Inclusion Criteria:  Age > or equal to 18 years Chronic hemodialysis during 3 months Patients with functioning arteriovenous-fistula assigned to "Center-Hemodialysis" at "Nyresygdomme, AUH Skejby"  Exclusion Criteria:  Active infection Conditions with vomiting or diarrhea Diabetes Active disease being treated with chemotherapy, radiationtherapy, biologic- or similar treatments. Disease under observation can be included. Liver disease Vessels on the upper extremities not suited for cannulation Prednisolone treatment during the last 8 weeks Pregnancy BMI > or equal to 30 or < or equal to 18 Physically or mentally condition that does not allow the project to be completed Language-difficulties that does not allow the project to be completed