title: Physical activity and bone mineral accrual in boys with different body mass parameters during puberty: a longitudinal study.
abstract: The aim of our longitudinal study was to investigate the relationships between physical activity and bone mass in boys with different body mass status during the years surrounding pubertal growth spurt. Two hundred and six boys entering puberty took part in this study. The subjects were divided into underweight (BMI < 15.35), normal weight (BMI ≥ 15.35-21.22), overweight (BMI ≥ 21.22-26.02) and obese (BMI > 26.02) groups at baseline according to age related categories. Whole-body DXA scans were performed at baseline, after 12 and 24 months to assess body composition (lean body mass, fat mass), and total body (TB), lumbar spine (LS) and femoral neck (FN) bone mineral density (BMD) parameters. Physical activity was measured by 7-day accelerometry. For longitudinal analysis, multilevel fixed effects regression models were constructed. Biological age, height and lean body mass had an effect for explanation of TB BMD, FN BMD and LS BMD. Moderate to vigorous physical activity (MVPA), vigorous physical activity (VPA) and sedentary time (SED) had the significant effect only on FN BMD. Being an underweight boy at the baseline indicated greater chance (p<0.01) to have lower TB BMD in the future (2 years at follow up) development, compared to normal weight (estimates = -0.038), overweight (estimates = -0.061) and obese boys (estimates = -0.106).
authors.affiliation: Institute of Sport Pedagogy and Coaching Sciences, Faculty of Exercise and Sport Sciences, Centre of Behavioral, Social and Health Sciences, University of Tartu, Tartu, Estonia.
authors.forename: Donvina
authors.initials: D
authors.lastname: Vaitkeviciute
authors.affiliation: Institute of Sport Pedagogy and Coaching Sciences, Faculty of Exercise and Sport Sciences, Centre of Behavioral, Social and Health Sciences, University of Tartu, Tartu, Estonia.
authors.forename: Evelin
authors.initials: E
authors.lastname: Lätt
authors.affiliation: Institute of Sport Pedagogy and Coaching Sciences, Faculty of Exercise and Sport Sciences, Centre of Behavioral, Social and Health Sciences, University of Tartu, Tartu, Estonia.
authors.forename: Jarek
authors.initials: J
authors.lastname: Mäestu
authors.affiliation: Institute of Sport Pedagogy and Coaching Sciences, Faculty of Exercise and Sport Sciences, Centre of Behavioral, Social and Health Sciences, University of Tartu, Tartu, Estonia.
authors.forename: Toivo
authors.initials: T
authors.lastname: Jürimäe
authors.affiliation: Institute of Sport Pedagogy and Coaching Sciences, Faculty of Exercise and Sport Sciences, Centre of Behavioral, Social and Health Sciences, University of Tartu, Tartu, Estonia.
authors.forename: Meeli
authors.initials: M
authors.lastname: Saar
authors.affiliation: Institute of Sport Pedagogy and Coaching Sciences, Faculty of Exercise and Sport Sciences, Centre of Behavioral, Social and Health Sciences, University of Tartu, Tartu, Estonia.
authors.forename: Priit
authors.initials: P
authors.lastname: Purge
authors.affiliation: Department of Traumatology and Orthopedics, Faculty of Medicine, University of Tartu, Tartu, Estonia.
authors.forename: Katre
authors.initials: K
authors.lastname: Maasalu
authors.affiliation: Institute of Sport Pedagogy and Coaching Sciences, Faculty of Exercise and Sport Sciences, Centre of Behavioral, Social and Health Sciences, University of Tartu, Tartu, Estonia.
authors.forename: Jaak
authors.initials: J
authors.lastname: Jürimäe
mesh_terms: D001823:Body Composition; D015992:Body Mass Index; D001835:Body Weight; D015519:Bone Density; D002648:Child; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009043:Motor Activity; D011627:Puberty