LEP and atrial fibrillation: When comparing changes from day 20 to 21, it is remarkable the significant increase in leptin expression in females of the WD-choline group, both at the mRNA and protein level, as described above for leptin levels in AF and stomach (Fig. 2a), while in males, there was only an increase at the mRNA level in control (CD-vehicle) animals, as occurring for leptin levels in AF, gastric content, and stomach (Fig. 2b), but not observed in the other male groups.