Treatment satisfaction with inhaled insulin in patients with type 1 diabetes: a randomized controlled trial

In patients with type 1 diabetes, glycemic control can be achieved as effectively with an inhaled insulin regimen, comprising preprandial inhaled intrapulmonary insulin plus a bedtime ultralente injection, as with a conventional subcutaneous insulin regimen involving two to three injections per day. Our objective was to compare patient satisfaction between inhaled insulin and subcutaneous insulin.

Subjects with type 1 diabetes participated in a 12-week open-label trial and were randomized to either an inhaled insulin regimen or a subcutaneous insulin regimen. Subjects (n = 69) were asked to complete a 15-item self-administered satisfaction questionnaire, the Patient Satisfaction with Insulin Therapy (PSIT) Questionnaire, at baseline and week 12. Outcomes included mean percentage changes in global (overall) satisfaction and two subscales: convenience/ease of use and social comfort.

The mean percentage improvement in overall satisfaction with inhaled insulin (35.1%, 95% CI 18.0-52.2) was greater than with subcutaneous insulin (10.6%, 4.7-16.5) (P < 0.01), as was the improvement in convenience/ease of use: inhaled insulin 41.3% (22.9-59.6) versus subcutaneous insulin 11.2% (4.1-18.3; P < 0.01). Improvement in social comfort was greater with inhaled insulin but was not statistically significant. The 12-week change in HbA(1c) was associated with improved overall satisfaction (r = -0.27, P = 0.04).

Inhaled insulin may offer the first practical, noninvasive alternative to insulin injections. For patients with type 1 diabetes, inhaled insulin maintains glycemic control and provides greater overall satisfaction and convenience/ease of use than subcutaneous insulin.