Background and aim: It is known that ultrasonography (US) cannot differentiate between non-alcoholic fatty liver disease (NAFLD) and steatohepatitis. However, US can accurately estimate the severity of the steatosis. The clinical significance of severe hepatic fatty change by US has not been explored. The aim of this study was to investigate the relationship between the severity of the fatty liver, classified by US, and the degree of metabolic disorders with insulin resistance.
Methods: In 16 486 Taiwanese patients, severity of fatty change on US was classified as follows: group A (n = 6950), absence of fatty change; group B (n = 8694), mild; and group C (n = 842), severe fatty liver change. Biometabolic parameters included body mass index (BMI), blood pressure (BP), fasting plasma glucose, triglycerides, cholesterol, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and serum creatinine. Nominal logistic regression analysis was used to estimate the odds ratio for different degrees of fatty liver.
Results: The frequencies of obesity, hypertension, glucose intolerance and hypertriglyceridemia were all significantly higher in group C than in group A or B (P < 0.0001), and the mean values of BMI, BP, fasting glucose, triglyceride and ALT were also higher in group C (P < 0.0001). High BMI (>or=30 kg/m(2)) appears to be the most important factor for progression from mild to severe fatty liver in both sexes.
Conclusions: The presence of severe fatty liver by US correlated significantly with the prevalence and degree of hypertension, abnormal glucose and triglyceride metabolism. Patients with severe fatty liver could be at an increased risk of atherosclerotic cardiovascular disease and should be screened regularly for metabolic disorders. The physician may also evaluate ALT and hepatic fat content by US in patients with metabolic syndrome. Evaluating the severity of fatty liver by US may be useful because it correlates with the status of hyperinsulinemia, the risks of developing cardiovascular disease, and the threshold for oxidative stress.