Hypothesis is that DPP-4 inhibition affects glucose levels through changes in incretin and islet hormones. The study examines this in relation to breakfast, lunch and dinner over an entire 24h study period by the use of three different DPP-4 inhibitors and placebo.

The study is a single-center study with a cross-over design to examine glycemia, incretin hormones and islet hormones over a 24h study period with standardized breakfast, lunch and dinner after administration of placebo, saxagliptin, vildagliptin or sitagliptin.

Inclusion Criteria:

• • Caucasian men or women with type 2 diabetes diagnosed according to ICD10 at time of inclusion

  • Ongoing treatment with life style adjustment including diet and exercise regimen together with metformin as oral antidiabetic . Metformin therapy should be stable the last three months
  • Age 40-75 years
  • HbA1c 52-80 mmol/mol (inclusive)
  • BMI: 20-40 kg/m2
  • Written informed consent has been given
  • Capability and willingness to participate in the whole study

Exclusion Criteria:

• • Liver disease (K70-77 in ICD10) or liver enzymes three times above upper reference range

  • Diabetic nephropathy (GFR < 30 mL/min/1.73 m2 or albuminuria) or other causes of renal disease
  • Proliferative diabetic retinopathy
  • Treatment with any glucose-lowering medication except metformin
  • Previous myocardial infarction, coronary heart disease or instable angina pectoris in the last 6 months.
  • Symptomatic heart failure (NYHA class II-III)
  • Previous surgery on the gastrointestinal tract
  • Larger surgical intervention during the last 12 weeks
  • Female subject who are pregnant or breast feeding
  • Women of child bearing potential not using a highly effective method of birth control
  • Treatment with oral steroids, thiazide diuretics, digoxin or growth hormone
  • Hypersensitivity to the active substances of to any of the excipients
  • Participation in another study the last 4 weeks
  • Smoker
  • Paracetamol intolerance