1. Home>
2. Specialties>
3. General Medicine>
4. Summary and Comment

Changes in Lung Function with Inhaled Insulin

A small initial decline in function did not appear to progress beyond 3 months.

In previous short-term studies, inhaled insulin caused small declines in lung function. In this industry-sponsored trial, researchers assessed longer-term respiratory effects of inhaled insulin.

Nearly 600 adults with type 1 diabetes were randomized to receive premeal inhaled insulin (Exubera) or premeal subcutaneous short-acting insulin; both groups also received long-acting basal insulin. At 3 months, mean FEV₁ had declined by 0.05 liters in the inhaled insulin group and 0.03 liters in the subcutaneous insulin group, a small but statistically significant difference. However, after 3 months (and through 24 months), FEV₁ declined at the same rate in both groups. For diffusing capacity, the same pattern was noted — a small initial decline, but no further separation between groups during months 3 to 24. Inhaled-insulin recipients reported cough more frequently than subcutaneous-insulin recipients (38% vs. 13%). Glycemic control was similar in the two groups.

Comment: This study demonstrates that inhaled insulin induces small changes in pulmonary function shortly after the start of treatment. On average, however, the changes do not appear to progress after 3 months. Patients are advised to have spirometry before starting inhaled insulin, after 6 months of treatment, and annually thereafter. Inhaled insulin is not recommended for patients with underlying lung disease and is contraindicated in smokers.

— Allan S. Brett, MD

Published in Journal Watch General Medicine March 29, 2007

Citation(s):

Skyler JS et al. Two-year safety and efficacy of inhaled human insulin (Exubera) in adult patients with type 1 diabetes. Diabetes Care 2007 Mar; 30:579-85.

• Original article (Subscription may be required)
• Medline abstract (Free)