Sleep Apnea Linked to Increased Diabetes, Stroke

For Immediate Use: May 1, 1999

DIABETES LINKED TO SLEEP APNEA AND HIGHER STROKE RISK, FINDS UCLA/VA STUDY: Excess Weight Increases Likelihood

Adults who suffer from obstructive sleep apnea are three times more likely to also have diabetes, according to a new UCLA School of Dentistry/Department of Veterans Affairs study published today in the Journal of Oral and Maxillofacial Surgery. Sleep apnea, a serious condition marked by loud snoring, irregular breathing and interrupted oxygen intake, affects an estimated nine million Americans.

The culprit? Carrying too many extra pounds.

"The blame falls squarely on excess weight gain," said Dr. Arthur H. Friedlander, associate professor of oral and maxillofacial surgery at the UCLA School of Dentistry and associate chief of staff at the Veterans Affairs Medical Center in Los Angeles.

Surplus weight interferes with insulin's ability to propel sugars from digested food across the cell membrane, robbing the cells of needed carbohydrates. Diabetes results when glucose builds up in the bloodstream and can't be utilized by the body.

Being overweight can also lead to obstructive sleep apnea, according to Friedlander.

"When people gain too much weight, fatty deposits build up along the throat and line the breathing passages," he explained. "The muscles in this region slacken during sleep, forcing the airway to narrow and often close altogether."

Reclining on one's back magnifies the situation. "When an overweight person lies down and goes to sleep," Friedlander said, "gravity shoves the fat in the neck backwards. This blocks the airway and can bring breathing to a halt."

Friedlander tested the blood sugar of 54 randomly selected male veterans whom doctors had previously diagnosed with obstructive sleep apnea. He discovered that 17 of the 54 patients, or 31 percent, unknowingly suffered from adult-onset diabetes.

Using the same sample, Friedlander also took panoramic X-rays of the men's necks and jaws. The X-rays indicated that 12 of the 54 patients, or 22 percent, revealed calcified plaques in the carotid artery leading to the brain. These plaques block blood flow, significantly increasing patients' risk for stroke. Seven of the 12, or 58 percent, were also diagnosed with diabetes.

In dramatic comparison, the 17 patients diagnosed with diabetes showed nearly twice the incidence of blockage. Seven of the 17 men, or 41 percent, had carotid plaques. Only five of the 54 patients who displayed plaques did not have also diabetes.

If he conducted this study today, Friedlander notes, he would likely find a higher number of diabetic patients. After he completed the study in 1997, the American Diabetes Association lowered its definition for diabetes from 140 to 126 milligrams of sugar per deciliter of blood.

"This is the first time that science has uncovered a link between sleep apnea and diabetes," said Friedlander. "The data suggest that someone afflicted with both diabetes and sleep apnea is more likely to suffer a stroke in the future."

"Persons going to the doctor for a sleep-apnea exam should request that their blood be screened for diabetes, especially if they are overweight," he cautioned. More than half of the individuals who develop diabetes as adults will need to modify their diet and take daily insulin in order to control the disease, he added.

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