New research has found high rates of sleep apnea in women, despite the condition usually being regarded as a disorder predominantly of males.

The study, published online Aug. 16 ahead of print in the European Respiratory Journal, also suggested that women with hypertension and/or obesity were more likely to experience sleep apnea.

“We were very surprised to find such a high occurrence of sleep apnea in women, as it is traditionally thought of as a male disorder,” said lead author Professor Karl Franklin said. “These findings suggest that clinicians should be particularly aware of the association between sleep apnea and obesity and hypertension, in order to identify patients who could also be suffering from the sleeping disorder.”

Obstructive sleep apnea is a condition in which there are frequent pauses in breathing during sleep. The incidence of the condition increases with age and it is considered more prevalent in men than in women.

In this new study, researchers from Uppsala and Umeå University in Sweden aimed to investigate the frequency and risk factors of sleep apnea in women.

The study analyzed 400 women from a random sample of 10,000 women aged 20 years. The participants answered a questionnaire and underwent a sleep examination.

The results found that obstructive sleep apnea was present in 50 percent of women aged 20 years.

The researchers also found links between age, obesity and hypertension: 80 percent of women with hypertension and 84 percent of obese women suffered from sleep apnea.

Additionally, severe sleep apnea was present in 31 percent of obese women aged 55-70 years old.