Activity of tissue plasminogen activator and plasminogen activator inhibitor in noninsulin-dependent diabetes mellitus.

The activity of free tissue plasminogen activator (f-tPA) and plasminogen activator inhibitor (PAI) in the plasma of 82 noninsulin-dependent diabetics (NIDDM) was measured by bioimmunoassay of the euglobulin fraction obtained from the plasma, and the levels were compared with those of age- and gender-matched normal subjects. Comparison of these levels in both groups revealed that the f-tPA activity tended to be lower in NIDDM than in the controls, although the differences were not significant. Normal activity of PAI was seen, but f-tPA in NIDDM, when accompanied by macroangiopathy such as ischemic heart disease, was significantly depressed. When glycosylated hemoglobin levels were in excess of 10%, the f-tPA activity was significantly decreased, but no reduction was found in PAI activity as compared with controls. When NIDDM is associated with either macroangiopathy or high glycosylated hemoglobin levels, a decreased f-tPA activity, rather than an increased PAI activity, may contribute to the development of a defective fibrinolytic state.