title: Body composition trajectories into adolescence according to age at pubertal growth spurt.
abstract: OBJECTIVE
  To investigate whether the development of body composition into adolescence differs among children with an early, average, or late pubertal growth spurt (age at take-off [ATO]).
  
  
  METHODS
  Mixed-effect polynomial models were applied to serial anthropometric measurements spanning from 4 years before to 4 years after ATO in 215 DONALD participants. Sex-specific trajectories of fat mass index (FMI, FM/m(2) ), fat-free mass index (FFMI, FFM/m(2) ), and their z-scores were compared among those with an early, average, or late ATO.
  
  
  RESULTS
  Compared with girls with a late ATO (reference group), those with an early or average ATO experienced a significant increase in FFMI z-scores [β (standard error) for linear trends in early and average ATO group: +0.15 (0.05) FFMI z-scores/year (P = 0.001) and +0.11 (0.04) FFMI z-scores/year (P = 0.005), respectively, adjusted for early life factors]. Similar differences were observed in boys [adjusted β (standard error): +0.20 (0.06) FFMI z-scores/year (P = 0.0004) and +0.07 (0.05) FFMI z-scores/year (P = 0.1), respectively]. Graphical illustration of the predicted trajectories revealed that differences in relative FFMI emerged from ATO onward. For FMI, comparison with late maturers showed a more pronounced quadratic trend (kg/m(2) /years(2) ) (P = 0.01) among early-maturing girls and a reduced linear trend in FMI z-scores/year (P = 0.04) among early-maturing boys.
  
  
  CONCLUSIONS
  This longitudinal study suggests that children who experience an early pubertal growth spurt accrue progressively more fat-free mass during the first years of puberty than late-maturing peers of the same age. Higher levels of adiposity commonly observed in adults with early puberty onset are, thus, likely to develop subsequently in later adolescence.
authors.affiliation: Department of Nutrition and Health, Research Institute of Child Nutrition, Rheinische Friedrich-Wilhelms-Universität Bonn, Dortmund, Germany. buyken@fke-do.de
authors.forename: Anette E
authors.initials: AE
authors.lastname: Buyken
authors.forename: Katja
authors.initials: K
authors.lastname: Bolzenius
authors.forename: Nadina
authors.initials: N
authors.lastname: Karaolis-Danckert
authors.forename: Anke L B
authors.initials: AL
authors.lastname: Günther
authors.forename: Anja
authors.initials: A
authors.lastname: Kroke
mesh_terms: D000293:Adolescent; D041923:Adolescent Development; D000328:Adult; D000367:Age Factors; D001823:Body Composition; D015992:Body Mass Index; D002648:Child; D002657:Child Development; D005260:Female; D005858:Germany; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D015233:Models, Statistical; D011446:Prospective Studies; D011627:Puberty; D012737:Sex Factors