Tight Blood Sugar Control Helps the Heart in Type 2 Diabetes

But study showed it's not enough to prevent related deaths

Wednesday, June 3, 2015

WEDNESDAY, June 3, 2015 (HealthDay News) -- Strictly controlling blood sugar levels appears to keep people with type 2 diabetes from developing heart problems, a new study finds.

Tight control of blood sugar reduces the odds of heart attack, stroke, heart failure or amputation by about 17 percent, according to the study.

But controlling blood sugar alone won't prevent deaths from heart disease or other causes. For that, lowering blood pressure and cholesterol are also needed, the researchers suggested.

"In addition to regular exercise, a good diet and not smoking, people with diabetes can dramatically reduce their risk of strokes and heart attacks by taking a statin, keeping their blood pressure under control and getting their average blood sugar at least to moderate control with an A1C of about 8," said lead researcher Dr. Rodney Hayward. He is a senior research scientist at the VA Center for Clinical Management Research and University of Michigan in Ann Arbor.

The A1C test -- an important tool in diabetes management -- is a blood test that estimates a person's average blood sugar levels for the past two or three months. A normal A1C for someone without diabetes is below 5.7, according to the American Diabetes Association. Prediabetes ranges from an A1C of 5.7 to 6.4, and diabetes is usually diagnosed when the A1C is 6.5 and above, according to the diabetes association.

In general, the diabetes association guidelines recommend an A1C of 7 or lower, but the group also recommends that patients discuss with their doctor whether or not that is the right goal for them. It's important to avoid serious reactions from low blood sugar, Hayward said.

The new report was published in the June 4 issue of the New England Journal of Medicine.

For the study, Hayward's team collected follow-up data on nearly 1,800 people enrolled in the Veterans Affairs Diabetes Trial. In that trial, people with type 2 diabetes were randomly assigned to have their blood sugar strictly controlled or not as tightly controlled.

The A1C in the intensive blood sugar control group was 6.9, on average. For those on standard care, the A1C average was 8.4, according to the study.

Over an average follow-up of almost 10 years, those who had their blood sugar strictly controlled had a significantly lower risk of heart attack, stroke, new or worsening heart failure, or amputation of feet or legs, compared with people whose blood sugar wasn't as strictly controlled.

Deaths from heart problems or other causes, however, were not reduced with strict blood sugar control, the researchers noted.

"This finding reinforces the importance of combining good blood sugar control with control of other cardiovascular risk factors for a combined effect, especially controlling cholesterol and blood pressure," Hayward said.

Dr. Joel Zonszein, director of the Clinical Diabetes Center at Montefiore Medical Center in New York City, said, "Even after the study was stopped, there was a legacy of tightly controlling blood sugar that reduced the risk of heart attack and stroke in subsequent years."

When patients with type 2 diabetes are diagnosed, they need to be treated aggressively from the start, said Zonszein, who was not involved with the study. "That is going to prevent complications," he said.

"When patients feel well and healthy is when there is much more benefit from aggressive treatment that will last for many years," Zonszein said. "The earlier we treat and the more aggressive we are then, the better."

SOURCES: Rodney Hayward, M.D., senior research scientist, VA Center for Clinical Management Research, and University of Michigan, Ann Arbor; Joel Zonszein, M.D., director, Clinical Diabetes Center, Montefiore Medical Center, New York City; June 4, 2015, New England Journal of Medicine

HealthDay