This study aims to measure the effect of GLP-1 analogues on non-alcoholic fatty liver disease in patients with diabetes and/or obesity in a clinical context. Previous studies showed a positive effect of this medication, but these studies always took place in highly controlled settings. The question is to what extent liver values evolve in a non-controlled context. The real effect and thus the clinical utility of GLP-1 analogues will be measured.

This study aims to measure the effect of GLP-1 analogues on non-alcoholic fatty liver disease in patients with diabetes and/or obesity in a clinical context. Previous studies showed a positive effect of this medication, but these studies always took place in highly controlled settings. The question is to what extent liver values evolve in a non-controlled context. The real effect and thus the clinical utility of GLP-1 analogues will be measured.

Patients in whom a GLP-1 analogue is started (as it would be outside the context of this study) may be recruited. Patients in whom a GLP-1 analogue was started 12 months earlier are also eligible. Once they were screened on the inclusion and exclusion criteria and they took into account and signed the informed consent, they can be definitively included. Participants will be followed for 12 months. There are 2 contact points, the first on the start day and the second after 12 months. During this period, serum markers of liver injury, type 2 diabetes and dyslipidaemia are monitored. With these, additional scores for hepatic steatosis (NAFLD liver fat score) and fibrosis (FIB-4 index) are calculated. A fibroscan (or elastography) is also performed to monitor the evolution of hepatic steatosis and fibrosis. The evolution of data is statistically analysed and hereby compared with the starting points.

Inclusion Criteria:

• The patient is older than 18 years old.
• The patient has obesity, defined as a BMI of 30 or higher; and/or the patient suffers from T2DM, defined as a twice measured sfG of 125 mg/dl or higher, or a sfG of 100 to 125 mg/dl and a twice measured oral glucose tolerance test (OGTT) with a serum glucose (sG) of 200 mg/dl, or higher after 2 hours, or a random sG of 200 mg/dl or higher in symptomatic patients.
• The patient suffers from NAFLD in any stage, except cirrhosis. This has to be objec-tively diagnosed by either a CAP fibroscan (cutoff: > 238 dB/m); or by the calculated NAFLD liver fat score (cutoff: > -0,64), at least one of which has to be positive.
• The patient is starting a GLP-1 analogue as treatment for T2DM or obesity as would be prescribed outside of this study; or the patient has started a GLP-1 analogue as treatment for T2DM or obesity as would be prescribed outside of this study 12 months prior.
• If the patient is part of the retro-prospective branch data collected 12 months prior include at least a (CAP) fibroscan, a blood sample (measuring AST, ALT, GGT, sfG, sfI, HbA1c, HDL, LDL, total cholesterol and platelets) and a physical examination (measuring blood pressure, waist circumference, weight and length).

Exclusion Criteria:

• The patient suffers from alcohol induced fatty liver disease. Macrocytic anemia; de-creased vitamin B12 and folic acid; increased GGT, bilirubin, ferritin, TG and AST/ALT ratio can be used as serum markers of alcohol abuse. Interpretation of these results will be the left to the patient's clinician and their clinical expertise. Alterna-tively a weekly alcohol consumption of 21 units for men and 14 units for women can be used as a cutoff.
• The patient suffers from drug induced liver steatosis. Drugs warranting exclusion include glucocorticoids, amiodarone, tamoxifen, methotrexate, valproate, tetracycline and chemotherapeutic agents.
• The patient suffers from any other chronic liver disease. These will be checked trough lab test results in the patients file.
• The patient has liver cirrhosis, defined as a fibroscan score of 14 kPa or more; or a FIB-4 index of > 2,67. Elastography
• The patient is pregnant at time of enrolment or at any time during the study.
• The patient refuses to agree to the informed consent.

Participants will be recruited from consultations in the diabetes- and obesity clinic in UZ Brussel. All diabetic and/or obese patients with objectified NAFLD starting a GLP-1 analogue, or whom have started a GLP-1 analogue 12 months prior, will be considered as possible candidates. Inclu-sion is definite after it is established that patients comply to all inclusion- and exclusion criteria and they agree to the informed consent.

adverse events were followed for 1 year after informed consent was given.

This study was purely observational for the patients. Everything in the study was done as part of the standard of care, therefor only SAE's were followed up. However no SAE occurred during the study.