OBJECTIVE: Patients with coronary artery disease (CAD) and diabetes show increased inflammatory activation. Thermography detects local inflammatory involvement as heat generation. The aim of this study was to investigate whether patients with CAD and diabetes have increased local heat generation compared with nondiabetic patients. RESEARCH DESIGN AND METHODS: We enrolled patients undergoing percutaneous coronary interventions: 45 diabetic patients and 63 nondiabetic patients, serving as the control group, matched for age, type of clinical syndrome, statin and aspirin intake, and angiographic stenosis (%). Coronary thermography was performed, and temperature difference (DeltaT) between the atherosclerotic plaque and the proximal vessel wall was measured. RESULTS: Patients with diabetes had increased temperature difference compared with nondiabetic patients (DeltaT: 0.17 +/- 0.18 degrees C vs. 0.09 +/- 0.02 degrees C, P = 0.01). Twenty-one diabetic and 22 nondiabetic patients suffered from acute coronary syndromes (ACSs) (P = 0.22). Patients with diabetes and ACSs had increased temperature difference compared with nondiabetic patients with ACSs (DeltaT: 0.29 +/- 0.31 degrees C vs. 0.15 +/- 0.21 degrees C, P = 0.02), which is the same as patients with diabetes and chronic stable angina (DeltaT: 0.09 +/- 0.08 degrees C vs. 0.05 +/- 0.04 degrees C, P = 0.006). Twenty-three diabetic and 30 nondiabetic patients were under therapy with statins (P = 0.72). Patients with diabetes under statins had lower temperature difference compared with untreated patients (DeltaT: 0.11 +/- 0.12 degrees C vs. 0.22 +/- 0.21 degrees C, P = 0.02), which is the same as nondiabetic patients under statins (DeltaT: 0.05 +/- 0.04 degrees C vs. 0.13 +/- 0.18 degrees C, P = 0.01). CONCLUSIONS: Patients with diabetes have increased temperature difference compared with nondiabetic patients. Patients with diabetes under statins showed decreased temperature difference compared with untreated patients, suggesting that statins have a favorable effect in patients with diabetes and CAD.