Association between socioeconomic and nutritional factors and height of Brazilian adolescents: results from the Study of Cardiovascular Risk in Adolescents.

This study aims to describe the mean height of adolescents from the five regions of Brazil and to evaluate socioeconomic and nutritional factors associated with normal growth. This is a cross-sectional study conducted in the Brazilian urban and rural areas with students aged 12 to 17 years (n = 71,553). Anthropometry, socioeconomic variables, physical activity, and diet were evaluated. Height-for-age z-scores were calculated and multiple linear regression models were used to investigate the association of exposure variables with height (outcome) by sex and age (12-13, 14-15, and 16-17 years). We observed a lower mean height in adolescents from the North Region and in individuals with low socioeconomic status. At 17 years of age, the closest to the final height in this sample, mean heights for girls and boys were 160.9 ± 0.1cm and 173.7 ± 0.3cm, respectively. In multiple linear regression analysis, physical activity (girls β = 0.119, 95%CI: 0.035; 0.202; boys β = 0.092, 95%CI: 0.012; 0.172) and high level of maternal education (girls β = 0.103, 95%CI: 0.001; 0.204; boys β = 0.39, 95%CI: 0.245; 0.534) were positively associated with height-for-age z-score in 16- to 17-year-old boys and girls. Other factors positively associated with height-for-age z-score in older students include higher protein consumption (β = 0.022, 95%CI: 0.010; 0.035) and obesity (β = 0.217, 95%CI: 0.084; 0.350) for boys, and low weight (β = 0.205, 95%CI: 0.028, 0.382) for girls. We observed differences in the mean height among adolescents from the five Brazilian regions. Normal growth, especially among older adolescents, was associated with high maternal education, practice of physical activity, protein consumption, and body mass index (BMI) categories.