Abstract

BACKGROUND
Visceral adipose tissue accumulation highly correlates with metabolic abnormalities and cardiovascular disease. Computed tomography (CT) is considered to be the standard method for visceral fat evaluation, but it is not used as a routine procedure. Ultrasonography (US) is a safe method, fairly inexpensive and widely available modality for measuring abdominal fat thickness. The aim of this study was to investigate the correlation between the intra-abdominal fat distance by US measurement and the visceral fat amount by CT and cardiovascular risk factors and to evaluate whether the intra-abdominal fat distance is better correlate with visceral fat amount by CT than other anthropometric parameters and to assess the cut-off value of intra-abdominal fat distance for visceral obesity in type 2 diabetic patients. METHODS: We obtained abdominal subcutaneous and intra-abdominal fat distance by using a high-resolution US (HDI 5000, ATL, Phillps, USA) at 1 cm above umbilical level in one hundred twenty-eight type 2 diabetic patients. CT scan (Light Speed plus, GE, USA) for the measurement of subcutaneous and intra-abdominal visceral fat area was also performed in the supine position at the L4-5 level. Lean body mass and % body fat were measured in a bioimpedance using DSM (Direct Segmental Measurement by 8-point electrode) method (InBody 3.0, Biospace, Seoul, Korea). We measured patient's height, weight, BMI (Body mass index), waist circumference, WHR(Waist-hip ratio) and blood pressure and also measured fasting blood glucose, HbA1c and lipid profiles. RESULTS: Abdominal subcutaneous and visceral fat distance measured by US is 2.05 +/- 0.52 cm, 4.43 +/- 1.54 cm, respectively. In pearson's correlations, visceral fat distance were correlated with BMI (r = 0.681, P < 0.001), waist circumference (r = 0.661, P < 0.001), WHR (r = 0.571, P < 0.001), triglyceride (r = 0.316, P < 0.001), HDL-cholesterol (r = -0.207, P < 0.004). US-determined visceral fat distance was also correlated with visceral fat amount by CT (r = 0.674, P < 0.001) and BMI (r = 0.610, P < 0.001), waist circumference (r = 0.626, P < 0.001), WHR (r = 0.557, P < 0.001). When we used waist circumference (men: 90 cm, women: 85 cm) as parameters for visceral obesity, the cutoff value of visceral fat distance, obtained by the receiver operating characteristic curve analysis, were 4.670 cm in men, 3.695 cm in women diabetic patients. CONCLUSION: Intra-abdominal fat distance measured by US reveals strongly correlated with visceral fat area, which is determined by CT and also well correlated with anthropometric parameters and lipid profiles. We suggest that US provided a better index compared to anthropometry for the prediction of visceral obesity and could be an alternative method for CT for visceral fat determination in diabetic patients.

• Keywords: Computed tomography;Ultrasonography;Visceral obesity;