Body composition of undergraduates – comparison of four different measurement methods

The objective of this study was to determine body composition of university students using four different methods and to find out the extent of agreement between these methods regarding the measurement of body fat percentage in body composition. The study group consisted of 52 students of the P.J. Šafárik University in Košice (29 males and 23 females) whose average age was 22.4 ± 1.9. The study group was formed by convenience sampling. Basic somatometric parameters (body height and weight) were determined and body mass index (BMI) was calculated. The body fat percentage was determined by indirect methods, that is by measuring skinfold thickness at 10 locations on the body using calliper Best II.K501 and by bioimpendance method using devices Bodystat 1500, Omron BF511 (tetra-polar electrode configuration) and Omron BF300 (bi-polar electrode configuration). Profile analysis based on one-sample Hotelling’s test with chi-squared approximation was used for assessing agreement among given four methods of body fat measurements. Statistical analysis of differences among methods was supplemented by the Bland-Altman graphical method with the Wilcoxon paired test. The whole statistical analysis was performed using Excel and software R. Hotteling’s Test (p < 2.2e-16) rejected the hypothesis of agreement between the methods. The greatest influence on this rejection was attributed to the Omron BF511 method. In addition, the results of Wilcoxon’s matched pairs test confirmed the difference of the Omron BF511 method from the other three measurement methods. Bland-Altman graphical analysis showed that the Omron BF511 provided clearly higher values in comparison to the three remaining measurement methods of body fat percentage. The skinfold measurement, the Omron BF300 and the Bodystat 1500 were almost identical. For all the indirect methods it is necessary to validate the accuracy of their measurements using reference methods for the current local population. The skinfold thickness measurement method by Pařízková meets this requirement. Based on our results, the values determined by the devices Omron BF300 and Bodystat 1500 can also be considered applicable. The Omron BF511 does not provide results that could be considered sufficiently accurate for the purposes of research. In order to verify this conclusion the larger group of probands (n = 100 - 300) and a method of repeated measurements would be necessary