Elderly women who suffer from sleep apnea may have a higher chance of developing dementia and other memory problems, according to a new study.
Sleep apnea , a treatable disorder that causes people to stop breathing momentarily while they sleep, have long since been associated with memory loss problems and dementia in particular. However, the study - conducted by researchers at the University of California, San Francisco and the California Pacific Medical Center - is the first to suggest that sleep problems may actually be the cause of cognitive impairment, not simply the result.
"The extent of information has been limited before, because the studies were based on people with advanced dementia who, surprise, surprise, had sleep problems. It's been hard to tell what's the chicken and what's the egg," said Dr. Kristine Yaffe, a professor of psychiatry, neurology and epidemiology at UCSF who led the study, told the San Francisco Chronicle.
Yaffe and her colleagues studied the sleeping habits and quality of 298 women without dementia who were an average of 82 years old. Researchers gave each of the women an overnight sleep apnea test, which monitored changes in breathing and oxygen discrepancies during the night, as well as the short, frequent breaks in sleep the characterize the condition.
Researchers concluded that approximately a third of the women had sleep apnea. Five years later, the study authors gave those same women a series of thinking and memory tests aimed at detecting any signs of cognitive decline. Approximately 36 percent of the original subjects were diagnosed with mild cognitive impairment or dementia.
However, the study authors found that the women diagnosed with sleep apnea in the overnight sleep test years before experienced a considerably higher rate of memory problems. Forty-five percent of those women showed signs of cognitive decline, compared to 31 percent of those who did not have the sleep disorder.
While the study focused on women, researchers believe the results likely apply to men as well.
The study findings could potentially have major public health implications. Although earlier studies have shown that treating sleep apnea can improve cognitive function, doctors are still unsure of whether treatment could prevent dementia.
Sleep apnea can affect people of all ages, although it is significantly more common among adults over the age of 65. Individuals who are overweight or obese are more likely to develop the condition, as in many cases fat deposits in the upper airway can obstruct breathing.
The condition may also be a precursor to several conditions besides dementia. The Centers for Disease Control and Prevention reports that insufficient sleep - a common side effect of sleep apnea - could potentially lead to plethora of chronic health conditions, including diabetes, cardiovascular disease, obesity and depression.