The University of Alabama, Tuscaloosa, AL COMPARISON OF LEAN SOFT TISSUE MEASURES FROM HAND-TO-FOOT, SINGLE-FREQUENCY BIOIMPEDANCE AND DUAL-ENERGY X-RAY ABSORPTIOMETRY Bailey A. Welborn, Brett S. Nickerson, Kelsey A. Pezzuti, and Michael R. Esco The University of Alabama, Tuscaloosa, AL Table 1. Comparison of BIA and DXA-derived LST (n = 118) Abstract Methods Method Mean ± SD CE P Cohen’s d R SEE DXA 53.04 ± 13.78 - BIA 51.26 ± 13.30 -1.8 <0.001 .14 0.91 5.9 Lean soft tissue (LST) is an important parameter of body composition assessment, especially as it relates to strength and conditioning. Dual-energy x-ray absorptiometry (DXA) is an accurate laboratory method of measuring LST. However, DXA measures are costly, time consuming, and not readily available. Some hand-to-foot bioelectrical impedance (BIA) devices provide a measurement of LST, yet little evidence is available to support their level of agreement with criterion measures. PURPOSE: The purpose of this study was to compare LST measures from hand-to-foot, single frequency BIA to DXA in a sample of healthy men and women. METHODS: One-hundred and eighteen participants (male = 51.8%, age = 21.7 ± 4.6 yrs, height = 171.9 ± 9.7 cm, weight = 72.6 ± 16.5 kg) volunteered for this study. LST was measured via the BIA and DXA devices on the same day. Statistics included comparing mean values, correlation coefficients (r), and standard error of estimate (SEE). RESULTS: The mean ± SD LST measures from BIA was 51.26 ± 13.30 kg and from DXA was 53.04 ± 13.78 kg, which was significantly different (p = 0.001, Cohen’s d = 0.14). The LST measures from BIA were strongly and significantly correlated with DXA (r = 0.91, p < 0.001), with a standard error of estimate of 5.86 kg. CONCLUSION: The LST measurements from BIA was significantly lower compared to DXA, yet the difference was trivial. Significant and strong correlation existed between the two measures, and the BIA provided a range of individual error compared to DXA. PRACTICAL APPLICATIONS: Practitioners should be aware of the study’s results before utilizing hand-to-foot single-frequency BIA as a surrogate for DXA when measuring LST. The BIA measures could provide LST values that are slightly less than DXA. One-hundred and eighteen adults (male= 51.8%) volunteered to participate (age = 21.7 ± 4.6 years). Prior to BIA measurements, all participants were required to be hydrated and provide a urine specific gravity < 1.020. Once hydration was confirmed, subjects had their height and weight measured. Following height and weight measurements, subjects were instructed to lie on a gurney for 5 min and LST was determined with a single-frequency hand-to-foot BIA device. After determining LST with the single-frequency BIA device, participants received a DXA scan LST= lean soft tissue, BIA= hand-to-foot, single-frequency bioelectrical impedance analysis, DXA= dual-energy x-ray absorptiometry, SEE = standard error of estimate; CE = constant error Significantly lower BIA LST values Trivial effect size Correlations were near perfect (r = 0.91) Results Conclusions The trivial effect size suggest the differences have minimal practical implications and that BIA can be used as an alternative to DXA for group LST values The 5.9 kg SEE suggest the use of BIA for individual estimates of LST should be done with caution * Practical Applications Health and fitness professionals often utilize practical devices such as BIA for the estimation of body composition The findings of the current study suggests practitioners can use BIA to estimate group LST when access to DXA is not available However, most practitioners are interested in the individual estimates body composition and the BIA device in the current study yielded a rather large SEE Intro & Purpose LST is a measurement of interest in health and fitness settings Laboratory methods such as DXA are preferred for LST determination due to its accuracy, but this method is expensive and time consuming BIA devices can now be used to measure LST, but agreement with DXA is limited The purpose of this study was to compare LST values derived from single-frequency BIA to DXA Figure 1. Mean between BIA and DXA-derived LST (n = 118) *BIA LST was significantly lower than DXA p < 0.001