Predicting somatic maturation from anthropometric variables: validation and proposed equations to school in Brazil.

Introduction: The assessment of biological maturation is considered essential to health, because it can be used directly for the clinical interpretation of endocrine, growth status and quality of life.Objective: To validate the proposed technique byMirwald et al (2002) to assess the maturity and developan equation to calculate the cross peak growth rate ofchildren and adolescents from public schools in the urban region of Campinas, SP, Brazil.Methods: We selected 914 stratified probability soboys and 839 girls, which correspond to 30% of a totalof 5931 school children 8-16 years of both sexes of anurban region of Campinas, SP, Brazil. We evaluated thedecimal age and anthropometric variables of height,weight and sitting height. Interrelationships were conducted weight / height and length was determined bycalculating the lower the difference between the sittingheight and stature. To validate the equation criterion (Mirwald et.al 2002) cross-validation was used both internally and externally.Results: We observed high correlations between ageand anthropometric variables in both boys (r = 0.56 to0.96) and in girls (r = 0.57 to 0.98). The internal andexternal validation no significant difference (p> 0.05)and acceptable agreement was observed between thetest and the equations developed for children of bothsexes to a 95% CI.Conclusions: We conclude that Mirwald et al (2002)regression equations are validated and can be applied toschools in the urban region of Campinas, SP (Brazil). Theequations developed in the study are an alternative toassess somatic maturation across.