Clinical role of DPP-4 inhibitors in type 2 diabetes

Dipeptidyl peptidase-4 (DPP-4) inhibitors are an effective alternative for second-line therapy in patients with type 2 diabetes, reports a meta-analysis in the British Medical Journal.

The analysis pooled data from 19 randomized trials, including 7136 patients assigned to a DPP-4 inhibitor and 6745 to other hypoglycemic treatments. The results showed a smaller decrease in glycated hemoglobin (HbA1c) with DPP-4 inhibitors compared with metformin alone, weighted mean difference 0.20; and a lesser decrease in body weight, weighted mean difference 1.50.

As second-line treatment to reduce HbA1c, DPP-4 inhibitors were less effective than glucagon-like peptide-1 (GLP-1) agonists and sulfonylureas but were similar to pioglitazone. The DPP-4 inhibitors led to more favorable changes in body weight compared with sulfonylureas or pioglitazone but not compared with GLP-1 agonists.

Studies comparing DPP-4 inhibitors against metformin alone or with pioglitazone or against a GLP-1 agonist included few episodes of hypoglycemia. Most studies comparing a DPP-4 inhibitor plus a sulfonylurea against metformin showed a higher risk of hypoglycemia in patients taking sulfonylureas. The DDP-4 inhibitors had a lower rate of serious adverse events than did pioglitazone. They did not increase the risks of nasopharyngitis, upper respiratory tract infection, or urinary tract infection.

The updated review and meta-analysis may help to clarify the clinical role of the DPP-4 inhibitors, a newer class of oral hypoglycemic drugs. These medications appear to be effective in lowering HbA1c in patients with type 2 diabetes who do not respond to metformin alone. Further study is needed to assess their cost effectiveness and long-term safety outcomes [Karagiannis T, et al. Dipeptidyl peptidase-4 inhibitors for treatment of type 2 diabetes mellitus in the clinical setting: systematic review and meta-analysis. BMJ 2012; 344:e1369].

May 2012 (Vol. 4, Number 5)