title: Scaling left ventricular mass in adolescent boys aged 11-15 years.
abstract: BACKGROUND
  Normalizing left ventricular mass (LVM) for inter-individual variation in body size is a central issue in human biology. During the adolescent growth spurt, variability in body size descriptors needs to be interpreted in combination with biological maturation.
  
  
  OBJECTIVE
  To examine the contribution of biological maturation, stature, sitting height, body mass, fat-free mass (FFM) and fat mass (FM) to inter-individual variability in LVM in boys, using proportional allometric modelling.
  
  
  METHODS
  The cross-sectional sample included 110 boys of 11-15 years (12.9-1.0 years). Stature, sitting height, body mass, cardiac chamber dimensions and LVM were measured. Age at peak height velocity (APHV) was predicted and used as an indicator of biological maturation. Percentage fat was estimated from triceps and subscapular skinfolds; FM and FFM were derived.
  
  
  RESULTS
  Exponents for body size descriptors were k = 2.33 for stature, k = 2.18 for sitting height, k = 0.68 for body mass, k = 0.17 for FM and k = 0.80 for FFM (adjusted R(2 )= 19-62%). The combination of body descriptors and APHV increased the explained variance in LVM (adjusted R(2)( )= 56-69%).
  
  
  CONCLUSIONS
  Stature, FM and FFM are the best combination for normalizing LVM in adolescent boys; when body composition is not available, an indicator of biological maturity should be included with stature.
authors.affiliation: Faculty of Sport Sciences and Physical Education, University of Coimbra , Coimbra , Portugal .
authors.forename: João
authors.initials: J
authors.lastname: Valente-Dos-Santos
authors.forename: Manuel J
authors.initials: MJ
authors.lastname: Coelho-E-Silva
authors.forename: António
authors.initials: A
authors.lastname: Ferraz
authors.forename: Joaquim
authors.initials: J
authors.lastname: Castanheira
authors.forename: Enio R
authors.initials: ER
authors.lastname: Ronque
authors.forename: Lauren B
authors.initials: LB
authors.lastname: Sherar
authors.forename: Marije T
authors.initials: MT
authors.lastname: Elferink-Gemser
authors.forename: Robert M
authors.initials: RM
authors.lastname: Malina
mesh_terms: D000293:Adolescent; D049628:Body Size; D001835:Body Weight; D002648:Child; D003430:Cross-Sectional Studies; D006321:Heart / Q000033:anatomy & histology*; D006352:Heart Ventricles / Q000254:growth & development*; D006801:Humans; D008297:Male; D011174:Portugal; D012741:Sexual Maturation
keywords: Allometry; echocardiography; growth; maturation; youth