In diabetes, there is a known increase in superoxide production, which contributes to a reduction in vascular nitric oxide bioactivity through increased NADPH oxidases and dysfunction endothelial nitric oxide synthase (Guzik et al., 2002) which is similar decreases in endothelial nitric oxide synthase and nitric oxide bioavailability are associated with atrial fibrillation (Cai et al., 2002). Here, NOS3 is linked to diabetes mellitus.