title: Aerobic capacity related to cardiac size in young children.
abstract: OBJECTIVE
  Aerobic capacity, defined as peak oxygen uptake (VO2PEAK), is generally considered to be the best single marker for aerobic fitness. We assessed if VO2PEAK is related to different cardiac dimensions in healthy young children on a population base.
  
  
  METHODS
  In a cross-sectional study, 245 children (137 boys and 108 girls) aged 8-11 years, were recruited from a population based cohort. VO2PEAK (ml/min-1/kg-1) was assessed by indirect calorimetry during a maximal exercise test. DXA-scan was used to measure lean body mass (LBM) and total fat mass (TBF). Echocardiography, with 2-dimensional guided M-mode, was performed in accordance with current guidelines. Left ventricular end-diastolic diameter (LVDD) and left atrial end-systolic diameter (LA) were measured, and left ventricular mass (LVM) was calculated.
  
  
  RESULTS
  Univariate correlations were found between VO2PEAK versus LVDD r=0.44 and LA r=0.27 (both P<0.05) and LVM r=-0.06 (NS) in boys. Corresponding values for girls were; 0.55, 0.34 (both P<0.05) and 0.11 (NS). Multiple regression analysis with VO2PEAK as dependent variable and inclusion of LBM, TBF, sex, age, Tanner stage, and maximal heart rate as independent variables showed that 67% of the total variance of VO2PEAK could be explained by these variables. Including LVDD or LA in the model, added 1% additional explained variance.
  
  
  CONCLUSIONS
  Findings from this population based cohort of young healthy children show that multiple cardiac dimensions at rest are related to VO2PEAK. However, the different cardiac dimensions contributed very little to the added explained variance of VO2PEAK.
authors.affiliation: Unit of Clinical Physiology and Nuclear Medicine Department of Clinical Sciences, Skåne University Hospital Lund University, Malmö, Sweden. magnus.dencker@skane.se
authors.forename: M
authors.initials: M
authors.lastname: Dencker
authors.forename: P
authors.initials: P
authors.lastname: Wollmer
authors.forename: M K
authors.initials: MK
authors.lastname: Karlsson
authors.forename: L B
authors.initials: LB
authors.lastname: Andersen
authors.forename: O
authors.initials: O
authors.lastname: Thorsson
mesh_terms: D002153:Calorimetry, Indirect; D002648:Child; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004452:Echocardiography; D005080:Exercise Test; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging*; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*