Stable blood sugar curbs diabetes complications

By Martha Kerr

NEW YORK (Reuters Health) - In people with type 1 diabetes, adequate control of blood sugar over the long haul helps reduce the risk of diabetes-related eye and kidney disease, new data suggest.

The findings stem from a look at 1,441 type 1 diabetic patients followed for roughly 9 years as part of the pivotal Diabetes Control and Complications Trial (DCCT).

By analyzing hemoglobin A1C levels over time -- a standard indicator of long-term blood sugar control -- the researchers observed that increasing variability in hemoglobin A1C heightens the risk of new or worsening diabetic retinopathy (damage to the retina) and diabetic kidney disease.

Specifically, for every 1 percent increase in hemoglobin A1C, they found that the risk of retinopathy increased more than twofold and the risk of diabetic kidney disease increased nearly twofold.

The findings suggest that the long-term stability of blood sugar, and not just the average blood sugar control, predict the risk of these complications, study investigator Dr. Eric S. Kilpatrick of Hull Royal Infirmary in Hull, England, noted in an interview with Reuters Health.

"It is probably another reason to aim for stable good glycemic control rather than only good glycemic control," Kilpatrick said.

However, blood sugar management "is only part of the story," he added. It is as important, he said, to ensure that blood pressure and cholesterol levels are "tightly controlled" in order to reduce the complications of diabetes.

SOURCE: Diabetes Care, November 2008.