title: Determinants of vascular phenotype in a large childhood population: the Avon Longitudinal Study of Parents and Children (ALSPAC).
abstract: OBJECTIVE
  To assess the feasibility and reproducibility of non-invasive vascular assessment in a childhood population setting and identify the determinants of vascular phenotype in early life.
  
  
  RESULTS
  We studied 7557 children (age 9.8-12.3 years) participating in the Avon Longitudinal Study of Parents and Children (ALSPAC). Six research technicians underwent a 5-month training protocol to enable study of brachial artery endothelial function by flow-mediated dilatation (FMD) and arterial stiffness by carotid to radial pulse wave velocity (PWV) and brachial distensibility [distensibility coefficient (DC)]. Reproducibility studies were performed at the beginning, the middle, and the end of the study. A blinded repeat evaluation of a random selection of 3% of the cohort was also undertaken throughout the study. The effect of anthropometric and environmental factors on each measure was examined. Successful measures were obtained in 88, 95, and 87% of the studied children for FMD, PWV, and DC, respectively. The coefficients of variation between technicians for FMD, PWV, and DC were 10.5, 4.6, and 6.6% at the beginning of the study and reached 7.7, 4.1, and 10% at the end. Baseline vessel diameter and gender were important determinants of all the vascular measures, with a small effect of room and skin temperatures on FMD and PWV. Boys consistently had lower FMD and DC and higher PWV measures (P < 0.01 for all).
  
  
  CONCLUSIONS
  Reproducible, high-quality assessments of vascular structure and function in children can be made on a large scale in field studies by suitably trained non-specialist operators. This study provides an invaluable resource for assessing the impact of early influences, genetic, and environmental factors on arterial phenotype.
authors.affiliation: Vascular Physiology Unit, Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UK.
authors.forename: Ann E
authors.initials: AE
authors.lastname: Donald
authors.forename: Marietta
authors.initials: M
authors.lastname: Charakida
authors.forename: Emanuela
authors.initials: E
authors.lastname: Falaschetti
authors.forename: Debbie A
authors.initials: DA
authors.lastname: Lawlor
authors.forename: Julian P
authors.initials: JP
authors.lastname: Halcox
authors.forename: Jean
authors.initials: J
authors.lastname: Golding
authors.forename: Aroon D
authors.initials: AD
authors.lastname: Hingorani
authors.forename: George Davey
authors.initials: GD
authors.lastname: Smith
authors.forename: John E
authors.initials: JE
authors.lastname: Deanfield
mesh_terms: D000886:Anthropometry; D050197:Atherosclerosis / Q000235:genetics / Q000503:physiopathology / Q000517:prevention & control; D001783:Blood Flow Velocity / Q000235:genetics; D001794:Blood Pressure / Q000235:genetics; D001916:Brachial Artery / Q000502:physiology; D002339:Carotid Arteries / Q000502:physiology; D002648:Child; D004730:Endothelium, Vascular / Q000502:physiology*; D004777:Environment; D005240:Feasibility Studies; D005260:Female; D006439:Hemodynamics / Q000235:genetics*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D010641:Phenotype; D014655:Vascular Resistance / Q000235:genetics; D014664:Vasodilation / Q000235:genetics