Poor Glucose Control and Cardiovascular Disease

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Selvin E, Marinopoulos G, Berkenblit T, et al.: Meta-Analysis: Glycosylated hemoglobin and cardiovascular disease in diabetes mellitus. Ann Intern Med 141:421–431, 2004.

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

Poor control over blood glucose levels in people with type 1 or type 2 diabetes is linked to cardiovascular disease (disease of the heart and blood vessels). Improving blood glucose control may help prevent people with diabetes from getting heart and blood vessel disease, blindness, nerve damage, heart disease, stroke, and kidney failure.

Researchers wanted to know whether controlling blood glucose lowered the chances of getting heart and blood vessel disease.

Who was studied?

Researchers reviewed 13 other studies totaling 9,123 participants from the National Library of Medicine's computer database. Only studies that included an A1C test (a measure of long-term blood glucose control) were included. A total of 1,688 participants in these studies had type 1 diabetes and 7,435 people had type 2 diabetes.

How was the study done?

The researchers checked the results of the study participants to see how many of them had developed heart and blood vessel disease.

What did the researchers find?

The higher their long-term blood glucose level, the more likely they were to develop heart and blood vessel disease. The higher the long-term blood glucose test score, the harder it was to control their blood glucose levels. The results were similar for people with type 1 and type 2 diabetes.

What were the limitations of the study?

The researchers didn't see any of the participants, but relied on data from previous studies. Some studies may have been missed. The large majority of people in this study had type 2 diabetes instead of than type 1.

What are the implications of the study?

Improving the control of blood glucose may lower the risk of getting heart and blood vessel disease.