Effect of the DPP-4 Inhibitor Sitagliptin on Islet Function After Mixed Meal in Patients With Type 2 Diabetes

Inclusion Criteria: * Caucasian men with type 2 diabetes diagnosed according to ICD10 * Ongoing treatment with life style adjustment or life style adjustment together with metformin as oral antidiabetic. Metformin therapy should not exceed 2 grams daily * Age 20-75 years * HbA1c ≤80 mmol/mol * BMI: 20-40 kg/m2 Exclusion Criteria: * Liver disease or ALAT three times above upper reference range * Diabetic nephropathy (GFR \< 50 mL/min/1.73 m2 or albuminuria) * Proliferative diabetic retinopathy * Treatment with any glucose-lowering medication except metformin * Previous myocardial infarction, coronary heart disease or insatiable angina pectoris in the last 6 months. * Previous surgery on the gastrointestinal tract * Larger surgical intervention during the last 12 weeks * Treatment with oral steroids or thiazide diuretics * Treatment with digoxin * Smokers * Participation in another study the last 4 weeks * Paracetamol intolerance