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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.
Am J Clin Nutr 2006; 83(1):95-102AJ

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.

Authors+Show Affiliations

Department of Core Clinical Pathology and Biochemistry, Royal Perth Hospital, University of Western Australia, Perth, Australia.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

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 -