title: Sexual disparity of copeptin in healthy newborn infants.
abstract: BACKGROUND
  Arginine vasopressin (AVP) regulates water balance and blood pressure and plays a role in social behavioral processes. Healthy adult men as compared with women have higher blood levels of AVP and its C-terminal precursor peptide, copeptin.
  
  
  OBJECTIVE
  The objective of the study was to investigate whether sexual disparity of copeptin is present at birth.
  
  
  METHODS
  In 241 prospectively enrolled healthy newborn infants, 131 boys and 110 girls, plasma copeptin concentrations were measured at birth and on day 3 of life.
  
  
  RESULTS
  Multivariable linear regression analysis revealed stressful delivery (regression coefficient β = .569, P <0.001), acidosis (β = -.347, P < .001), and male gender (β = .132, P < .01) as independent determinants of copeptin at birth. In infants born without stress, that is by primary cesarean section (n = 81), male gender was the sole variable associated with copeptin (β = .286, P < .05), copeptin concentrations being higher in boys [median 5.5 pmol/L (interquartile range 4.4-10.2)] than in girls [4.8 pmol/L (interquartile range 3.6-5.8), P < .05]. At day 3 of life, copeptin was determined independently by postnatal physiological dehydration (β = .485; P < .001) and birth weight (β = .279; P < .01).
  
  
  CONCLUSIONS
  Sexual disparity of copeptin is already present at birth, indicating increased activation of the AVP system in newborn boys as compared with girls.
authors.affiliation: Departments of Pediatric Endocrinology (M.-A.B., G.S.) and Neonatology (S.F., J.B., S.W.), University Children's Hospital Basel, CH-4056 Basel, Switzerland; Division of Obstetrics and Gynecology (M.W., O.L.), University Hospital Basel, CH-4031 Basel, Switzerland; Neonatal Intensive Care Unit (S.F.), University Hospital of Patras, 26500 Patras, Greece; Department of Obstetrics (T.B.), University Hospital Zurich, Zurich 8091, Switzerland; Zurich Center for Integrative Human Physiology (T.B., S.W.), University of Zurich, CH-8032 Zurich, Switzerland; Department of Neonatology (C.B.), Charité University Medical Center, D-10117 Berlin, Germany; and Department of Neonatology (S.W.), University Hospital Zurich, CH-8091 Zurich, Switzerland.
authors.forename: Marie-Anne
authors.initials: MA
authors.lastname: Burckhardt
authors.forename: Maike
authors.initials: M
authors.lastname: Wellmann
authors.forename: Sotirios
authors.initials: S
authors.lastname: Fouzas
authors.forename: Olav
authors.initials: O
authors.lastname: Lapaire
authors.forename: Tilo
authors.initials: T
authors.lastname: Burkhardt
authors.forename: Jörg
authors.initials: J
authors.lastname: Benzing
authors.forename: Christoph
authors.initials: C
authors.lastname: Bührer
authors.forename: Gabor
authors.initials: G
authors.lastname: Szinnai
authors.forename: Sven
authors.initials: S
authors.lastname: Wellmann
mesh_terms: D003681:Dehydration / Q000097:blood* / Q000503:physiopathology; D036861:Delivery, Obstetric / Q000009:adverse effects; D005260:Female; D005865:Gestational Age; D006020:Glycopeptides / Q000097:blood*; D064368:Healthy Volunteers; D006801:Humans; D007231:Infant, Newborn; D016014:Linear Models; D008297:Male; D015999:Multivariate Analysis; D009481:Neurophysins / Q000097:blood; D011247:Pregnancy; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood; D012727:Sex Characteristics; D013312:Stress, Physiological / Q000502:physiology*; D014667:Vasopressins / Q000097:blood
chemical_list: C438657:AVP protein, human; D006020:Glycopeptides; D009481:Neurophysins; D011498:Protein Precursors; C048197:copeptins; D014667:Vasopressins