Measurement of visceral fat and abdominal obesity by single-frequency bioelectrical impedance and CT: a cross-sectional study

OBJECTIVES: The measurement of visceral fat (VF) is clinically important for the identification of individuals at high risk of visceral obesity-related health conditions. Bioelectrical impedance analysis (BIA) is a widely available and frequently used body composition assessment method, but there have been few validation studies for the measurement of VF. This validation study investigated agreement between BIA and CT for the assessment of VF in adults. DESIGN: Cross-sectional study. SETTING: Between 2015 and 2016 in China. PARTICIPANTS: A total of 414 adults (119 men and 295 women) aged 40-82 years. PRIMARY AND SECONDARY OUTCOME MEASURES: CT-visceral fat area (VFA) was derived at the L2-3 and umbilicus level and VFA cut-offs for visceral obesity applied. BIA measurements of visceral fat level were compared with CT VFA findings using scatter plots and receiver operator characteristic (ROC) curves. RESULTS: Scatter plots showed poor agreement between BIA and CT-derived visceral fat measurements in both sexes (R=0.387-0.636). ROC curves gave optimum figures for sensitivity and specificity of 65% and 69% in women and 76% and 70% in men, respectively, for BIA to discriminate between adults with normal levels of VF and those with visceral obesity determined by CT. CONCLUSION: BIA has limited accuracy for the assessment of VF in adults in practice when compared with the criterion method.