IMR Press / RCM / Volume 22 / Issue 3 / DOI: 10.31083/j.rcm2203085
Open Access Review
Trimethylamine N-oxide—a marker for atherosclerotic vascular disease
Guinan Xie1,†An Yan1,†Peng Lin2Yi Wang1,*Liping Guo3,*
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1 Institute of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, 301617 Tianjin, China
2 Graduate School, Tianjin University of Traditional Chinese Medicine, 301617 Tianjin, China
3 Department of Cardiology, Tianjin Academy of Traditional Chinese Medicine Affiliated Hospital, 300120 Tianjin, China
*Correspondence: (Yi Wang); (Liping Guo)
These authors contributed equally.
Academic Editor: Gianluca Rigatelli
Rev. Cardiovasc. Med. 2021, 22(3), 787–797;
Submitted: 8 July 2021 | Revised: 2 August 2021 | Accepted: 6 August 2021 | Published: 24 September 2021
(This article belongs to the Special Issue Coronary Artery Atherosclerosis: Translation from Basic to Clinic)
Copyright: © 2021 The Author(s). Published by IMR Press.
This is an open access article under the CC BY 4.0 license (

As a potential causative factor in various cardiovascular diseases, the gut microbe-generated metabolite trimethylamine N-oxide (TMAO) has courted considerable research interest as a potential biomarker. TMAO is a small molecule considered to be beneficial for the health of deep-water animals due to its ability to protect proteins against hydrostatic pressure stress. However, it may cause deleterious effects in humans as mounting evidence suggests that TMAO may enhance atherosclerosis, independent of traditional risk factors. This may be mediated by its capacity to enhance inflammation, platelet activation and thrombosis, and inhibit reverse cholesterol transport. In humans, circulating levels of TMAO have been found to be associated with increased risk of developing atherosclerotic diseases such as carotid atherosclerosis, coronary atherosclerotic heart disease, stroke, and peripheral arteriosclerosis. This review aims to discuss the current role of TMAO in the atherosclerosis process, using animal models and clinical studies, with special attention to determining whether TMAO could be used as a marker for monitoring severity and prognosis in atherosclerosis and to evaluate evidence for its role as a mediator in the pathogenesis of atherosclerotic vascular disease.

Trimethylamine N-oxide
Coronary heart disease
Cardiovascular risk
Fig. 1.
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