The statistics are startling. According to the American Academy of Sleep Medicine, 26 percent of adults ages 30 to 70 have sleep apnea.
Left untreated, its sleep-disturbing effects can lead to life-threatening cardiovascular problems, including high blood pressure, chronic heart failure, atrial fibrillation and stroke. And for women, the impact can be even more severe.
Studies led by UCLA School of Nursing professor Paul Macey have repeatedly shown that there are significant differences between the impacts of sleep apnea on men and women. While men are more likely to have sleep apnea, women with sleep apnea have a higher degree of brain injury.
"Because women report different symptoms, they tend to be misdiagnosed," Macey said. "Early detection and treatment is the best way to protect against damage to the brain and other organs."
In his most recent study, Macey and colleagues examined medical records and brain scans of a group of patients who were diagnosed with sleep apnea and a group without sleep apnea. Macey found several apparent connections between thinning of the brain's cerebral cortex and apnea symptoms. The researchers also found distinct changes in brain structures and cognitive symptoms that differed between men and women. For example, in the frontal lobe, which controls cognitive skills and motor function, more regions appear thinner in women with apnea than men or in the group of patients without sleep apnea. That difference might explain the impact on memory and other mental processes among women with the disorder, the researcher said.
The study continues to illustrate the significant clinical differences between men and women with sleep apnea, and points to the need for different treatment approaches to address these varied symptoms. The higher degree of brain injury in women may underlie their more common cognitive problems compared with men, while thinning associated with both men and women who have sleep apnea may be behind the disordered breathing seen between both, the researchers said. It is not clear whether these physical brain changes precede the sleep apnea disorder, or worsen sleep apnea's symptoms as the disorder progresses.
Each study "is like uncovering another piece of what might be going on," Macey says.