Effects on Clinical Outcomes of Adding Dipeptidyl Peptidase-4 Inhibitors Versus Sulfonylureas to Metformin Therapy in Patients With Type 2 Diabetes Mellitus

This cohort study found the addition of DPP-4 inhibitors (versus sulfonylureas) to metformin in type 2 diabetes was associated with lower risks for all-cause death, ischaemic stroke and hypoglycaemia; no differences were seen for risk of MI or hospitalisation for heart failure.

The authors acknowledge the limitations of their research, mainly those inherent to observational studies. For example the possibility of unmeasured confounding cannot be ruled out; the choice of sulfonylureas or DPP-4 inhibitors was based on the decisions of physicians in charge, which may have caused selection bias. Although this study adds to the available evidence, additional longer-term studies are required to document the effects of DPP-4 inhibitors, a relatively new class of oral hypoglycaemic, on cardiovascular outcomes.

 

NICE published a clinical guideline on type 2 diabetes in 2009 (CG87). This is currently being updated; a draft issued for consultation makes the following recommendations for dual therapy in adults where initial metformin treatment has not continued to control HbA1c to below their individually agreed threshold for intensification:

 

• metformin and pioglitazone, or
• metformin and a sulfonylurea, or
• metformin and a DPP-4 inhibitor