Article

Impact of vitamin E on plasma asymmetric dimethylarginine (ADMA) in chronic kidney disease (CKD): a pilot study.

Division of Nephrology, University of Michigan, Ann Arbor, MI 48103-4262, USA.
Nephrology Dialysis Transplantation (impact factor: 3.4). 11/2003; 18(11):2415-20. pp.2415-20
Source: PubMed

ABSTRACT Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of endothelial nitric oxide synthase and a proposed cardiovascular risk factor, is elevated in chronic kidney disease (CKD). Pharmacological strategies that lower plasma concentration of ADMA may be expected to increase nitric oxide (NO.) bioavailability and potentially limit atherosclerosis. We hypothesized that the antioxidant alpha-tocopherol (vitamin E) reduces ADMA levels in CKD.
An open-label pilot interventional study using 800 IU of vitamin E was undertaken in eight stable out-patients with non-diabetic CKD (creatinine clearance <30 ml/min/1.73 m(2)) and six healthy controls, with the objective of measuring plasma ADMA levels at baseline and after 8 weeks of treatment. Plasma ADMA, symmetric dimethylarginine (SDMA) and alpha-tocopherol concentrations were determined at study entry and exit using high-performance liquid chromatography, while plasma total F2-isoprostanes, an index of oxidative stress, were measured using a commercially available enzyme-linked immunosorbent assay kit.
ADMA and SDMA concentrations were significantly higher in the plasma of patients compared with that of controls (P </= 0.001). After treatment with vitamin E, ADMA decreased by 23% in six of eight patients (P <0.001). The remaining two patients showed either an increase or no change (overall, P = 0.16). There was no significant change in plasma F2-isoprostanes with vitamin E treatment for 8 weeks.
Antioxidant therapy with vitamin E has the potential to lower ADMA levels in CKD patients, implying increased NO. availability. This strategy merits further exploration in the setting of CKD prior to renal replacement.

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Keywords

alpha-tocopherol concentrations
 
CKD patients
 
commercially available enzyme-linked immunosorbent assay kit
 
endothelial nitric oxide synthase
 
healthy controls
 
increase nitric oxide
 
limit atherosclerosis
 
lower plasma concentration
 
non-diabetic CKD
 
open-label pilot interventional study
 
oxidative stress
 
Plasma ADMA
 
plasma ADMA levels
 
plasma total F2-isoprostanes
 
proposed cardiovascular risk factor
 
remaining two patients
 
renal replacement
 
SDMA concentrations
 
strategy merits
 
study entry