Serum N (1)‐Methylnicotinamide is Associated With Coronary Artery Disease in Chinese Patients

BACKGROUND: We previously reported that serum N (1)‐methylnicotinamide (me‐Nam), an indicator of nicotinamide N‐methyltransferase activity, is associated with obesity and diabetes mellitus in Chinese patients. However, whether nicotinamide N‐methyltransferase plays a role in human coronary artery disease (CAD) remains to be elucidated. We aim to investigate the associations of serum me‐Nam with CAD in Chinese patients. METHODS AND RESULTS: Serum me‐NAM was measured by liquid chromatography‐mass spectrometry in patients with (n=230) or without (n=103) CAD as defined by coronary angiography. The severity of CAD was expressed by number of diseased coronary arteries. Serum me‐Nam was higher (7.65 ng/mL versus 4.95 ng/mL, P<0.001) in patients with CAD than in those without. Serum me‐Nam was positively correlated with high‐sensitivity C‐reactive protein and negatively correlated with high‐density lipoprotein before and after adjustment for potential confounding variables (P≤0.002). In multivariable logistic regression analyses, compared with those in the lowest tertile of serum me‐NAM levels, patients in the top tertile had the highest risks for CAD (odds ratio, 4.21; 95% CI, 1.97–8.97 [P<0.001]). After adjustment for potential confounding variables, serum me‐NAM was also increased from 0‐ to 3‐vessel disease (P for trend=0.01). CONCLUSIONS: Serum me‐Nam is strongly associated with presence and severity of CAD, suggesting nicotinamide N‐methyltransferase as a potential target for treating atherosclerosis in humans.