title: Associations between adiposity, hormones, and gains in height, whole-body height-adjusted bone size, and size-adjusted bone mineral content in 8- to 11-year-old children.
abstract: We examined fat-independent associations of hormones with height and whole-body bone size and mineral content in 633 school children. IGF-1 and osteocalcin predict growth in height, while fat, osteocalcin, and in girls also, IGF-1 predict growth in bone size. Leptin and ghrelin are inversely associated with bone size in girls.
  
  
  BACKGROUND
  Obesity causes larger bone size and bone mass, but the role of hormones in this up-regulation of bone in obesity is not well elucidated. We examined longitudinal associations between baseline body fat mass (FM), and fat-independent fasting levels of ghrelin, adiponectin, leptin, insulin, insulin-like growth factor-I (IGF-1), osteocalcin, and intact parathyroid hormone, and subsequent changes in height and in whole-body height-adjusted bone area "BAheight" and size-adjusted bone mineral content "BMCsize" in 8- to 11-year-olds.
  
  
  METHODS
  Analyses were carried out separately for boys (n = 325) and girls (n = 308) including data from baseline, 3 and 6 months from OPUS School Meal Study.
  
  
  RESULTS
  In both sexes: gain in BAheight was positively associated with baseline FM (≥2.05 cm(2)/kg, both p ≤ 0.003). Furthermore, gain in height was positively associated with baseline IGF-1 (≥0.02 cm/ng/ml, p = 0.001) and osteocalcin (≥0.13 cm/ng/ml, p ≤ 0.009); and gain in BAheight was positively associated with baseline osteocalcin (≥0.35 cm(2)/ng/ml, p ≤ 0.019). In girls only, gain in BAheight was also positively associated with baseline IGF-1 (0.06 cm(2)/ng/ml, p = 0.017) and inversely associated with both baseline ghrelin (-0.01 cm(2)/pg/ml, p = 0.001) and leptin (-1.21 cm(2)/μg/ml, p = 0.005). In boys, gain in BMCsize was positively associated with osteocalcin (0.18 g/ng/ml, p = 0.030).
  
  
  CONCLUSIONS
  This large longitudinal study suggests that in 8- to 11-year-old children, IGF-1 and osteocalcin predict growth in height, while FM, osteocalcin, and in girls also, IGF-1 predict growth in BAheight. Fat-independent inverse associations of leptin and ghrelin with BAheight in girls' are contrary to proposed growth-stimulating effects of leptin. Osteocalcin in boys predicts gain in BMCsize.
authors.affiliation: Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958, Frederiksberg C, Denmark. smdalskov@hotmail.com.
authors.forename: S
authors.initials: S
authors.lastname: Dalskov
authors.affiliation: Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958, Frederiksberg C, Denmark.
authors.forename: C
authors.initials: C
authors.lastname: Ritz
authors.affiliation: Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958, Frederiksberg C, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Larnkjær
authors.affiliation: Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958, Frederiksberg C, Denmark.
authors.forename: C T
authors.initials: CT
authors.lastname: Damsgaard
authors.affiliation: Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958, Frederiksberg C, Denmark.
authors.forename: R A
authors.initials: RA
authors.lastname: Petersen
authors.affiliation: Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958, Frederiksberg C, Denmark.
authors.forename: L B
authors.initials: LB
authors.lastname: Sørensen
authors.affiliation: MRC Epidemiology Unit, University of Cambridge School of Clinical Medicine, Cambridge, UK.
authors.forename: K K
authors.initials: KK
authors.lastname: Ong
authors.affiliation: Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958, Frederiksberg C, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Astrup
authors.affiliation: Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958, Frederiksberg C, Denmark.
authors.forename: K F
authors.initials: KF
authors.lastname: Michaelsen
authors.affiliation: Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958, Frederiksberg C, Denmark.
authors.forename: C
authors.initials: C
authors.lastname: Mølgaard
mesh_terms: D050154:Adiposity / Q000502:physiology*; D000886:Anthropometry / Q000379:methods; D001827:Body Height / Q000502:physiology*; D015519:Bone Density / Q000502:physiology*; D001846:Bone Development / Q000502:physiology; D002648:Child; D002657:Child Development / Q000502:physiology*; D002664:Child Nutritional Physiological Phenomena / Q000502:physiology; D005260:Female; D005522:Food Services; D054439:Ghrelin / Q000097:blood; D006728:Hormones / Q000097:blood*; D006801:Humans; D007328:Insulin / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D020738:Leptin / Q000097:blood; D008137:Longitudinal Studies; D062409:Lunch; D008297:Male; D015675:Osteocalcin / Q000097:blood; D012574:Schools; D012727:Sex Characteristics; D012741:Sexual Maturation / Q000502:physiology
chemical_list: D054439:Ghrelin; D006728:Hormones; D007328:Insulin; D020738:Leptin; D015675:Osteocalcin; D007334:Insulin-Like Growth Factor I
keywords: Bone area; Children; Ghrelin; IGF-1; Leptin; Osteocalcin