title: Heart rate recovery is associated with obesity traits and related cardiometabolic risk factors in children and adolescents.
abstract: OBJECTIVE
  Increased vagal activity is associated with obesity and metabolic risk in children and adolescents. The aim of the present cross-sectional study was to examine the association of parasympathetic function, as assessed by heart rate recovery (HRR) from a maximal exercise cycle-ergometer test, with obesity traits and related cardiometabolic risk factors in Spanish children and adolescents.
  
  
  RESULTS
  A sample of 437 Spanish 9-year-old-children and 235 15-year-old-adolescents participated in the study. The variables measured were anthropometric characteristics (height, body mass and waist circumference) and physical activity using the Actigraph accelerometer. Additional measured outcomes included fasting insulin, triglycerides, high-density lipoprotein cholesterol (HDLc) and blood pressure. A metabolic risk score was computed as the mean of the standardised outcomes scores. The HRR was calculated as the difference between peak heart rate and heart rate 1, 3 and 5 min after cessation of the maximal ergometer test. Diastolic blood pressure was associated with all the HRR parameters in 9-year-old-girls. In 9-year-old-boys, the 3-min HRR was inversely associated with systolic blood pressure (p < 0.05) and Homeostasis Model Assessment (HOMA) (p < 0.05). Five minute HRR was inversely associated with waist circumference (p < 0.05), sum of five skinfolds (p < 0.01) and HOMA (p = 0.004). There were no significant associations in adolescents. In 9-year-old-girls, the adjusted 5-min HRR showed significant differences between quartile 2 and 4 of metabolic risk (p = 0.011). In all samples, the adjusted HRR (1-, 3- and 5-min HRR) did not show significant differences across quartiles.
  
  
  CONCLUSIONS
  HRR was inversely associated with obesity traits and related cardiometabolic risk factors mainly in healthy boys.
authors.affiliation: PAFS-UCLM Research Group, Faculty of Sports Sciences, University of Castilla-La Mancha, Avda. Carlos III, s/n. 45071, Toledo, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Laguna
authors.forename: S
authors.initials: S
authors.lastname: Aznar
authors.forename: M T
authors.initials: MT
authors.lastname: Lara
authors.forename: A
authors.initials: A
authors.lastname: Lucía
authors.forename: J R
authors.initials: JR
authors.lastname: Ruiz
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D001341:Autonomic Nervous System / Q000502:physiology / Q000503:physiopathology; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000378:metabolism / Q000503:physiopathology*; D002648:Child; D002652:Child Behavior; D003430:Cross-Sectional Studies; D005080:Exercise Test; D005260:Female; D006339:Heart Rate; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D008659:Metabolic Diseases / Q000453:epidemiology / Q000378:metabolism / Q000503:physiopathology*; D009043:Motor Activity; D009765:Obesity / Q000453:epidemiology / Q000378:metabolism / Q000503:physiopathology*; D010275:Parasympathetic Nervous System / Q000502:physiology / Q000503:physiopathology*; D012307:Risk Factors; D012727:Sex Characteristics; D013030:Spain / Q000453:epidemiology; D055105:Waist Circumference