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Another Reason to Avoid a Sugar High: Study Links High Blood Sugar to Mortality After Stroke


For release: Friday, August 23, 2002

Stroke has long been regarded as an untreatable condition with potentially devastating consequences. But in recent years, new treatments have markedly improved patients' ability to recover from stroke, and researchers now have a new clue about how to further improve stroke treatment.

A study published in the July 9, 2002, issue of the journal Neurology shows that stroke victims who have high blood sugar have a higher risk of dying than stroke patients with normal blood sugar levels.

The researchers reviewed 5 years of medical records from 656 adults who were hospitalized because of a stroke. More than 40 percent of those patients had abnormally high blood sugar levels when they were admitted to the hospital.

Patients were studied from 1 to 5 years after their strokes, depending on availability of hospital records. Those with high blood sugar (glucose) when they were admitted to the hospital were at higher risk of dying within 30 days, 1 year, or 5 years after their stroke. They also had longer hospital stays and higher hospital costs than patients with normal blood sugar levels.

Although most of the patients had a previous history of diabetes, their blood sugar levels were not under control and often were not managed during hospitalization. Study author Askiel Bruno, M.D., associate professor of neurology at Indiana University (IU) School of Medicine, says finding high glucose levels, or hyperglycemia, in stroke patients was not surprising. "Glucose levels tend to rise during acute stress, especially in people with diabetes," says Bruno.

What was surprising, says co-author Linda Williams, M.D., assistant professor of neurology at IU, was that blood sugar levels remained high in about 90 percent of the patients.

When blood glucose levels rise, a substance called lactic acid begins to build up in various tissues, including the brain. When there is insufficient blood flow, as in stroke, this acid build-up accelerates a series of reactions that cause cell death following a stroke.

With the incidence of diabetes on the rise, this link between high blood sugar and death after stroke suggests that glucose management with insulin needs to be an important part of inpatient care after stroke.

It's possible that patients with one poorly controlled risk factor may also have other poorly controlled risk factors for stroke, says Dr. Williams. Hyperglycemia occurring with stroke also could indicate something unique about a patient's response to stress in general, she adds.

Bruno, Williams, and their colleagues have teamed up again to study the effectiveness and safety of intravenous insulin treatments for hyperglycemia beginning within 12 hours after stroke. Their goal is to see if strict control of blood sugar in the first 3 days after stroke will result in better outcomes than standard treatments. The pilot clinical trial, which is funded by the National Institute of Neurological Disorders and Stroke (NINDS), will begin this year and is expected to last 3 years.

"We're very interested in reducing functional deficits after stroke, since the overwhelming majority of stroke patients become disabled in some way," says Dr. Bruno. "We hope there will be a significant difference in cognitive and motor function between the aggressive and the standard treatment groups."

If the trial is successful, managing blood sugar would likely add to the existing ammunition against stroke, such as the clot-busting drug tissue plasminogen activator (tPA), which is used to treat strokes caused by blood clots. "You can think of insulin treatment as complementary to current stroke treatments," says Dr. Bruno. However, stroke patients would still need emergency care, he adds.

While tPA, or thrombolysis, takes care of treating the clot, insulin would deal with the negative effects of high blood sugar. "If it works, it would be easier to use than some new drug, because most physicians are familiar with insulin," says Dr. Bruno.

One possible risk associated with insulin treatment is hypoglycemia, or low blood sugar, but the researchers say intensive monitoring during treatments will allow them to detect rapidly dropping blood sugar levels.

Reference: Williams LS, Rotich J, Qi R, Fineberg N, Espay A, Bruno A, Fineberg SE, and Tierney WR. "Effects of Admission Hyperglycemia on Mortality and Costs in Acute Ischemic Stroke." Neurology, Vol. 59, No. 1, July 9, 2002, pp. 67-71.

- By Tania Zeigler



 

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Last Modified April 16, 2014