Evaluation of whole-abdominal fat volume by 700-slice CT scanning and comparison with the umbilical fat area anthropometric indices

Abstract

The fat area at the umbilical region on CT scans is widely used to identify visceral obesity. However, whether it precisely represents the abdominal visceral fat volume is uncertain, because of technical difficulty in evaluating whole-abdominal visceral fat volume. In this study, we compared the whole-abdominal visceral fat and subcutaneous fat volumes with the visceral fat area at the umbilical region and anthropometric indices. The study population consisted of 131 Japanese diabetic and non-diabetic subjects (72 males and 59 females) who underwent anthropometric measurements (height, weight, waist circumference, and hip circumference) and CT scanning from the top of the liver to the pelvic floor (about 700 slices) to analyze the whole-abdominal and umbilical contents of visceral and subcutaneous fat. The visceral fat volume of the male group was 1.3-fold higher than that of the female group, while the subcutaneous fat volume of the female group was 1.3-fold higher than that of the male group. The visceral fat area at the umbilical region was strongly correlated with visceral fat volume (r = 0.921 in males and 0.931 in females). Both visceral and subcutaneous fat volumes were strongly correlated with the waist circumference (r = 0.768 and 0.809 in males and 0.744 and 0.803 in females), but not with the BMI or waist/hip ratio. The visceral fat area at the umbilical region is an optimal indicator for whole-abdominal visceral fat volume, and the waist circumference is the anthropometric index that reflects visceral obesity more closely than BMI or the waist/hip ratio.