Sleep-disordered breathing may increase risk of cognitive impairment, dementia among older women

August 10, 2011

Older women with sleep-disordered breathing, as indicated by measures of hypoxia (oxygen deficiency), were more likely to develop cognitive impairment or dementia than women without this disorder, according to a study in the August 10 issue of JAMA.

"Sleep-disordered breathing, a disorder characterized by recurrent arousals from sleep and intermittent hypoxemia, is common among older adults and affects up to 60 percent of elderly populations. A number of adverse including hypertension, , and diabetes have been associated with sleep-disordered breathing," according to background information in the article. impairment also has been linked to sleep-disordered breathing in some studies, but the design of most of these studies has limited the ability to draw conclusions regarding this association. "Given the high prevalence and significant associated with both sleep-disordered breathing and cognitive impairment in older populations, establishing whether a prospective association exists between sleep-disordered breathing and cognition is important. This is especially important because effective treatments for sleep-disordered breathing exist."

Kristine Yaffe, M.D., of the University of California, San Francisco, and colleagues examined the association between prevalent sleep-disordered breathing as measured with polysomnography (monitoring of physiological activity during sleep) and subsequent diagnoses of and . The study included 298 women without dementia at the beginning of the study (average age, 82.3 years) who had overnight polysomnography measured between January 2002 and April 2004 in a substudy of the Study of . Sleep-disordered breathing was defined as an apnea-hypopnea index of 15 or more events per hour of sleep. The apnea-hypopnea index is the number of complete cessations (apnea) and partial obstructions (hypopnea) of breathing occurring per hour of sleep. Cognitive status (normal, dementia, or mild cognitive impairment) was based on data collected between November 2006 and September 2008. Measures of hypoxia, sleep fragmentation, and sleep duration were investigated as underlying mechanisms for any association between sleep-disordered breathing and cognitive impairment.

Among the 298 women, 35.2 percent met criteria for sleep-disordered breathing. After an average of 4.7 years of follow-up, 35.9 percent of the women developed mild cognitive impairment or dementia (mild cognitive impairment: 20.1 percent; dementia: 15.8 percent). Forty-seven women (44.8 percent) with prevalent sleep-disordered breathing developed mild cognitive impairment or dementia compared with 31.1 percent of those without sleep-disordered breathing. Analysis of the data indicated that the presence of sleep-disordered breathing was associated with an increased odds of subsequent mild cognitive impairment or dementia.

The researchers also found, after adjusting for various demographic risk factors, that two measures of hypoxia (an oxygen desaturation index of 15 or greater and a high percentage of total sleep time [greater than 7 percent] in apnea or hypopnea) were associated with higher incidence of mild cognitive impairment or dementia. "Measures of sleep fragmentation (arousal index and wake after sleep onset) or sleep duration (total sleep time) were not associated with risk of cognitive impairment." The authors add that their finding that sleep-disordered breathing was associated with an increased risk of cognitive impairment seems to be related primarily to measures of hypoxia.

"Given the high prevalence of both sleep-disordered breathing and cognitive impairment among , the possibility of an association between the 2 conditions, even a modest one, has the potential for a large public health impact. Furthermore, the finding that hypoxia and not sleep fragmentation or duration seems to be associated with risk of mild cognitive impairment or dementia provides clues to the mechanisms through which sleep-disordered breathing might promote cognitive impairment. The increased risk for cognitive impairment associated with sleep-disordered breathing opens a new avenue for additional research on the risk for development of mild or dementia and exploration of preventive strategies that target sleep quality including sleep-disordered breathing," the researchers write.

They add that to fully evaluate the impact of treatment for sleep-disordered breathing in elderly populations, additional trials with larger sample sizes, longer treatment periods, and more diverse populations are required. "Of interest, our findings suggest a potential role for supplemental oxygen therapy for sleep-disordered breathing in elderly individuals; however, its role requires critical evaluation in intervention studies."

Explore further: Sleep apnea linked to increased risk of dementia in elderly women

More information: JAMA. 2011;306[6]613-619.

Related Stories

Sleep apnea linked to increased risk of dementia in elderly women

August 9, 2011
characterized by disrupted breathing and sleep and a reduction in the intake of oxygen -- are about twice as likely to develop dementia in the next five years as those without the condition, according to a multi-center study ...

Sleep apnea may increase the risk of adverse pregnancy outcomes

June 13, 2011
Sleep apnea is associated with an increased risk of adverse pregnancy outcomes, suggests a research abstract that will be presented Monday, June 13, in Minneapolis, Minn., at SLEEP 2011, the 25th Anniversary Meeting of the ...

Polysomnography for sleep-disordered breathing prior to tonsillectomy in children

June 15, 2011
A multidisciplinary clinical practice guideline, "Polysomnography for Sleep-Disordered Breathing Prior to Tonsillectomy in Children" will be published as a supplement to the July issue of Otolaryngology—Head and Neck ...

Recommended for you

Researchers developing new tool to distinguish between viral, bacterial infections

July 28, 2017
Antibiotics are lifesaving drugs, but overuse is leading to one of the world's most pressing health threats: antibiotic resistance. Researchers at the University of Rochester Medical Center are developing a tool to help physicians ...

Finish your antibiotics course? Maybe not, experts say

July 27, 2017
British disease experts on Thursday suggested doing away with the "incorrect" advice to always finish a course of antibiotics, saying the approach was fuelling the spread of drug resistance.

Co-infection with two common gut pathogens worsens malnutrition in mice

July 27, 2017
Two gut pathogens commonly found in malnourished children combine to worsen malnutrition and impair growth in laboratory mice, according to new research published in PLOS Pathogens.

Phase 3 trial confirms superiority of tocilizumab to steroids for giant cell arteritis

July 26, 2017
A phase 3 clinical trial has confirmed that regular treatment with tocilizumab, an inhibitor of interleukin-6, successfully reduced both symptoms of and the need for high-dose steroid treatment for giant cell arteritis, the ...

A large-scale 'germ trap' solution for hospitals

July 26, 2017
When an infectious airborne illness strikes, some hospitals use negative pressure rooms to isolate and treat patients. These rooms use ventilation controls to keep germ-filled air contained rather than letting it circulate ...

Researchers report new system to study chronic hepatitis B

July 25, 2017
Scientists from Princeton University's Department of Molecular Biology have successfully tested a cell-culture system that will allow researchers to perform laboratory-based studies of long-term hepatitis B virus (HBV) infections. ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.