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

BACKGROUND We previously reported that serum N1-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.