We included data addressing structural, electrical, autonomic, metabolic, and inflammatory mechanisms of AF in diabetes, as well as clinical evidence regarding the impact of metformin, insulin, dipeptidyl peptidase-4 (DPP-4) inhibitors, sodium-glucose cotransporter-2 (SGLT-2) inhibitors, and glucagon-like peptide-1 (GLP-1) receptor agonists on AF incidence or recurrence. This evidence concerns the gene SLC5A2 and diabetes mellitus.