title: Trends in blood pressure in 9 to 11-year-old children in the United Kingdom 1980-2008:  the impact of obesity.
abstract: OBJECTIVE
  High blood pressure (BP) is a major public health issue, both in the United Kingdom and worldwide. Although BP levels in UK adults are declining, there is little published information on BP trends in children, a particular concern in the context of the rising levels of childhood adiposity. Our aims are to determine whether BP in children has changed over time and whether the change reflected trends in adiposity.
  
  
  METHODS
  We collated data from seven population-based BP studies conducted in the United Kingdom between 1980 and 2008. Children of white European origin were included (9-11 years, mean 10.3 years). Adjustments were made to account for differences in mean ages, BP devices and cuff sizes used in different studies.
  
  
  RESULTS
  Mean SBP increased over time both in boys and girls: annual increases were 0.45 mmHg (95% CI: 0.43, 0.48) for boys; 0.51 mmHg (0.49, 0.53) for girls. Mean BMI increased by 0.064 kg/m(2) (0.060, 0.068) per year for boys; 0.070 kg/m(2) (0.065, 0.074) for girls; the prevalence of overweight/obesity increased from 5.7 to 21.1% and from 9.7 to 24.1%, respectively. The SBP trends occurred both in children with low and high BMI, but were more marked in low BMI group; BMI explained only 15.3% (15.1%, 15.6%) of increases in SBP for boys and 14.9% (14.6%, 15.1%) for girls. The BMI/SBP association appeared to become weaker over time (P < 0.001 for negative interaction from 1984). There was only a modest annual increase in DBP (<0.1 mmHg).
  
  
  CONCLUSIONS
  SBP levels have increased with time, but the increase is not explained by increased BMI. Further research is needed to identify the factors responsible.
authors: Centre for Paediatric Epidemiology & Biostatistics/MRC Centre of Epidemiology for Child Health, UCL Institute of Child Health, London, UK.
authors: Helen
authors: H
authors: Peters
authors: Peter H
authors: PH
authors: Whincup
authors: Derek G
authors: DG
authors: Cook
authors: Catherine
authors: C
authors: Law
authors: Leah
authors: L
authors: Li
mesh_terms: D001794:Blood Pressure; D015992:Body Mass Index; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000503:physiopathology*; D006113:United Kingdom; D044465:White People