Principles for the design of rheological studies in diabetes mellitus

Abstract

The reduced red cell deformability which has been demonstrated in badly controlled diabetic patients is an end point resulting from different abnormalities. Moreover, diabetes is an heterogeneous disease that is associated with various pathological alterations. This review outlines some of the numerous factors influencing blood rheology in diabetes mellitus. The volume, membrane, intracellular milieu, and life span of the red cells are abnormal; all of these parameters may be linked with the cell rheological properties. The diabetic population is heterogeneous. Blood glucose varies from subject to subject and in the same patient from time to time. Plasma insulin may be low (in type I insulin dependent patients) normal or even high (in type II non insulin dependent obese diabetic patients). A lot of metabolic substrates and hormones are modified and liable to influence rheological properties of the red cells. Diabetes is often associated with hyperliproteinemia, arterial hypertension, cardio-vascular disease, or renal insufficiency - all of these conditions may modify blood rheology. Finally, the variability of treatments used, such as modification of the diet, and the various forms of insulin therapy, is another parameter which has to be taken into account. Therefore, attempts should be made to study diabetic patients that have been selected as carefully as possible and to use clinical models in which the above variables can be controlled or are known to be negligible in their effect.