Tight Glucose Control and Heart Risk

Recent studies such as the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial and the Action in Diabetes and Vascular Disease (ADVANCE) trial have reached conflicting conclusions about whether intensive blood glucose control is effective in reducing cardiovascular risk in people with Type 2 diabetes. A new study finds that it may depend on what other health problems a person has, besides diabetes.

The researchers in this study collected medical information on 2,613 people with Type 2 diabetes being treated in doctors’ offices in Italy. The information included the participants’ HbA1c levels (an indicator of blood glucose control over the previous 2–3 months) at the start of the study and their history of conditions such as heart disease, lung disease, heart failure, urinary tract disease, arthritis, foot problems, and digestive conditions. Based on this data, the researchers classified the study subjects as having low, moderate, or high levels of other health conditions. The subjects were then followed for roughly five years to see who would develop new cardiovascular conditions.

At the end of the trial period, the results indicated that in people categorized as having low to moderate levels of health problems, tight blood glucose control — defined in this study as an HbA1c level of 7% or less — lowered the risk of a new cardiovascular event such as a heart attack or stroke. In people classified as having high levels of health problems, however, intensive blood glucose management was not associated with a lower risk of new cardiovascular events.

According to study coleader Sherrie Kaplan, PhD, MPH, “The findings reveal that strict glucose control benefits some patients but not others depending on certain factors, mainly concurrent illnesses. They also raise serious questions about guidelines advocating a single approach for all diabetics.”

The researchers note that the study had a number of limitations, including that it did not collect information on how people managed their diabetes or other health conditions, nor did it look at other potential benefits of intensive blood glucose control, such as the prevention of kidney and eye disease.

To learn more, read the article “Strict Blood Sugar Control in Some Diabetics Does Not Lower Heart Attack, Stroke Risk” or see the study’s abstract or the “Summaries for Patients” piece in the Annals of Internal Medicine.

Editor’s Note: This study was observational only and does not prove cause and effect. Its findings should not be used as the basis for changes your blood glucose management regimen. Speak to your physician if you have any concerns about the appropriate level of treatment for you.