Effect of below-the-knee compression stockings on severity of obstructive sleep apnea

Background: Overnight fluid shift from the legs to the neck may narrow the upper airway and contribute to obstructive sleep apnea (OSA) pathogenesis. We hypothesized that below-the-knee compression stockings will decrease OSA severity in a general OSA population by decreasing daytime leg fluid accumulation and overnight fluid shift and increasing upper-airway size. Methods: Patients with OSA (apnea-hypopnea index >= 10) were randomized to wear compression stockings during the daytime or to a control group for 2 weeks. Overnight polysomnography with measurement of leg and neck fluid volumes and upper-airway cross-sectional area before and after sleep was performed at baseline and follow-up. The primary outcome was change in the apnea-hypopnea index. Results: Twenty-two patients randomized to compression stockings and 23 to control completed the study. The apnea-hypopnea index decreased significantly more in the compression stockings than in the control group (from 32.4 +/- 20.0 to 23.8 +/- 15.5 vs. from 31.2 +/- 25.0 to 30.3 +/- 23.8, p = 0.042), in association with a significantly greater reduction in the overnight decrease in leg fluid volume (p = 0.028), and a significantly greater increase in morning upper-airway cross-sectional area (p = 0.006). Overnight change in neck fluid volume was unchanged. Conclusion: These observations suggest that in, a general OSA population, below-the-knee compression stockings decrease OSA severity modestly via attenuation of overnight fluid shift and consequent upperairway dilatation. (C) 2014 Elsevier B.V. All rights reserved.