What are ideal BP levels to prevent repeat strokes, heart attacks?

The study found that people admitted to the hospital with A1C levels a test to determine average blood sugar level  above the 6.8 per cent to 7 per cent range had an increased risk of having a vascular event like a heart attack, as well as having another stroke.

"We know that having diabetes may be associated with an increased risk of having a first stroke," said researcher Moon-Ku Han from Seoul National University College of Medicine in Korea.

"But our results indicate that there is an optimal blood sugar level that may start to minimise the risk of having another stroke, a heart attack or other vascular problems and it's right in the 6.8 per cent to 7 per cent range," Han added.

For the study, published in the journal Neurology, the team involved 18,567 people with diabetes with an average age of 70.

All participants were admitted to the hospital for an ischemic stroke, which is caused by a blood clot. Upon admission, researchers used a test called the hemoglobin A1C to determine people's average blood sugar level over the past two to three months.

This test measures a percentage of hemoglobin proteins in the blood coated with sugar. A level below 5.7 per cent is considered normal; 6.5 per cent or higher generally indicates diabetes.

The participants had an average A1C of 7.5 per cent.

Researchers then followed up one year later to find out if there was an association between A1C levels with the risk of having another stroke, a heart attack, or dying from these or other vascular causes.

Of all participants, 1,437, or about 8 per cent, had a heart attack or died from the vascular disease within a year of starting the study, and 954, or 5 per cent, had another stroke.