PREDICTORS OF BONE MINERAL DENSITY IN ADOLESCENTS WITH EXCESS WEIGHT

ABSTRACT Introduction: Adolescence is characterized as a phase of intense development of the skeletal system. Maximizing bone mass acquisition during adolescence may reduce the risk of bone fractures later in life. Objectives: To analyze bone mineral density (BMD) and its relation to nutritional status and serum vitamin D in adolescents with excess weight. Methods: This is a cross-sectional, exploratory study. Data from 102 adolescents with excess weight, of both sexes, were analyzed. The following indices were evaluated: body mass index (BMI), abdominal circumference (AC), intake of micronutrients (vitamin D, calcium, magnesium and phosphorus), serum 25-hydroxycholecalciferol (25(OH)D concentration, BMD of the proximal femur, lumbar spine (L1-L4) and total body, % body fat mass (% BFM), total BFM, total body lean mass (BLM), body fat mass (BFMI) and lean mass (BLMI). Results: The male adolescents (n=53) had higher values for weight, height, AC, BLM and BLMI, while the females (n=49) had higher % BFM. The majority were obese (53.9%) and had a BMD within the normal range for all evaluation sites. Of the 84 adolescents (n=84) with laboratory examination of 25OHD, 33.3% presented values considered insufficient or deficient. Multivariate linear regression analysis showed that the most important independent predictor of BMD for the girls was BLMI, regardless the evaluation site. For boys, in addition to BLMI, BMI-Z of the proximal femur (neck of the femur and total) was also was a determinant variable for BMD. Conclusion: In this sample of adolescents, BLMI was a positive predictor of BMD in both sexes; and BMI-Z was a positive predictor only in proximal femur in the boys. Level of evidence II; Prognostic studies. RESUMEN Introducción: La adolescencia se caracteriza como una fase de intenso desarrollo del sistema esquelético. La maximización del pico de masa ósea durante la adolescencia contribuye para la reducción del riesgo de fracturas en la vida adulta. Objetivos: Analizar la densidad mineral ósea (DMO) y su relación con el estado nutricional y la concentración plasmática de vitamina D en adolescentes con exceso de peso. Métodos: Se trata de una investigación transversal, de carácter exploratoria, en donde se analizaron datos de 102 adolescentes con exceso de peso, de ambos sexos. Se evaluaron Índice de masa corporal (IMC), circunferencia abdominal (CA), consumo de micronutrientes (vitamina D, calcio, magnesio y fósforo), concentración sérica de 25-hidroxic