Sleep disorders are more frequently diagnosed in men, but women with the same problems may be at greater risk of health problems than previously thought.

Researchers found that the heart problems associated with obstructive sleep apnea (OSA) and snoring may show up earlier in women than in men. They also found that OSA may be underdiagnosed.

OSA affects about 22 million Americans. If untreated, it can contribute to high blood pressure, stroke, and cardiovascular problems including chronic heart failure and atrial fibrillation. It is also associated with Type 2 diabetes and depression, the American Sleep Apnea Association said.

OSA is caused by an airway blockage. Usually the tongue falls against the soft palate on the roof of the mouth, which collapses against the throat. This causes breathing to start and stop repeatedly while sleeping.

“Our analysis showed that in both genders of the OSA and snoring groups, there was an increase in left ventricular mass,” said lead author Adrian Curta, a radiology resident at Munich University Hospital in Germany.

An increase in left ventricular mass causes the enlargement of the walls of the heart’s main pumping chamber, which make the heart work harder, he said.

When researchers compared the group that snored to the unaffected group, they found a more significant increase in left ventricular mass in women than in men.