title: Relative Skeletal Maturation and Population Ancestry in Nonobese Children and Adolescents.
abstract: More rapid skeletal maturation in African-American (AA) children is recognized and generally attributed to an increased prevalence of obesity. The objective of the present study was to evaluate the effects of population ancestry on relative skeletal maturation in healthy, non-obese children and adolescents, accounting for body composition and sexual maturation. To do this, we leveraged a multiethnic, mixed-longitudinal study with annual assessments for up to 7 years (The Bone Mineral Density in Childhood Study and its ancillary cohort) conducted at five US clinical centers. Participants included 1592 children, skeletally immature (45% females, 19% AA) who were aged 5 to 17 years at study entry. The primary outcome measure was relative skeletal maturation as assessed by hand-wrist radiograph. Additional covariates measured included anthropometrics, body composition by dual-energy X-ray absorptiometry (DXA), and Tanner stage of sexual maturation. Using mixed effects longitudinal models, without covariates, advancement in relative skeletal maturation was noted in self-reported AA girls (∼0.33 years, p < 0.001) and boys (∼0.43 years, p < 0.001). Boys and girls of all ancestry groups showed independent positive associations of height, lean mass, fat mass, and puberty with relative skeletal maturation. The effect of ancestry was attenuated but persistent after accounting for covariates: for girls, 0.19 years (ancestry by self-report, p = 0.02) or 0.29 years (ancestry by admixture, p = 0.004); and for boys, 0.20 years (ancestry by self-report, p = 0.004), or 0.29 years (ancestry by admixture, p = 0.004). In summary, we conclude that advancement in relative skeletal maturation was associated with AA ancestry in healthy, non-obese children, independent of growth, body composition, and puberty. Further research into the mechanisms underlying this observation may provide insights into the regulation of skeletal maturation. © 2016 American Society for Bone and Mineral Research.
authors.affiliation: Division of Endocrinology and Diabetes, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.|Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Shana E
authors.initials: SE
authors.lastname: McCormack
authors.affiliation: Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Chesi
authors.affiliation: Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.|Division of Gastroenterology, Hepatology, and Nutrition, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Mitchell
authors.affiliation: Division of Endocrinology and Diabetes, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Sani M
authors.initials: SM
authors.lastname: Roy
authors.affiliation: Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Diana L
authors.initials: DL
authors.lastname: Cousminer
authors.affiliation: Division of Gastroenterology, Hepatology, and Nutrition, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Heidi J
authors.initials: HJ
authors.lastname: Kalkwarf
authors.affiliation: Division of Endocrinology, Department of Medicine, Creighton University, Omaha, NE, USA.
authors.forename: Joan M
authors.initials: JM
authors.lastname: Lappe
authors.affiliation: Department of Radiology, Children's Hospital Los Angeles, Los Angeles, CA, USA.
authors.forename: Vicente
authors.initials: V
authors.lastname: Gilsanz
authors.affiliation: Division of Pediatric Endocrinology, Diabetes, and Metabolism, Department of Pediatrics, Columbia University Medical Center, New York, NY, USA.
authors.forename: Sharon E
authors.initials: SE
authors.lastname: Oberfield
authors.affiliation: Department of Radiology, University of California San Francisco, San Francisco, CA, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Shepherd
authors.affiliation: Department of Radiology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Soroosh
authors.initials: S
authors.lastname: Mahboubi
authors.affiliation: Pediatric Growth and Nutrition Branch (PGNB), Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, USA.
authors.forename: Karen K
authors.initials: KK
authors.lastname: Winer
authors.affiliation: Division of Endocrinology and Diabetes, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.|Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Andrea
authors.initials: A
authors.lastname: Kelly
authors.affiliation: Division of Endocrinology and Diabetes, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.|Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.|Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Struan Fa
authors.initials: SF
authors.lastname: Grant
authors.affiliation: Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.|Division of Gastroenterology, Hepatology, and Nutrition, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Babette S
authors.initials: BS
authors.lastname: Zemel
mesh_terms: D000293:Adolescent; D000365:Age Determination by Skeleton; D017677:Age Distribution; D001823:Body Composition; D001827:Body Height; D015992:Body Mass Index; D001846:Bone Development; D002648:Child; D002675:Child, Preschool; D005260:Female; D005828:Genetics, Population; D006801:Humans; D008297:Male; D009765:Obesity / Q000453:epidemiology*; D044469:Racial Groups; D012044:Regression Analysis; D012741:Sexual Maturation; D055815:Young Adult
keywords: BONE AGE; GROWTH; PEDIATRIC ENDOCRINOLOGY; POPULATION ANCESTRY; SKELETAL MATURATION