Diabetics have to monitor their blood glucose levels

The research, published in The Lancet, looked at the incidence of Type 2 diabetes in 470,000 people living in Fyn, Denmark between 1993 and 1999.

Type 2 diabetes, which usually develops in people over 45 or the obese, is becoming more prevalent they said.

But this was because people with diabetes were living longer, and fewer are dying from the disease.

The researchers found that the total number of people with diabetes, the prevalence, increased by around 3% annually.

But the number of new cases diagnosed - the incidence - was unchanged over the years.

In addition, the number of deaths had fallen by 3% from 1993 to 1999.

Prescriptions

To evaluate the numbers of people with Type 2 diabetes, researchers from the University of Southern Denmark looked at the numbers of people prescribed anti-diabetic drugs, which are taken by most people with this form of the condition.

They looked at how many people started treatment because they were newly diagnosed in each year, and how many deaths there were in patients who had been prescribed the drugs in that year.

The prevalence of type 2 diabetes may have risen mainly because people are being picked up and treated earlier or are living longer Professor Edwin Gale, Southmead Hospital, Bristol

The team, led by Dr Henrik Stovring, wrote: "The increase in prevalence is largely the result of incidence in absolute numbers being higher than mortality in treated diabetics, rather than as a result of rising incidence."

They recommend the decrease in mortality should be taken into account in any future research.

"Otherwise, incorrect conclusions could be drawn about the relation between the western lifestyle and the rising number of diabetics."

Sedentary lifestyles

In an editorial in the Lancet, Professor Edwin Gale a diabetes specialist at Southmeads Hospital, said: "This report reminds us that the rising prevalence of type 2 diabetes is complex and deserves more detailed examination.

"Make no mistake, obesity and diabetes are indeed on the increase, a problem big and deadly enough to need no supporting rhetoric, but not all increases are sinister.

"Let us take some comfort from the hint that, in some populations at least, the prevalence of type 2 diabetes may have risen mainly because people are being picked up and treated earlier or are living longer."

Dr Eleanor Kennedy, research manager at Diabetes UK said "This interesting study shows that if diabetes is diagnosed early and managed well, people can live successfully with the condition.

"However, the increase of obesity and sedentary lifestyles, along with other factors such as the age and ethnicity of a population indicate that more people around the world are developing Type 2 diabetes."

She added: "It is vital that we continue to take this condition seriously.