsan Research Centre, Helsinki, Finland.|Department of General Practice and Primary Health Care, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.|Vasa Central Hospital, Vasa, Finland.
Johan G
JG
Eriksson
Chronic Disease Prevention Unit, Department of Health, National Institute for Health and Welfare, Helsinki, Finland.|Children's Hospital, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland.
Petteri
P
Hovi
Chronic Disease Prevention Unit, Department of Health, National Institute for Health and Welfare, Helsinki, Finland.|Children's Hospital, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland.|PEDEGO Research Group, Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland.
Eero
E
Kajantie
D000328:Adult; D002940:Circadian Rhythm; D003907:Dexamethasone / Q000008:administration & dosage*; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis*; D007030:Hypothalamo-Hypophyseal System; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D010913:Pituitary-Adrenal System; D012463:Saliva / Q000737:chemistry; D055815:Young Adult
D003907:Dexamethasone; D006854:Hydrocortisone