Determination of alpha-tocopherol in plasma, platelets and erythrocytes of type I and type II diabetic patients by high-performance liquid chromatography.

Vitamin E (alpha-tocopherol) concentrations of plasma, platelets and erythrocytes were determined by HPLC in insulin-dependent (type I) and age-matched non-insulin-dependent (type II) diabetic patients and in two control groups. Plasma alpha-tocopherol levels were significantly increased in diabetic patients compared to control groups. Platelet and erythrocyte alpha-tocopherol levels were not significantly different in type I and type II diabetics as compared to their respective control groups, but differed from one another. Plasma vitamin E concentrations showed a significant correlation with plasma cholesterol and apoprotein B concentrations in different groups. The alpha-tocopherol/cholesterol and alpha-tocopherol/apoprotein B ratios in plasma were higher in diabetic patients, as were triglyceride contents. Platelet vitamin E levels were not significantly correlated with plasma concentrations. These findings suggest that vitamin E activity is altered in diabetic patients but that no diet supplementation seems necessary.