A study on the action of vitamin E supplementation on plasminogen activator inhibitor type 1 and platelet nitric oxide production in type 2 diabetic patients

Background and aim: Type 2 diabetic (T2DM) patients show decreased fibrinolysis, mainly linked to high plasminogen activator inhibitor type 1 (PAI-1) production, together with a reduced bioavailability of nitric oxide and an impairment in Na+/K+-ATPase activity possibly involved in increased cardiovascular risk. Vitamin E is the major natural lipid-soluble antioxidant in human plasma. The present work was conducted in order to measure PAI-1, ICAM and VCAM-1 plasma levels, platelet nitric oxide production and membrane Na+/K+-ATPase activity in type 2 diabetic subjects treated with vitamin E (500 IU/day) for 10 weeks and then followed for other 20 weeks. Methods and results: Thirty-seven T2DM patients (24 mates and 13 females) were studied. None of them were affected by any other disease or diabetic complications. Significant differences were detected for PAI-1 antigen (p < 0.001), PAI-1 activity (p < 0.001), nitric oxide (NO) production (p < 0.001), and Na+/K+-ATPase activity (p < 0.001) among the 4 phases of the study. A significant decrease both in ICAM and VCAM-1 plasma levels was also found at the 10th week compared with baseline (respectively p < 0.001 and p < 0.05). Conclusion: Our data suggest that vitamin E counteracts endothelial activation in T2DM patients possibly representing a new tool for endothelial protection. (c) 2007 Elsevier B.V. All rights reserved.