Rapid-acting insulins such as Novolog and Humalog often show peak insulin levels up to 3 hours after injection. In this period, glucose levels may fluctuate considerably. Inhaled insulin starts working more quickly and peaks in less than one hour.
Diabetes in Control reports on a recent 60-participant study that investigated the effect of multiple inhalations versus previous studies of one before-meal inhalation in conjunction with an injection (Novolog). The study used continuous glucose monitoring, to report on ‘time-in-range, prandial glucose excursions (the difference between highest CGM glucose and premeal glucose), and time in hypoglycemia.’
An interesting part of the conclusions is that participants seemed to have not followed instructions since they underdosed themselves after evening meals compared to the study guidelines for inhaled insulin. The study investigators speculate that this underdosing is due to participants fear of nighttime hypoglycemia.
The study was funded by MannKind, the company that makes the inhaled insulin product.
Source: http://www.diabetesincontrol.com/inhaled-vs-injected-insulin/
