Letter by Hoang et al Regarding Article, "Novel Biomarker of Oxidative Stress Is Associated With Risk of Death in Patients With Coronary Artery Disease".

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HomeCirculationVol. 133, No. 22Letter by Hoang et al Regarding Article, “Novel Biomarker of Oxidative Stress Is Associated With Risk of Death in Patients With Coronary Artery Disease” Free AccessLetterPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessLetterPDF/EPUBLetter by Hoang et al Regarding Article, “Novel Biomarker of Oxidative Stress Is Associated With Risk of Death in Patients With Coronary Artery Disease” Sophie Hoang, MD, Xavier Girerd, MD and Philippe Giral, MD Sophie HoangSophie Hoang Institut E3M, pôle coeur et métabolisme Groupe Hospitalier Pitié Salpétrière, AP-HP Paris, France Search for more papers by this author , Xavier GirerdXavier Girerd Institut E3M, pôle coeur et métabolisme Groupe Hospitalier Pitié Salpétrière, AP-HP Paris, France Search for more papers by this author and Philippe GiralPhilippe Giral Institut E3M, pôle coeur et métabolisme Groupe Hospitalier Pitié Salpétrière, AP-HP Paris, France Search for more papers by this author Originally published31 May 2016https://doi.org/10.1161/CIRCULATIONAHA.116.022260Circulation. 2016;133:e666To the Editor:We have read with great interest the article entitled “Novel Biomarker of Oxidative Stress Is Associated With Risk of Death in Patients With Coronary Artery Disease” by Patel et al.1 The authors have shown a positive association between plasma levels of cystine, glutathione, their ratio, and mortality and cardiovascular events. Quantification of these biomarkers may thus be used to assess in vivo oxidative stress and to help stratify the risk of death in patients with coronary artery disease. Nevertheless, Lim et al2 had previously documented that γ-glutamyltransferase (GGT) activity, the action of which on glutathione results in its cleavage to produce cysteine and cysteinylglycine, might be an early marker of oxidative stress and is inversely associated with serum concentrations of antioxidant. Moreover, it has been previously demonstrated that significant elevation in GGT activity is closely associated with a potentially prooxidant profile of circulating thiol compounds as demonstrated by low plasma levels of glutathione and by elevated concentrations of cysteine-glycine and cysteine.3 It is now well established that GGT activity is positively associated with cardiovascular disease.4 More recently, it has even been proved that elevated serum GGT levels are independently associated with coronary artery calcification.5 Because assaying the activity of GGT is simpler than the quantification of the thiol profile, we wonder whether the association between cystine, glutathione, and coronary artery disease still persisted after adjustment with GGT activity.Sophie Hoang, MDXavier Girerd, MDPhilippe Giral, MDInstitut E3M, pôle coeur et métabolismeGroupe Hospitalier Pitié Salpétrière, AP-HPParis, FranceDisclosuresNone.