Kallikrein-kinin system in diabetic patients.

Various factors in the kallikrein-kinin (K-K) system were examined in diabetic patients, and their clinical significance was evaluated. The plasma prekallikrein level was slightly increased in the entire diabetic group, but was decreased in the patients with microangiopathy. While the plasma kallikrein-like activity was increased in the diabetic patients. The urinary glandular kallikrein activity was decreased in the diabetic patients, and was significantly correlated with the urinary C-peptide level. High-molecular-weight kininogen was increased in the entire diabetic group. In the patients with microangiopathy its level was significantly lower than in diabetic patients without microangiopathy. Low-molecular-weight kininogen was increased significantly in the diabetic patients. These results suggest that the glandular K-K system is suppressed in diabetic patients and the plasma K-K system in those patients is activated according to the degree of impairment of glucose metabolism, and that changes in the plasma levels of its components are associated with those in the components of the coagulation system.