Background: Despite demonstrated benefits, intensive insulin therapy has no
t 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 o
f administering insulin are being evaluated.
Objective: To assess the efficacy and safety of pulmonary delivery of insul
in in type 2 diabetic patients who require insulin.
Design: Randomized, open-label, 3-month study consisting of a screening vis
it, a 4-week baseline lead-in phase, and a 12-week treatment phase.
Setting: General clinical research center and outpatient research clinics.
Patients: 26 patients (16 men, 10 women) with type 2 diabetes (average age,
51.1 years; average duration of diabetes, 11.2 years).
Intervention: Patients received inhaled insulin before each meal plus a bed
time injection of ultralente insulin, performed home glucose monitoring, an
d had weekly adjustment of insulin dose; target level for preprandial plasm
a glucose was 5.55 to 8.88 mmol/L (100 to 160 mg/dL).
Measurements: Glycemic control (hemoglobin A,. level) obtained at baseline
and monthly for 3 months, Pulmonary function tests were done at baseline an
d at the end of the study.
Results: Inhaled insulin treatment for 3 months significantly improved glyc
emic 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.
Conclusions: Pulmonary delivery of insulin in type 2 diabetic patients who
require insulin improved glycemic control, was well tolerated, and demonstr
ated no adverse pulmonary effects. Larger-scale studies are ongoing to prov
ide long-term efficacy and safety data.