Effects of -Tocopherol and Mixed Tocopherol Supplementation on Markers of Oxidative Stress and Inflammation in Type 2 Diabetes
Wu, J.H.Y., Ward, N.C., Indrawan, A.P., Almeida, C.M., Hodgson, J.M., Proudfoot, J.M., Puddey, I.B. and Croft, K.D. (2007) Effects of -Tocopherol and Mixed Tocopherol Supplementation on Markers of Oxidative Stress and Inflammation in Type 2 Diabetes. Clinical Chemistry, 53 (3). pp. 511-519.
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Background: Vitamin E isomers may protect against atherosclerosis. The aim of this study was to compare the effects of supplementation with either α-tocopherol (αT) or mixed tocopherols rich in γ-tocopherol (γT) on markers of oxidative stress and inflammation in patients with type 2 diabetes. Methods: In a double-blind, placebo-controlled trial, 55 patients with type 2 diabetes were randomly assigned to receive (500 mg/day) (a) αT, (b) mixed tocopherols, or (c) placebo for 6 weeks. Cellular tocopherols, plasma and urine F 2-isoprostanes, erythrocyte antioxidant enzyme activities, plasma inflammatory markers, and ex vivo assessment of eicosanoid synthesis were analyzed pre-and postsupplementation. Results: Neutrophil αT and γT increased (both P <0.001) with mixed tocopherol supplementation, whereas αT (P <0.001) increased and γT decreased (P <0.005) after αT supplementation. Both αT and mixed tocopherol supplementation resulted in reduced plasma F 2-isoprostanes (P <0.001 and P = 0.001, respectively) but did not affect 24-h urinary F 2-isoprostanes or erythrocyte antioxidant enzyme activities. Neither αT nor mixed tocopherol supplementation affected plasma C-reactive protein, interleukin 6, tumor necrosis factor-α, or monocyte chemoattractant protein-1. Stimulated neutrophil leukotriene B 4 production decreased significantly in the mixed tocopherol group (P = 0.02) but not in the αT group (P = 0.15). Conclusions: The ability of tocopherols to reduce systemic oxidative stress suggests potential benefits of vitamin E supplementation in patients with type 2 diabetes. In populations with well-controlled type 2 diabetes, supplementation with either αT or mixed tocopherols rich in γT is unlikely to confer further benefits in reducing inflammation.
|Publication Type:||Journal Article|
|Murdoch Affiliation:||Centre for Clinical Immunology and Biomedical Statistics|
|Publisher:||American Association for Clinical Chemistry Inc.|
|Copyright:||© 2007 American Association for Clinical Chemistry.|
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