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Body phenotypes in adolescence: is it necessary to adjust body mass index according to sexual maturation stages?

Abstract:

This study aimed to analyze the effect of sexual maturation on body phenotypes, based on multivariate analysis of adolescents’ nutritional status. This was a cross-sectional study with a sample of 833 adolescent schoolchildren 10 to 15 years of age, selected by complex sampling in Piracicaba, São Paulo State, Brazil. Body phenotypes were defined by principal components analysis (PCA), based on age, anthropometric data (body mass, height, skinfolds, and waist circumference), body composition (phase angle measured by bioelectrical impedance), and biochemical parameters (triglycerides, glucose, total cholesterol/LDL ratio, hemoglobin). Body phenotypes were classified as: P1adiposity characterized as positive association with skinfolds, body mass, and waist circumference; P2growth characterized as positive association between height and age; P3biochemical characterized as positive association with total cholesterol/LDL ratio, triglycerides, and glucose; and P4metabolic characterized as positive association with phase angle and hemoglobin and negative association with glucose. The phenotypes were later considered outcomes in the mixed effects analysis, incorporating sex at the first level and sexual maturation, age, sex, and socioeconomic score at the second level. This analysis allowed measuring the effect of sexual maturation on body phenotypes. Our results indicate that sexual maturation only a displayed relevant explanation of body phenotype that represents linear growth (height and age). Thus, it is not necessary to adjust anthropometric measures by sexual maturation.

Keywords:
Adolescent; Nutrition Assessment; Sexual Maturation; Body Composition; Biomarkers

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