Different metabolic correlations of thrombin-activatable fibrinolysis inhibitor and plasminogen activator inhibitor-1 in non-obese type 2 diabetic patients

We investigated the plasma levels of thrombin-activatable fibrinolysis inhibitor (TAFI), plasminogen activator inhibitor-1 (PAI-1) and their relation with clinical and metabolic parameters in non-obese type 2 diabetic patients. The plasma levels of TAFI and PAI-1 were evaluated in 47 non-obese type 2 diabetic patients and 31 normal subjects. The intra-abdominal visceral and subcutaneous fat areas were measured by computed tomography (CT). The degree of insulin resistance was evaluated by the euglycemic-hyperinsulinemic clamp technique using artificial pancreas. The plasma levels of TAFI (169.0 ± 108.8% versus 103.7 ± 52.3%; p < 0.001, mean ± S.D.) and PAI-1 (82.7 ± 54.5 ng/ml versus 52.9 ± 51.7 ng/ml; p < 0.05) were significantly higher in non-obese type 2 diabetic patients than in normal subjects. Univariate analysis showed that the plasma TAFI levels are significantly and inversely correlated with the glucose infusion rate (GIR) (r = −0.42, p < 0.005) in all diabetic patients. Moreover, the plasma levels of TAFI were significantly correlated with fasting plasma glucose levels (r = 0.47, p < 0.001) and HbA1c (r = 0.38, p < 0.005) in all subjects. The plasma levels of PAI-1 were significantly and proportionally correlated with the visceral fat area (r = 0.42, p < 0.005) and body mass index (r = 0.33, p < 0.05). There was no significant correlation between plasma levels of TAFI and PAI-1 (r = 0.04). These results show that the plasma levels of TAFI and PAI-1 differently correlate with insulin resistance and visceral fat accumulation, suggesting that different factors are implicated in the plasma elevation of TAFI and PAI-1 in non-obese type 2 diabetes mellitus.