The efficacy of low dose aspirin appears to be substantially lower in diabetic patients, compared to patients without diabetes. The aim of the investigators study is to test the laboratory response to different dosing of aspirin in type 2 Diabetes Mellitus. The investigators will compare the regular dose of 75mg once daily to 75 mg twice daily or to 320 mg once daily. The hypothesis of the study is that twice daily dosing of aspirin may improve the response to aspirin.

Inclusion Criteria:

• Type 2 DM with micro- or macroangiopathy.
• HbA1c 6-9 % (Mono-S method).
• Need for, or already on-going aspirin treatment.
• Age 50-75 years
• Antecubital forearm veins allowing technically good sampling for platelet studies

Exclusion Criteria:

• Diet controlled DM.
• Acute ischemic stroke, acute coronary syndrome, (myocardial infarction or unstable angina pectoris), or revascularization by PCI or by-pass surgery within the last 6 months.
• Acute or chronic kidney disease (P-cystatin C within the reference interval)
• Acute or chronic liver disease (ALAT ≤2 times the upper reference value).
• A history of gastric or duodenal ulcer disease.
• Need for treatment with anticoagulants, clopidogrel, NSAID's, or thiazolidinediones.
• Thrombocytopenia (platelet count <150 x 109/L)
• Anticipated need for alteration of concomitant drug therapy during the course of the study.
• Enrollment in another clinical study.
• Contraindication(s) to aspirin treatment.