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Supplementation with mixed tocopherols increases serum and blood cell gamma-tocopherol but does not alter biomarkers of platelet activation in subjects with type 2 diabetes.

Abstract

BACKGROUND

Some studies have shown potential benefit of vitamin E on platelet function, but several clinical trials failed to show improved cardiovascular outcome with alpha-tocopherol supplementation. Gamma-tocopherol, a major dietary form of vitamin E, may have protective properties different from those of alpha-tocopherol.

OBJECTIVE

We compared the effects of supplementation with alpha-tocopherol (500 mg) and a gamma-tocopherol-rich compound (500 mg, containing 60% gamma-tocopherol) on serum and cellular tocopherol concentrations, urinary tocopherol metabolite excretion, and in vivo platelet activation in subjects with type 2 diabetes.

DESIGN

Fifty-eight subjects were randomly assigned to receive either 500 mg alpha-tocopherol/d, 500 mg mixed tocopherols/d, or matching placebo. Serum, erythrocyte, and platelet tocopherol and urinary metabolite concentrations were measured at baseline and after the 6-wk intervention. Soluble CD40 ligand, urinary 11-dehydro-thromboxane B2, serum thromboxane B2, soluble P-selectin, and von Willebrand factor were measured as biomarkers of in vivo platelet activation.

RESULTS

Serum alpha-tocopherol increased with both tocopherol treatments. Serum and cellular gamma-tocopherol increased 4-fold (P < 0.001) in the mixed tocopherol group, whereas red blood cell gamma-tocopherol decreased significantly after alpha-tocopherol supplementation. Excretion of alpha-carboxyethyl-hydroxychroman increased significantly after supplementation with alpha-tocopherol and mixed tocopherols. Excretion of gamma-carboxyethyl-hydroxychroman increased significantly after supplementation with mixed tocopherols and after that with alpha-tocopherol, which may reflect the displacement of gamma-tocopherol by alpha-tocopherol due to incorporation of the latter into lipoproteins in the liver. Neither treatment had any significant effect on markers of platelet activation.

CONCLUSIONS

Supplementation with alpha-tocopherol decreased red blood cell gamma-tocopherol, whereas mixed tocopherols increased both serum alpha-tocopherol and serum and cellular gamma-tocopherol. Changes in serum tocopherol closely reflect changes in cellular concentrations of tocopherols after supplementation.

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  • Authors+Show Affiliations

    ,

    Department of Core Clinical Pathology and Biochemistry, Royal Perth Hospital, University of Western Australia, Perth, Australia.

    , , , ,

    Source

    MeSH

    Analysis of Variance
    Blood Platelets
    Chromans
    Chromatography, High Pressure Liquid
    Diabetes Mellitus, Type 2
    Dietary Supplements
    Enzyme-Linked Immunosorbent Assay
    Erythrocytes
    Female
    Humans
    Isomerism
    Male
    Middle Aged
    Platelet Activation
    Tocopherols
    alpha-Tocopherol
    gamma-Tocopherol

    Pub Type(s)

    Journal Article
    Randomized Controlled Trial
    Research Support, Non-U.S. Gov't

