Premenopausal women experience obstructive sleep apnea less often than men, but prevalence increases after menopause. In sleep laboratories, menopause status is rarely considered, and differences in symptom presentation in women complicate diagnosis, explained Sandhya Matthes, MD, Institute for Pulmonology, University of Cologne, Bethanien Hospital, Solingen, Germany, during the 66^th Congress of the German Society for Pneumology and Respiratory Medicine in Munich, Germany.

Matthes described a case of 50-year-old woman evaluated in a sleep laboratory as part of a study of obstructive sleep apnea (OSA). The patient was a smoker, overweight, and had mild OSA on polygraphy, with an apnea-hypopnea index (AHI) of 7.4 events/h of sleep. "The first question should be: Is the patient in menopause or peri- or postmenopause?" Matthes said. She noted that this question is usually not asked.

"We as sleep specialists are not gynecologists. We do not perform hormone tests. But we can estimate," she said. In Germany, women reach menopause, defined as the time of the last menstrual period, between ages 45-56 years, with a mean age of 49.7 years.

Rising Burden

In the French HypnoLaus study of more than 2000 participants, the prevalence of moderate to severe OSA, defined as AHI ≥ 15, was 23.4% in women and 49.7% in men. 

According to Matthes after menopause, the number of apnea and hypopnea events in women increased and reached comparable levels in later analyses of the cohort. Prevalence remained lower before menopause but increased after 50 years of age and approached 50%.

"It is no longer only a men's disease. After menopause, OSA in women is almost as common as in men," Matthes said.

Early menopause also increased the risk for OSA. Among postmenopausal women younger than 40 years, OSA prevalence was higher by 21%. Surgical menopause after bilateral oophorectomy doubled the risk for developing OSA.

Atypical Signs

Women reported sleep disorders differently. Across several analyses of sleep questionnaires, women more often reported fatigue, headaches, memory and concentration problems, and frequent urination at night compared with men. These symptoms are not immediately linked to OSA, in contrast to snoring. The symptoms described in the OSA screening for women are therefore often "not taken seriously at first glance," said Matthes.

Dora Triché, MD, from the University Hospital Nuremberg, Nuremberg, Germany, and session moderator, said, "Obstructive sleep apnea in women is often underdiagnosed because many colleagues focus on the 'typical' male symptoms such as snoring." These patterns reflect the evidence base and are commonly taught, which contributes to missed diagnoses in women, she noted.

The phenotype of OSA in women, often marked by sleep disturbance, also affects treatment. Acceptance of continuous positive airway pressure therapy (CPAP) is lower because of sleep disruption. An overlap of OSA with insomnia, referred to as comorbid insomnia and sleep apnea (COMISA), is associated with increased all-cause mortality and higher risk for major adverse cardiovascular events. COMISA therefore requires targeted treatment, Matthes explained.

Mandibular advancement devices and cognitive behavioral therapy (CBT) are effective treatment options for women with OSA. She concluded that CBT could improve insomnia and adherence to CPAP.

Hormone Effects

Earlier studies suggested that hormone replacement therapy (HRT) might reduce OSA in postmenopausal women. In the Sleep Heart Health Study, which included more than 2800 women, the prevalence of AHI ≥ 15 was about half among postmenopausal women receiving HRT compared with those not receiving HRT. In another study, transdermal HRT reduced movement-related sleep disturbances but did not significantly change sleep architecture.

Because these studies included small numbers of participants, evidence remained inconclusive. "A recommendation of HRT as a primary therapy for OSA cannot be made," Triché emphasized.

This story was translated from Medscape’s German edition.