We analyzed the role of sleep position in obstructive sleep apnea syndrome (OSAS). The polysomnograms of 120 patients with sleep apnea syndrome were analyzed. We associated the apnea hypopnea index (AHI) of the supine position with the AHI of the other positions. Patients were stratified in a group of positional patients (PP) (AHI supine >or= 2 x AHI other positions) and a group of non-positional patients (NPP). In 55.8% of our patients, OSAS was position dependent. PP patients were significantly (6.7 years) younger. BMI and AHI were higher in the NPP group, but the difference was not significant. Level of obstruction in the upper airway (retropalatinal vs retrolingual vs both levels) as assessed by sleep endoscopy was not significantly different between the two groups. Total sleep time (TST) was equal in both groups, but the average time in supine position was 37 min longer in the PP group. This study confirms the finding that in more than 50% of patients, OSAS is position dependent. Apart from age, no patient characteristics were found indicating the position dependency. Overall AHI does not identify positional OSAS.

Summary Obstructive sleep apnoea syndrome is a common clinical problem. Positional sleep apnoea syndrome, defined as having a supine apnoea–hypopnoea index of twice or more compared to the apnoea–hypopnoea index in the other positions, occurs in 56% of obstructive sleep apnoea patients. A limited number of studies focus on decreasing the severity of sleep apnoea by influencing sleep position. In these studies an object was strapped to the back (tennis balls, squash balls, special vests), preventing patients from sleeping in the supine position. Frequently, this was not successful due to arousals while turning from one lateral position to the other, thereby disturbing sleep architecture and sleep quality. We developed a new neck‐worn device which influences sleep position by offering a vibration when in supine position, without significantly reducing total sleep time. Thirty patients with positional sleep apnoea were included in this study. No side effects were reported. The mean apnoea–hypopnoea index dropped from 27.7 ± 2.4 to 12.8 ± 2.2. Seven patients developed an overall apnoea–hypopnoea index below 5 when using the device in ON modus. We expect that positional therapy with such a device can be applied as a single treatment in many patients with mild to moderate position‐dependent obstructive sleep apnoea, while in patients with a more severe obstructive sleep apnoea such a device could be used in combination with other treatment modalities.

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These results suggest that not only the amount of atherosclerosis, but also arterial remodeling and lipid deposition in plaques, are influenced by systemic factors. The nonhomogeneous distribution of inflammation in atherosclerotic arteries supports the hypothesis that plaque inflammation is locally affected.