title: Trends in blood pressure over 10 years in adolescents: analyses of cross sectional surveys in the Northern Ireland Young Hearts project.
abstract: OBJECTIVE
  To examine secular trends in blood pressure over a 10 year period between two representative cohorts of adolescents from Northern Ireland.
  
  
  METHODS
  Repeat cross sectional study.
  
  
  METHODS
  Randomly selected post-primary schools from Northern Ireland.
  
  
  METHODS
  1015 adolescents studied between 1989 and 1990, and 2017 adolescents studied between 1999 and 2001. Participants were aged 12 or 15 years.
  
  
  METHODS
  Systolic and diastolic blood pressure measured by one observer in each study.
  
  
  RESULTS
  The four groups for sex and age showed decreases in both systolic blood pressure (mean decrease 7.7 mm Hg to 10.0 mm Hg) and diastolic blood pressure (8.8 mm Hg to 11.0 mm Hg). These decreases were not accounted for by adjustment for potential confounders including age, height, body mass index, smoking, physical activity, aerobic fitness, and stratification of school by education board area and type. The findings were not altered by additional adjustment for social class, pubertal status, birth weight, and infant feeding. No evidence was found of systematic variation between observers.
  
  
  CONCLUSIONS
  Substantial decreases in systolic and diastolic blood pressure over the past decade in adolescents from Northern Ireland are likely to have important benefits to public health and may help offset the increasing risk of cardiovascular disease due to increases in obesity.
authors.affiliation: Department of Child Health, Queens University of Belfast, Institute of Clinical Science, Royal Victoria Hospital, Belfast BT12 6JB. david.watkins@stockport-tr.nwest.nhs.uk
authors.forename: David
authors.initials: D
authors.lastname: Watkins
authors.forename: Peter
authors.initials: P
authors.lastname: McCarron
authors.forename: Liam
authors.initials: L
authors.lastname: Murray
authors.forename: Gordon
authors.initials: G
authors.lastname: Cran
authors.forename: Colin
authors.initials: C
authors.lastname: Boreham
authors.forename: Paula
authors.initials: P
authors.lastname: Robson
authors.forename: Claire
authors.initials: C
authors.lastname: McGartland
authors.forename: George
authors.initials: G
authors.lastname: Davey Smith
authors.forename: Maurice
authors.initials: M
authors.lastname: Savage
mesh_terms: D000293:Adolescent; D001794:Blood Pressure; D016009:Chi-Square Distribution; D002648:Child; D003430:Cross-Sectional Studies; D003971:Diastole; D005260:Female; D006801:Humans; D008297:Male; D009660:Northern Ireland; D015588:Observer Variation; D012044:Regression Analysis; D013599:Systole; D013997:Time Factors