Histopathological differences in patients with biopsy-proven non-alcoholic fatty liver disease with and without type 2 diabetes.

BACKGROUND AND AIMS: Prevalence of non-alcoholic fatty liver disease (NAFLD) in developed countries is 30% in the general population and 50% in patients with type 2 diabetes mellitus (T2DM). The aim of this study was to compare the severity of NAFLD, as assessed by liver biopsy and using the non-invasive index NAFLD Fibrosis Score (NFS), in subjects with and without T2DM.

PATIENTS AND METHODS: The study sample consisted of 217 patients with biopsy-proven NAFLD. Anthropometric assessments, laboratory tests, histological criteria established by the Non-alcoholic Steatohepatitis Clinical Research Network (NASH CRN), and the NFS were recorded.

RESULTS: Patients with T2DM (n=36; 16.5%) had higher HOMA-IR values (6.3±3.6 vs. 3.3±2.4; p<0.0001), GGT levels (125.2±102.3 vs. 82.5±70.6IU/l; p<005), and NFS index (-0.6±0.2 vs. -1.8±0.1; p<0.001) than subjects with no T2DM. Patients with T2DM were found higher rates of NASH (72.2% vs. 48.6%; p<0.05), advanced steatosis (80.6% vs. 63%; p<0.05), and liver fibrosis (75% vs. 43.1%, p<0.05) than patients with no T2DM. Patients with T2DM also had higher NFS values (-0.6±1.2 vs. -1.8±1.8: p=0.01). A logistic regression analysis adjusting for age, gender and BMI showed a significant independent association between NASH and presence of T2DM (OR=4.2: 95% CI: 1.4-12.1; p=0.007). A second model adjusting for the same covariates showed T2DM to be an independent factor associated to advanced fibrosis (OR=4.1; 95% CI: 1.7-9.7).

CONCLUSION: Patients with T2DM have more advanced degrees of NAFLD and advanced fibrosis as assessed by liver biopsy and the NFS index. Particular attention should be paid to the study and monitoring of NASH in patients with T2DM.