Sex differences in the optimal cut-off values of visceral fat area for predicting metabolic syndrome among Chinese middle-aged and elderly populations: a cross-sectional study

The threshold values of visceral fat area (VFA) proposed by existing studies for predicting metabolic syndrome (MetS) are contentious, necessitating further empirical evidence. We conducted a cross-sectional study to assess VFA using bioelectrical impedance analysis technology among middle-aged and elderly individuals in the Sichuan area of China. First, we compared the predictive ability of VFA, waist circumference (WC) and body mass index (BMI) among participants with MetS (excluding WC). In males, the area under the receiver operating characteristic curve (AUC) was 0·680 for VFA, 0·670 for WC and 0·665 for BMI, with corresponding optimal cut-off values of 77·45 cm², 83·50 cm and 24·19 kg/m². In females, the AUC values and optimal cut-offs were 0·628 (103·55 cm²) for VFA, 0·671 (77·50 cm) for WC and 0·643 (24·32 kg/m²) for BMI. Additionally, for MetS defined with WC included, the AUC of VFA for prediction was higher in males (0·785) than in females (0·717), with optimal cut-offs of 85·15 cm² (males) and 109·55 cm² (females). Further age-stratified analysis revealed sex-specific VFA cut-offs: in males, 80·95 cm² (45–59 years), 85·15 cm² (60–74 years) and 77·50 cm² (≥ 75 years); in females, 109·65 cm² (45–59 years), 112·15 cm² (60–74 years) and 103·05 cm² (≥ 75 years). In conclusion, VFA is an effective predictor of MetS, with its optimal cut-off value varying by age and being higher in females than in males.