Combination therapy with insulin glargine plus metformin but not insulin glargine plus sulfonylurea provides similar glycemic control to triple oral combination therapy in patients with type 2 diabetes uncontrolled with dual oral agent therapy.

AIMS: Evaluate substituting insulin glargine (GLAR) for a thiazolidinedione (TZD) versus adding a third oral antidiabetes drug (OAD) in patients with uncontrolled type 2 diabetes mellitus (T2DM) on TZD+metformin or TZD+sulfonylurea.

METHODS

In this multicenter, open-label study, 337 T2DM patients with a glycated hemoglobin A1c (A1C) of 7.5-12.0% despite≥3months of treatment with a TZD plus metformin or a sulfonylurea were randomized to a third OAD (3OAD; metformin or glyburide) or GLAR+1 OAD (metformin or sulfonylurea) with TZD cessation, titrated to a fasting blood glucose≤94mg/dL.

RESULTS

Substitution of GLAR for a TZD led to an adjusted mean A1C change from baseline of-1.66% versus-1.86% in the 3OAD arm (adjusted mean difference 0.20 [95% confidence interval, - 0.11, 0.51], not meeting the noninferiority criteria). This difference was driven by the GLAR+sulfonylurea stratum. GLAR+metformin was as effective as 3OAD in achieving glycemic control but with greater improvements in lipid parameters, less weight gain, and lower hypoglycemia rates.

CONCLUSIONS

These findings favor substitution of GLAR for a TZD in T2DM patients not controlled on TZD+metformin. GLAR+sulfonylurea was less effective at lowering A1C than 3OAD and not associated with the benefits observed with GLAR+metformin.