Inhaled human insulin treatment in patients with type 2 diabetes mellitus

Despite demonstrated benefits, intensive insulin therapy has not gained widespread clinical acceptance for several reasons: Multiple daily injections are inconvenient, adherence is a concern, and the time-activity profile may not mimic normal insulin secretion. As such, alternate means of administering insulin are being evaluated.

To assess the efficacy and safety of pulmonary delivery of insulin in type 2 diabetic patients who require insulin.

Randomized, open-label, 3-month study consisting of a screening visit, a 4-week baseline lead-in phase, and a 12-week treatment phase.

General clinical research center and outpatient research clinics.

26 patients (16 men, 10 women) with type 2 diabetes (average age, 51.1 years; average duration of diabetes, 11.2 years).

Patients received inhaled insulin before each meal plus a bedtime injection of ultralente insulin, performed home glucose monitoring, and had weekly adjustment of insulin dose; target level for preprandial plasma glucose was 5.55 to 8.88 mmol/L (100 to 160 mg/dL).

Glycemic control (hemoglobin A(1c) level) obtained at baseline and monthly for 3 months. Pulmonary function tests were done at baseline and at the end of the study.

Inhaled insulin treatment for 3 months significantly improved glycemic control compared with baseline: Mean hemoglobin A(1c) levels decreased by 0.0071 +/- 0.0072 (0.71% +/- 0.72%). Patients experienced an average of 0.83 mild to moderate hypoglycemic event per month; no severe events were recorded. Patients showed no significant weight gain or change in pulmonary function compared with baseline.

Pulmonary delivery of insulin in type 2 diabetic patients who require insulin improved glycemic control, was well tolerated, and demonstrated no adverse pulmonary effects. Larger-scale studies are ongoing to provide long-term efficacy and safety data.