ORIGINAL ARTICLE 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 Emanuele Ausili • Donato Rigante • Elio Salvaggio • Benedetta Focarelli • Claudia Rendeli • Valentina Ansuini • Valentina Paolucci • Silvia Triarico • Lucilla Martini • Paolo Caradonna Received: 15 March 2011 / Accepted: 10 July 2011 / Published online: 2 August 2011 Ó Springer-Verlag 2011 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, pub- erty, and physical activity on total body areal bone mineral density, regional (lumbar and femoral) bone mineral den- sities, 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 tra- becular bone. Keywords Bone mineral density Á Bone mineral content Á Fat mass Á Lean mass Á Child Abbreviations BMD Bone mineral density BMC Bone mineral content DXA Dual-energy X-ray absorptiometry L/S Lumbar spine F/N Femoral neck Introduction The achievement of an optimal bone mass is widely rec- ognized as a primary healthy goal during childhood and adolescence: the process of bone mass acquisition occurs throughout the first phases of life and manifests itself through a balanced skeletal growth [1]. Despite the dif- ferent opinions concerning the exact period when the peak bone mass is reached, there is general agreement that the maximal accrual of bone mineral density (BMD) is acquired in the years surrounding puberty [2]. Therefore, it is essential to define which factors are capable of influ- encing BMD, bone mineral content (BMC), and body composition in childhood with the goal of optimizing the E. Ausili (&) Á D. Rigante (&) Á E. Salvaggio Á B. Focarelli Á C. Rendeli Á V. Ansuini Á V. Paolucci Á S. Triarico Á L. Martini Department of Pediatric Sciences, Universita ` Cattolica Sacro Cuore, Largo A. Gemelli 8, 00165 Rome, Italy e-mail: emanuele.ausili@tin.it D. Rigante e-mail: drigante@gmail.com P. Caradonna (&) Department of Internal Medicine, Universita ` Cattolica Sacro Cuore, Rome, Italy e-mail: pcaradonna@rm.unicatt.it 123 Rheumatol Int (2012) 32:2737–2743 DOI 10.1007/s00296-011-2059-8