Investigation of factors associated with circulating gamma-tocopherol concentrations Restricted; Files Only

Abdulla,Kennadiid (Fall 2017)

Permanent URL: https://etd.library.emory.edu/concern/etds/r781wg01v?locale=en
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Abstract

  

Background:  Although a- and g-tocopherol are co-consumed antioxidants, circulating g-tocopherol concentrations were paradoxically found to be inversely associated with total vitamin E intake and circulating a-tocopherol concentrations.  There are limited data on this apparent paradox or on determinants of circulating g-tocopherol concentrations.

Methods:  We pooled data from two outpatient, elective colonoscopy populations (pooled n=419) on whom extensive dietary, lifestyle, and medical information was collected, and the following circulating concentrations were measured:  a- and g-tocopherol (via high-performance liquid chromatography), F2-isoprostanes (FiP; via gas chromatography-mass spectrometry, and high sensitivity C-reactive protein (hsCRP; via latex-enhanced immunonephelometry).  Multivariable general linear models were used to assess mean g-tocopherol differences across quantiles of FiP, hsCRP, and multiple dietary and lifestyle factors.

Results:  Adjusted for serum total cholesterol, mean g-tocopherol concentrations among those in the highest relative to the lowest tertiles of circulating a-tocopherol and b-carotene, a composite dietary/lifestyle oxidative balance score (higher score indicates higher antioxidant relative to pro-oxidant exposures), and total calcium and dietary fiber intakes, were -31.0% (p<0.0001), -29.0% (p<0.0001), -27.6% (p=0.0001), -29.7% (p<0.0001), and -18.6% (p=0.008) lower, respectively.  For those in the highest relative to the lowest tertiles of circulating FiP and hsCRP, mean g-tocopherol concentrations were +50% (p<0.0001) and +39.0% (p<0.0001) higher, respectively.

Conclusions:  These findings suggest that circulating g-tocopherol concentrations may be inversely associated with antioxidant exposures and directly associated with systemic oxidative stress and inflammation.  Additional research on possible mechanisms underlying these findings and on whether circulating g-tocopherol may serve as a biomarker of oxidative stress and/or inflammation is needed.

 

Table of Contents

Table of Contents

Chapter 2. Manuscript……………………………………………………………………………

Introduction……………………………………………………………………………………..1

Methods……………………………………………………………………………………...….2

   Study Population……………………………………………………………………………...2

   Data collection and Laboratory Analysis………………………………………………..........2

   Statistical Analysis……………………………………………………………………………4

Results…………………………………………………………………………………………..6

Discussion……………………………………………………………………………………....8

References……………………………………………………………………………………...15

Tables…………………………………………………………………………………………..19

 

 

 

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