The positional dependency of obstructive sleep apnea
(OSA) is well known, but objective evidence for the positional effect on
snoring is lacking. The aim of this study is to elucidate the effect of body
position on snoring, and that of sleep stage as well.
Retrospective analysis of the effects of body position and sleep
stage on snoring in nonapneic snorers (snorer group) and OSA patients
A sleep laboratory in a national hospital in Japan.
Seventy-two patients who complained of habitual snoring and
underwent overnight polysomnography.
Measurements and Results:
In the lateral position, most subjects in the
snorer group showed decreased snoring both in time (p=0.0004) and
intensity (p=0.0003), but subjects in the apneic group showed variable
changes. In the apneic group, the positional dependency of snoring (the ratio of lateral value to supine value) was correlated with supine apneahypopnea
index (AHI), that is, OSA patients with higher supine AHI tended
to show increased snoring in the lateral position. As to the effect of
sleep stage, snoring was increased in deeper non-rapid eye movement
sleep and decreased in rapid eye movement sleep in a given position.
This study demonstrated that the positional dependency is
different between nonapneic snorers and OSA patients. Most of the nonapneic
snorers snore less in the lateral position than in the supine position
in contrast to OSA patients who often fail to decrease snoring even in the