A SIGNIFICANT RELATIONSHIP BETWEEN PLASMINOGEN-ACTIVATOR INHIBITOR TYPE-1 AND LIPOPROTEIN(A) IN NON-INSULIN-DEPENDENT DIABETES-MELLITUS WITHOUT COMPLICATIONS

We previously found a relationship between plasminogen activator inhib itor type-1 and lipoprotein(a) in non-insulin-dependent diabetes melli tus and hypothesized that this could be due to a compensatory mechanis m able to lower the risk of hypofibrinolysis found in type II diabetes mellitus. The aims of the present study were: (1) to confirm the asso ciation between plasminogen activator inhibitor type-1 and lipoprotein (a) in a different group of non-insulin-dependent diabetes mellitus pa tients and (2) to investigate whether the association could be related to diabetic complications. Other vascular risk factors able to influe nce fibrinolytic parameters such as glycemia, obesity, hypertension, d yslipidemia, and oxidative stress were also considered. Sixty-six non- insulin-dependent diabetes mellitus patients without diabetic complica tions (48 men, 18 women), 45 non-insulin-dependent diabetes mellitus p atients with complications (21 men, 24 women), and 31 control subjects (17 men, 14 women) were studied. Plasma concentrations of lipoprotein (a), plasminogen activator inhibitor type-1 antigen and activity, and the main parameters of lipo- and glycometabolic balance were determine d. Antioxidant defense was assayed as oxygen radical absorbance capaci ty of serum. Statistically significant differences among controls and the two diabetic groups were found for fasting glucose, cholesterol, t riglycerides, and oxygen radical absorbance capacity of serum, while n o statistically significant differences were evident for plasminogen a ctivator inhibitor type-1 antigen and activity and lipoprotein(a). Reg ression analysis of log plasminogen activator inhibitor type-1/lipopro tein(a) showed a significant correlation only in diabetic patients wit hout complications (r = -0.57, P<0.001). These results show that a rel ation ship between plasminogen activator inhibitor type-1 and lipoprot ein(a) is characteristic of a diabetic population without complication s, supporting the suggestion that this relationship could be a compens atory mechanism of the fibrinolytic system to limit the risks of hypof ibrinolysis. A lack or a loss of capacity to balance lipoprotein(a) an d plasminogen activator inhibitor type-1 could contribute to the patho genesis of the diabetic complications.