The Relationship between Insulin Resistance and Liver Damage in non-alcoholic Fatty Liver Patients

Objectives: Non-alcoholic fatty liver disease (NAFLD) is closely associated with diseases, such as obesity, diabetes mellitus, metabolic syndrome, which are characterized by insulin resistance. NAFLD is thought to be a manifestation of metabolic syndrome in the liver. Liver fibrosis has a high prognostic significance in non-alcoholic steatohepatitis (NASH). In this study, the relationship between insulin resistance and the histopathological changes in the liver was investigated in biopsy-proven NAFLD patients. Methods: In this study, 85 biopsy-proven NAFLD patients (64 NASH, 21 non-NASH) and 40 healthy control subjects were enrolled. Insulin resistance was calculated using the "homeostasis model assessment of insulin resistance" (HOMA-IR). Results: C reactive protein, total cholesterol, low-density lipoprotein, triglyceride, body mass index (BMI), HOMA-IR levels were significantly higher in the NAFLD group compared to the control group. In the NASH group, the HOMA-IR level was significantly higher than the non-NASH group (p=0.026). When NAFLD patients with advanced fibrosis (stage 3-4, n=27) and without fibrosis (stage 0-2, n=58) are compared, in advanced fibrosis group BMI (35.2 +/- 4.6 kg/m(2) and 32.7 +/- 4.1 kg/m(2), respectively; p=0.031) and HOMA-IR (6.3 [5.8-6.8] and 3.4 [2.6-4.81, respectively, p=0.001) levels were higher significantly. In the covariance analysis, when confounding factors, such as BMI, age and gender, were corrected, it was observed that the elevation of HOMA-IR level in the advanced fibrosis group continued statistically significantly. Conclusion: HOMA-IR levels were high in NAFLD patients with advanced fibrosis. HOMA-IR, which can be easily measured in daily practice, is an independent predictor for fibrosis.