Correlation of appendicular muscle mass measured with dual-energy X-ray absorptiometry and anthropometry in a healthy population of pediatric and adolescent subjects.

Background: Children and adolescents present changes in their body composition during their growth and development process. The appendicular muscle mass (AMM) is related to mobility, ambulation and, consequently, with the activities of daily life. The objective of this study was to determine the correlation of the AMM of upper and lower limbs, obtained by dual X-ray absorptiometry (DXA), as a reference method compared to the appendicular muscular area (AMA) obtained by anthropometric measurements. Methods: Cross sectional study in healthy children and adolescents from 5 to 20 years of age, residents of Mexico City and the Metropolitan Area. A total sample of 1081 clinically healthy subjects were included. Results: The AMM obtained with DXA and the AMA obtained by anthropometry showed a coefficient of determination (r(2)) of 0.90. Categorizing by percentile of body mass index, the correlation is maintained, being slightly lower in the group of obese subjects, where the coefficient was r(2) = 0.84. Conclusions: Measurement of AMM in Mexican children and adolescents with anthropometry is a valid and accurate technic with a high correlation with methods such as DXA. Anthropometry could be implemented as part of the assessment of AMM in the first level care.