title: Systolic and fourth- and fifth-phase diastolic blood pressure from ages 8 to 18 years: Project HeartBeat!
abstract: BACKGROUND
  Systolic and fourth-phase and fifth-phase diastolic blood pressure (SBP, DBP4, DBP5) have appeared to differ in their patterns of age-related change, and SBP and DBP5 differ in their respective associations with anthropometric variables. Project HeartBeat! investigated trajectories of change in SBP, DBP4, and SBP5 with age and their relationships with indices of adiposity, controlling for energy intake, physical activity, and sexual maturation.
  
  
  METHODS
  Project HeartBeat! was a mixed longitudinal study in 678 black and white girls and boys aged 8, 11, or 14 years at first examination, followed at 4-month intervals for up to 4 years (1991-1995). A statistical model was estimated for the trajectory of change in each blood pressure measure from ages 8 to 18 years.
  
  
  RESULTS
  For SBP, DBP4, and DBP5, the trajectories were sigmoid, parabolic, and linear in form, respectively. SBP and DBP4 differed significantly by gender; DBP4 and DBP5 were significantly related to race. Adjusted for age, gender, and race, all relationships of adiposity-related variables (percent body fat, abdominal circumference, skinfold thickness, and BMI and its fat and fat-free components) with SBP were positive and significant. Corresponding relationships for DBP4 were notably weaker but significant, and for DBP5, weak or not significant. After adjusting for diet, physical inactivity, and maturation, no DBP5 relationship with adiposity indices remained significant.
  
  
  CONCLUSIONS
  SBP, DBP4, and DBP5 are distinct in patterns of change with age, relationships to gender and race, and patterns of association with multiple anthropometric indices related to adiposity.
authors.affiliation: Division for Heart Disease and Stroke Prevention, CDC, 4770 Buford Highway NE, Atlanta, GA 30341-3724, USA. dlabarthe@cdc.gov
authors.forename: Darwin R
authors.initials: DR
authors.lastname: Labarthe
authors.forename: Shifan
authors.initials: S
authors.lastname: Dai
authors.forename: Janet E
authors.initials: JE
authors.lastname: Fulton
authors.forename: Ronald B
authors.initials: RB
authors.lastname: Harrist
authors.forename: Syed M
authors.initials: SM
authors.lastname: Shah
authors.forename: Mona A
authors.initials: MA
authors.lastname: Eissa
mesh_terms: D000273:Adipose Tissue / Q000502:physiology; D050154:Adiposity / Q000502:physiology*; D000293:Adolescent; D000367:Age Factors; D044383:Black People / Q000706:statistics & numerical data; D001794:Blood Pressure / Q000502:physiology*; D015992:Body Mass Index; D002648:Child; D003971:Diastole; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D015233:Models, Statistical; D012737:Sex Factors; D012885:Skinfold Thickness; D013599:Systole; D013781:Texas; D055105:Waist Circumference; D044465:White People / Q000706:statistics & numerical data; D001741:Black or African American