Sleep Apnea, Daytime Sleepiness: Risky Combo

April 1, 2011 -- Older adults who have sleep apnea and who are excessively sleepy in the daytime may have more than twice the risk of death as people who do not have both conditions, new research suggests.

In a study of 289 adults over age 65 without depression or dementia, the risk of death was not increased for people with sleep apnea without excessive daytime sleepiness or for those who reported only excessive daytime sleepiness without having sleep apnea, the researchers say.

“Excessive daytime sleepiness, when associated with sleep apnea, can significantly increase the risk of death in older adults,” study researcher Nalaka S. Gooneratne, MD, MSc, of the University of Pennsylvania Health System in Philadelphia, says in a news release. “We did not find that being sleepy in and of itself was a risk. Instead, the risk of increased mortality only seemed to occur when sleep apnea was also present.”

Sleep Apnea and Excessive Daytime Sleepiness

Both sleep apnea and excessive daytime sleepiness are common problems, with sleep apnea affecting up to 20% of older adults.

Excessive daytime sleepiness affects 10% to 33% of the elderly, the researchers write, and this problem often is viewed as a normal result of getting older. But previous studies have shown that people who are overly sleepy in the daytime have an increased incidence of falls, functional impairment, and cognitive deficits.

The most common form of sleep apnea is obstructive sleep apnea, which occurs when soft tissue in the back of the throat collapses, blocking the upper airway during sleep.

Older people are also at risk for a condition called central sleep apnea, which involves a repetitive absence of breathing effort during sleep that is caused by a problem in the brain.

Researchers say only 4% of participants in the study had this condition, and there was no meaningful change in study results when this information was excluded from the analysis.

Looking for Clues on Sleep Apnea Risks

In the study, 74% of participants were female. The mean age of participants at the start of the study was 78.

About half of participants had significant levels of excessive daytime sleepiness and reported that they felt sleepy or struggled to stay awake during daylight hours at least three to four times per week.

Sleep apnea testing was performed at night in a sleep lab.

Participants in the study were recruited between 1993 and 1998. Survival status was determined by searching the Social Security death index, ending Sept. 1, 2009.

The study says 160 people, or 55% of the participants, died during an average follow-up period of 14 years.

Those participants who had both sleep apnea and excessive daytime sleepiness had a risk of death that was more than two times higher than those who did not have the combination of these conditions.

The researchers say it’s unclear just why sleep apnea combined with excessive daytime sleepiness may increase the death risk of older adults.  

Whether treatment reduces the risk of death for these people remains to be tested.

Obstructive sleep apnea generally is treated with a device that provides a steady stream of air through a mask that is worn at night during sleep. This is known as CPAP therapy.

The study is published April 1 in the journal SLEEP.