Inhaled human
insulin (
Exubera (human
insulin of
rDNA origin) Inhalation
Powder) causes small, early and reversible changes in pulmonary function in subjects with
diabetes mellitus. The present study assessed whether changes occur in cellular and soluble constituents of airway lining fluid consistent with
inflammation as a possible cause for
Exubera-associated lung function alterations. Two 31-week, open-label, sequential design phase 2 studies were conducted, one with 20 subjects with type 1 and one with 24 subjects with
type 2 diabetes. After run-in, all subjects received subcutaneous
insulin for 12 weeks, followed after 1 week by 12 weeks of
Exubera. Bronchoalveolar lavage fluid cell counts and
protein constituents were determined at baseline, after 12 weeks of subcutaneous
insulin and after 12 weeks of
Exubera. Baseline cellular and soluble constituents of lavage fluid were similar to those reported for nondiabetic adults.
Exubera produced no consistent clinically or statistically significant changes in total or differential lavage fluid cell counts or
protein concentrations, even though
Exubera-associated changes in pulmonary function are known to be fully manifest within 12 weeks. Therefore, 12 weeks of
Exubera treatment is not associated with evidence of
pulmonary inflammation. The treatment effects on lung function observed in
Exubera trials are not caused by
lung inflammation.