Over one third of English adults have prediabetes, according to a study by researchers in the US and UK, and published in BMJ Open. The study shows rates of prediabetes have risen sharply in England - from 12% of adults affected in 2003 to 35% in 2011 - and the researchers warn that without action, this will lead to a sharp rise in full-blown type 2 diabetes in years to come.
For the study, University of Florida (UF) researchers worked with a team from the University of Leicester. Lead author professor Arch G. Mainous III, chair of UF's department of health services research, management and policy, says:
"The rapid rise was exceptionally surprising and suggests that if something doesn't happen, there is going to be a huge increase in the prevalence of diabetes."
Co-author Richard Baker, professor of quality in health care at the University of Leicester Department of Health Sciences, says the findings send "an important signal that we need to take action to improve our diet and lifestyles. If we don't," he warns, "many people will have less healthy, shorter lives."
Of adults in England, 35% have prediabetes
Prediabetes is a condition where blood glucose is higher than normal but not high enough to warrant a diabetes diagnosis. However, compared with those who have normal levels of blood glucose, people with prediabetes have a higher risk of developing vascular problems, nerve and retinal damage, and kidney disease.
In England, over 50% of those aged 40 and over who were overweight fell into the prediabetes category.
And every year, 5-10% of people with prediabetes go on to develop full-blown type 2 diabetes.
However, while prediabetes is a risk factor, it is possible to prevent type 2 diabetes with medication and lifestyle changes, says Prof. Mainous.
For their study, the researchers analyzed Health Survey for England data collected in 2003, 2006, 2009 and 2011, comprising a mix of questionnaire responses, physical measurements and blood test results.
Participants - who were all aged 16 and over - were classed as prediabetic if they said they had never received a diagnosis for diabetes, and their blood glucose lay between 5.7-6.4%, a band defined by the American Diabetes Association.
For 2011, the results showed 35% of adults in England - including over 50% of those aged 40 and over who were overweight (body mass index or BMI over 25) - fell into the prediabetes category.
Lower socioeconomic status appeared to increase risk of prediabetes
After ruling out age, sex, race/ethnicity, BMI and high blood pressure, being of lower socioeconomic status appeared to increase the risk of having prediabetes, note the researchers.
The results reflect similar rates recently released for the US, where more than 1 in 3 adult Americans have prediabetes.
However, the researchers note that England's prediabetes rates have risen faster than the ones in the US over a similar time frame.
The study did not look at what might be causing this steep climb in prediabetes in England. However, the team points to the rapid rise in obesity in England in the late 1990s, and the fact the metabolic changes associated with weight gain tend to lag by several years.