Development and validation of a bioelectrical impedance prediction equation estimating fat free mass in Greek - Caucasian adult population

Abstract

Background and aims: Excessive body fat accumulation is associated with adverse health effects; therefore its accurate and reliable assessment is of great significance. The aim of the study was to develop and validate an easy and applicable equation, based on bioelectrical impedance analysis, estimating fat free mass in Greek general population and compare it with those of the literature.

Methods: Anthropometric and bioelectrical impedance parameters were obtained from 694 Greek adults (429 women and 265 men) so as to develop and validate the equation, using DXA as reference method. The validation and the reliability of the equation were examined with Bland-Altman analysis and Intraclass Correlation Coefficient (ICC).

Results: The developed prediction equation was FFM (kg) = 12.299 + (0.164 * Weight (kg)) + (7.287 * Gender (0:female, 1:male)) - (0.116 * Resistance (ohm)/Height (m)²) + (0.365 * Reactance (ohm)/Height (m)²) + (21.570 * Height (m)) (R² = 0.944, p < 0.0001). Regarding the current population, the current equation presented the lowest bias (-0.069 kg, p = 0.707) and the highest ICC (0.985) compared to those of the literature.

Conclusion: The current prediction equation was found to be valid and reliable in a representative sample of the Caucasian Greek general population and its utilization for body composition assessment could be an alternative of using labor-intensive, expensive and time-consuming reference methods.

Keywords: BIA; Bioelectrical impedance analysis; Body composition; Caucasian.