Trial results evaluating valsartan as an antihypertensive agent indicate the drug may significantly reduce risk for diabetes, especially in people at high risk, according to a presentation at the annual meeting of the American Society of Hypertension.

In new results from the VALUE trial, which compared valsartan with amlodipine, patients taking valsartan had a 23 percent lower risk of developing diabetes during the four or more years of the study. The two drugs had previously been shown to be roughly equivalent in reducing the risk of myocardial infarction and stroke.

The new, in-depth analysis of data from the two groups of patients shows that the difference in diabetes onset risk appears to be attributable to valsartan and not to other underlying factors. However, the researchers did determine that certain risk factors made some patients more likely to develop diabetes -- and that the more of these risk factors a patient had, the more protective the effect of valsartan.

The randomized trial involved 15,313 patients at 942 sites in 31 countries, of whom 9,995 did not have diabetes at enrollment. All patients were over age 50 years, had hypertension, and were at high risk for a cardiac event. By the end of four or more years of follow-up, 11.5 percent of patients taking valsartan had developed diabetes compared with 14.5 percent of patients taking amlodipine.

"These new results should help physicians as they select anti-hypertensive agents for their patients, especially for those at higher risk of developing diabetes," said Ken Jamerson, MD, who presented the results in a late-breaking session and served as VALUE chair for the United States. "Since we know from other studies that other hypertension medications such as diuretics come with a higher risk of diabetes, this result is especially interesting."

High blood sugar, faster heart rate, high body mass index, concurrent use of a diuretic drug and a beta blocker, non-white race, and younger age were all associated with a higher risk of developing diabetes in all VALUE participants. But after all these variables were taken into account, patients who took valsartan had less risk of developing diabetes.

Jamerson noted that diabetes onset prevention was not a primary goal of the VALUE study, and that therefore more research is needed to confirm the finding. But he also pointed out that it's the first study in which an angiotensin II receptor blocker was compared with a calcium-channel blocker.

"We know many factors increase the risk of diabetes, but valsartan appears to be important in that it provides protection against diabetes," said Jamerson. "Many patients with hypertension are also obese and have other risk factors that predispose them to develop diabetes. This trial adds to the armamentarium that physicians can choose from when treating patients with high diabetes risk."

The researchers separated the VALUE trial participants who weren't diabetic at the start of the trial into three groups, depending on the number of diabetes-predicting factors they had. The patients in the highest-risk group were six times more likely than the lowest-risk group to develop diabetes during the trial period. But among the patients in the highest-risk and second-highest-risk groups, the patients taking valsartan were significantly less likely to develop diabetes.

This finding, the authors say, suggests valsartan has some effect on glucose metabolism -- a crucial factor in diabetes risk.