High triglycerides – a type of blood fat – are a strong independent predictor of a person's risk of stroke, a new study suggests.

The study is the first to identify the risk of stroke associated with triglycerides, according to the author, David Tanne. Tanne is the stroke unit director at the Sheba Medical Center in Israel.

The results mean doctors may have a new predictor to consider when determining a patient's risk of stroke. Doctors may need to look at a patient's triglyceride levels, even if their cholesterol level is normal.

Previous research has shown high triglycerides sharply increase the risk of dying from a heart attack, but Tanne said earlier studies didn't show a clear connection between stroke and triglycerides.

"More effective screening and detection of high blood triglycerides and treatments to modify this stroke risk factor could further reduce the health burdens of stroke," said Tanne in a news release.

Dion Graybeal, neurology professor at the University of Texas Southwestern Medical Center, thinks Tanne's findings may encourage doctors to consider prescribing drugs that lower triglycerides as well as LDL or "bad" cholesterol.

"Cholesterol is where all the money's been, where all the research has been, where all the fuss has been," he said. He's convinced Tanne's research proves doctors have been overlooking an important predictor of stroke.

For some time, doctors have known the traditional risk factors for strokes, but Tanne says they haven't provided the whole story. He says in addition to managing bad cholesterol, triglycerides shouldn't be ignored.

The findings appear in the Dec. 11 issue of the American Heart Association journal, Circulation .

Broader look at strokes

Stroke is the third-largest cause of death in the United States and Canada after coronary heart disease and all forms of cancer. The most common type of stroke, accounting for about 80 per cent of all cases, is ischemic stroke. Ischemic strokes are caused by the interruption of blood supply to the brain.

Tanne said previous research focused on fatal strokes, neglecting other types such as the ischemic stroke.

In Tanne's study, researchers followed over 11,000 patients with heart disease but no history of stroke for six to eight years.

High triglycerides, higher stroke risk

The study focused primarily on Israeli men 40 to 74-years-old. It showed those with high levels of triglycerides (about one-fourth of those studied), had a nearly 30 per cent higher risk of stroke. The increased risk associated with elevated triglyceride levels was found across age, gender, patient characteristics and cholesterol groups.

Of those 25 per cent, most had triglyceride levels of 200 mg/dL. According to the American Heart Association, levels below 150 mg/dL are considered normal.

Graybeal, however, believes the findings may be skewed by the narrow focus on Israelis, whose diet and genetics may differ from those of many Americans and Canadians.

And in Canada, women have a lower risk than men. But women tend to live longer so more women die from stroke each year, according to the Canadian Heart and Stroke Foundation.

Tanne said further research needs to be done to see if a similar link between triglycerides and stroke risk exists in those without heart disease.