title: Temporal stability of ambulatory blood pressure and heart rate in youths.
abstract: BACKGROUND
  The use of ambulatory blood pressure monitoring for pediatric populations is increasing.
  
  
  OBJECTIVE
  ; To determine the 2-year stability of ambulatory blood pressure in youths.
  
  
  METHODS
  We evaluated 2-year stabilities of resting and ambulatory blood pressures in 197 youths (aged 13.9+/-2.3 years at initial evaluation). Readings were taken every 20 min during the daytime (0800-2200 h) and every 30 min at night (0000-0600 h).
  
  
  RESULTS
  Daytime and night-time systolic blood pressure increased (P < 0.01 for both) as did resting systolic blood pressure (P < 0.05). Measures of diastolic blood pressure did not change. Changes in systolic blood pressure were related to changes in body size. Estimates of stability for resting and ambulatory measurements were similar, ranging from 0.65 to 0.75. In addition, correlation coefficients for relationships between first and second readings for resting and ambulatory measurements were similar ranging from 0.43 and for resting heart rate to 0.72 for 24h systolic blood pressure (P < 0. 001 for each). The only significant correlation between change scores for resting and ambulatory values was that between resting and night-time diastolic blood pressures (r = 0.33, P < 0.001).
  
  
  CONCLUSIONS
  Measures of blood pressure derived from ambulatory blood pressure monitoring reflect changes in blood pressure in youths at least as well as do changes in resting blood pressure despite the high degree of variability in levels of physical activity and affective states of the children during the ambulatory recordings.
authors.affiliation: Department of Pediatrics, Medical College of Georgia, Augusta, Georgia 30912-3710, USA. hgarshfi@mcg.edu
authors.forename: G A
authors.initials: GA
authors.lastname: Harshfield
authors.forename: F A
authors.initials: FA
authors.lastname: Treiber
authors.forename: H
authors.initials: H
authors.lastname: Davis
authors.forename: M
authors.initials: M
authors.lastname: Johnson
authors.forename: G A
authors.initials: GA
authors.lastname: Slavens
authors.forename: W
authors.initials: W
authors.lastname: Thompson
mesh_terms: D000293:Adolescent; D001794:Blood Pressure; D018660:Blood Pressure Monitoring, Ambulatory; D006339:Heart Rate; D006801:Humans