Study population

The participants in this study were recruited among patients admitted to the Medical University Hospital in Lublin (Poland) between April 2012 and December 2013. Information on medical history and lifestyle characteristics was obtained from all subjects by a questionnaire (S1 Table). From the group of interest, we excluded those with the presence of different potential causes of liver disease: (a) seropositivity for HBsAg or anti-HCV antibody, (b) daily alcohol consumption over 20g, (c) treatment with hepatotoxic, steatosis-provoking, or immunosuppressive drugs during the previous 6 months, (d) Wilson’s disease or haemochromatosis. Other exclusion criteria included T2DM, malignancy, clinical atherosclerosis, hematological or chronic kidney diseases, active infection, metformin treatment, and smoking. Finally, we chose 48 individuals, all Caucasians of Polish descent, who had never been treated due to liver diseases before. The control group comprised 22 healthy individuals undergoing a routine health check-up program. Informed written consent was obtained from all participants in this study, which was conducted according to the ethical principles stated in the Declaration of Helsinki and approved by the institutional review board at the Medical University in Lublin, Poland (Permit Number: KE-0254/112/2011).