“We found that in patients with chronic venous insufficiency, compression stockings reduced daytime fluid accumulation in the legs, which in turn reduced the amount of fluid flowing into the neck at night, thereby reducing the number of apneas and hypopnea by more than a third, ” said study leader Stefania Redolfi.
CVI happens whenever a patient’s veins are unable to pump sufficient oxygen-depleted blood back to the heart, usually happening in the veins of the lower limbs.
Continuous positive airway pressure devices, known as CPAP, are usually one of the only treatments presently suggested for individuals with obstructive sleep apnea. However, some find using a mask all night prohibitively uncomfortable and compliance is low, leading to a lot of individuals experiencing untreated obstructive sleep apnea along with its significant health consequences. Finding a more effective method of managing obstructive sleep apnea, therefore, is a high priority.
The researcher sought to find out if a straightforward intervention such as using compression stockings could be effective in some individuals with obstructive sleep apnea.
In active individuals, fluid accumulation in the legs is counteracted by means of leg muscle contractions which squeeze the veins. However, lengthy periods of sitting down could prevent this process, and the accumulated fluid in the legs then shifts rostrally overnight. This shift ends up in fluid accumulation in neck tissue and is considered to increase apneic events by means of increasing the amount of the tissue, resulting in repetitive collapse of the pharynx in the course of night breathing. In normally healthy subjects with heart failure or hypertension, the amount of this overnight rostral fluid shift is clearly correlated with the amount of overnight increase in neck circumference and the quantity of apneas and also hypopnea each hour of sleep.
“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,” said Dr. Redolfi. “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. “
To be able to research if compression stockings might relieve this problem, the investigators recruited 12 individuals who were randomly designated to one week of using the compression stockings or to a one-week control period with no compression stockings. At the conclusion of the 1st week, they crossed over to the other arm of the study. Every subject underwent polysomnography and overnight changes in leg fluid volume and neck circumference were measured at base line and at the conclusion of the compression stockings and control periods.
At the conclusion of the compression stocking period, subjects had an average of a 62 % decrease in overnight leg fluid volume change in comparison with when they did not use the stockings. People also had a 60 % decrease in neck circumference increase, that the investigators used as a proxy measurement to approximate fluid shift in to the neck and a 36 % decrease in the amount of apneas and hypopnea every hour of sleep.
“Our findings provide proof-of-concept that among subjects with CVI, overnight rostral fluid displacement is a mechanism of disease for obstructive sleep apnea. The effect of compression stockings on obstructive sleep apnea is based on counteracting this fluid displacement. Prevention of dependent fluid accumulation could constitute a new therapeutic approach to obstructive sleep apnea, “said Dr. Redolfi.
“These findings are what we expected,” she continued, “but the extent to which simply wearing compression stockings reduced obstructive sleep 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 obstructive sleep apnea in other patient populations is an important issue that remains to be addressed in future studies,” she added.
References:
1. American Thoracic Society
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