Dueling Studies on Diabetes and “Tight Control” of Blood Sugar

Reuters is reporting the American Diabetes Association featuring dueling studies on the question of whether intensive blood sugar lowering in diabetics provides health benefits. (see also the coverage on WebMD)

One study showed that lowering the A1C level to 6.5% – a measure of long-term blood sugar control – reduces kidney damage and is an admirable goal. After an average of 5 years, the group that got aggressive blood sugar control had a 10 percent overall reduced risk of serious diabetes complications and a 21 percent reduced risk of kidney disease, a common complication of diabetes.

And, this trial did NOT find an increased risk of death among patients whose blood sugar was intensively lowered. Patients had a A1C blood sugar goal of 6.5% or lower, instead of the traditional 7%.

A second study (Australian Advance Trial) found no major heart benefits to intensive blood sugar lowering (reaching A1C of 6.9%) but also NO increase in risk either.

This is important, because in February a study (U.S. and Canadian Accord Trial) showed lowering the A1C level to 6.5% increased the risk of death from heart disease by 35% (2.6% vs 1.8%).

The experts that have looked at both trials believe weight gain, the use of multiple drug combinations, and perhaps even getting blood sugar too low, too fast may all have been factors in causing early deaths in the Accord Trial.

What is of most concern to me is the fact that patients in the intensive arm of Advance were treated primarily with moderate-release gliclazide (not available in the U.S.), a drug in an older class known as sulfonylureas (of which several are available in the U.S.).

But rosiglitazone (Avandia) was the drug given to 90 percent of the intensive therapy group in Accord.

However, yet a fourth study (VA Diabetes Trial) appears to vindicate rosiglitazone and declares it safe (although that conclusion has been questioned.

My Take?

For now, several experts agreed, the goal should be to get average blood sugar levels as measured by hemoglobin A1c to 7 and no lower. I’m still happy to aim for 6.5, but to do it slowly.

The bottom line for patients hoping to avoid all the diabetes-related complications?

Lowering blood glucose levels does help reduce kidney and eye complications from diabetes, but paying attention to blood pressure and cholesterol levels is crucial to reduce the heart attack and stroke-related risks that accompany a diagnosis of type 2 diabetes, researchers from both studies say.

“You can safely reduce glucose A1c to about 6.5% by using the sort of gradual, gentle approach that we used,” says Stephen MacMahon, PhD, an investigator of one study, called ADVANCE. “It won’t improve cardiovascular risks, but it will improve kidney risks.”

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