"One in three adults in England 'on cusp' of diabetes," BBC News and others report. The media reports are based on a study that estimated that 35.3% of adults in the UK now have prediabetes (also known as borderline diabetes).
Prediabetes is where blood sugar levels are abnormally high, but lower than the threshold for diagnosing diabetes. It is estimated that around 5-10% of people with prediabetes will go on to progress to "full-blown" type 2 diabetes in any given years.
Researchers analysed information from the Health Survey for England (HSE). This is a survey that combines questionnaire-based answers with physical measurements and the analysis of blood samples from a representative sample of the English population.
This study found that there has been a significant increase between 2003 and 2011 in the proportion of people aged 16 or older with prediabetes, from 11.6% in 2003 to 35.3% in 2013.
Known risk factors, confirmed in this study, include age (40 and above), body mass index (25 and above), being of south Asian ethnicity, and having high blood pressure.
If you think you may be at high risk of prediabetes, you can ask your GP for a blood test. It is often possible to prevent the condition progressing into diabetes proper through lifestyle changes, such as improving your diet and exercising more.
Where did the story come from?
The study was carried out by researchers from the University of Florida and the University of Leicester, and was somewhat surprisingly funded by the US Department of Defense.
This study was accurately reported in the UK media, with many articles also helpfully outlining the complications of diabetes, its impact on public health, and some relevant contextual information.
For example, this included information about the NHS Health Check programme, which invites people between the ages of 40 and 74 to have a check to assess their risk of heart disease, stroke, kidney disease and diabetes, and to give support and advice to help people reduce or manage their risk.
But as the NHS Health Check programme is in its infancy, it is hard to estimate what the likely take-up will be in the future and what impact it will have on public health.
What kind of research was this?
This was a cross-sectional study that aimed to report trends in the prevalence of prediabetes among people aged 16 or older in England.
Cross-sectional studies are the ideal way of determining how many people have a condition.
What did the research involve?
The research used information collected by the Health Survey for England (HSE) in the years 2003, 2006, 2009 and 2011.
The HSE is an annual population-based survey that combines questionnaire-based answers with physical measurements and the analysis of blood samples from a random sample of participants.
People were classified as having prediabetes if they had glycated haemoglobin (an indicator of blood sugar levels) between 5.7% and 6.4% and had not previously been diagnosed with diabetes.
Glycated haemoglobin is formed when haemoglobin is exposed to glucose in the blood. As the amount of glucose in the blood increases, the fraction of haemoglobin that is glycated increases.
Diabetes is diagnosed when the level is 6.5% or above. However, there is no internationally agreed lower level for prediabetes.
The prevalence of prediabetes increased over the study period. It was:
11.6% in 2003
20.4% in 2006
32.6% in 2009
35.3% in 2011
Age, being overweight, obesity, blood pressure level and cholesterol level exhibited significant relationships with prediabetes in all years that these were measured.
People with greater socioeconomic deprivation were more likely to have prediabetes in 2003 and 2006, but the relationship was no longer significant in 2009 and 2011.
The researchers found that predictors of prediabetes in 2003 and 2011 included:
being 40 years or older
being of south Asian ethnicity
having a high body mass index (BMI) of 25 or over
having been diagnosed with high blood pressure
being socioeconomically deprived (being in the second most deprived quintile)
How did the researchers interpret the results?
The researchers concluded that, "There has been a marked increase in the proportion of adults in England with prediabetes. The socioeconomically deprived are at substantial risk.
"In the absence of concerted and effective efforts to reduce risk, the number of people with diabetes is likely to increase steeply in coming years."
This study indicates that there had been an increase between 2003 and 2011 in the proportion of people aged 16 or older with prediabetes, with more than a third of adults in 2011 having prediabetes.
The study is useful because it is based on information from the Health Survey for England (HSE), which sampled a representative sample of the English population.
However, the researchers defined prediabetes using cut-offs used by the American Diabetes Association (5.7-6.4%), but in the UKNICE recommends higher cut-offs to identify people at high risk of diabetes (6.0-6.4%).