title: Comparisons between salivary cortisol levels in six-months-olds and their parents.
abstract: BACKGROUND
  There is a close relation between the psychosocial environment of the infant--including the perception of maternal behaviour--and cortisol levels of the infant. One previous study has also demonstrated a correlation between mother and infant mean cortisol levels. In this study, this relation was further explored, also including father cortisol levels.
  
  
  METHODS
  Saliva cortisol samples were collected from 51 six-months-olds and their parents on the same day in the morning, afternoon and evening. Analyses were performed with a radioimmunoassay technique. All mothers were at home with their child at this age and 47/51 mothers were breast feeding.
  
  
  RESULTS
  Strong correlations were found between mother and child levels on all sampling occasions whereas weaker correlations were found between father and child levels and only in the afternoon and the evening samples. There was also a strong relation between waking up/bedtime-difference in mother and child and a weaker relation between the corresponding measure in father and child.
  
  
  CONCLUSIONS
  The stronger mother-infant than father-infant cortisol level correlations probably mirror that mother and infant not only have genetic similarities but also have been exposed to similar environmental conditions to a higher degree than father and infant.
authors.affiliation: Karolinska Institutet, Department of Clinical Science and Education, Södersjukhuset, Section of Pediatrics, Sachs' Children's Hospital, 118 83 Stockholm, Sweden. fredrik.stenius@sodersjukhuset.se
authors.forename: Fredrik
authors.initials: F
authors.lastname: Stenius
authors.forename: Töres
authors.initials: T
authors.lastname: Theorell
authors.forename: Gunnar
authors.initials: G
authors.lastname: Lilja
authors.forename: Annika
authors.initials: A
authors.lastname: Scheynius
authors.forename: Johan
authors.initials: J
authors.lastname: Alm
authors.forename: Frank
authors.initials: F
authors.lastname: Lindblad
mesh_terms: D000328:Adult; D001942:Breast Feeding; D002940:Circadian Rhythm / Q000502:physiology; D005220:Fathers; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D007223:Infant; D008297:Male; D009035:Mothers; D012463:Saliva / Q000378:metabolism*; D012984:Software
chemical_list: D006854:Hydrocortisone