The influence of body fat percentage in the anthropometric prediction of cardiac structure size in infants

Predicting normal values of cardiovascular structure size are essential in managing congenital and pediatric heart diseases. Conventionally, normal values of cardiovascular structure size are predicted based on body surface area （BSA）, which is calculated from the infant’s weight and height. However, the predicted normal values may be more accurate if the actual body composition measurement is considered because there are large individual differences in lean body mass （LBM） and fat mass （FM）. The objective of this study was to evaluate the efficacy of measuring body fat percentage using the PEA POD Infant Body Composition System, a novel pediatric body composition measurement tool, in assessing cardiovascular structures focused on the diameters of the aortic valve （AVD） and mitral valve （MVD） and the left ventricular mass （LVM） in infants. We evaluated the associations between diameters of the AVD and MVD, LVM, and percent body fat （％BF） using the PEA POD system at term-equivalent age （37-42 weeks）. AVD and MVD were not significantly different between groups with high or low ％BF, whereas the differences between the predicted normal values and AVD and between the predicted normal values and MVD were significantly larger in the high ％BF group than those in the low ％BF group （p＜0.05 and p＜0.01, respectively）. The high ％BF group had significantly larger LVM/height2.16 than the low ％BF group （p＜0.05）, whereas no significant difference in LVM/BSA was found between the two groups. Body composition analysis is crucial for evaluating cardiovascular structure in infants because the existing methods for predicting normal values for valve diameter and LVM are significantly influenced by ％BF.