Body Composition Using DXA Versus Multifrequency BIA In A Multi-race Cohort Of College Students

Body composition assessment is an important clinical and research tool. Dual energy x-ray absorptiometry (DXA) is the ‘gold standard’ and useful in the research environment, however, it is expensive, reliant on a trained technician, requires a large space, and is immoveable. Bioelectrical impedance (BIA) measurements have improved with the application of 8-electrode multifrequency units and could offer a faster, cheaper, and portable alternative if measurements are comparable. PURPOSE: To determine how well bone mineral content (BMC), lean body mass (LBM), and fat mass measurements made with BIA compared to those made with DXA. METHODS: 46 (36 female) college students [avg 21.2 yr, 167.2 cm, 67.2 kg, 28.9% fat; 6 Asian, 4 Hispanic, 3 Black] had their BIA and DXA whole body composition measured within minutes of each other. Three compartments were compared BIA vs DXA: BMC, fat mass, and LBM. Pearson’s correlation coefficients were determined. RESULTS: Absolute fat mass (r = 0.95), lean mass (r = 0.98), and BMC (r = 0.91) were highly correlated between the assessment methods. CONCLUSIONS: A quadripolar multifrequency BIA device can be a valid body composition surrogate in research environments using college students when a DXA machine is impractical to use.