Global Study to Focus on Diabetes Prevention

Two drugs are target of early detection efforts in largest-ever trial

WEDNESDAY, Jan. 2, 2002 (HealthDayNews) -- Recruitment has just begun for an international study that will involve 7,500 patients from 40 countries in the largest-ever trial on the prevention of diabetes and related cardiovascular disease.

The research, which is expected to run until 2007, will examine whether early detection of a condition known as impaired glucose tolerance (IGT) and long-term use of the drugs nateglinide and valsartan can reduce or delay the development of Type II diabetes and cardiovascular disease in people who have IGT.

IGT is a seldom-diagnosed condition that occurs when blood glucose levels are higher than normal but not high enough to be classified as diabetes. Having IGT puts people at greater risk of developing diabetes and cardiovascular disease. As many as 1 in 7 people over the age 40 has IGT, and about half of those with IGT will develop Type II diabetes within 10 years.

People with diabetes are two to four times more likely to suffer a heart attack than those without diabetes, and 70 percent of people with diabetes die as a result of cardiovascular disease.

The trial, called NAVIGATOR (Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research), is being conducted by the pharmaceutical company Novartis. About a third of the study patients will be from the United States, where recruitment began last month. Recruitment has also started in Holland, and recruitment efforts in other countries will start soon.

"We view diabetes as a global problem," says Dr. Richard Pratley, NAVIGATOR medical director and senior clinical research physician at the East Hanover, N.J.,-based pharmaceutical company.

About 120 million people worldwide have diabetes, and that number is expected to almost double over the next 25 years, Pratley says. Most of those new cases will be in developing countries, he adds.

"So, from our perspective, if we're going to impact on the global epidemic of diabetes and its complications of microvascular and cardiovascular disease, we need to start at a very early stage," before people actually develop diabetes, Pratley says.

Nateglinide is an oral drug used to correct mealtime glucose spikes in diabetics, and Pratley says it may turn out to be effective in treating IGT.

"So we think it might be actually a very good drug to help prevent progression to diabetes," Pratley says.

Valsartan is a drug used to treat high blood pressure. But there's growing evidence that it may also improve insulin sensitivity and reduce the risk of developing Type II diabetes, Pratley says.

The NAVIGATOR study could hold great potential for diabetes prevention, says Scott Campbell, vice president of research programs at the American Diabetes Association.

He agrees that since these drugs seem effective treatment for patients with diabetes, they may indeed help people with IGT avoid developing diabetes.

"So the question is, how early can you intervene and can you delay or prevent (diabetes') onset? If you can do that, let me tell you, you've got something big," Campbell says.

The huge size and global scope of the study are important factors. By using people in 40 different countries, it eliminates the possibility that results may be particular to a certain country or ethnic population. And the large number of patients will lend weight to the findings.

"Your statistical power goes up tremendously. The more patients you have, the more data you have and the easier it is to find statistical differences between whatever you're looking at," Campbell says.

What To Do

About 20 million Americans have IGT. The International Diabetes Institute says healthy eating and exercise can help people with IGT protect themselves from developing Type II diabetes. About 16 million Americans have diabetes, but about a third of them haven't been diagnosed, says the U.S. National Institute of Diabetes and Digestive and Kidney Diseases.

Here's where to go to learn more about impaired glucose tolerance.

For more about diabetes, go to the U.S. National Institute of Diabetes and Digestive and Kidney Diseases, or the American Diabetes Association.

SOURCES: Interviews with Richard Pratley, M.D., NAVIGATOR medical director, and senior clinical research physician, Novartis Pharmaceuticals Corp., East Hanover, N.J.; Scott Campbell, Ph.D., vice president of research programs, American Diabetes Association, Alexandria, Va.
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