Generalized predictive equation for hematocrit by biological impedancemetry

Bioelectrical impedancemetry (BIA) has been used to evaluate hemorheological parameters from whole body measurements. In a previous study, we have determined a set of predictive equations for hematocrit, whole blood viscosity and plasma viscosity in athletes. In another previous study, we also found other predictive equations in sedentary lean and obese subjects. This study aims at developing more generalized BIA-derived predictive equations for hemorheological parameters in both sedentary and trained individuals. 72 subjects, either athletes, sedentary obese or insulin resistant patients (33.57+/-1.60 yr; 80.81+/-2.06 kg; 171.03+/-1.19 cm) were enrolled into the study. Body composition was assessed with a multifrequency bioelectrical impedancemeter (Dietosystem Human IM Scan) using low intensity at the following frequencies: 1, 5, 10, 50 and 100 kHz. Viscometric measurements were done at 1000 s(-1) with a falling ball viscosimeter (MT 90 Medicatest). Hematocrit (Hct) was measured with microcentrifuge. Hematocrit was correlated with impedance (Z) measurements at 50 kHz (r=-0.591, p=0.01). A generalized empirical predictive equation can thus be proposed. These findings further suggest that one can predict hematocrit in the general population with whole body electric properties.