[Combination therapy of metformin vs dipeptidulpeptidase inhibitors and sulfonylureas in type 2 diabetes: clinical and economic impact].

Objectives: Determine the clinical repurcussions of adherence, metabolic control, hypoglycemia and cardiovascular events (CVE) and economics (resources and costs) in the combination therapy of metformin vs DPP-4 (dipeptidyl peptidase-4) inhibitors and sulfonylureas in patients with type 2 diabetes. Materials and methods. Observational-multicenter and retrospective design. We evaluated patients ≥ 30 years of age in treatment with metformin and who started a second oral antidiabetic treatment during 2008-2009. 2 study groups were established: a) metformin + DPP-4 inhibitors, and b) metformin + sulfonylurea.

Main Measures: comorbidity, metabolic control (HbA1c <7%), compliance and complications (hypoglycemia, CVE). Follow up was conducted over two years. The cost model differentiated between direct healthcare costs (primary/ specialty care), and indirect costs (labor productivity).

Statistical Analysis: logistic regression and ANCOVA models. Results. 1,405 patients were recruited (average age 67.1 years old; 56.2% male). 37.0% started a second treatment with DPP-4 inhibitors, and 63.0% with sulfonylureas. After two years of follow up, patients treated with DPP-4 inhibitors showed greater treatment adherence (70.3% vs. 60.6%; p <0.001); better metabolic control (64.3% vs. 60.6%; p<0.001), and a lower proportion of hypoglycemia (13.9% vs. 40.4%; p <0.001, respectively). The average/unit of adjusted total costs was € 2,341 vs. € 2,512; p = 0.038. CVE and renal failure rates were 3.7% vs. 6.4%; p = 0.027. Vildagliptin was the most used drug among DPP-4 inhibitors. Conclusions. Sulfonylureas were the most used drug for diabetes treatment. Patients treated with DPP-4 inhibitors had higher adherence and control of diabetes, with lower rates of hypoglycemia and CVE, resulting in lower healthcare costs.