Diabetics With Severely Low Blood Sugar Have Higher Death Rates

Diabetics who experience episodes of dangerously low blood sugar levels are more likely than those who don’t to develop a host of complications and die within five years, researchers found.

Those with Type 2 diabetes who experienced severe hypoglycemia were more likely in the study to have heart attacks, strokes, eye problems, kidney damage and die than those who didn’t have an episode, according to research published today in the New England Journal of Medicine. Hypoglycemia occurs when blood sugar in the body drops so much it causes fatigue, weakness and even unconsciousness.

About 23.6 million children and adults in the U.S., or 7.8 percent of the population, have diabetes, according to the American Diabetes Association. It is unclear whether hypoglycemia causes the complications seen in the study or whether it is just a marker indicating the impact of the diabetes, the authors wrote.

“What we might be doing is just identifying people who are very sick,” Simon Heller, a study author and a professor of clinical diabetes at the University of Sheffield in the U.K., said yesterday in a telephone interview. “We have to be a little cautious in saying that hypoglycemia causes death. Nevertheless, hypoglycemia is bad news.”

Diabetes occurs when the body is unable to metabolize sugar to make fuel for cells’ energy. If unused sugar builds up in the bloodstream, it can cause complications such as eye disease and kidney damage.

Lowering Blood Sugar

Physicians often try to reduce diabetics’ blood sugar to a level close to normal in the hopes of preventing heart attacks and strokes, Heller said. Research such as that published today shows that in some patients lowering blood sugar too much may instead cause heart attacks and even death.

“This assumption that lower is better may not be the case and that’s really an important clinical message,” Heller said. “You don’t want to keep pushing people down and down because there may be side effects with the treatment, of which hypoglycemia is one.”

Heller said hypoglycemia makes the body release the hormone adrenaline, which can be harmful to those with heart problems, causing an increase in their heart rate that may trigger a heart attack or lead to death.

Today’s findings support the diabetes association’s recommendations that doctors make individual assessments of how much to lower a patient’s blood sugar, said Sue Kirkman, the group’s senior vice president of medical affairs and community information in Alexandria, Virginia.

Severe Hypoglycemia

Researchers in the study looked at the link between severe hypoglycemia and the risk of heart attack, stroke, eye damage, kidney disease and death in 11,140 patients with Type 2 diabetes, the most common form of the disease.

In the study, 231 patients, or 2.1 percent, had 299 severe episodes of low blood sugar over five years.

Those who had hypoglycemia were 3.5 times more likely than those who didn’t to have a heart attack or stroke, about 2.2 times more likely to suffer from eye damage or kidney disease and about 3.3 times more likely to die from all causes, the study showed.

Doctors should look at a patient’s entire medical picture to identify why hypoglycemia is occurring, said Matthew Riddle, a professor of medicine at Oregon Health and Science University in Portland, who wasn’t involved in the study. Their condition may be influenced by behavioral factors like diet and stress, along with the medicines they’re taking to treat their diabetes, Riddle said yesterday in a telephone interview.

Individual Assessments

Spyros Mezitis, an endocrinologist at Lenox Hill Hospital in New York, said doctors may decide to treat each diabetic patient differently when assessing how far to lower their blood sugar to prevent episodes of severe hypoglycemia.

“Now, because of these kind of data, we are worried about hypoglycemia causing heart attack and death, so we are more careful and tailor the treatment to the patient,” Mezitis, who wasn’t an author of today’s paper, said yesterday in a telephone interview. “If a patient has a history of coronary artery disease, we’re going to be careful to not cause any hypoglycemia in that patient. If the patient is a healthy person who has diabetes, we’re going to be more aggressive with our controls.”

To contact the reporter on this story: Nicole Ostrow in New York at nostrow1@bloomberg.net.

To contact the editor responsible for this story: Reg Gale at rgale5@bloomberg.net

Press spacebar to pause and continue. Press esc to stop.

Bloomberg reserves the right to remove comments but is under no obligation to do so, or to explain individual moderation decisions.

Please enable JavaScript to view the comments powered by Disqus.