Wearing compression stockings during the day may slightly improve sleep apnea at night, a small study suggests.

In the new study, 22 patients with obstructive sleep apnea who wore compression stockings during the day for two weeks saw their frequency of apneas decrease by 27 percent, compared to 23 patients who didn’t wear the stockings, Dr. T. Douglas Bradley and colleagues report in Sleep Medicine.

This new study points to another potential mechanism, Bradley told Reuters Health. He believes fluid can move from the legs into the neck, restrict the flow of oxygen and cause obstructive sleep apnea.

Compression stockings, widely used to treat varicose veins and by workers whose jobs keep them on their feet all day, exert pressure on the legs and reduce fluid movement.