New research shows that many people who have heart disease - or are at risk of developing it owing to factors such as being overweight - also have undiagnosed diabetes, which increases their chance of an early death.

A Glasgow-based scientist involved in the recruitment of thousands of heart patients for a drug trial told the European Society of Cardiology conference in Munich yesterday that routine screening had revealed that one in five had unrecognised diabetes, while one in four had impaired glucose tolerance, which could develop into diabetes.

Professor John McMurray, from the Western Infirmary in Glasgow, said that 43,509 patients were recruited for the trial, of whom 20% had heart disease while the rest were at risk.

Meanwhile Professor Lars Ryden, from the Karolinska University hospital in Solna, Sweden, warned that the many people with undiagnosed diabetes or glucose intolerance was cause for concern because they had a worse prognosis than other heart patients.

One year into the Euro Heart Survey on diabetes and the heart, which is following 4,961 patients with coronary artery disease who have been tested for diabetes and impaired glucose tolerance, Prof Ryden said it was clear that heart patients without diabetes did best and those with known diabetes had the worst outcomes.

"Diabetic patients have a high mortality," said Prof Ryden. "We need to detect them because we need to do something."

The patients should be advised to lose weight and improve their lifestyle, and could be helped with drug treatment, he said. "There are new drugs coming up which will decrease mortality."

Of the 4,961 patients in the Euro survey, only about a third knew they had diabetes, but 58% had either diabetes or impaired glucose tolerance.

"Cardiologists all over the world have to start to measure glucose tolerance in their patients with cardiovascular disease, because they are ill," he said.

He made a plea for specialists to take a more integrated approach to medicine rather then looking at only their own small area of the body.

"We need to get back to a sort of medicine that is much more comprehensive," Prof Ryden said.

Prof McMurray backed his call, pointing out that before 1994, most cardiologists did nothing about cholesterol.

Both cardiovascular disease and type 2 diabetes - type 1 is genetic and usually has its onset in youth - are strongly linked to being overweight or obese. Prof Ryden said the world should be paying much more attention to preventing heart disease and diabetes through diet and exercise. "We need to dramatically increase people's awareness," he said.

People must be encouraged to lose weight and walk for 30 minutes to an hour each day for at least three days a week. "We are not talking about turning everybody upside down or putting jogging shoes on them."

But if more is not done, he said, "we will face a very dramatically bad future".

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