Serum Trimethylamine N-Oxide Levels Correlate with Metabolic Syndrome in Coronary Artery Disease Patients

Trimethylamine N-oxide (TMAO) is a gut microbial metabolite that affects atherogenesis and glucose dysregulation. The purpose of this study was to look at the link between blood TMAO levels and metabolic syndrome (MetS) in individuals with coronary artery disease (CAD). Blood samples were obtained in fasting status, and serum TMAO level was quantified by high-performance liquid chromatography–mass spectrometry. MetS and its components were defined according to the International Diabetes Federation diagnostic criteria. Of 92 enrolled patients, 51 (55.4%) had MetS. Patients with MetS had a greater proportion of hypertension and diabetes mellitus, higher body weight, waist circumference, body mass index, systolic blood pressure, fasting glucose, triglycerides, blood urea nitrogen, creatinine, C-reactive protein (CRP), insulin level, homeostasis model assessment of insulin resistance, and TMAO level. Multivariable logistic regression models revealed that TMAO level (odds ratio: 1.036, 95% confidence interval: 1.005–1.067, p = 0.023) could be an effective predictor of MetS among the CAD population. In these patients, the log-TMAO level was positively associated with log-CRP (β = 0.274, p = 0.001) and negatively associated with eGFR (β = −0.235, p = 0.022). In conclusion, our study revealed a positive association between serum TMAO level and MetS among patients with CAD.