The £2m study by the UK Prospective Diabetes Study Group (UPDSG) is the largest ever into the disease.

It studied the effect of strong hypertension drugs and glucose treatments on 1,148 people with type 2 diabetes, the most common form of diabetes affecting up to 95% of all sufferers.

Diabetes costs the NHS £2.2bn a year and is the single largest cause of blindness in the UK.

It also increases the risk of heart disease, lower limb amputation and kidney failure.

Blood pressure

One project in the study looked at the difference between patients whose blood pressure was tightly controlled - through enzyme inhibitor drugs and beta blockers - and those who were subject to less tight controls.

It found that tight control of blood pressure reduced the risk of deaths and all diseases linked to diabetes.

Those on tight controls were 32% less likely to die from diseases linked to diabetes, 44% less likely to suffer a stroke, 21% less at risk of suffering a heart attack, 56% less prone to heart failure and 47% less likely to suffer significant visual deterioration.

The researchers, from Oxford University, said their results showed the need for reduction of blood pressure to be a high priority for caring for diabetes patients.

Another research project found that using different blood pressure drugs had no significant impact on reducing the incidence of diabetes-related disease.

The project compared beta blocker drug, atenolol, and enzyme inhibitor drug, captopril.

It concluded: "This study provided no evidence that either drug has any specific beneficial or deleterious effect, suggesting that blood pressure reduction in itself may be more important than the treatment used."

Cost

Researchers also looked at the cost implications of treating patients with drugs which tightly control blood pressure, compared with drugs which are not as strong.

Blood sugar control drugs like insulin can save lives

They found that the more expensive tight control drugs substantially reduced the cost of long-term treatment for the disease since sufferers did not develop as many complications, such as major illnesses, did not require as much treatment or hospitalisation and lived longer.

The research on blood pressure is published in The British Medical Journal.

The Lancet published two other projects in the study, on the effect of drugs that reduce blood sugar.

They also found that drug treatment, including insulin, reduced the likelihood of patients developing illnesses such as heart disease, stroke and eye disease.

Confidence

The study is being launched at a conference of the European Association for the Study of Diabetes in Barcelona on Thursday.

The British Diabetic Association, members of the UPDSG and the Medical Research Council are to hold a press conference in London to coincide with the launch.

Professor Robert Turner, of the UPDSG, said: "At present, diabetic complications are often regarded as being a natural outcome of this chronic disease.

"The study shows definitively that good management, including improved blood pressure and blood glucose, does help to prevent complications.