Assessment of total and regional bone mineral density using bioelectrical impedance vector analysis in elderly population

This study aimed to investigate the relationship between bone mineral density (BMD) and heightadjusted resistance (R/H), reactance (Xc/H) and phase angle (PhA). A total of 61 male and 64 female
subjects aged over 60 years were recruited from middle Taiwan. The R and Xc were measured using
Bodystat Quadscan 4000 at a frequency of 50 kHz. BMD at the whole body, L2–L4 spine, and dual
femur neck (DFN), denoted as BMDTotal, BMDL2–L4, and BMDDFN, were calculated using a Hologic DXA
scanner. The R-Xc graph was used to assess vector shift among diferent levels of BMD. BMD was
positively correlated with Xc/H and negatively correlated with R/H (p< 0.001). The General Linear
Model (GLM) regression results were as follows: BMDTotal = 1.473–0.002 R/H+ 0.007 Xc/H, r = 0.684;
BMDL2–L4 = 1.526–0.002 R/H+ 0.012 Xc/H, r = 0.655; BMDDFN = 1.304–0.002 R/H+Xc/H, r = 0.680;
p < 0.0001. Distribution of vector in the R-Xc graph was signifcantly diferent for diferent levels of
BMDTotal, BMDL2–L4 and BMDDFN. R/H and Xc/H were correlated with BMD in the elderly. The linear
combination of R/H and Xc/H can efectively predict the BMD of the whole body, spine and proximal
femur, indicating that BIVA may be used in clinical and home-use monitoring tool for screening BMD in the elderly in the future.