Abstract 12622: Gut-microbiota-derived Trimethylamine-N-oxide levels and Risk of Major Adverse Cardiovascular Events: A Systematic Review and Meta-analysis of Prospective Cohort Studies
Introduction: Gut microbial metabolite trimethylamine-N-oxide (TMAO) has been implicated as a novel risk factor for cardiovascular events. The strength and consistency of the association between blood levels of the gut microbiota-related risk factor and cardiovascular events or deaths remain unclear.
Hypothesis: We performed a systematic review and meta-analysis of prospective cohort studies to quantify the association of blood levels of TMAO and the risk of major adverse cardiovascular events (MACE).
Methods: PubMed and Embase databases were searched up to 3 May 2016 and prospective studies with either quantitative estimates of the association of blood TMAO levels with incident MACE were included. MACE was indicated by myocardial infarction, stroke, heart transplant, heart failure, other ischemic cardiovascular events or death (either cardiovascular or all-cause). Two reviewers independently extracted data and assessed study quality. Generalized least-squares trend estimation was used to assess dose-response relationships. Summary relative risk (RR) for higher TMAO levels as compared to lower levels was calculated using only prospective cohort studies.
Results: A total of 12 cohorts were included in the meta-analysis. High circulating TMAO levels were associated with an increased risk of MACE with a pooled RR of 1.76 (95% confidence interval: 1.50, 2.07; heterogeneity p = 0.22; I-squared = 22.8%) compared with low TMAO levels. Elevated TMAO levels were consistently associated with an increased risk of MACE regardless of older ages, high prevalence of diabetes, histories of cardiovascular diseases or renal failure at the baseline across studies. Pooled adjusted RR (95% confidence interval) of MACE was 1.02 (1.01, 1.04) per 1 μM (n=6 cohorts) or 1.22 (1.12, 1.32) per log-transformed 1 SD (n=4) increment in TMAO levels.
Conclusions: Higher blood TMAO levels were consistently and dose-dependently associated with the development of MACE across diverse populations, independently of traditional risk factors.
Author Disclosures: Y. Heianza: None. W. Ma: None. L. Qi: None.
- © 2016 by American Heart Association, Inc.