Evaluation of air-displacement plethysmography for body composition assessment in preterm infants.

BACKGROUND

Adiposity may contribute to the future risk of disease. The aim of this study was to evaluate the accuracy and reliability of an air-displacement plethysmography (ADP) system to estimate percentage fat mass (%FM) in preterm infants and to evaluate interdevice reliability in infants.

METHODS

A total of 70 preterm and 9 full-term infants were assessed. The accuracy of ADP measurements was assessed by determining reference %FM values using H(2)(18)O dilution measurement.

RESULTS

Mean %FM by ADP was 5.67 ± 1.84 and mean %FM by H(2)18O dilution was 5.99 ± 2.56. Regression analysis showed that %FM by ADP was associated with %FM by H(2)(18)O dilution (R2 = 0.63, SE of estimate (SEE) = 1.65, P = 0.006). Bland-Altman analysis showed no bias (r = -0.48, P = 0.16) and 95% limits of agreement were -3.40 to 2.76 %FM. There was no difference in mean interdevice reliability %FM values (8.97 vs. 8.55 %FM) between ADP 1 and 2. Regression analysis indicated a low SEE (1.14% FM) and high R2 (0.91); 95% limits of agreement were -1.87 to 2.71 %FM. The regression line did not differ significantly from the line of identity.

CONCLUSION

ADP is a noninvasive, reliable, and accurate technique to measure preterm infants' body composition in both research and clinical settings.