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(Stroke. 2008;39:e89.)
© 2008 American Heart Association, Inc.

Letters to the Editor

Response to Letter by Proctor

Jesse Dawson, MRCP; Terence J. Quinn, MRCP Matthew R. Walters, MD

Division of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK

Response:

Dr Proctor¹ raises several important issues which concur with Amoro and colleagues’ conclusion² that the potential benefits of elevated serum uric acid are independent of the likely relationship between chronically elevated serum uric acid and cardiovascular disease. Thanks to Amoro et al, there is now data from both the basic science and clinical research arenas to suggest that infusion of uric acid after stroke could reduce free radical–mediated injury, a potential treatment for an area sorely in need of an advance. However, as discussed, data exist to support uric acid reduction as a preventative strategy in those at risk of atherosclerotic disease.

It seems unlikely, however plausible, that explanations for a circumstantial beneficial or detrimental effect of uric acid may be that these differences will not lead to confusion in wider nonspecialist circles. Such confusion could ultimately hinder adoption of these strategies in either research or clinical circles—"you want me to administer uric acid, but I thought uric acid was bad for you?" As such, we welcome the attention given to this area in recent issues of Stroke.

Proctor also highlights evidence suggesting that uric acid itself may mediate oxidative stress–related damage, rather than this being a consequence of its mechanism of generation (xanthine oxidase activity). Again, there is evidence for (some of which he highlights) and against this hypothesis. A series of elegant studies by Struthers et al³ suggest that the beneficial effects of allopurinol on a variety of measures of endothelial function relate to a reduction in xanthine oxidase activity, and not uric acid reduction while other data suggest uric acid reduction is important.⁴ Clearly, more studies are needed to disentangle causal mechanisms so we can better direct evaluation of potential therapies.

Acknowledgments

Disclosures

None.

References

1. Proctor PH. Uric acid: neuroprotective or neurotoxic. Stroke. 2008; 39: e88.[Free Full Text]

2. Chamorro A, Planas AM. Yin and yang of uric acid in patients with stroke. Response. Stroke. 2004; 35: e11–e12.[CrossRef][Medline] [Order article via Infotrieve]

3. George J, Carr E, Davies J, Belch JJ, Struthers A. High-dose allopurinol improves endothelial function by profoundly reducing vascular oxidative stress and not by lowering uric acid. Circulation. 2006; 114: 2508–2516.[Abstract/Free Full Text]

4. Høiggen A, Alderman M, Kjeldsen SE, Julius S, Devereux RB, De Faire U, et al. The impact of serum uric acid on cardiovascular outcomes in the LIFE study. Kidney International. 2004; 65: 1041–1049.[CrossRef][Medline] [Order article via Infotrieve]

This article has been cited by other articles:

				P. H. Proctor Uric Acid and Neuroprotection Stroke, August 1, 2008; 39(8): e126 - e126. [Full Text] [PDF]

This Article Extract Full Text (PDF) All Versions of this Article: 39/5/e89    most recent STROKEAHA.108.515635v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Dawson, J. Articles by Walters, M. R. Search for Related Content PubMed Articles by Dawson, J. Articles by Walters, M. R.