The American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine published a study in which French researchers discovered that wearing compression stockings could be an easy, low-cost possibility to improve obstructive sleep apnea (OSA) in patients with chronic venous insufficiency. The findings appear online ahead of the final publication of the Journal.

Chronic venous insufficiency (VI) happens when veins are unable to pump enough oxygen-depleted blood back to the heart, which most often occurs in the veins of the legs.

Head of research, Stefania Redolfi, MD, of the University of Brescia in Italy reported, that patients with chronic venous insufficiency wearing compression stockings showed a reduced daytime fluid accumulation in the legs. This subsequently reduces the amount of fluid flowing into the neck at night and therefore decreases the number of apneas and hypopnea by more than a third.

At present, the main treatment option for people with OSA is continuous positive airway pressure machines, known as CPAP. Unfortunately many patients find wearing a mask overnight as prohibitive and uncomfortable. Hence, compliance is low, resulting in many patients living with untreated OSA and its serious health consequences. It is therefore vital to find a more effective means of treating OSA.

Fluid accumulation in the legs is counteracted by leg muscle contractions that squeeze the veins in active people. This process is prevented if a person sits for prolonged periods of time, forcing the accumulated fluid in the legs to shift rostrally overnight. As a consequence of this shift, fluid accumulation is gathered in the tissues of the neck and is thought to increase apneic events by increasing the tissue volume leading to repetitive collapse of the pharynx during night breathing. The volume of this overnight rostral fluid shift is strongly correlated with the degree of overnight increase in neck circumference and the number of apneas and hypopneas per hour of sleep in patients with heart failure or hypertension who are otherwise healthy.

Dr. Redolfi and her team wanted to establish whether OSA might be alleviated in some patients by simply wearing compression stockings.

Dr. Redolfi said:

“We hypothesized that the fluid accumulation that occurs in the legs of people with chronic venous insufficiency would be reduced by wearing compression stockings, and that the reduction in the fluid would also reduce the shift of that fluid to the neck during the night. There is strong evidence linking that rostral shift of fluid overnight to apnea. If we could reduce that, we would expect that apneic events would likewise be reduced.”

Researchers recruited subjects from the chronic venous insufficiency clinic at La Pitié-Salpêtrière hospital in Paris for the study. The trial included twelve patients randomly assigned to either wearing compression stockings for one control week or without, with a crossover at the end of the first week. Each patient had a polysomnography and overnight changes in leg fluid volume and neck circumference were measured at baseline and at the end of the compression stockings and control periods.

At the end of the testing period, findings revealed an average reduction of 62 percent in overnight leg fluid volume in patients wearing stockings compared to those who did not. Patients also showed a reduction of 60 percent in neck circumference based on a proxy measurement to estimate fluid shift into the neck and a 36 percent reduction in the number of apneas and hypopneas per hour of sleep.

Dr. Redolfi stated:

“Our findings provide proof-of-concept that among subjects with CVI, overnight rostral fluid displacement is a mechanism of disease for OSA. The effect of compression stockings on OSA is based on counteracting this fluid displacement. Prevention of dependent fluid accumulation could constitute a new therapeutic approach to OSA.

These findings are what we expected but the extent to which simply wearing compression stockings reduced apnea in just one week was not expected. It would be very interesting to see whether the wearing of the stockings over longer periods would have an even greater effect. Whether prevention of overnight rostral fluid displacement can attenuate OSA in other patient populations is an important issue that remains to be addressed in future studies.”

Written by Petra Rattue