Blood's increased transient resistance in diabetes is generated by its fibrinogen and globulin content

Blood manifests a rapidly recovered form of thixotropy called transient resistance. Thixotropy and transient resistance are closely related to each other. Both are elevated in diabetes. Transient resistance has been shown to be mediated by the need to restore the orientation of individual red blood cells as flow becomes reestablished. In resting blood, the red cells start as rouleaux that must be disrupted to start flow. The red cells are able to form enough structure between heartbeats to generate a sharp resistance peak as blood flows in arteries during the next systole. Transient resistance measures this peak load in arteries due to the predilection of red blood cells to aggregate. Transient resistance and plasma fibrinogen are both elevated in diabetes. A recent analysis of Diabetes Control & Complications Trial (DCCT) patients has shown a strong relation between fibrinogen and total globulin levels and the development of diabetic eye and kidney complications. The complications were measured as major end points in that study. DCCT blood viscosity and thixotropy results have already been reported in this journal. They were developed in a study of 45 DCCT patients in Tampa. Both fibrinogen and hemoglobin A1c levels were shown to influence low shear rate blood viscosity. Total globulin is not elevated in diabetes. Its linkage to the development of diabetic complications therefore has particular interest. Some details of the already reported study have greater interest now than when the report was prepared. They are reported now because of their relation to the recently discovered roles of fibrinogen and total globulin levels. The new findings of interest are a close relation between low shear rate blood viscosity and transient resistance. Fibrinogen influences both. Total globulin influences transient resistance but not low shear rate viscosity. Transient resistance is made higher by fibrinogen and total globulin levels linked to diabetic complications and generates a peak systolic flow resistance.