This new approach represents a less-invasive treatment option compared with conventional treatment involving the use of subcutaneous insulin injections.

Effective blood glucose control in type-1 diabetes mellitus usually requires two or more insulin injections daily. Inhaled delivery of insulin offers a potential new way to deliver insulin, eliminating the need for preprandial (before a meal) injections.

Jay Skyler and colleagues from the University of Miami and 9 other US research centers studied 73 patients with type-1 diabetes mellitus.

In this randomized trial, patients in the experimental group received preprandial inhaled insulin in addition to a bedtime subcutaneous insulin injection.

Patients in the control group received their usual insulin treatment of two to three injections per day.

All patients monitored their blood glucose four times daily, and adjusted insulin doses weekly to achieve normal preprandial glucose targets.

The primary outcome measure was change in glycosylated hemoglobin (HbA1c) after 12 weeks. Secondary outcome measures were fasting and postprandial glucose response to a mixed meal; frequency and severity of hypoglycemia (low blood glucose); lung function; and patients' satisfaction.

The investigators found that changes in HbA1c were indistinguishable between the two groups. Similarly, there was little difference in changes in fasting and postprandial glucose concentrations, and occurrence and severity of hypoglycemia. Inhaled insulin was well tolerated and had no effect on lung function.

In an accompanying Commentary (p324), Edwin Gale from the University of Bristol, UK, states that the sample size is too small to confirm beyond doubt that inhaled insulin is as good as conventional injections. He concludes, "Whatever the practical limitations of inhaled insulin, the deeper meaning that this report will hold for many people should not be overlooked.

"Diabetes is intangible yet all-pervasive, and alters the whole context within which an individual lives his or her life. It changes the self-image, the social relations, the daily existence, the hopes and dreams of those who are affected.

"For people trapped within this subculture the needle is not just an irksome necessity, but a symbol of their bondage to an invisible parasite. The medical community should therefore join with them in celebrating this small step forward, in the knowledge that when the hype subsides, the hope will remain."

02-Feb-2001