Purpose: We aimed to examine the association between plasma trimethylamine N-oxide (TMAO), a gut microbial metabolite from dietary phosphatidylcholine, and coronary atherosclerotic burden in patients with type 2 diabetes (T2D).
Methods: In total, 349 patients with T2D were studied, including 70 controls and 279 patients with coronary artery disease (CAD) by coronary angiography. Coronary atherosclerotic burden is quantified by the number of diseased coronary branches and SYNTAX (Synergy between PCI with Taxus and Cardiac Surgery) score. Plasma TMAO levels were determined by UHPLC–MS/MS technique.
Results: The TMAO concentration was significantly higher in the patients with triple vessel disease (TVD) (3.33 [IQR: 1.81– 6.65] μM) than those without TVD (2.62 [IQR: 1.50– 4.73] μM) (P = 0.015). A similar difference was found between patients with SYNTAX score > 22 (3.93 [IQR: 1.81– 6.82] μM) and those with SYNTAX score ≤ 22 (2.54 [IQR: 1.44– 4.54] μM) (P = 0.014). TMAO was not significantly correlated with the presence of CAD. Among patients with eGFR < 60 mL/min/1.73 m², the highest tertile of TMAO was significantly associated with TVD (OR = 25.28, 95% CI [2.55– 250.33], P = 0.006) and SYNTAX score > 22 (OR = 7.23, 95% CI [1.51– 34.64], P = 0.013) independent of known risk factors of CAD, compared with lower TMAO tertiles.
Conclusion: TMAO was not independently correlated with the presence of CAD and severity of coronary atherosclerosis in the included population. Nevertheless, the significant association between circulating TMAO and higher coronary atherosclerotic burden was observed in patients with eGFR of lower than 60 mL/min/1.73 m².
Keywords: trimethylamine N-oxide, coronary artery disease, SYNTAX score, type 2 diabetes