Abstract: Patients with diabetes mellitus develop hyperproteinaemia with a consequential increase in erythrocyte aggregation and blood viscosity. Evidence for a loss of erythrocyte deformability is more controversial, however, with steady-state diabetics showing largely normal rheology when studied by micropipette, ektacytometric, or filtration techniques. Decompensated diabetics with hyperosmolar plasma or a very high intraerythrocytic sorbitol concentration may, however, have impaired erythrocyte deformability. Membrane studies of erythrocytes from diabetics have shown insulin-dependent abnormalities of lipid fluidity, cholesterol/phospholipid ratio, and Na+/K+ ATPase activity but most of the rheological methods used in clinical studies are not yet sufficiently sensitive or specific to assess the rheological consequences of these membrane changes.
