For much of her life, Sarah Gorman, 71, battled a mysterious illness that left her tired, sleepless, and unable to concentrate. When her symptoms first started in her 20s, she turned to doctors for help. They diagnosed her with depression and referred her to a psychiatrist, but Gorman soon rejected that diagnosis because, she said, she simply did not feel depressed.
But Gorman’s symptoms continued to worsen, and by the time she was 30, she had developed prediabetes. She also experienced periods of forgetfulness and seemed more accident-prone: twice she fell and broke her kneecap.
“I was really turning into a zombie,” said Gorman, who worked as a lawyer for a major corporation. “It was getting hard to concentrate and do work, or read and retain a paragraph. I needed to get my brain back.”
At 52 and by then desperate for help, Gorman found her way to a sleep laboratory, where doctors told her she had a condition she had never heard of: obstructive sleep apnea, a common disorder that causes people to experience episodes of difficult breathing during sleep.
Gorman would later learn that millions of Americans suffer from the condition, but like her, more than half go undiagnosed. For more than two decades, researchers have known that sleep apnea can cause severe health consequences if left untreated. Studies have linked it to an increased risk of heart disease, stroke, obesity, diabetes, glaucoma, and even a higher risk of accidents. And recent findings indicate that pregnant women with sleep apnea have a higher chance of developing high blood pressure and giving birth prematurely.
Yet unlike for men, diagnosing sleep apnea in women has presented challenges, and Gorman’s experience is a case in point. One problem: Until recently, many doctors viewed sleep apnea as mostly a man’s disease, and that resulted in many more men than women getting diagnosed with the disorder. Studies now show that sleep apnea in women is likely underestimated and undertreated, as signs and symptoms of sleep apnea in premenopausal women are different compared to men. For example, some women with sleep apnea do not snore and do not have excessive daytime sleepiness, symptoms that are common in men with sleep apnea. In postmenopausal women, the diagnosis of sleep apnea is almost as common in women as in men of the same age.
To help better understand why, an NHLBI-funded study recently explored sex differences in sleep apnea among participants in the Multi-Ethnic Study of Atherosclerosis, an NHLBI-sponsored research study that aims to identify factors that contribute to cardiovascular disease. The researchers analyzed data from 2,057 study participants who underwent a comprehensive sleep study. Their mean age was 68.5 and half were women.
The researchers analyzed sleep apnea severity based on the apnea-hypopnea index (AHI), or the number of pauses in breathing per hour of sleep. They measured AHI during both REM sleep (dream sleep) and non-REM sleep (other stages of sleep). The researchers found that during non-REM sleep, twice as many men as women had a top AHI score of 15. However, during REM sleep, the prevalence of a high AHI score was the same in both men and women. That’s important because this is the number that some studies show is most predictive of a person’s risk for developing hypertension and cardiovascular disease, the researchers said.
The researchers also identified other physiological mechanisms that influence sleep apnea that differ between men and women: Women had more stable breathing, less airway collapsibility, and were more easily awakened after the airway starts to close during breathing pauses. These differences could make promising targets for new treatments for sleep apnea that are sex specific, such as a pill that takes advantage of different patterns observed in REM versus non-REM sleep, the researchers said. They published their results in the journal SLEEP.
“I hope this study will be a wake-up call for physicians to be better at spotting sleep apnea in women—and spotting therapies that are more likely to work for them,” said study senior author Susan Redline, M.D., a physician scientist at Brigham and Women’s Hospital in Boston who has studied sleep health and sleep disparities for years.
“This is the strongest evidence yet that sleep apnea may need to be measured differently in women compared to how it is measured in men in order to protect against risks to health,” said Michael Twery, Ph.D., director of the National Center on Sleep Disorders Research at NHLBI. Twery noted that researchers are continuing to sift through scientific data to better understand the root causes of sleep apnea in both men and women and identify biomarkers and genes to speed diagnosis and improve treatment. Several treatments for sleep apnea are now available, and even more are in the pipeline, he said.
The most common treatment is the CPAP machine (continuous positive airway pressure), a device that delivers air through a mask to keep the airway open when worn during sleep. Invented more than three decades ago, the device is growing in use and undergoing continuous refinement.
Gorman, who had been misdiagnosed for decades, said the first time she used a CPAP machine was life changing. “I woke up in the next morning having slept through the night for the first time in I don’t know when,” she said. “I felt like a 10-year-old with springs in my legs. Here I was this 56-year-old woman, and I went hopping around the house like I was on a pogo stick. I suddenly had so much energy that I hadn’t had before. ”
After three and a half years of faithful treatment using the machine, her concentration, memory, and sleep all improved dramatically. “I got my brain back,” Gorman said. She has since switched to an APAP machine (automatic positive airway pressure), a device similar to a CPAP that automatically adjusts air pressure levels, but with even better results.
Now retired, Gorman currently volunteers as a patient advocate for sleep apnea, using her experiences to help motivate other women to get diagnosed and treated. Her advice to women who might have sleep apnea: “Read as much as you can about it. The sooner you get sleep apnea diagnosed and treated, the better you’re going to feel. You’ll get your life back, you’ll get your brain back, and you might even get your waistline back.”
If you have symptoms of sleep apnea, health professionals urge that you see a doctor.