Health bosses in Norfolk said they will continue to tackle the causes of diabetes as new figures show one in five patients admitted to hospital suffers with the condition.

The first diabetes audit of NHS hospitals found that while 4pc of the UK population have diabetes, 20pc of hospital patients have the disease.

Some are being treated for the direct consequences of diabetes – many can fall into comas or suffer kidney failure – while others suffer heart attacks or strokes which can increase if someone has diabetes.

It is believed a major reason for the rise in type 2 diabetes each year is the increasing number of people who are overweight or obese.

In the NHS Norfolk area, which has a population of about 750,000, about 30,000 people are registered with diabetes, which equates to about 4pc.

Jonathan Williams, NHS Norfolk’s assistant director of public health, said: “There are a number of reasons why people may develop diabetes, such as genetic factors or as a result of a heart attack or stroke, but obesity is also associated with being a cause of diabetes. “Therefore, by maintaining a healthy weight – by taking regular exercise and having a well-balanced diet – you can reduce your risk of developing this life-changing and very serious condition.

“It is estimated that more than 80pc of people diagnosed with type-two diabetes are overweight and are five times more likely to succumb to cardiovascular disease than people who do not have diabetes.

“Due to the links between diabetes and a number of other serious conditions, such as these, this may be an indication as to why the proportion of people in hospital with diabetes may be higher than that in the general population.”

This year it is expected that the prevalence of diabetes will rise to more than 5pc in some areas with there is a minimum of 25,000 new cases expected over the next decade.

Some 2.6m people in the UK have diabetes, with 2.3m having the type 2 version linked to obesity, smoking, alcohol or lack of exercise.

The government’s diabetes tsar Dr Rowan Hillson said all patients with diabetes should be given access to specialist advice to ensure potentially lethal complications were not missed.