Non-Alcoholic Fatty Liver in Obesity with Deteriorating Glucose Control

Abstract

Background: The incidence of non-alcoholic fatty liver disease (NAFLD) is rising in parallel with increasing bodyweight and loss of glucose control, implicating a high risk of hepatic and extra-hepatic complications. Subjects / Methods: This longitudinal observational study analysed several indicators for NAFLD in 240 overweight subjects (body mass index (BMI) > 28 kg/m²) at 2 visits within in average 16 months. Subjects were categorised according to their insulin sensitivity (HOMAIR) and diabetic status. Methods: Liver fat and liver stiffness were measured with sonographic elastography (FibroScan®), and by calculation of Fatty Liver Index (FLI), and NAFLD Fibrosis Score (NFS). Results: Parameters indicative for liver steatosis, i.e., the controlled attenuation parameter (CAP) and the FLI, were significantly higher in the T2DM group compared to the normal glucose tolerance (NGT) and impaired glucose tolerance (IGT) groups (p<0.05). FLI values and the HOMAIR significantly correlated with sonographic liver fat content (CAP) (r=0.53, p<0.0001; r=0.34, p<0.001, respectively). An inverse correlation was observed between serum adiponectin levels and CAP (r=-0.20; p<0.019) and adiponectin levels and FLI (r=-0.37; p<0.0001). Over 16 months, fasting insulin levels and HOMAIR score increased mainly driven by the group of obese subjects with T2DM. No significant change in liver fat or stiffness was observed that period. Conclusions: In subjects with a BMI ≥ 28kg/m², the prevalence of NAFLD increases in line with increasing insulin resistance and loss of glucose control. Despite some ongoing deterioration in insulin sensitivity, liver fat content appeared relatively unchanged over 16 months.