Inter-methods agreement for the assessment of percentage of body fat between two laboratory methods in male adolescent cyclists

Nutr Hosp. 2013 Jul-Aug;28(4):1049-52. doi: 10.3305/nh.2013.28.4.6502.

Abstract
in English, Spanish

Objective: To examine inter-methods agreement between dual energy X-ray absorptiometry (DXA) and air displacement plethysmography (ADP) in male adolescent cyclists for assessing percentage of body fat (PBF).

Methods: PBF of 24 male adolescent cyclists was assessed by DXA and ADP. Agreement between ADP and DXA was determined according to a Bland-Altman plot; validity and lack of agreement was assessed by calculating inter-methods difference. The limits of agreement and differences between methods were also calculated by paired t-tests. Heteroscedasticity was also examined.

Results: The values obtained by DXA were higher than those obtained by ADP, and the graph presented heteroscedasticity (both p < 0.05; r = 0.74).

Conclusion: DXA and ADP methods were not comparable in terms of PBF assessment in our sample of male adolescent cyclists; it needs to be taken into account when evaluating longitudinal changes in this determined population.

Objetivo: Examinar la validez inter-métodos entre la absorciometría rayos X (DXA) y la pletismografía por desplazamiento de aire (PDA) en ciclistas varones adolescentes, para la evaluación del porcentaje de grasa corporal. Métodos: Se evaluó el porcentaje de grasa corporal de 24 ciclistas varones adolescentes mediante DXA y PDA. La validez inter-métodos se determinó mediante un gráfico de Bland-Altman; se calculó la diferencia intermétodo y los límites de concordancia mediante test t de Student. Se examinó también la heteroscedasticidad ente ambos métodos. Resultados: Los valores de porcentaje de grasa corporal obtenidos por el DXA fueron más elevados que los obtenidos por PDA, y el gráfico presentó heteroscedasticidad (ambos p < 0,05; r = 0,74). Conclusión: El DXA y la PDA no son métodos comparables para la evaluación del porcentaje de grasa en nuestra muestra de ciclistas varones adolescentes; esto debería ser tenido en cuenta a la hora de evaluar cambios longitudinales en esta determinada población.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorptiometry, Photon / methods*
  • Adiposity / physiology*
  • Adolescent
  • Anthropometry
  • Bicycling / physiology*
  • Body Composition / physiology*
  • Humans
  • Male
  • Plethysmography, Whole Body / methods*
  • Reproducibility of Results