Background: Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the western world and an important cause of morbidity and mortality including risk of cardiovascular disease. A ruling dogma is that a fatty liver is well-functioning. Recent studies imply the contrary but quantitative measurements of metabolic liver function have not been systematically investigated in NAFLD.

Objectives: To study and quantify specific metabolic liver functions in varying degrees of NAFLD. Furthermore to map the coagulation system of patients with NAFLD.

Methods: A human clinical study. Metabolic liver functions are studied by a series of functional tests (Galactose elimination capacity (GEC), Aminopyrine breath test (ABT), Indocyanine green plasma disappearance rate (ICG-PDR), Functional hepatic nitrogen clearance (FHNC)). Regional liver function evaluated by 2-[18F]fluoro-2-deoxy-D-galactose (FDGal) PET/CT is compared to fat infiltration assessed by Magnetic resonance imaging (MRI). Primary and secondary hemostasis, natural anti-coagulants and fibrinolysis are evaluated.

Perspectives: To challenge the dogma, that hepatic metabolic function is not affected in NAFLD, improving the understanding of the relationship between the clinical degree of NAFLD, histology, metabolic functions, and imaging. Furthermore to disclose a proposed procoagulant imbalance in NAFLD.

Inclusion Criteria:

• Age ≥ 18
• Hepatic steatosis found on ultrasound
• Clinical indication for liver biopsy (typically persistently elevated alanine transaminase (ALT) levels)

Exclusion Criteria:

• Other liver pathology
• Alcohol consumption > 20g/day
• Chronic inflammatory disease, current infection or cancer
• Diabetes mellitus type I, II or HbA1c ≥ 48 mmol/mol (6.5 %)
• Prednisolone treatment within last 8 weeks
• Pregnancy within last 12 months
• Contraindication for MRI

Patients with varying degrees of NAFLD