Previous studies hypothesised that vitamin E could protect against coronary
heart disease and vascular complications in diabetes, but no studies have
been performed regarding its eventual effects on fibrinolysis. Nevertheless
, in Type 2 diabetes mellitus (T2DM) a profound reduction in the fibrinolyt
ic activity has been demonstrated to be involved in vascular complications,
probably due to plasminogen activator inhibitor type 1 (PAI-1) overproduct
ion. On this basis we aimed to verify whether an antioxidant treatment with
vitamin E is able to lower PAI-1 plasma levels in T2DM, Thirteen T2DM pati
ents (9 males and 4 females; mean age +/- SD, 64.4 +/-3.3 yr) were selected
through strict admission criteria. These patients were treated with vitami
n E (500 IU/die) for 10 weeks. Glyco-lipometabolic, oxidative and haemocoag
ulative parameters were evaluated at baseline and after 5, 10, 30 and 60 we
eks. Vitamin E levels at different times were [median (interquartile range)
] 6.1 (5.3-7.7), 8.5 (7.3-9.9), 9.7 (8,9-12,9), 5.6 (4.4-6.8), 5.7 (4.5-7.1
) mug/ml, respectively. Significant differences were found for PAI-1 antige
n (p=0.006), PAI-1 activity (p=0.028), apolipoprotein B (p=0.015) and antio
xidant defence, evaluated as ferric reducing ability of plasma (FRAP) value
s (p=0.005). Particularly, decrements were detected for PAI-1 antigen betwe
en baseline and the 10(th) week (p <0.05), followed by an increase back to
basal at the 30(th) week. Similar behaviour was found for PAI-1 activity. R
egarding the antioxidant defence, FRAP values increased until the 30(th) we
ek (p <0.05) with a decrease at the 60(th) week. These results demonstrate
that vitamin E is able to lower PAI-1 levels in diabetic patients but this
effect does not seem related to improvements of glycometabolic data or to t
he increase in FRAP values, suggesting that PAI-1 overproduction can be dec
reased by other effects of vitamin E on endothelial cells. (C) 2001. Editri
ce Kurtis.