Decrease in urokinase-type plasminogen activator (u-PA) levels in patients with non-insulin dependent diabetes mellitus

The objective of the study was to investigate the activity and antigen levels of u-PA in non-insulin dependent diabetes mellitus (NIDDM) patients, and their changes after venous stasis. A cross-sectional case-control study was carried out in the out-patient diabetelogy clinical unit of the General Hospital in Pescara, Italy. Fifty-nine unselected NIDDM patients (23 females and 36 males; mean age 63 ± 10, with diabetes definition by WHO criteria) were studied. A group of 50 subjects, age matched (age 58 ± 9, 42 males, 8 females), without a history of diabetes, were consecutively recruited among healthy relatives of patients admitted to the hospital for surgical interventions to serve as a control group. The levels of both u-PA activity (scu-PA) and antigen (u-PA Ag) were significantly lower in NIDDM patients compared to controls, in contrast, t-PA, PAI-1 antigan and PAI activity levels were increased in NIDDM patients. There was no change in u-PA levels (bath activity and antigen) after venous stasis, while t-PA levels were significantly increased. There was no difference in u-PA (both activity and antigen) and in t-PA levels between male and female patients. However, fibrinogen levels were lower and PAI-1, both antigen and activity, was higher in men than in women. No difference was found between patients with and without macrovascular complications in the parametres studied. Besides changes in t-PA and PAI-1 levels, NIDDM is also characterized by a decrease in u-PA activity and antigen levels. Such impairment of the fibrinolytic system, together with the increase in fibrinogen levels, could contribute to the prothrombotic condition peculiar to these patients.