High Blood Glucose Linked to Stroke

---

Glycated hemoglobin and risk of stroke in people without known diabetes in the European Prospective Investigation into Cancer (EPIC)-Norfolk prospective population study: a threshold relationship? by P.K. Myint and colleagues. Stroke 38:271-275, 2007.

What is the problem and what is known about it so far?

It is widely known that people with diabetes are more likely to develop cardiovascular disease (CVD, disease of the heart and blood vessels). Research indicates that the higher a person’s blood glucose level—even at levels below those found in diabetes—the greater the chances that he or she will have a heart attack. Less is known about the link between blood glucose levels and stroke.

Why did the researchers do this particular study?

The researchers wanted to examine the link between blood glucose levels and stroke in a large and diverse group of people.

Who was studied?

The study included 10,489 people enrolled in the European Prospective Investigation into Cancer (EPIC) study, a long-term project in the United Kingdom to study men and women who were between 40 and 79 years old.

How was the study done?

Participants completed a detailed health and lifestyle questionnaire and underwent a physical exam. Blood was drawn for lab tests, including A1C, a measure of long-term blood glucose control. Participants were kept track of for an average of 8.5 years.

What did the researchers find?

People whose A1C level was below 7%—the level recommended by the American Diabetes Association—were all about equally likely to have a stroke. The chance of stroke increased dramatically in people with A1C levels above 7%. These people were nearly 3 times as likely to have a stroke as people with an A1C level below 5%.

What were the limitations of the study?

Many people in the community were unable to fulfill all the obligations to participate in the study, for reasons such as health problems. The group studied could be healthier or different in some other way from the general population.

Also, there are other factors not measured that could be important, such as how long a participant had high blood glucose.

What are the implications of the study?

Unlike the link between blood glucose levels and heart attack, there appears to be a threshold effect with stroke, above which the chance of stroke markedly rises.

More research is needed to determine whether high blood glucose levels trigger heart attack and stroke in different ways.

For more information

Learn About the A1C Test

Diabetes, Heart Disease, and Stroke