Sleep Apnea May Damage Women Earlier Than Men

By Jane Farrell

Obstructive sleep apnea and snoring may damage heart function earlier in women than in men, according to new European research.

The same study, presented at the annual meeting of the Radiological Society of North America (RSNA), also suggested that obstructive sleep apnea (OSA) may be greatly underdiagnosed among snorers.

OSA is a common but serious sleep disorder, which carries an increased risk for left ventricular and, less frequently, right ventricular dysfunction of the heart.

OSA, the most common type of sleep apnea, occurs when the throat muscles intermittently relax and block the airway while a person is sleeping. There are several symptoms of OSA–such as gasping for air during sleep, waking with a dry mouth, morning headache and irritability. Loud snoring is a common sign. Complications of OSA may include daytime fatigue and sleepiness, complications with medications and surgery, and cardiovascular problems. (See our story, “Always Tired? You May Have Sleep Apnea.”)

For their study, the researchers investigated cardiac function in relation to diagnosed OSA and self-reported snoring from data available through UK Biobank. A national and international health resource, UK Biobank is open to researchers and follows the health and well-being of 500,000 volunteer participants.

The investigators analyzed data from 4,877 UK Biobank participants who had received a cardiac MRI. The patients were divided into three groups: those with OSA (118 patients), those with self-reported snoring (1,886 patients), and those who are unaffected–without OSA or snoring (2,477 patients). There were 396 people who did not meet research criteria.

Snoring is a common symptom of obstructive sleep apnea.

“Our analysis showed that in both genders of the OSA and snoring groups there was an increase in left ventricular mass, meaning that the walls of the heart’s main pumping chamber are enlarged, making the heart work harder,” said lead author Adrian Curta, M.D., radiology resident at Munich University Hospital in Munich, Germany..

When the researchers compared the snoring group to the unaffected group, they found a more significant difference in the left ventricular mass in women than in men. The cardiac changes in the self-reported snorers point to earlier impairment and might be an indication of undiagnosed OSA, they saud.

“We found that the cardiac parameters in women appear to be more easily affected by the disease and that women who snore or have OSA might be at greater risk for cardiac involvement,” Curta said. “We also found that the prevalence of diagnosed OSA in the study group was extremely low. Together with the alterations in cardiac function in the snoring group, it leads us to believe that OSA may be grossly underdiagnosed.”

The findings suggest that the transition from snoring to OSA is an evolving process that is associated with left ventricular hypertrophy, an independent predictor for increased adverse events and in-hospital mortality in many procedures.

Curta stresses the importance for people who snore to get screened for OSA, and cautioned that those with OSA should be properly treated.

“I would encourage people who snore to ask their partner to observe them and look for phases during sleep when they stop breathing for a short while and then gasp for air,” Curta said. “If unsure, they can spend the night at a sleep lab where breathing is constantly monitored during sleep and even slight alterations can be recorded.”

Treatment is dependent on the cause of an individual’s OSA, Curta noted. Weight loss, for example, can often improve OSA in overweight individuals. Apart from that, there are surgical techniques and special machines that keep the upper airways open at nighttime by applying continuous positive airway pressure (CPAP).