title: Determinants of bone mineral density, bone mineral content, and body composition in a cohort of healthy children: influence of sex, age, puberty, and physical activity.
abstract: Interventions directed to the recognition of abnormal bone mineral density, bone mineral content, and body composition in the pediatric age require the definition of factors influencing bone mass acquisition during growth. We have evaluated in a cross-sectional manner by dual-energy X-ray absorptiometry the impact of sex, age, puberty, and physical activity on total body areal bone mineral density, regional (lumbar and femoral) bone mineral densities, bone mineral content, and body composition (fat mass and lean mass) in a cohort of 359 healthy Italian children aged 3-14 years and investigated their specific contribution to bone mass accrual. Statistical multiple regression analysis was performed dividing the population in pre- and post-pubertal groups. Bone mineral density at the lumbar spine has resulted equally distributed in both sexes before puberty while has resulted higher at the femoral necks in males at whatever age. A significant effect on bone mass acquisition was exerted by male sex and lean mass. In the areas where the cortical bone is prevalent, males of the pre-pubertal group have presented the highest values; in the areas where the cancellous bone is prevalent, both sexes were equivalent until the age of 9 years, but after this age, females have presented higher increases, probably related to the inferior dimensional development of lumbar vertebrae. Conclusively, male sex and lean mass seem to represent independent predictors of bone mass accrual in the cortical bone of the examined children, while female sex and pubertal maturation are independent predictors of bone mass accrual in the trabecular bone.
authors.affiliation: Department of Pediatric Sciences, Università Cattolica Sacro Cuore, Largo A. Gemelli 8, 00165 Rome, Italy. emanuele.ausili@tin.it
authors.forename: Emanuele
authors.initials: E
authors.lastname: Ausili
authors.forename: Donato
authors.initials: D
authors.lastname: Rigante
authors.forename: Elio
authors.initials: E
authors.lastname: Salvaggio
authors.forename: Benedetta
authors.initials: B
authors.lastname: Focarelli
authors.forename: Claudia
authors.initials: C
authors.lastname: Rendeli
authors.forename: Valentina
authors.initials: V
authors.lastname: Ansuini
authors.forename: Valentina
authors.initials: V
authors.lastname: Paolucci
authors.forename: Silvia
authors.initials: S
authors.lastname: Triarico
authors.forename: Lucilla
authors.initials: L
authors.lastname: Martini
authors.forename: Paolo
authors.initials: P
authors.lastname: Caradonna
mesh_terms: D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000502:physiology; D000293:Adolescent; D000367:Age Factors; D001823:Body Composition / Q000502:physiology*; D015519:Bone Density / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D005272:Femur Neck / Q000502:physiology; D006801:Humans; D007558:Italy; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D011627:Puberty / Q000502:physiology*; D012737:Sex Factors; D013223:Statistics as Topic