Platelet functional activity in patients with insulin-dependent diabetes mellitus

Platelet aggregability and the reaction of isolation of thrombocytic granules were studied in 17 patients with type 1 diabetes mellitus with and without vascular involvement over the course of therapy with human insulin preparations (Lilly, France). Platelet aggregation in response to low concentrations of ADP and adrenalin was found increased; in patients with angiopathies no changes were induced by 5 mcM of ADP and collagen. In the patients without vascular involvement platelet aggregation was the same as in donors. The content of ATP released in the course of ADP or collagen-included aggregation reduced in the diabetics in comparison with donors irrespective of the presence of vascular complications, the lower level of ATP observed, however, in the patients without angiopathies. Our data indicate platelet hyperactivation and devastation of platelet granules in uncomplicated diabetes mellitus. Therapy with Lilly insulins was conducive to recovery of the functional activity of platelets which normalized 6 weeks after therapy was started, no matter what types of insulin were administered. The detected changes seem to be largely due to the effects of insulins proper but not so much to the compensation of glucose level, because they were unidirectional in the groups of patients with subcompensated and compensated diabetes.</jats:p

Biosynthetic insulin effect on red cell membrane lipid peroxidation in patients with insulin-dependent diabetes

The aim of our research was elucidation of a relationship between red cell membrane lipid peroxidation (LPO) and antioxidant' defense enzymes, on the one hand and the age disease duration and presence of vascular complications in patients with type I diabetes mellitus on the other. The possibility of correcting red cell peroxide status with human insulin preparations was investigated. Red cell membrane LPO was found increased more than twofold and antioxidant defense enzymes activities virtually unchanged vs. controls in 16 patients with diabetes aged 20 to 43. These characteristics of red cell peroxidation status do not depend on patients age disease standing or presence of vascular complications. A twelve-week therapy with biosynthetic insulin resulted in complete normalization of LPO processes in patients with angiopathies aged under 35 and with disease standing of less than 10 years. In diabetics with angiopathies aged over 35 and disease standing of more than 10 years red cell MDA level reduced under the effect of therapy with human insulin preparations but was still increased vs. that in healthy donors by 1.5 times. Red cell GP and SOD activities reduced in the course of insulin therapy in all the examined groups of diabetics. Catalase activity increased by approximately 50% in patients with angiopathies those aged over 35 and a disease standing of more than 10 years under the effect of insulin. In the rest groups of patients catalase activity did not differ from its initial level. Our results permit us recommending besides human insulin preparations antioxidant therapy for patients with vascular complications those aged over 35 and a disease standing of more than 10 years.</jats:p