NEW YORK (Reuters Health) – Use of compression stockings during the day by patients with chronic venous insufficiency leads to a reduction in nighttime apnea episodes, a French group has shown.

By reducing daytime fluid accumulation in the legs, the rostral shift of fluids to neck tissues at night is also decreased, thus reducing the likelihood of repeated pharyngeal closure during sleep, the authors explain in the American Journal of Respiratory and Critical Care Medicine released online August 4.

Their study “provides proof-of-principle that reducing overnight rostral fluid displacement is a new means of attenuating OSA (obstructive sleep apnea),” they write. “Whether this holds true outside the CVI (chronic venous insufficiency) population and whether or not this has clinical implications will have to be determined.”

Dr. Stefania Redolfi, at Hopital Pitie-Salpetriere in Paris, and colleagues previously showed that the apnea-hypopnea index is strongly linked to the volume of fluid shifting from the legs into the neck overnight. In the current study, they tested the effect of compression stockings on obstructive sleep apnea in 12 non-obese subjects with CVI, in a cross-over trial.

The participants were randomly assigned to wear the stockings for one week or not, then switched for another 1-week period. Polysomnography and measurement of overnight changes in leg fluid volume and neck circumference – a surrogate for fluid displacement to neck tissues – were performed at baseline and at the end of compression stockings and control periods.

Wearing compression stockings reduced the overnight change in leg fluid volume by 62% compared to the change seen without the stockings, the team found. Similarly, the increase in neck circumference was reduced by 60%.

Furthermore, these effects were associated with a 36% reduction in the apnea-hypopnea index (from 48.4 to 31.3 episodes per hour), according to the report.

“The extent to which simply wearing compression stockings reduced apnea in just one week was not expected,” Dr. Redolfi commented in a journal press release. “It would be very interesting to see whether the wearing of the stockings over longer periods would have an even greater effect.”

She and her colleagues also point out that they used off-the-shelf compression stockings, and these may not be as effective as custom-made stockings. “Thus future studies should involve more subjects over longer periods using custom-made compression stockings, and clinical outcomes such as sleepiness and neurocognitive function should be assessed.”

Am J Respir Crit Care Med 2011;