The effects of instruction regarding sleep posture on the postural changes and sleep quality among middle-aged and...

The purpose of this study was to examine whether instruction to sleep in a lateral posture prior to falling asleep could increase the frequency of instructed posture and sleep quality, as evaluated by sleep parameters and a questionnaire for subjective assessment of sleep. The participants were comprised of 8 middle-aged and elderly men who had an awareness of their habitual snoring during sleep. Data were gathered from observations of sleep posture, sleep polysomnography and a subjective sleep quality questionnaire. As a result of the instruction, the frequency of the instructed posture was significantly increased, and there were no significant effects on sleep parameters or the frequency of postural changes. The subjective sleep quality during the instructed sleep showed worse scores than free postural-sleep for all factors. Our findings suggest that the instructed sleep posture could be increased during sleep without substantially worsening the sleep parameters and the frequency of postural changes. Future studies will therefore be required to clarify the mechanism and the long-term effects of such instruction on sleep posture, including the influence on subjective sleep quality.