A drug used to reduce sugar levels in diabetics appears to be useful in delaying or even preventing the disease in people predisposed to developing diabetes, a study in Japan has found.

The study, published in The Lancet, found that fewer people who were given the generic drug voglibose, available in Japan and other countries, went on to develop diabetes compared to those who received placebo, or dummy look-alike pills with no therapeutic value.

While the study was supposed to last three years, researchers found that voglibose was much better than placebo before the end of the first year, and an independent monitoring panel terminated the study early.

"Long-term prophylaxis with this (drug) in high-risk individuals with impaired glucose tolerance could provide a pharmacological option, along with lifestyle modification, to help reduce the burden of type 2 diabetes in Japan," the researchers wrote in the article.

The trial, headed by Ryuzo Kawamori of Juntendo University School of Medicine in Tokyo, involved 1,780 patients who were assessed to be at high risk of developing diabetes.

Among them, 897 took voglibose three times a day, while 883 were given placebos.

Fifty of the voglibose patients went on to develop diabetes, compared to 106 in the placebo group — which meant that those treated with voglibose had a 40 percent lower risk of progression to type 2 diabetes than those receiving placebo.

Furthermore, patients on voglibose were 54 percent more likely to achieve normal blood sugar levels than those given placebo.

"This study showed that, if best efforts to educate individuals do not work, treatment with voglibose could be an important way forward," said Andre Scheen of the division of diabetes at Belgium's University of Liege.