    Language

    eng

    PubMed ID

    16400056

    Citation

    Clarke, Michael W., et al. "Supplementation With Mixed Tocopherols Increases Serum and Blood Cell Gamma-tocopherol but Does Not Alter Biomarkers of Platelet Activation in Subjects With Type 2 Diabetes." The American Journal of Clinical Nutrition, vol. 83, no. 1, 2006, pp. 95-102.
    Clarke MW, Ward NC, Wu JH, et al. Supplementation with mixed tocopherols increases serum and blood cell gamma-tocopherol but does not alter biomarkers of platelet activation in subjects with type 2 diabetes. Am J Clin Nutr. 2006;83(1):95-102.
    Clarke, M. W., Ward, N. C., Wu, J. H., Hodgson, J. M., Puddey, I. B., & Croft, K. D. (2006). Supplementation with mixed tocopherols increases serum and blood cell gamma-tocopherol but does not alter biomarkers of platelet activation in subjects with type 2 diabetes. The American Journal of Clinical Nutrition, 83(1), pp. 95-102.
    Clarke MW, et al. Supplementation With Mixed Tocopherols Increases Serum and Blood Cell Gamma-tocopherol but Does Not Alter Biomarkers of Platelet Activation in Subjects With Type 2 Diabetes. Am J Clin Nutr. 2006;83(1):95-102. PubMed PMID: 16400056.
    * Article titles in AMA citation format should be in sentence-case
    TY - JOUR T1 - Supplementation with mixed tocopherols increases serum and blood cell gamma-tocopherol but does not alter biomarkers of platelet activation in subjects with type 2 diabetes. AU - Clarke,Michael W, AU - Ward,Natalie C, AU - Wu,Jason H Y, AU - Hodgson,Jonathan M, AU - Puddey,Ian B, AU - Croft,Kevin D, PY - 2006/1/10/pubmed PY - 2006/2/24/medline PY - 2006/1/10/entrez SP - 95 EP - 102 JF - The American journal of clinical nutrition JO - Am. J. Clin. Nutr. VL - 83 IS - 1 N2 - BACKGROUND: Some studies have shown potential benefit of vitamin E on platelet function, but several clinical trials failed to show improved cardiovascular outcome with alpha-tocopherol supplementation. Gamma-tocopherol, a major dietary form of vitamin E, may have protective properties different from those of alpha-tocopherol. OBJECTIVE: We compared the effects of supplementation with alpha-tocopherol (500 mg) and a gamma-tocopherol-rich compound (500 mg, containing 60% gamma-tocopherol) on serum and cellular tocopherol concentrations, urinary tocopherol metabolite excretion, and in vivo platelet activation in subjects with type 2 diabetes. DESIGN: Fifty-eight subjects were randomly assigned to receive either 500 mg alpha-tocopherol/d, 500 mg mixed tocopherols/d, or matching placebo. Serum, erythrocyte, and platelet tocopherol and urinary metabolite concentrations were measured at baseline and after the 6-wk intervention. Soluble CD40 ligand, urinary 11-dehydro-thromboxane B2, serum thromboxane B2, soluble P-selectin, and von Willebrand factor were measured as biomarkers of in vivo platelet activation. RESULTS: Serum alpha-tocopherol increased with both tocopherol treatments. Serum and cellular gamma-tocopherol increased 4-fold (P < 0.001) in the mixed tocopherol group, whereas red blood cell gamma-tocopherol decreased significantly after alpha-tocopherol supplementation. Excretion of alpha-carboxyethyl-hydroxychroman increased significantly after supplementation with alpha-tocopherol and mixed tocopherols. Excretion of gamma-carboxyethyl-hydroxychroman increased significantly after supplementation with mixed tocopherols and after that with alpha-tocopherol, which may reflect the displacement of gamma-tocopherol by alpha-tocopherol due to incorporation of the latter into lipoproteins in the liver. Neither treatment had any significant effect on markers of platelet activation. CONCLUSIONS: Supplementation with alpha-tocopherol decreased red blood cell gamma-tocopherol, whereas mixed tocopherols increased both serum alpha-tocopherol and serum and cellular gamma-tocopherol. Changes in serum tocopherol closely reflect changes in cellular concentrations of tocopherols after supplementation. SN - 0002-9165 UR - https://www.unboundmedicine.com/medline/citation/16400056/Supplementation_with_mixed_tocopherols_increases_serum_and_blood_cell_gamma_tocopherol_but_does_not_alter_biomarkers_of_platelet_activation_in_subjects_with_type_2_diabetes_ L2 - https://academic.oup.com/ajcn/article-lookup/doi/10.1093/ajcn/83.1.95 DB - PRIME DP - Unbound Medicine ER -