A new study has suggested an "early and aggressive" approach to people who are on the cusp of developing Type 2 diabetes is justified to reduce cases of the disease.
People with "pre-diabetes" have higher than normal blood sugar which has not yet reached diabetic levels.
A US study showed that restoring normal sugar levels more than halved the numbers going on to Type 2 diabetes.
Experts said the findings were clinically important.
It is thought that seven million people have pre-diabetes in the UK and 79 million in the US. They are at heightened risk of Type 2 diabetes, heart attack and stroke. Many are undiagnosed.
Some measures, such as weight loss and more exercise, can reverse pre-diabetes. The study, by the US Diabetes Prevention Program Research Group, tried to determine how effective the treatment was at preventing Type 2 diabetes.
The study followed 1,990 people with pre-diabetes. Some were being treated through drugs or lifestyle change, others were not.
It showed that patients, who reduced their blood sugar levels to normal, even briefly, were 56 percent less likely to develop Type 2 diabetes during the six years of the study.
"This analysis draws attention to the significant long-term reduction in diabetes risk when someone with pre-diabetes returns to normal glucose regulation, supporting a shift in the standard of care to early and aggressive glucose-lowering treatment in patients at highest risk," the BBC quoted Leigh Perreault, lead author of the study from the University of Colorado, as saying.
Dr Natalia Yakubovich, from McMaster University in Ontario, Canada, said the "findings clearly suggest" that restoring normal blood sugar levels was "of clinical relevance".
"Identification of regression to normal glucose regulation could be an important way to stratify people into those at higher and lower risk of progression to diabetes," she said.
"Such stratification could therefore identify individuals for whom additional treatment might be needed to prevent diabetes or to slow down disease progression," she added.
The study has been published in the Lancet.