title: Sexual dimorphism of body composition and insulin sensitivity across pubertal development in obese Caucasian subjects.
abstract: Background Puberty is a period of rapid growth associated with metabolic, hormonal, and body composition changes that can influence risk factors for chronic diseases such as type 2 diabetes. Objective To evaluate body composition and insulin sensitivity (IS) modifications throughout puberty in a large group of obese Caucasian subjects. Methods Five hundred and nineteen obese subjects (4-19 years), grouped according to gender and Tanner stage (T), underwent oral glucose tolerance test. Quantitative insulin check index (QUICKI) and ISI were calculated as indexes of IS. In 309 subjects, body composition by dual-energy X-ray absorptiometry, IGF1, adiponectin, and leptin were also evaluated. Results Body composition modifications were sexually dimorphic, with girls not modifying fat and lean percentage and fat distribution (P>0.15), and boys decreasing fat percentage and increasing lean percentage and central fat depot (P<0.001) across Ts. IS decreased during mid-puberty and returned to prepubertal levels by the end of puberty. Girls showed lower IS than boys (P<0.01 and =0.03 for QUICKI and ISI respectively). In multivariate analysis factors that negatively influenced IS, independently from T or age, were total fat mass and central fat depot in girls (P<0.05 and <0.01, respectively), total fat and lean mass in boys (P<0.01). IGF1, adiponectin, and leptin were not related to pubertal IS. Conclusions In obese Caucasian subjects, further decrease of IS observed during puberty is a transient phenomenon. Factors that independently from T or age influence IS are central fat depot in girls, lean amount in boys, and total fat mass in both sexes.
authors.affiliation: Endocrinology and Diabetes Unit, Department of Paediatric Medicine, Bambino Gesù Children's Hospital-IRCCS, Piazza S. Onofrio 4, 00165 Rome, Italy. cbrufani@libero.it
authors.forename: Claudia
authors.initials: C
authors.lastname: Brufani
authors.forename: Alberto
authors.initials: A
authors.lastname: Tozzi
authors.forename: Danilo
authors.initials: D
authors.lastname: Fintini
authors.forename: Paolo
authors.initials: P
authors.lastname: Ciampalini
authors.forename: Armando
authors.initials: A
authors.lastname: Grossi
authors.forename: Rossana
authors.initials: R
authors.lastname: Fiori
authors.forename: Daniela
authors.initials: D
authors.lastname: Kiepe
authors.forename: Melania
authors.initials: M
authors.lastname: Manco
authors.forename: Riccardo
authors.initials: R
authors.lastname: Schiaffini
authors.forename: Ottavia
authors.initials: O
authors.lastname: Porzio
authors.forename: Marco
authors.initials: M
authors.lastname: Cappa
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Barbetti
mesh_terms: D052242:Adiponectin / Q000097:blood; D000293:Adolescent; D041923:Adolescent Development / Q000502:physiology; D001823:Body Composition / Q000502:physiology*; D002648:Child; D002657:Child Development / Q000502:physiology; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D020738:Leptin / Q000097:blood; D008297:Male; D009765:Obesity / Q000097:blood / Q000208:ethnology / Q000378:metabolism* / Q000503:physiopathology; D011627:Puberty / Q000378:metabolism* / Q000502:physiology; D012727:Sex Characteristics; D044465:White People; D055815:Young Adult
chemical_list: C499918:ADIPOQ protein, human; D052242:Adiponectin; D020738:Leptin; D007334:Insulin-Like Growth Factor I