NUTRITIONAL ANTIOXIDANTS, RED-CELL MEMBRANE FLUIDITY AND BLOOD-VISCOSITY IN TYPE-1 (INSULIN-DEPENDENT) DIABETES-MELLITUS

The study was designed to evaluate whether the antioxidant nutrients s elenium, vitamin A, and vitamin E are associated with alterations of b lood viscosity in patients with insulin-dependent (Type 1) diabetes me llitus (IDDM). We assessed selenium concentrations in plasma and red b lood cells (RBC), glutathione peroxidase activity in REC, vitamin A an d vitamin E, and the viscosity of whole blood and plasma in 20 patient s with IDDM and 20 sex, age and body mass index-matched healthy contro ls. While selenium was not altered in plasma in IDDM, it was markedly decreased in RBC of IDDM (1.24 +/- 0.32 vs 0.92 +/- 0.38 mu mol l(-1), p = 0.006) correlating negatively with the elastic and viscous compon ent of whole blood viscosity. Plasma viscosity increased with stage of retinopathy. Mean glutathione peroxidase activity in RBC was reduced in IDDM (5.78 +/- 0.77 vs 5.13 +/- 1.03 U gHb(-1), p = 0.029). In IDDM with normal renal function (creatinine less than or equal to 97.2 mu mol l(-1), no albuminuria) vitamin A was significantly reduced (1.26 /- 0.62 vs 1.89 +/- 0.56 mu mol l(-1), p = 0.005). Vitamin A levels in creased with impaired renal function. They strongly correlated with pl asma creatinine (r = 0.86, p < 0.001) and plasma viscosity (r = 0.71, p = 0.001). However, in vitro experiments with different vitamin A pla sma concentrations indicated that this particular correlation may not represent a causal one, No changes in vitamin E were found in IDDM. We conclude that reduced selenium concentrations in RBC contribute to im paired haemorheology in IDDM patients. Plasma visocisty was not affect ed by the plasma concentrations of vitamins A and E.