This Article Full Text Full Text (PDF) 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 Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Woo, K. S. Articles by Celermajer, D. S. Search for Related Content PubMed PubMed Citation Articles by Woo, K. S. Articles by Celermajer, D. S. Related Collections Pathophysiology Risk Factors Endothelium/vascular type/nitric oxide Mechanism of atherosclerosis/growth factors

(Circulation. 2000;101:e116.)
© 2000 American Heart Association, Inc.

Circulation Electronic Pages

Hyperhomocyst(e)inemia Is a Risk Factor for Arterial Endothelial Dysfunction in Humans

K. S. Woo, MD, FRACP; J. E. Sanderson, MD, FRCP; Y. Y. Sun, MD; P. Chook, MD; A. S. P. Cheung, BN; L. T. Chan, RN

Department of Medicine & Therapeutics

C. Metreweli, MD, FRCR

Department of Diagnostic Radiology and Organic Imaging The Chinese University of Hong Kong, Hong Kong SAR, People’s Republic of China

Y. I. Lolin, MD, PhD

Department of Clinical Chemistry Kent and Sussex Hospital, Kent, UK

D. S. Celermajer, PhD, FRACP

Department of Cardiology University of Sydney, Sydney, Australia

	Introduction

 
To the Editor:

We have previously published an article in Circulation demonstrating that hyperhomocyst(e)inemia is associated with endothelial dysfunction in middle aged Chinese,¹ in agreement with the findings of Tawakol et al in older white subjects.² We now write to correct an important error in the reporting of our biochemical results.

On repeated measurement of fasting total plasma homocyst(e)ine (tHcy) levels in our subject group, we have been unable to reproduce the very high homocyst(e)ine levels previously reported. We believe that this is related to problems with sample preparation and analyses by high-performance liquid chromatography, where measurement of tHcy level and all sulfated groups may have accounted for a significant overestimation of the true level in a proportion of subjects, particularly those with high homocyst(e)ine. We have now recalled all the subjects and remeasured tHcy in those involved in our previous report, using more appropriate sample preparation and analyses by an enzymatic immunoassay method. The "high tHcy" group had levels of 10.5±3.0 µmol/L, and the "low tHcy" group had levels of 8.5±1.1 µmol/L (P<0.05). Therefore, although the absolute values previously reported appear to have been overestimated, there remains a significant difference between groups, and the article’s major finding concerning the relationship between tHcy and endothelial function is supported in our study and other studies. Because our study is one of the few reports of tHcy levels in an Asian population, we thought it important to bring this to your attention.

	References

 
1. Woo KS, Chook P, Lolin YI, Cheung ASP, Chan LT, Sun YY, Sanderson JE, Metreweli C, Celermajer DS. Hyperhomocyst(e)inemia is a risk factor for arterial endothelial dysfunction in humans. Circulation. 1997;96:2542–2544.[Abstract/Free Full Text]

2. Tawakol A, Omland T, Gerhard M, Wu JT, Creager MA. Hyperhomocyst(e)inemia is associated with impaired endothelium-dependent vasodilation in humans. Circulation. 1997;95:1119–1121.[Abstract/Free Full Text]