Concordance between whole-body scan and half-body scan to evaluate body composition in dual-energy X-ray absorptiometry in children and adolescents with different nutritional and pubertal conditions

Abstract Introduction The evaluation of body composition is a relevant clinical instrument for the follow-up assessments of children and adolescents, and dual-energy X-ray absorptiometry (DXA) is an accurate method for the pediatric population. However, DXA has limited scan area for the obese population. Thus, half-body scans emerged as an alternative to evaluate individuals with obesity. Objective To compare body composition of children and adolescents with whole-body and half-body DXA scans, considering nutritional status, pubertal development, gender and age. Methods This is a cross-sectional, analytical and diagnostic intervention study with a sample of 82 participants of both genders, aged between 4 and 20 years. Body composition was evaluated by DXA using an iDXA bone densitometer (GE Healthcare Lunar). Two evaluations were performed: whole-body and half-body scans. The Bland-Altman, correlation and linear regression tests were applied to identify the presence of association bias between the techniques. Alpha = 0.05. Results Of the 82 participants, 20 were excluded. A high correlation was observed between the data (correlation coefficient ∼0.999). Bland-Altman plots and regression analyses demonstrated correlation and randomness bias between whole-body and half-body scan techniques in obese or normal weight participants for all DXA markers. Conclusion The use of half-body scans was feasible and accurate to evaluate whole-body composition. The difference bias between techniques occurred randomly, being clinically irrelevant. A high correlation was observed between half-body scan and whole-body analysis techniques.