Most studies focusing on DPP-4 inhibitors and renal function did not indicate any renoprotective effects of DPP-4 inhibitors; however, these reports clarified the safety and tolerability of DPP-4 inhibitors in patients with renal dysfunction (Chan et al., 2008; Kothny et al., 2012; Groop et al., 2014). This evidence concerns the gene DPP4 and Abnormal renal physiology.