Cross-sectional study of the association of body composition and physical fitness with bone status in children and adolescents from 11 to 16 years old.
BACKGROUND
The aim of the study was to verify the association between body composition and physical fitness with bone status in children and adolescents.


METHODS
A cross-sectional study was conducted with 300 healthy students (148 boys, 152 girls). Weight, height, fat and fat-free mass, and percentage of body fat (%BF) were evaluated, as were physical fitness (abdominal exercise, flexibility, and horizontal jump tests) and maximum oxygen consumption. Bone parameters (amplitude-dependent speed of sound; AD-SoS) and the Ultrasound Bone Profile Index (UBPI) were evaluated using DBM Sonic BP ultrasonography.


RESULTS
In the study group, girls had higher bone parameter values than boys. A univariate analysis assessed in a stepwise multiple regression model was conducted. It showed that for boys, the %BF and height were significant independent variables for AD-SoS and UBPI, but the horizontal jump test only for AD-SoS (adjusted r2 = 0.274; p < 0.001), and pubertal maturation only for UBPI (adjusted r2 = 0.295; p < 0.001). For girls, age and %BF were identified as significant independent variables for AD-SoS and UBPI (adjusted r2 = 0.093; p < 0.001) but height only for AD-SoS (adjusted r2 = 0.408; p < 0.001).


CONCLUSIONS
Variables related to growth (age, height, and pubertal maturation) are independent positive predictors for the bone parameters in both boys and girls. %BF is an independent negative predictor. For boys, the horizontal jump test was an independent positive predictor for AD-SoS, indicating that physical fitness related to the neuromotor system can influence the amount of bone present.
Anderson Marques
AM
de Moraes
Ezequiel Moreira
EM
Gonçalves
Vinicius Justino de Oliveira
VJ
Barbeta
Gil
G
Guerra-Júnior
D000293:Adolescent; D000375:Aging / Q000502:physiology*; D001823:Body Composition / Q000502:physiology*; D015519:Bone Density / Q000502:physiology*; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D050278:Finger Phalanges / Q000000981:diagnostic imaging / Q000502:physiology*; D006801:Humans; D008297:Male; D010809:Physical Fitness / Q000502:physiology*; D012016:Reference Values; D012741:Sexual Maturation; D014463:Ultrasonography