Validity and reliability of the sagittal abdominal diameter as a predictor of visceral abdominal fat

Abstract

Objectives: To evaluate the reliability of the sagittal abdominal diameter and its validity as a predictor of visceral abdominal fat, as well as to identify the most appropriate cut-off points to identify the area of visceral fat that is known to represent a risk factor for cardiovascular disease. Design: Validation study. Subjects: 92 healthy volunteers (57 women, 35 men), age: 20-83 y, body mass index: 19.3 to 35.9 kg/m2. Measurements: Sagittal abdominal diameter (SAD), weight, height, circumferences (waist, hip, and thigh), sub-scapular skinfold thickness, abdominal diameter index, and waist-hip ratio (WHR). Method of choice: Computed tomography (CT). Statistic: Receiver operating characteristic (ROC) curve. Results: The reliability for SAD measurement was very high (Inter-class coefficient = 0.99). Visceral fat as measured by VAF through CT was highly correlated with SAD (women r = 0.80; men r = 0.64, p < 0.001), waist circumference (women r = 0.77; men r = 0.73, p < 0.001), and WHR (women r = 0.72; men r = 0.58, p < 0.001). The ROC curve indicated 19.3 cm and 20.5 cm as the threshold values for abdominal sagittal diameter in women and men (sensitivity 85% and 83%, specificity 77% and 82%, respectively). Conclusions: There was a high correlation between SAD and VAF. The cut-off values identified for SAD presented a sensitivity and specificity that were considered adequate.