The relation between adolescents' body mass index and bone age

Introduction: adolescents' health and nutritional status is demonstrated in the quality of their growth and development. Bone age (BA) is the skeletal development index, which reflects an individual's maturation and is considered as the best expression of human development. Poor nutritional conditions, which extend for long periods, may influence bone development, causing a delay in BA, in relation to chronological age (CA). The aim of this study is evaluating the relation between adolescents' body mass index and bone age. Methods: cross-sectional study carried out with 172 adolescents. The variables evaluated were body mass index (BMI), CA, BA and maturational stage. The BA was determined by taking digital carpal radiographs. Results: the majority of the adolescents presented an adequate nutritional state (73.9%), 42.5% were classified as initial pubertal, followed by 40.6% as in peak height velocity (PHV), with a difference between the sexes (p < 0.001). PHV adolescents presented higher BA averages in both sexes (p = 0.005). There was a correlation between BMI and BA, with a strong correlation for girls in the pre-pubertal stage (r = 0.998; p < 0.05) and moderate correlation for those in PHV (r = 0.421; p < 0.001). By analyzing the relation of the variables to predict adolescents' BA, it was observed that the CA model, maturational stage and BMI explained the variability noted in BA in up to 50.3%. Conclusion: BMI has a relation with BA. It should be noted that BA is influenced by CA, the maturational stage and BMI.