Date Published: March 15, 2019
Publisher: Impact Journals
Author(s): Jingjing Zhang, Xuting Jin, Ruohan Li, Ya Gao, Jiamei Li, Gang Wang.
Introduction: Although the proportion and duration of rapid eye movement (REM) sleep are correlated with neurological and cardiovascular diseases, whether REM sleep is associated with all-cause mortality in community-based populations remains unknown.
The sleep process can be divided into two predominant phases, non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. The former consists of three stages (N1, N2, N3) and constitutes 75% to 80% of the total sleep  while the latter  accounts for approximately 20% to 25% of the total sleep. The REM sleep is characterized by a low-voltage, high-frequency pattern in the beta or theta range on an electroencephalograph (EEG), as well as by muscle-tone attenuation and REM . Resembling wakefulness, REM sleep is a highly active mental state associated with dreaming, suspended thermoregulation, and autonomic irregularities . Further, REM sleep plays a profound role in the early development of sensory systems (i.e., visual, auditory, etc.) , as well as learning and memory functions by selectively maintaining the newly formed synapses .
Our study identified an association between the duration and proportion of REM sleep and all-cause mortality. Moreover, we found that all-cause mortality decreases with an increase in the duration and proportion of REM sleep. This association was found to be independent of age, sex, race, BMI, AHI, smoking status, blood lipid spectrum, history of diabetes and hypertension. In addition, we found a positive correlation between all-cause mortality and the proportion of N1 and N2 stages (light sleep). However, our study did not identify a statistically significant association between the proportion of N3 stage and all-cause mortality, likely because the N3 stage alone has no obvious predictive value in the community population.