HOSPITAL PRACTICE

Researchers make headway on oral, nasal insulin

There were some promising studies of oral and inhaled insulin reported at the American Diabetes Association's annual meeting in Philadelphia last month. There were also some disappointments—both in preventing diabetes itself in high-risk individuals and preventing its many cardiovascular and other complications.

"Too often, healthcare providers and patients don't take diabetes seriously," said John Buse, M.D., director of the Diabetes Care Center at the University of North Carolina. As a result, he explained, "patients don't receive adequate education and treatment to control their risk factors for cardiovascular disease." Buse, who is also chair of the ADA's new Diabetic Cardiovascular Disease Initiative, hopes to change all that.

Citing the results of the landmark Diabetes Control and Complications Trial and the Epidemiology of Diabetes Interventions and Complications follow-up, Buse said that the DCCT/EDIC follow-up report at six years showed that carotid artery-wall thickness was 24% less in patients on the intensive treatment regimen compared with those on conventional treatment. This provides the first proof of decreased cardiovascular morbidity and mortality with good blood glucose control, he said.

The big disappointment at the meeting was the report of the DPT-1 trial, aimed at preventing or delaying the onset of Type 1 diabetes in individuals at high risk for the disease. In this trial, injections of low-dose insulin failed to prevent or stall the onset of the disease, as had been hoped.

Disappointing also was the fact that more patients with diabetes were not being properly treated to avoid their heightened risk for cardiovascular disease. As Brian Nightengale, Ph.D., of Applied Health Outcomes, put it, a survey of 600,000 patients in 12 managed care groups showed that only 42% of those with hypertension were controlled, and only 20% of those with both diabetes and high blood pressure had those conditions under control. Nightengale also said that of the 1,131 patients with both conditions, fewer than 500 were being prescribed an ACE inhibitor, which has been shown to offer a unique protective effect in this type of patient. Other studies showed that lipid problems in diabetics were also, in many cases, left untreated.

The wave of the future may well be, for many patients, to take their insulin either orally or by inhalation, according to several studies reported at the ADA meeting. In a phase III study involving 299 patients with Type 2 diabetes who were randomized to either insulin injections alone or to an inhaled insulin (Exubera, Aventis) before meals plus an insulin injection at bedtime, blood glucose control was similar. Those who took the inhaled form of insulin, however, had fewer episodes of hypoglycemia, according to Priscilla Hollander, M.D., Ph.D., medical director at Baylor University Medical Center in Dallas.

In announcing the results of Nobex Corp.'s phase II studies of its fast-acting oral insulin, Mark Kipnes, M.D., an endocrinologist at the Diabetes and Glandular Disease Clinic in San Antonio, said the product controlled blood glucose with lower levels of insulin in the peripheral circulation than is the case with injectable insulin.

Meanwhile, the insulin sensitizer rosiglitazone (Avandia, GlaxoSmithKline) reduced inflammatory mediators such as C-reactive protein, which are associated with the development of atherosclerosis, in a group of 11 nondiabetic but obese patients in a study by Paresh Dandona, M.D., of the University of Buffalo. The study thus demonstrates that rosiglitazone may be effective in preventing cardiovascular disease in people without diabetes.

Other reports at the meeting also centered on lowering insulin resis-tance to try to prevent the onset of Type 2 diabetes. Thomas Buchanan, M.D., professor of medicine at the University of Southern California, reported on the results of the Troglitazone in Prevention of Diabetes (TRIPOD) trial in 235 Latino women with recent gestational diabetes. When troglitazone (Rezulin, Parke-Davis) was recalled by the Food & Drug Administration, pioglitazone (Actos, Takeda) was substituted. According to Buchanan, the study showed that women in the placebo group developed diabetes at a rate of 12% a year, compared with less than 5% of the women on a drug. He said these results indicate that reducing secretory demands on beta-cell function by chronic insulin resistance stopped or slowed the underlying deterioration of beta-cell function.

The ADA meeting also saw the unveiling of several devices for diabetics. Among them is the InDuo System, an insulin doser and blood glucose monitor combined. Offered by LifeScan and Novo Nordisk, the device will be released this fall.

Jean McCann

Based in Ohio, the author has extensive experience covering national and international medical and pharmaceutical meetings and is a clinical contributor to Drug Topics.

Jean Mccann. Researchers make headway on oral, nasal insulin.

Drug Topics

2001;14:22.