Association between Non-alcoholic Fatty Liver and Metabolic Diseases

Background: Non-alcoholic fatty liver disease (NAFLD) is known to be frequently associated with obesity, type 2 diabetes and dyslipidemia. Recently, the diagnosis of fatty liver disease, based on ultrasonographic findings, has increased. Therefore, we examined the association between NAFLD and various metabolic diseases, such as obesity, glucose intolerance, dyslipidemia, and hypertension or metabolic syndrome, and tried to find out whether NAFLD was independently related to insulin resistance. Methods: From April to June 2000, 262 subjects, attending for routine physical check-ups, were screened. Of these, 115 one hundred fifteen subjects were studied, with the other 147 excluded due to significant alcohol consumption, evidence of viral or toxic hepatitis, significant liver or renal dysfunction, and overt thyroid disease. Fatty liver was diagnosed if the subject had a bright liver on ultrasonographic examination. All diagnoses were made by a single experienced radiologist. Results: Of the 115 subjects. 30 (26%) showed NAFLD. 1. Systolic and diastolic blood pressures, body weight, serum total cholesterol, triglyceride, fasting insulin levels and HOMA IR (homeostasis model assessment insulin resistance index) were higher in the subjects with NAFLD than in the controls. 2. Multiple logistic regression analysis, including age, sex, BMI, waist to hip ratio, fasting serum glucose, lipids and insulin levels, HOMA IR, and hypertension showed that BMI, total cholesterol and HOMA IR were independently related with NAFLD. 3. 27% of the subjects with NAFLD showed metabolic syndrome, and 53% of subjects with metabolic syndrome had NAFLD. 4. The percentage of subjects who had more than two factors of metabolic syndrome was three times higher in the subjects with NAFLD compared to the controls. Conclusion: These results suggest that NAFLD may be independently related with insulin resistance. Metabolic diseases, such as glucose intolerance, obesity, dyslipidernia and hypertension, were more prevalent in the subjects with NAFLD than in the controls. Therefore, we should try to assess the status of the metabolic diseases, and treat them in patients with NAFLD.