Background: In patients with type 2 diabetes, published data suggest that glycemic control can be achieved as effectively with an inhaled insulin regimen (preprandial inhaled intrapulmonary insulin plus a single bedtime Ultralente injection) as with a conventional subcutaneous insulin regimen involving 2 to 3 injections per day. It is unknown whether inhalation delivery of insulin improves patient satisfaction.
Objective: Our objective was to compare patient satisfaction between an inhaled insulin regimen and a subcutaneous insulin regimen.
Methods: This was a 12-week randomized, open-label, parallel-group, controlled trial in patients with type 2 diabetes. They were randomized to receive either a subcutaneous insulin regimen (split/mixed insulin with 2 to 3 injections daily) or an inhaled insulin regimen (inhaled insulin before meals and a single Ultralente insulin injection at bedtime). Change in glycosylated hemoglobin (HbA1c) from baseline to week 12 was the study's primary end point. At baseline and week 12, patients completed a questionnaire (Patient Satisfaction with Insulin Therapy Questionnaire) covering attributes of patient satisfaction. Treatment regimens were compared on each item with the Wilcoxon rank sum test and on the overall score with a t test.
Results: Fifty-one patients (age range, 35-65 years) participated in the study, 26 receiving inhaled insulin and 25 receiving subcutaneous insulin. Forty-seven patients (22 inhaled insulin, 25 subcutaneous insulin) completed the satisfaction questionnaire. The mean percent improvement in overall satisfaction with an inhaled insulin regimen (31%; 95% CI, 14-50) was significantly greater (P < 0.05) than that with a subcutaneous insulin regimen (13%; 95% CI, 7-19). Increases in overall satisfaction correlated with improvements in glycemic control (r = 0.30; P < 0.05). Both treatment regimens experienced a mean HbA1c reduction of approximately 0.7%. Although patient satisfaction was the chief focus of this article, these results should be considered exploratory, as the trial was powered prospectively for HbA1c values (the primary end point) and not for patient satisfaction.
Conclusions: Administration of an inhaled insulin regimen may offer the first practical, noninvasive alternative to insulin injections. In the patients with type 2 diabetes studied, an inhaled insulin regimen with the need for only 1 subcutaneous injection at bedtime appeared to offer more ease of use, comfort, and convenience, as well as greater overall satisfaction, than a subcutaneous insulin regimen of 2 to 3 injections daily.