Vitamin E Supplementation and Plasma 8-Isoprostane and Adiponectin in Overweight Subjects

Authors

  • Wayne H. F. Sutherland,

    Corresponding author
    1. Medicine Section, Department of Medical and Surgical Sciences, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
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  • Patrick J. Manning,

    1. Medicine Section, Department of Medical and Surgical Sciences, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
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  • Robert J. Walker,

    1. Medicine Section, Department of Medical and Surgical Sciences, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
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  • Sylvia A. De Jong,

    1. Medicine Section, Department of Medical and Surgical Sciences, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
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  • Anne R. Ryalls,

    1. Medicine Section, Department of Medical and Surgical Sciences, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
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  • Elizabeth A. Berry

    1. Medicine Section, Department of Medical and Surgical Sciences, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
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Medicine Section, Department of Medical and Surgical Sciences, University of Otago, P.O. Box 913, Dunedin, New Zealand. E-mail: wayne.Sutherland@stonebow.otago.ac.nz

Abstract

Objective: Isoprostanes are a marker of oxidant stress and atherosclerotic risk, and plasma concentrations are elevated in obesity. Adiponectin is a regulator of insulin sensitivity, and low circulating levels are associated with oxidant stress and obesity. The aim of this study was to determine the effect of vitamin E supplementation on plasma concentrations of 8-isoprostane and adiponectin in overweight/obese subjects.

Research Methods and Procedures: The study was a 6-month, randomized, double-blind, placebo-controlled trial in 80 overweight subjects (60 women and 20 men, BMI >27 kg/m2). Exclusion criteria were serious illness, smoking, or taking antioxidant supplements. Participants were randomized to receive 800 IU/d natural vitamin E (n = 39) or placebo (n = 41) for 3 months with an increase in the dose to 1200 IU/d for a further 3 months. Plasma 8-isoprostane and adiponectin concentrations were measured at baseline and 3 and 6 months.

Results: During 6 months of supplementation with vitamin E, plasma vitamin E concentration increased significantly (p < 0.001) by 76%, and plasma 8-isoprostane concentrations decreased significantly (−11%, p = 0.03), whereas plasma adiponectin concentrations did not change significantly.

Discussion: These findings suggest that supplementation with high-dose vitamin E decreases systemic oxidative stress and 8-isoprostane concentrations in overweight/obese individuals. A decrease in plasma 8-isoprostane has the potential to reduce risk of cardiovascular disease in obesity.

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