By Esther Csapo Rastegari, RN

BOSTON, Aug 30 (Reuters Health) - Researchers here have found that aspirin can fight diabetes symptoms in mice, and they are conducting human trials to determine if the drug could be used to treat the disease.

In type 2 diabetes, which affects about 15 million Americans, the body loses its ability to respond to insulin, a hormone that helps the body to use sugar as fuel. This loss of sensitivity is referred to as insulin resistance. Obesity, a high-fat diet, and sedentary lifestyle are all known to increase insulin resistance.

During the 1950s, researchers discovered that aspirin could lower blood sugar levels. A team at the Joslin Diabetes Center at Harvard Medical School in Massachusetts has revived this research, and has found that aspirin fights insulin resistance. The findings are published in the August 31st issue of Science.

"We've been able to combine information already available to make a very exciting discovery," Dr. Steven Shoelson, a senior study researcher, told Reuters Health.

Shoelson and his colleagues conducted their research in mice genetically predisposed to develop obesity and diabetes. Giving the rodents high-dose aspirin reversed their insulin resistance, brought down their blood sugar and reduced blood levels of fats known as triglycerides. The effect lasted as long as the mice received the aspirin.

Aspirin treatment, Shoelson and colleagues propose, reverses chronic, low-level inflammation caused by obesity-related insulin resistance and high blood sugar. The drug works, they suggest, by acting on a cell-signaling pathway known as IKK-beta.

The Joslin team, in conjunction with researchers at Yale University, is conducting clinical trials of high-dose aspirin in patients with diabetes and obese participants without diabetes who are most likely already suffering from chronic, undiagnosed insulin resistance. The trials are open.

Shoelson warns that these trials are in the early stages and that people should not use high-dose aspirin to treat their diabetes. In high doses, aspirin can lead to potentially fatal complications such as stomach bleeding and liver and kidney damage.

Joslin researchers have also begun working with pharmaceutical companies to develop a "better aspirin" without these harmful side effects.

SOURCE: Science 2001;293:1673-1677.