Effect of prone positioning in mild to moderate obstructive sleep apnea syndrome

Sleeping in prone position could be effective in the management of obstructive sleep apnea (OSA) syndrome by reducing the gravity effect on the upper airway and hence collapsibility. Effect of pure prone positioning (PPP) treatment was investigated in mild to moderate OSA.

Twenty-nine mild to moderate OSA patients (17 males, 12 females) who gave informed consent were tested with polysomnography at diagnostic and PPP nights. PPP device consisted of a pillow mounted on a table with a hole in the middle keeping the neck 180° extended in prone position. Mean ± SD of age and AHI were 48.4 ± 10.6 and 15.5 ± 6.2, respectively. Patients did not have abdominal and/or truncalobesity, or any condition that could interfere with prone sleeping.

AHI (mean difference: PPP treatment - diagnostic night: -5.2/h, 95% confidence interval [CI]: -0.1/h to -10.3/h, p = 0.04) and sleep oxygen saturation below 90% (mean difference: -1.80%, 95% CI: -0.22% to -3.37%, p = 0.02) and sleep efficiency (81.0 ± 21.2% and 88.1 ± 7.1 %, respectively, p = 0.02) were significantly lower in PPP than diagnostic night. Response to PPP treatment defined as AHI <5/h in the PPP night was observed in 15 (51.7%) patients, with a better rate in female than male patients (9/12 vs. 6/17, respectively, p = 0.03).

To our knowledge, this is the first study to examine the effect of prone positioning in the treatment of mild to moderate OSA. Application of PPP with a more comfortable design in a randomized clinical trial is required to investigate its long term effect in the treatment of mild to moderate OSA.