title: Sleep quality, cortisol levels, and behavioral regulation in toddlers.
abstract: This study examines the association between nighttime sleep characteristics and cortisol levels and how these variables relate to aspects of children's temperament and behavior. Twenty-seven healthy children, aged 12-36 months, attending group childcare settings, participated in the study. Each child's sleep was measured at home with actigraphy over three nights. Saliva samples were collected by the mothers at bedtime and within 30 min of awakening. In addition, both the mother and the daycare teacher rated the child's behavioral difficulties and negative emotionality. It was found that children with more fragmented sleep displayed higher awakening cortisol levels compared to children with more efficient sleep. Moreover, elevated awakening cortisol levels were correlated with teachers' ratings of internalizing behavior and negative emotionality. These preliminary findings suggest that awakening cortisol may serve as a useful index of adrenocortical reactivity in young children, signaling a disturbance in physiological regulation, and underscore the need for more research pertaining to the dynamic associations between sleep and HPA-axis across the 24-hr period.
authors.affiliation: Faculty of Education, Department of Counseling and Human Development, University of Haifa, Haifa, Mount Carmel 31905, Israel. anats@construct.haifa.ac.il
authors.forename: Anat
authors.initials: A
authors.lastname: Scher
authors.forename: Wendy A
authors.initials: WA
authors.lastname: Hall
authors.forename: Anat
authors.initials: A
authors.lastname: Zaidman-Zait
authors.forename: Joanne
authors.initials: J
authors.lastname: Weinberg
mesh_terms: D002652:Child Behavior / Q000502:physiology*; D002656:Child Day Care Centers; D002675:Child, Preschool; D002940:Circadian Rhythm / Q000502:physiology*; D004644:Emotions / Q000502:physiology; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D007223:Infant; D007389:Internal-External Control; D008297:Male; D010552:Personality Assessment; D010913:Pituitary-Adrenal System / Q000502:physiology; D012016:Reference Values; D012890:Sleep / Q000502:physiology*; D013694:Temperament; D014851:Wakefulness / Q000502:physiology
chemical_list: D006854:Hydrocortisone