Plasma t-PA and PAI-1 antigen concentrations in non-insulin dependent diabetic patients: Implication for diabetic retinopathy

Abstract

Parameters of fibrinolysis, including basal plasma tissue type plasminogen activator (t-PA) and plasminogen activator inhibitor type 1 (PAI-1) antigen levels were studied in 49 non-insulin dependent diabetic patients (23 men, 26 women: ages 51.3 ± 14.9 years) and 16 age matched non-diabetic subjects (9 men, 7 women ages 49.8 ± 12.2 years) as a control group. Compared to a control group, the diabetic patients had a significantly higher mean plasma t-PA antigen (4.94 ± 2.68 vs 3.20 ± 2.30 ng/ml) and PAI-1 antigen (34.86 ± 16.71 vs. 17.60 ± 15.36 ng/ml) levels ( P < 0.05). Significant univariate correlations were observed between t-PA and body mass index (BMI) ( P = 0.0009, r = 0.7217), and PAI-1 were positively correlated with BMI and FBS (fasting blood sugar) in the total diabetic patients ( P = 0.0003, r = 0.7217; P = 0.0477, r = 0.2858, respectively). In diabetic patients with proliferative diabetic retinopathy, both PAI-1 and t-PA antigen levels were significantly lower than those of diabetic patients with negative or background retinopathy ( P = < 0.05). There were no significant differences of the plasma t-PA and PAI-1 levels between diabetic patients with micro- and macroproteinuria. This study conducted on non-insulin dependent diabetic patients suggests that they have significantly higher t-PA and PAI-1 antigen levels than do control subjects, and these findings appear to correlate negatively with proliferative retinopathy observed among the patients studied.