Higher Blood Sugar Helps Heart Failure

Diabetes patients with heart failure benefit from higher blood sugar levels

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Most people with diabetes need to lower their blood sugar levels to get healthy. Diabetes patients with heart failure, on the other hand, may do better if they keep their blood sugar a little high.

People with both diabetes and heart failure may have a better chance of survival if they have higher blood sugar levels.

"Watch your blood sugar carefully if you have diabetes."

Normally, diabetes patients want to lower their blood sugar levels in order to have better outcomes. When blood sugar levels get too high, patients run the risk of serious problems like heart disease, stroke, and kidney disease.

The case may be different for diabetes patients with advanced heart failure, according to new research by Tamara Horwich, M.D., assistant professor of cardiology at the University of California, Los Angeles (UCLA), and colleagues.

The researchers found that diabetic heart failure patients with the highest blood sugar levels had the best chance of survival within a two year period.

Their results show that heart failure patients with diabetes should aim for HbA1c levels between 8.3 and 8.9 percent. In comparison, current targets are lower than seven percent.

"For heart failure patients with diabetes, we found that higher, not lower, levels of the marker had better outcomes," says Sofia Tomova, a medical student at the Geffen School of Medicine at UCLA and first author of the study.

"We were surprised that the optimal [HbA1c level] in this patient population with diabetes was higher than levels in current treatment guidelines," says Dr. Horwich.

"We may find that doctors who treat patients who have both advanced heart failure and diabetes may not need to focus on aggressively lowering blood sugar, but rather keep it under moderate control," she says.

Diabetes is much more common in people with heart failure than in the general population.

The findings from this study may help guide doctors who are treating people with both of these serious conditions.

For their study, Dr. Horwich and her colleagues looked at the medical records of 845 patients with advanced heart failure. Seventy-two percent of the patients were men. Their average age was 55 years.

There was a 65 percent 2-year survival rate among patients with HbA1c (a measure of blood sugar over three months) of more than 8.6 percent, while patients with HbA1c between 7.3 and 8.5 percent had a survival rate of 61 percent.

Survival rates were even worse for patients with the lowest HbA1c levels. The survival rate for patients with HbA1c of less than 6.4 percent was 48 percent. Patients with an HbA1c between 6.5 and 7.2 percent had a survival rate of 42 percent.

It is important to remember, the researchers point out, that these findings apply to people with diabetes and heart failure. Diabetes patients without heart failure should strive to keep their blood sugar levels lower and under control.

The study by Dr. Horwich and colleagues - which received no outside funding - was published March 29 in the American Journal of Cardiology.

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Review Date: 
April 9, 2012
Last Updated:
August 23, 2012