REDUCING LIPID-PEROXIDATION STRESS OF ERYTHROCYTE-MEMBRANE BY ALPHA-TOCOPHEROL NICOTINATE PLAYS AN IMPORTANT ROLE IN IMPROVING BLOOD RHEOLOGICAL PROPERTIES IN TYPE-2 DIABETIC-PATIENTS WITH RETINOPATHY

The effects of alpha-tocopherol nicotinate on blood viscoelasticity an d viscosity and on lipid peroxidation stress in erythrocyte membranes in patients with Type 2 DM were investigated. Thirteen Type 2 diabetic subjects with retinopathy were given alpha-tocopherol nicotinate 300 mg tds, after meals, for 3 months. The treatment resulted in significa nt reductions of blood viscosity at different shear rates (e.g. -2.231 +/- 2.82 p<0.015, gamma = 1.5 s(-1)) and viscoelasticity (p<0.004); r esistance of erythrocyte deformation (p<0.001) and lipid peroxidation stress in red cell membrane (malondialdehyde or MDA reduced by 0.17 +/ - 0.13 nmol l(-1) p<0.005). Plasma viscosity, red cell rigidity, and H bA(1c) were unchanged. There were negative linear correlations between the indices of red cell deformability and the levels of MDA of red ce ll membrane both pre- and post-treatment (e.g. R = -0.79, p<0.001; R = -0.78, p < 0.002, n = 13; pre- and post-, respectively). We suggest t hat the improvements of rheological properties of blood and red cell d eformability by ol-tocopherol nicotinate are mainly attributed to redu cing lipid peroxidation stress on membrane of red blood cells. The tre atment may be useful in slowing deterioration of microangiopathy in Ty pe 2 DM. (C) 1998 John Wiley & Sons, Ltd.