title: Circadian and ultradian cardiovascular rhythmicity in obese children.
abstract: Altered circadian and ultradian blood pressure (BP) and heart rate (HR) rhythmicity have been described in diseases with increased cardiovascular risk. We analyzed cardiovascular rhythmicity in obese children. BP and HR rhythmicity was assessed with Fourier analysis from 24-h ambulatory BP measurements in 75 obese children and compared with an age- and gender-matched, lean healthy reference group of 150 subjects. Multivariate regression analysis was applied to identify significant independent factors explaining variability of rhythmicity. Prevalence of 24- and 6-h BP rhythmicity in the obese group was lower (p = 0.03 and p = 0.02), whereas the prevalence of HR rhythmicity was comparable in both groups. Excluding hypertensive participants, the results remained similar. Twenty-four-hour BP and HR acrophase were delayed in obese children (p = 0.004, p < 0.0001), 24-h BP amplitude did not differ (p = 0.07), and 24-h HR amplitude was blunted (p = < 0.0001). BP Mesor in the obese group was higher (p = 0.02); HR Mesor did not differ (p = 0.1). Multivariate regression analysis failed to identify a single anthropometric or blood pressure parameter explaining the variability of BP and HR rhythmicity.
  
  
  CONCLUSIONS
  Prevalence and parameters of circadian and ultradian BP and HR rhythmicity in obese children are altered compared to a healthy reference group, independent of preexisting hypertension.
  
  
  BACKGROUND
  • Altered cardiovascular rhythmicity has been described in children with different diseases such as primary hypertension or chronic renal failure. What is New: • This study reveals altered cardiovascular rhythmicity in obese children compared to an age and gender-matched healthy reference group independent from preexisting hypertension.
authors.affiliation: University Children's Hospital UKBB, Spitalstrasse 33, CH-4056, Basel, Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Saner
authors.affiliation: Division of Pediatric Nephrology, Department of Pediatrics, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse 15, CH-3010, Bern, Switzerland. giacomo.simonetti@eoc.ch.|Pediatric Department of Southern Switzerland, Via Ospedale, CH-6500, Bellinzona, Switzerland. giacomo.simonetti@eoc.ch.
authors.forename: Giacomo D
authors.initials: GD
authors.lastname: Simonetti
authors.affiliation: Center for Pediatrics and Adolescent Medicine, University of Heidelberg, Im Neuenheimer Feld 430, D-69120, Heidelberg, Germany.
authors.forename: Elke
authors.initials: E
authors.lastname: Wühl
authors.affiliation: Division of Pediatric Endocrinology, Diabetology and Metabolism, Department of Pediatrics, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse 15, CH- 3010, Bern, Switzerland.
authors.forename: Primus E
authors.initials: PE
authors.lastname: Mullis
authors.affiliation: Division of Pediatric Endocrinology, Diabetology and Metabolism, Department of Pediatrics, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse 15, CH- 3010, Bern, Switzerland.
authors.forename: Marco
authors.initials: M
authors.lastname: Janner
mesh_terms: D000293:Adolescent; D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory / Q000379:methods; D016022:Case-Control Studies; D002648:Child; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000209:etiology; D016014:Linear Models; D008297:Male; D063766:Pediatric Obesity / Q000503:physiopathology*; D012189:Retrospective Studies; D012307:Risk Factors; D018709:Statistics, Nonparametric; D000071218:Ultradian Rhythm / Q000502:physiology*
keywords: Blood pressure; Heart rate; Hypertension; Obesity; Rhythmicity