Effect of alpha-tocopherol on the metabolic control and oxidative stress in female type 2 diabetics

In this study we evaluate the effects of alpha-tocopherol on the metabolic control and oxidative stress in female patients with type 2 diabetes mellitus. Thirty-four female type 2 diabetics 40-70 years old up to 14 years with diabetes, under medical treatment, were randomly divided in two groups. One group received placebo (Control group, n = 21) and the other received alpha-tocopherol (800 IU/day, n = 13) during 6 weeks. Blood samples were collected at the beginning and at the end of the study to measure malondialdehyde production, glycated hemoglobin, selenium dependent-glutathione peroxidase, Cu,Zn-superoxide dismutase in erythrocytes and total antioxidant status, glucose, lipid and lipoproteins in serum. Erythrocyte malondialdehyde decreased and serum-total antioxidant status increased after alpha-tocopherol treatment (P < 0.0001). However, an unexpected increase on cholesterol levels and a reduced erythrocyte-Cu,Zn-superoxide dismutase activity was observed after alpha-tocopherol treatment. alpha-Tocopherol administration did not affect glucose, glycated hemoglobin, triacylglycerides, lipoprotein levels and serum malondialdehyde. A minor oxidative stress was observed in female type 2 diabetic patients after alpha-tocopherol treatment inferred from the reduced levels of erythrocyte malondialdehyde and the increased values of total antioxidant status. On the other hand, no beneficial changes were observed on glycemic control or lipid metabolism.