Graduate Thesis Or Dissertation

 

Vitamins E and C in patients with end-stage renal disease undergoing hemodialysis Público Deposited

Conteúdo disponível para baixar

Baixar PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/02870z958

Descriptions

Attribute NameValues
Creator
Abstract
  • Patients with end-stage renal disease undergoing hemodialysis have a high incidence of oxidative stress-related diseases. This study evaluated oxidative stress and inflammatory markers in patients undergoing hemodialysis before and during vitamin E supplementation. Blood samples were obtained before and after dialysis during two separate dialysis sessions to establish baseline measurements. For the next two months, subjects consumed 400 IU RRR-α-tocopherol daily. At one month and two months of supplementation, blood samples were also obtained before and after dialysis. Circulating concentrations of α- and γ-tocopherols and their metabolites (carboxyethyl-hydroxychromans, α- and γ-CEHCs), vitamin C, and uric acid were determined by HPLC with electrochemical detection. C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were measured using standard clinical assays. F₂-isoprostanes were evaluated using an enzyme immunoassay. Dietary vitamins E and C were assessed using two 24-hour recalls. In response to vitamin E supplementation, plasma α-tocopherol concentrations increased from 18 ± 1.7 μM to 31 ± 5.4 μM (p<0.0001), while γ-tocopherol concentrations decreased from 2.8 ±1.0 μM to 1.7 ± 0.6 μM (p=0.001). Additionally, serum vitamin E metabolites increased, α-CEHCs from 68 ± 20 pmol/ml to 771 ± 161 (p<0.0001) and γ-CEHC from 837 ± 161.8 pmol/ml to 1136 ± 225.9 (p=0.0083). Both CEHCs are well above reported normal values (p<0.0001). Dietary antioxidants (vitamins E and C) were low in most subjects; thus, plasma ascorbic acid levels were low in most subjects, but high in a few, resulting a wide range of responses (88 ± 84 μM). Nonetheless, ascorbic acid concentrations decreased significantly after dialysis to 33 ± 34 μM (p=0.0124), but were unaffected by vitamin E supplementation. Indeed, many parameters decreased significantly by dialysis but were unchanged by vitamin E supplementation, including plasma concentrations of uric acid and TNF-α. Both IL-6 and F₂-isoprostane concentrations were elevated in the subjects but were unaffected by either vitamin E supplementation or dialysis. CRP increased significantly after dialysis (p=0.0161, ANOVA main effect), but in the vitamin E supplemented subjects CRP concentrations were slightly lower before dialysis , but increased following dialysis (p=0.0041, ANOVA interaction). Taken together, the data suggest that there is a complex relationship between chronic inflammation and oxidative stress. Longer supplementation with vitamin E might be necessary in order to observe beneficial effects.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Declaração de direitos
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome, 256 Grayscale) using Scamax Scan+ V.1.0.32.10766 on a Scanmax 412CD by InoTec in PDF format. LuraDocument PDF Compressor V.5.8.71.50 used for pdf compression and textual OCR.
Replaces

Relações

Parents:

This work has no parents.

Em Collection:

Itens