Hepatic steatosis: correlations of body mass index, CT fat measurements, and liver density with biopsy results

PURPOSE To assess the relationship between body mass index (BMI), subcutaneous and intra-abdominal fat, liver density, and histopathologic hepatic steatosis. MATERIALS AND METHODS In this retrospective study, 143 patients (male/female, 67/76; mean age, 50 years) underwent a non-targeted transjugular (n=125) or percutaneous (n=18) liver biopsy between 2006 and 2010. The biopsy indications included chronic liver parenchymal disease staging (n=88), elevated enzymes (n=39), or other reasons (n=16). The BMI and non-contrast liver computed tomography liver density were recorded for each patient. The thicknesses of the anterior, posterior, and posterolateral subcutaneous fat, along with the intra-abdominal fat, were measured. The values were then correlated with histopathologic steatosis. RESULTS Of the patients, 47/143 (32%), 39/143 (28%), and 57/143 (40%) were normal weight, overweight, and obese, respectively. Steatosis was present in 13/47 (28%) of normal weight, 18/39 (46%) of overweight, and 38/57 (67%) of obese patients. Significant differences in BMI (26.7 kg/m(2) vs. 31.7 kg/m(2) vs. 35.0 kg/m(2), P < 0.001), liver density (52.8 HU vs. 54.4 HU vs. 42.0 HU, P < 0.001), anterior subcutaneous (1.8 cm vs. 2.4 cm vs. 2.9 cm, P < 0.001), posterolateral subcutaneous (2.8 cm vs. 3.2 cm vs. 4.4 cm, P < 0.004), posterior subcutaneous (1.9 cm vs. 2.5 cm vs. 3.4 cm, P < 0.001), and intra-abdominal fat thickness (1.1 cm vs. 1.3 cm vs. 1.4 cm, P < 0.013) were identified in patients with different degrees of steatosis (none, minimal to mild, moderate to severe, respectively). BMI (r=0.37, P < 0.001) and the anterior subcutaneous fat (r=0.30, P < 0.001) had a moderate correlation with the presence of liver steatosis. A combination of a BMI >= 32.0 kg/m(2) and an anterior subcutaneous fat thickness >= 2.4 cm had a 40% sensitivity and 90% specificity for the identification of steatosis. CONCLUSION Increase in the anthropomorphic metrics of obesity is associated with an increased frequency of liver steatosis.