Prognostic implications of DPP-4 inhibitor vs. sulfonylurea use on top of metformin in a real world setting - results of the 1 year follow-up of the prospective DiaRegis registry

Abstract

DPP-4 inhibitors (DPP4-I) have been shown to provide non-inferior glycaemic control compared with sulfonylureas (SU), but result in a reduction of body weight and a significantly lower risk of hypoglycaemia in patients with type 2 diabetes. We aimed to validate these results in a large real-world sample of patients participating in the prospective DiaRegis registry and to assess prognostic implications. DiaRegis included 3810 patients with type 2 diabetes in which antidiabetic therapy was intensified. We defined two patient subgroups, the first receiving either a DPP4-I or SU on top of prior metformin monotherapy and the second containing patients out of subgroup 1 with unaltered treatment for 1 year. After enrolment 884 patients with prior metformin monotherapy received a dual combination of metformin with either DPP4-I (n = 628; 71%) or SU (n = 256; 29%). Patient characteristics, blood glucose and blood pressure control as well as comorbidity burden were virtually identical. There were neither significant differences in the change of HbA1c over the 12 months treatment period nor in the reduction of body weight, but fasting (p = 0.033) and postprandial glucose levels (p = 0.01) were significantly lower in those receiving DPP4-I. Hypoglycaemia was significantly less frequent in patients receiving DPP4-I (OR 0.32; 95% CI 0.19-0.54). Qualitative changes were robust for subgroup 2 (except of fasting plasma glucose). Patients receiving DPP4-I had significantly less stroke/transitory ischaemic attack (0.2 vs. 2.0; p < 0.05) during the 1 year follow-up, whereas other vascular events (coronary artery bypass graft, percutaneous coronary intervention) were borderline significant. The present results confirm prior randomised controlled trial results in patients with type 2 diabetes from real world clinical practice demonstrating that DPP4-I on top of prior metformin monotherapy result in similar HbA1c reductions within 12 months but a significant reduction in hypoglycaemia compared with sulfonylurea added to metformin. The reduction in vascular events observed has to be verified in larger cohorts.