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

August 10, 2011, JAMA and Archives Journals

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

New long-acting approach for malaria therapy developed

January 22, 2018
A new study, published in Nature Communications, conducted by the University of Liverpool and the Johns Hopkins University School of Medicine highlights a new 'long acting' medicine for the prevention of malaria.

Virus shown to be likely cause of mystery polio-like illness

January 22, 2018
A major review by UNSW researchers has identified strong evidence that a virus called Enterovirus D68 is the cause of a mystery polio-like illness that has paralysed children in the US, Canada and Europe.

Creation of synthetic horsepox virus could lead to more effective smallpox vaccine

January 19, 2018
UAlberta researchers created a new synthetic virus that could lead to the development of a more effective vaccine against smallpox. The discovery demonstrates how techniques based on the use of synthetic DNA can be used to ...

Study ends debate over role of steroids in treating septic shock

January 19, 2018
The results from the largest ever study of septic shock could improve treatment for critically ill patients and save health systems worldwide hundreds of millions of dollars each year.

New approach could help curtail hospitalizations due to influenza infection

January 18, 2018
More than 700,000 Americans were hospitalized due to illnesses associated with the seasonal flu during the 2014-15 flu season, according to federal estimates. A radical new approach to vaccine development at UCLA may help ...

Flu may be spread just by breathing, new study shows; coughing and sneezing not required

January 18, 2018
It is easier to spread the influenza virus (flu) than previously thought, according to a new University of Maryland-led study released today. People commonly believe that they can catch the flu by exposure to droplets from ...

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.