ИСТИНА

Diabetes mellitus is a systemic disease that is gaining higher and higher social problem due to the quickly growing number of Earth population suffering from it and due to severe alterations of vitally important systems of the human organism involved including the cardiovascular system. Diabetes is a group of metabolic diseases, characterized by high blood sugar level in the blood of patients, because the pancreas does not produce enough insulin (insulin-dependent diabetes mellitus, abbreviated IDDM), or because cells do not respond to the insulin that is produced (non-insulin-dependent diabetes mellitus, abbreviated NIDDM). This high blood sugar produces the classical symptoms of polyuria (frequent urination), polydipsia (increased thirst) and polyphagia (increased hunger). Globally, as at 2013, an estimated number of 382 million people have diabetes worldwide. In 2012 diabetes resulted in 1.5 million deaths worldwide making it the 8th leading cause of death. Its rate has increased, and by 2030, this number is estimated to almost double. Diabetes mellitus occurs throughout the world, but is more common (especially NIDDM) in more developed countries. Diabetes without proper treatments can cause many complications. Acute complications include hypoglycemia, diabetic ketoacidosis, or nonketotic hyperosmolar coma. Serious long-term complications include chronic renal failure and diabetic retinopathy (retinal damage). The major long-term diabetes complications are related to the damage to blood vessels and capillaries (causes microangiopathy) and impairment of blood rheological properties and lead to doubling the risk of cardiovascular diseases. Based on the above, it is obvious that control and monitoring of diabetic complications is very important. Thus, it is necessary to control the parameters of the blood flow (during diabetes diagnostics and treatment), in particular microrheological and rheological parameters. The rheological parameters are mostly related to the deformability and aggregation properties of red blood cells, which are expected to be impaired in diabetic patients. The main goal of this work was to estimate the alterations of these parameters for rat and human blood in case of diabetes diseases. In this work, we conducted measurements with Laser Aggregometer – Deformometer of Erythrocytes – LADE-6 (RheoMedLab, Russia) and Rheoscan (Rheomeditech, Korea). Operation of this device is based on laser aggregometry and diffractometry techniques. Laser diffractometry is one of the convenient, fast and relatively simple techniques for measuring the erythrocytes deformability in blood samples. Deformability of red blood cells characterizes the ability of red blood cells to deform passing through the thin blood vessels and capillaries. Laser aggregometry technique is allows to register the kinetics of the spontaneous aggregation and disaggregation of RBCs for obtaining characteristic times of linear and three-dimensional aggregates formation, as well as hydrodynamic strength of erythrocytes. All experimental measurements were performed with human blood drawn from patients with diabetes mellitus (23 patients) and practically healthy volunteers (12 volunteers), as well as with rat blood drawn from healthy individuals (8 samples) and from rats with experimentally induced diabetes. The experimentally obtained results show that the microcirculation gets impaired due to the alterations of the blood microrheology properties in case of diabetes diseases. For instance, the ability of red blood cells to deform in shear flow decreases about 8-10 % in comparison with control group. Characteristic time of three-dimensional aggregates formation decreases about 20-60 % (both in cases of IDDM and NIDDM) in comparison with healthy blood. Alterations of the related parameters obtained with Rheoscan are quantitatively different and more pronounced.