Official Position of the Brazilian Association of Bone Assessment and Metabolism (ABRASSO) on the evaluation of body composition by densitometry-part II (clinical aspects): interpretation, reporting, and special situations.

OBJECTIVE: To present an updated and evidence-based guideline for the use of dual-energy x-ray absorptiometry (DXA) to assess body composition in clinical practice. MATERIALS AND METHODS: This Official Position was developed by the Scientific Committee of the Brazilian Association of Bone Assessment and Metabolism (Associação Brasileira de Avaliação Óssea e Osteometabolismo, ABRASSO) and experts in the field who were invited to contribute to the preparation of this document. The authors searched current databases for relevant publications in the area of body composition assessment. In this second part of the Official Position, the authors discuss the interpretation and reporting of body composition parameters assessed by DXA and the use of DXA for body composition evaluation in special situations, including evaluation of children, persons with HIV, and animals. CONCLUSION: This document offers recommendations for the use of DXA in body composition evaluation, including indications, interpretation, and applications, to serve as a guiding tool in clinical practice and research for health care professionals in Brazil.

Official position of the Brazilian Association of Bone Assessment and Metabolism (ABRASSO) on the evaluation of body composition by densitometry: part I (technical aspects)-general concepts, indications, acquisition, and analysis.

OBJECTIVE: To review the technical aspects of body composition assessment by dual-energy X-ray absorptiometry (DXA) and other methods based on the most recent scientific evidence. MATERIALS AND METHODS: This Official Position is a result of efforts by the Scientific Committee of the Brazilian Association of Bone Assessment and Metabolism (Associação Brasileira de Avaliação Óssea e Osteometabolismo, ABRASSO) and health care professionals with expertise in body composition assessment who were invited to contribute to the preparation of this document. The authors searched current databases for relevant publications. In this first part of the Official Position, the authors discuss the different methods and parameters used for body composition assessment, general principles of DXA, and aspects of the acquisition and analysis of DXA scans. CONCLUSION: Considering aspects of accuracy, precision, cost, duration, and ability to evaluate all three compartments, DXA is considered the gold-standard method for body composition assessment, particularly for the evaluation of fat mass. In order to ensure reliable, adequate, and reproducible DXA reports, great attention is required regarding quality control procedures, preparation, removal of external artifacts, imaging acquisition, and data analysis and interpretation.

The use of dual-energy X-ray absorptiometry in the evaluation of obesity in women with obstructive sleep apnea-hypopnea syndrome.

The inflammatory state caused by obesity increases the level of adipokines, such as leptin, with a direct impact on the central respiratory regulation. The present study addresses this problem by evaluation of the association of sleep apnea diagnosis in relation to body fat measured by dual-energy X-ray absorptiometry (DXA), anthropometric parameters and biochemical variables. All patients carried out overnight polysomnography, anthropometric evaluations [Body Mass Index (BMI), neck and waist circumference], body composition analyzed by DXA and blood sample collection (lipid profile, fasting glycemia, insulin, glycated hemoglobin, C-reactive protein and serum leptin levels). Obstructive sleep apnea-hypopnea syndrome (OSAHS) was defined by the apnea-hypopnea index (AHI) from the overnight polysomnography. According to the AHI, the women were divided into two groups: with and without apnea. Twenty-seven of them had OSAHS (AHI = 22.04 ± 17.55). The main results are the following: (a) BMI was not capable of predicting OSAHS in this study (p = 0.204); (b) for each 1 % increase in TBF %, the probability of having sleep apnea increased by 12.8 %; (c) comparing all variables (anthropometrics, DXA and blood sample), serum leptin was the only variable with a significant difference between the groups (p = 0.0257). The results reinforce the role of total body fat and leptin in the etiology of OSAHS and the need to include the evaluation of corporal composition measures by DXA in studies of sleep apnea.