ABSTRACT
Abstract Background: Trimethylamine N-oxide (TMAO), a gut microbiota metabolite, is associated with cardiovascular disease (CVD) development. TMAO can trigger an inflammatory response by inducing the nuclear factor-kappa B (NF-κB) signaling cascade and increasing the expression of pro-inflammatory cytokines, contributing to the worsening of CVD. This study aimed to evaluate the association between TMAO plasma levels and inflammation in patients with coronary artery disease (CAD). Methods: A cross-sectional study was carried out including 29 patients with CAD. Peripheral blood mononuclear cells (PBMC) were isolated from fasting blood samples, and NF-κB and vascular cell adhesion protein 1 (VCAM1) mRNA expression were estimated using real-time quantitative PCR. We determined TMAO plasma levels by LC-MS/MS and TNF-α by ELISA. Routine biochemical parameters were evaluated using an automatic biochemical analyzer. Correlations were estimated by Spearman or Pearson test. Statistical significance was set at the level of p < 0.05. Results: All patients presented TMAO levels within the normal range according to EUTox (normal range: 2.83 ± 1.53 mg/L; CAD patients: 0.2 [0.1 to 0.2] ng/μL). TMAO plasma levels were positively correlated with NF-κB mRNA expression (0.555; p = 0.002). Conclusion: TMAO plasma levels may be associated with NF-κB mRNA expression in patients with CAD and may contribute to the pathogenesis of this disease.