ABDOMINAL-WALL FAT INDEX, ESTIMATED BY ULTRASONOGRAPHY, FOR ASSESSMENT OF THE RATIO OF VISCERAL FAT TO SUBCUTANEOUS FAT IN THE ABDOMEN

PURPOSE: To establish a new index of regional fat distribution using u ltrasonography for assessment of the ratio of the visceral fat area (V ) to the subcutaneous fat area (S) (V/S ratio). SUBJECTS AND METHODS: The subjects examined were 62 patients (23 males and 39 females); 51 p atients had hyperlipidemia and 11 patients had glucose intolerance. Th e mean body mass indices ranged from 20.3 to 42.9. The mean age of the patients was 44 +/- 13 years. The thicknesses of the preperitoneal fa t layer (P) and subcutaneous fat layer (S) in the abdomen were measure d by ultrasonography and the P/S ratio was calculated. The V/S ratio w as obtained with radiographic computed tomography. RESULTS: Of the var ious P/S ratios examined, the ratio of the maximum thickness of preper itoneal fat to the minimum thickness of subcutaneous fat was most clos ely correlated with the V/S ratio (r = 0.746, p <0.0001). This ratio w as termed the abdominal wall fat index (AFI). AFI was positively corre lated with serum triglyceride levels and negatively correlated with hi gh-density lipoprotein cholesterol (r = -0.312, p < 0.05), whereas the V/S ratio was correlated with triglyceride levels. AFI was positively correlated with basal insulin levels in both men and women. CONCLUSIO N: These results suggest that AFI measured by ultrasonography may be a new indicator of visceral fat deposition, and may reflect metabolic d isorders such as lipid metabolism and glucose metabolism disorders.