Alonso A, et al. - In an independent sample of 2,003 white and black Atherosclerosis Risk in Communities participants, researchers examined the associations of 2 circulating secondary bile acids (glycocholenate and glycolithocolate sulfate) with atrial fibrillation (AF) risk (a link that has been previously established in 1,919 blacks in the Atherosclerosis Risk in Communities cohort). In baseline serum samples, they performed metabolomic profiling using gas and liquid chromatography mass spectrometry. Using electrocardiograms, hospitalizations, and death certificates, they determined AF. A prospective association among a previously identified secondary bile acid, glycocholenate sulfate, and AF incidence, was replicated in this study. Also, they identified novel metabolites involved in nucleoside and polyamine metabolism as markers of AF risk. Pseudouridine, uridine and acisoga were the 3 additional metabolites that were found to be related to AF after multiple-comparison correction in an analysis of 245 metabolites in the combined cohort.