Inhaled insulin (brand name Exubera) has been getting some negative press lately, focusing on its high price, large inhaler, slow sales, and concerns about its effects on lung function. While the results of a new study may not be able to do much to address the first three issues, they have shown inhaled insulin to be safe for the lungs and effective for diabetes management over a two-year period of use.
The study, which is published in this month’s issue of the journal Diabetes Care, enrolled 582 adults with Type 1 diabetes. Participants were randomly assigned to use either inhaled insulin or injections of short-acting Regular insulin or the rapid-acting insulin analogs insulin lispro (Humalog) or insulin aspart (NovoLog) before meals. All participants also injected basal, or background, insulin (NPH, Ultralente, or insulin glargine [Lantus]) once or twice a day.
The researchers tested participants’ lung function throughout the study and found that both groups experienced small declines within the first three months. The decline observed in the inhaled insulin group was larger. However, neither group experienced a drop in lung function of more than 2%, and deterioration did not progress in either group for the rest of the study period (two years). The inhaled insulin group also experienced more coughing than the injected insulin group (38% vs. 13%). Rates of other side effects were similar between the two groups.
Blood glucose control was also similar between the two groups, and both groups had similar rates of hypoglycemia, or low blood glucose. However, the inhaled insulin group had fewer episodes of severe hypoglycemia (very low blood glucose) and also gained less weight than the injected insulin group.
The researchers concluded that inhaled insulin was safe for the lungs and efficient for diabetes management in adults with Type 1 diabetes over the two-year period. This study is actually part of a longer-term study that will follow the two groups for a total of 5.5 years to provide more data about the safety and effectiveness of inhaled insulin over the long term.