ARTICLE

Aims/hypothesis There are limited data comparing dipeptidyl peptidase-4 (DPP-4) inhibitors directly. We compared the safety and efficacy of vildagliptin and sitagliptin in patients with type 2 diabetes and severe renal impairment (RI). Methods This study was a parallel-arm, randomised, multicentre, double-blind, 24 week study conducted in 87 cen-tres across Brazil and the USA. Patients with type 2 diabetes, either drug naive or treated with any glucose-lowering agents, who had inadequate glycaemic control (HbA1c 6.5–10.0% [48–86 mmol/mol]) and an estimated GFR <30 ml min−1 [1.73 m]−2 were randomised (via interactive voice response technology) to vildagliptin 50 mg once daily or sitagliptin 25 mg once daily. These doses are recommended in this patient population and considered maximally effective. Participants, investigators and the sponsor were blinded to group assign-ment. Efficacy endpoints included change in HbA1c and fasting plasma glucose (FPG) at all visits and the primary safety end-point was assessment of treatment-emergent adverse events. Results In total, 148 patients were randomised, 83 to vildagliptin and 65 to sitagliptin. All patients were analysed. After 24 weeks, the adjusted mean change in HbA1c was −0.54 % (5.9 mmol/mol) from a baseline of 7.52% (59 mmol/mol) with vildagliptin and −0.56 % (6.1 mmol/ mol) from a baseline of 7.80 % (62 mmol/mol) with sitagliptin (p=0.874). FPG decreased by 0.47±0.37 mmol/l with vildagliptin and increased by 0.16±0.43 mmol/l with sitagliptin (p=0.185). Both treatments were well tolerated with overall similar safety profiles. Conclusions/interpretation At their recommended doses for severe RI, vildagliptin (50 mg once daily) compared with sitagliptin (25 mg once daily) demonstrated similar efficacy and both drugs were well tolerated. This study provides fur-ther support for the use of DPP-4 inhibitors in patients with severe RI