Dehydroascorbic acid and oxidative stress in haemodialysis patients.
BACKGROUND
The amount of dehydroascorbic acid contained within total ascorbic acid (oxidized as well as non-oxidized forms) in plasma, hereafter referred to as the dehydroascorbic acid fraction, may be a measure of oxidative stress during haemodialysis. In the present study, we determined this fraction in chronic haemodialysis patients.


METHODS
Using high performance liquid chromatography, dehydroascorbic acid and total ascorbic acid levels were measured in 80 maintenance haemodialysis patients for a period of > 2 years as well as in 49 controls, to examine a possible association of these compounds with clinical parameters and/or drugs taken by the patients.


RESULTS
Dialysis patients who had an increased plasma urate level (P < 0.05) and had been taking allopurinol (P < 0.05) or NSAID (non-steroid anti-inflammatory drugs) (P < 0.01), and dialysis patients who were younger (< or = 55 years), as compared with older dialysis patients (P < 0.01), were found to have a lower dehydroascorbic acid fraction by multivariate analysis. Mean plasma dehydroascorbic acid levels and dehydroascorbic acid fractions were significantly lower in the younger haemodialysis patients (4.8 +/- 0.7 micromol/l and 28.4 +/- 3.9%) than in healthy younger controls (13.3 +/- 1.1 micromol/l and 41.1 +/- 1.8%) (P < 0.0001 and P < 0.01, respectively). Moreover, a correlation was found between plasma dehydroascorbic acid fraction and plasma lipid peroxide (r = 0.66, P < 0.01) in patients who had not been taking allopurinol and/or NSAID.


CONCLUSIONS
We found that dehydroascorbic acid fraction was related to patients' age, plasma urate level and to taking allopurinol or NSAID. Dehydroascorbic acid fraction may be another indirect index of oxidative stress.
Department of Renal Medicine, Saiyu Soka Hospital, 1-21-37 Kitaya, Soka City, Saitama 340-0076, Japan.
H
H
Nakayama
S
S
Akiyama
M
M
Inagaki
Y
Y
Gotoh
K
K
Oguchi
D000375:Aging / Q000097:blood; D000493:Allopurinol / Q000627:therapeutic use; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D000963:Antimetabolites / Q000627:therapeutic use; D016022:Case-Control Studies; D003683:Dehydroascorbic Acid / Q000097:blood*; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000628:therapy*; D008054:Lipid Peroxides / Q000097:blood; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D018384:Oxidative Stress; D012016:Reference Values; D006435:Renal Dialysis; D014527:Uric Acid / Q000097:blood
D000894:Anti-Inflammatory Agents, Non-Steroidal; D000963:Antimetabolites; D008054:Lipid Peroxides; D014527:Uric Acid; D000493:Allopurinol; D003683:Dehydroascorbic Acid