title: Secular trends in blood pressure among Japanese schoolchildren: a population-based annual survey from 1994 to 2010.
abstract: BACKGROUND
  Monitoring secular trends in blood pressure (BP) among children is important in predicting subsequent hypertension and cardiovascular disease. We investigated secular trends in BP using data from population-based annual screenings of Japanese schoolchildren.
  
  
  METHODS
  The participants were 10 894 children (all fourth graders between 1994 and 2010 and all seventh graders between 1997 and 2010) living in the town of Ina in Saitama Prefecture, Japan. Body height, weight, and BP were measured, after which children were classified as non-overweight, overweight, or obese. Trends in variables relative to calendar year were analyzed using regression models.
  
  
  RESULTS
  Systolic BP was significantly associated with calendar year among fourth- and seventh-grade boys (-0.350 and -0.434 mm Hg/year, respectively) and fourth- and seventh-grade girls (-0.513 and -0.473 mm Hg/year, respectively) (all P < 0.001), respectively, over time. Systolic BP and calendar year were significantly negatively correlated regardless of physique or sex among all fourth graders, but not among obese seventh-grade girls. In addition, diastolic BP and calendar year did not significantly correlate among seventh-grade overweight or obese boys or obese seventh-grade girls.
  
  
  CONCLUSIONS
  BP decreased among fourth-grade schoolchildren in Ina during the past 17 years, regardless of sex or physique. However, BP and calendar year did not significantly correlate among obese seventh graders.
authors.affiliation: Department of Public Health, Showa University School of Medicine, Tokyo, Japan. shirasawa@med.showa-u.ac.jp
authors.forename: Takako
authors.initials: T
authors.lastname: Shirasawa
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Ochiai
authors.forename: Rimei
authors.initials: R
authors.lastname: Nishimura
authors.forename: Aya
authors.initials: A
authors.lastname: Morimoto
authors.forename: Naoki
authors.initials: N
authors.lastname: Shimada
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Ohtsu
authors.forename: Hiromi
authors.initials: H
authors.lastname: Hoshino
authors.forename: Naoko
authors.initials: N
authors.lastname: Tajima
authors.forename: Akatsuki
authors.initials: A
authors.lastname: Kokaze
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D001794:Blood Pressure; D001835:Body Weight; D002648:Child; D005260:Female; D006306:Health Surveys; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology; D050177:Overweight / Q000175:diagnosis / Q000453:epidemiology; D012044:Regression Analysis; D017678:Sex Distribution