BACKGROUND: Cell adhesion molecules (CAMs) have been shown to be highly expressed in atherosclerotic lesions. Membrane-bound CAMs allow the tethering and rolling of monocytes and lymphocytes as well as the firm attachment and transendothelial migration of leukocytes. Soluble forms of CAMs may serve as monitors for increased expression of membrane-bound CAMs and thus may reflect progressive formation of atherosclerotic lesions. We assessed the role of the solu-ble CAMs in patients with type 2 Diabetes. METHODS: Serum levels of soluble E-selectin (sE-selectin), soluble intercellular adhesion molecule-1 (sICAM-1), and soluble vascular cell adhesion molecule-1 (sVCAM-1) were measured by enzyme immunoassay (R and D Systems, Minneapolis, USA) in patients with type 2 Diabetes (n=69) and normal control subjects (n=38). RESULTS: Fasting blood sugar, serum cholesterol, and blood pressure were significantly (P < 0.001) higher in diabetic patients than in control subjects. Serum sE-selectin, sICAM-1, and sVCAM-1 concentrations in diabetic patients were significantly (P < 0.001) higher than in the control subjects (69.7 +/- 32.0, 257.1 +/- 73.0 and 813.8 +/- 322.6 ng/mL versus 43.3 +/- 19.5, 173.1 +/- 66.8, and 400.4 +/- 77.4 ng/mL, respectively). The serum sICAM-1 concentrations in diabetic patients with microalbu-minuria were significantly (P=0.004) higher than in those patients without microalbuminuria (311.3 +/- 79.0 ng/mL versus 245.2 +/- 60.2 ng/mL). However, the sE-selectin and sVCAM-1 concentrations in diabetic patients with microalbuminuria were only slightly (P < 0.10) higher than in the patients without microalbuminuria. CONCLUSIONS: These results suggest that three kinds of circulating CAMs measured in this study increased significantly in patients with type 2 Diabetes. It is considered that circulating CAMs may be markers for atherosclerotic lesions in patients with type 2 Diabetes with symptomatic and asymptomatic atherosclerosis.