More than one in three adults across England are affected by pre-diabtetes, a study has revealed.
New research published in BMJ Open shows that the number of people with higher than normal blood glucose levels has tripled over eight years.
People who are of black and minority ethnicity and those from disadvantaged families are "disproportionately affected", researchers found.
The researchers claim that if the trend continue, the country will face a steep rise in the prevalence of diabetes, as one in 10 of those with pre-diabetes go on to develop the condition.
Pre-diabetes was classified as a glycated haemoglobin - a measure of blood glucose control - of between 5.7% and 6.4%. Diabetes is usually classified as a glycated haemoglobin of 6.5%.
Analysis of the data showed that the prevalence of diagnosed diabetes rose from 3.55% in 2003 to 5.59% in 2011. But the rise in the prevalence of pre-diabetes was much greater. This rose from 11.6% to 35.3% between 2003 and 2011. Older age, overweight, obesity, high blood pressure and high cholesterol were all associated with pre-diabetes risk.
By 2011, half the survey participants (50.6%) who were overweight with a BMI of more than 25, and aged at least 40, had pre-diabetes. There was no gender difference in rates.
Those living in some of the most deprived areas of the country were more likely to have pre-diabetes in 2003 and 2006, but this association was no longer significant by 2009 and 2011.
But after taking account of age, sex, ethnicity, BMI and high blood pressure, people who lived in the second most economically deprived areas of the country were 45% more likely to have diabetes by 2011.
The researchers concluded: “In the absence of concerted and effective efforts to reduce risk, the number of people with diabetes is likely to rise steeply in coming years.”