Inclusion Criteria:  The ESRD group  Men/women between 18 and 75 years of age Chronic haemodialysis-treated ESRD for at least 3 months Dialysis access via a fistula or a permanent catheter Normal liver function (alanine aminotransferase (ALAT), aspartate aminotransferase (ASAT), albumin and coagulation factor II, VII and X (INR) within normal range, Informed consent  The cirrhosis group  Men/women between 18 and 75 years of age Verified diagnosis of cirrhosis - Child-Pugh Score of 5-12 Normal kidney function (estimated glomerular filtration rate (eGFR) above 60 ml/min/1.73m2 and absence of proteinuria) Informed consent  The control group  Men/women between 18 and 75 years of age Normal kidney function (estimated glomerular filtration rate (eGFR) above 60 ml/min/1.73m2 and absence of proteinuria)(plasma creatinine ≤105 micromol/L (µM) for men and ≤90 µM for women) Normal liver function (alanine aminotransferase (ALAT), aspartate aminotransferase (ASAT), albumin and coagulation factor II, VII and X (INR) within normal range Informed consent  Exclusion Criteria:  All groups  Diagnosis of diabetes and/or HbA1c ≥43 mmol/mol and/or fasting plasma glucose ≥6 mmol/l. Previous kidney transplantation with remaining kidney graft Present treatment with oral glucocorticoids Polycystic kidney disease Pregnancy or breastfeeding Inflammatory bowel disease Surgical procedure within the last 3 months Haemoglobin < 6 mmol/l (women) or < 7 mmol/l (men) First-degree relatives with diabetes Any condition that the investigators feel would interfere with trial participation