Proposição de equação preditiva de adiposidade corporal para adultos brasileiros

Abstract

Obesity is a serious public health problem worldwide that reduces life expectancy as it increases the risk of developing non communicable chronic diseases such as high blood pressure, type 2 diabetes, cardiovascular and cerebrovascular diseases. Thus, for the elaboration of dietary programs and / or physical exercises for the prevention and treatment of obesity, a diagnostic evaluation is necessary to allow health professionals to identify body composition, in order to propose the most appropriate prescription. . The Body Adiposity Index (BAI), calculated from the measurement of hip perimeter and height, has been suggested as a new index to assess body adiposity. Thus, there is a need to verify whether BAI is a valid predictor for assessing body fat percentage in adults in northeastern Brazil, as well as proposing a valid equation to serve the population of Brazil. This is a descriptive cross-sectional study. The sample consisted of 425 individuals aged between 20 and 59 years, 203 men and 222 women, who underwent anthropometric evaluation. As standard technique for fat percentage evaluation, double energy radiographic absorptiometry (DXA) was used. Statistical analysis was performed using Pearson's linear correlation and linear regression. Bland-Altman plotting was used to verify the limits of agreement between the standard technique and the alternative technique. Multivariate linear regression analysis with variable selection by the model reduction method (STEPWISE) was used to develop the equation to estimate specific body fat percentage for adults from northeastern Brazil. No significant differences were found between the fat percentage estimated by BAI and the reference values by DXA, however, the correlation between the techniques was below that considered for BAI validation (P ≥ 0.586). Knowing the limitations of BAI, we developed an equation to serve the adult population of northeastern Brazil aged between 20 and 59 years, which we call the Body Adiposity Equation (EAC). The resultant model for prediction of CG presented an R2 = 0.79 and EPE = 4.5% CG, based on the variables: gender, age, height, waist circumference (WC) and hip circumference (QC). Although BAI did not differ from the estimated values, the low correlation and the limits of agreement indicate that in our study BAI does not appear to be a good predictor of body fat in adults from northeastern Brazil. Thus, for a better diagnostic evaluation of the studied population, the CAE developed in our research proved to be a valid index to serve the adult population of northeastern Brazil. Key words: Obesity, physical evaluation, body composition, body adiposity index, BAI.