Inhaled Insulin Outperforms Metformin as Add-On Rx

A comparison of the efficacy and safety of adding inhaled insulin (Exubera) or metformin (Glucophage) to sulfonylurea monotherapy in patients with poorly controlled type 2 diabetes showed found that the addition of premeal inhaled insulin improved glycemic control more than the addition of metformin therapy in this patient population (Diabetes Care. 2006;29:1282-1287).

This open-label, parallel, 24-week, multicenter trial included patients with poorly controlled type 2 diabetes (aged 35-80 years) who were divided into 2 groups based on their hemoglobin (Hb) A_1c levels?moderately high (≥8% to ≤9.5%) and very high (>9.5% to ≤12%). The patients where then randomized to receive either adjunctive premeal inhaled insulin (n = 225) or metformin (n = 202). The primary end point was change in HbA_1c from baseline.

In patients with HbA_1c levels >9.5%, adjunctive use of inhaled insulin significantly reduced HbA_1c levels compared with metformin. Mean adjusted changes from baseline were ?2.17% and ?1.79%, respectively; the between-treatment difference was ?0.38% (P = .002). In patients with HbA_1c ≤9.5%, mean adjusted HbA_1c changes were ?1.94 and ?0.87, respectively, in favor of inhaled insulin, and the between-treatment difference was ?0.07% (P = .61).

A total of 7 serious adverse events occurred in the patients taking inhaled insulin and 15 in the patients taking metformin; however, none was considered to be treatment related. The most frequently reported adverse event was hypoglycemia, reported by 114 patients in the group assigned to inhaled insulin and by 53 patients assigned to metformin. No notable changes were reported related to blood pressure, heart rate, physical examination findings, or electrocardiograms for either group.

The patients included in this study were typical of patients normally seen in clinical practice and had a range of body mass index values.

These results "demonstrate that adding [inhaled insulin] to sulfonylurea therapy provides effective glycemic control and may be an alternative to oral agent combination therapy in patients with type 2 diabetes," the investigators write.