NEW YORK (Reuters Health) - Older women with sleep-related breathing problems may have a heightened risk of impairments in thinking and memory, a new study suggests.
The findings, reported in the Journal of the American Geriatrics Society, suggest that so-called sleep-disordered breathing, including sleep apnea, may be a risk factor for age-related cognitive decline.
They also open the possibility that treating these sleep-related breathing disorders could prevent mental impairment in some older adults, researchers say.
Sleep-disordered breathing, or SDB, refers to a group of sleep-related breathing problems. Obstructive sleep apnea, where breathing stops briefly and restarts repeatedly through the night, is one of the most common forms. People with SDB may also have repeated episodes of hypopnea, during which breathing diminishes but does not stop entirely.
Signs of SDB include chronic snoring and daytime sleepiness owing to poor sleep quality.
Sleep apnea has been linked to a number of health consequences, including high blood pressure and an increased risk of cardiovascular disease. Whether it affects cognitive function as people age has been less clear.
The new study included 448 women with an average age of 83 who underwent an overnight sleep study to detect breathing problems. They also took standard tests of memory, attention and other cognitive abilities.
In general, the study found, women with SDB were more likely than those without breathing problems to show cognitive impairment. Those with severe breathing problems had a more than three-fold increased risk of impairment.
What's more, the link between SDB and cognitive impairment was particularly strong among women who carried a gene linked to Alzheimer's disease -- a variant of the apolipoprotein E gene known as APOE e-4.
The findings do not prove that nighttime breathing problems directly contribute to cognitive decline, according to Dr. Adam P. Spira, a research fellow at the University of California San Francisco and the lead investigator on the study.
