It works by detecting levels of a genetic molecule in their blood, it was claimed.
The same molecule, called a microRNA (MiR), could help pinpoint sufferers at high risk of heart and artery disease.
Amongst the two million people in Britain who already have diabetes, the test can also distinguish between those who will and will not go on to develop some of the complications of diabetes caused by damage to blood vessels, such as heart attack, stroke and poor circulation.
The lead scientist Dr Manuel Mayr, from King’s College London, said he expected the MiR test to be used in conjunction with conventional methods. It is likely to cost around £2.
Its biggest advantage was that it directly assessed the damage diabetes was causing to blood vessels.
“It’s very important for doctors to define those diabetic patients that are at the highest risk of developing cardiovascular complications,” said Dr Mayr.
“We hope that this new class of blood markers may give additional insight that we’re currently not getting from other clinical tests.”
Being able to identify which people with diabetes are particularly at risk of having a heart attack or stroke should allow doctors to begin early treatment with cholesterol and blood pressure lowering drugs and target it at those who are most likely to benefit.
Treating diabetes costs the NHS £9bn a year.
One type of micro-RNA, known as MiR-126, protects blood vessels from damage.
Healthy blood vessel cells are able to release substantial MiR-126 in to the blood stream.
However, when they become damaged, they need to keep the MiR-126 for themselves and shed less in to the blood.
Dr Mayr studied 822 adults aged between 40 and 79 living in northern Italy.
Of the two types of diabetes, type 2, or adult onset, diabetes is much more common.
Around five per cent of adults in England have diagnosed type 2 diabetes. A further three percent of men and two per cent of women aged over 35 may have undiagnosed type 2 diabetes.
The risk of having a heart attack is between two and five times greater in people with diabetes. Around 15 per cent of heart attacks in western Europe are due to diabetes.
The findings were published in the journal Circulation Research.
Professor Jeremy Pearson, associate medical director at the British Heart Foundation, which funded the research, said: “This is important because right now there is no quick and simple way to monitor blood vessel health.
“Problems go unnoticed until symptoms appear, and the first symptom could be as serious as a heart attack.”