Blood rheology in diabetes mellitus and its complications : assessment of new methods

• Main Author: MacRury, Sandra M
• Format: Dissertation
• Language: English
• Published: University of Glasgow 1990

This thesis reviews blood rheology and its known associations with diabetes mellitus and vascular complications in diabetic patients. The relationship between blood viscosity and two conditions which are common in diabetes, namely hypertension and peripheral neuropathy, was examined for the first time. Type 2 (non-insulin dependent) diabetics with hypertension were found to have increased blood viscosity compared with normotensive type 2 diabetics. Blood viscosity and red cell deformability were measured in diabetic patients with peripheral neuropathy. When compared with diabetics who have no evidence of neuropathy but were matched for other microvascular complications, no differences were found. Using the recently-introduced Carri-Med filtrometer, red cell deformabiltiy was assessed by filtration through Nuclepore membranes in a large group of type 1 (insulin-dependent) and type 2 diabetic patients. Compared with healthy control subjects, deformability was impaired in all diabetic patients, but to a greater extent in type 1 patients. In the control population, red cell filterability was related to mean cell volume; while in diabetic patients, it was related to mean cell haemoglobin concentration. Within the diabetics, red cell filtration was not significantly different in patients with microvascular or macrovascular complications. Red cell aggregation was measured in the new Myrenne photometric aggregometer and found to be increased in both type 1 and type 2 diabetic patients, particularly hypertensive type 2 diabetics. Aggregation was found to be related to plasma triglyceride and very low density lipoprotein levels. Deformability of white cell subpopulations was measured by a filtration method in type 2 diabetics, and although non significant differences were found when compared with non-diabetic control subjects, a correlation of both mononuclear and polymorphonuclear cell filtration pressure was demonstrated with glycaemic control. The implications of the findings in these studies are discussed, and suggestions for further rheology studies in diabetic patients are proposed.