A Preliminary Study of the Effect of Mattress Temperature on the Subjective and Objective Sleep Quality of Healthy Young Adults

Objective: We evaluated the effects of microclimate temperature on the subjective and objective sleep quality of healthy young adults. For this purpose, we maintained a constant ambient temperature and manipulated the mattress temperature to change the microclimate.Methods: We enrolled 34 healthy young adults (12 males and 22 females; mean age: 24.06±2.70 years). Data from 26 individuals were analyzed (8 males and 18 females; mean age: 23.46±2.40 years). Nocturnal polysomnography (nPSG) was performed and self-reported questionnaires were completed at an ambient temperature of 27°C and mattress temperature of 28°C, 30°C, or 32°C.Results: The subjective sleep satisfaction was lower at a mattress temperature of 32°C than at 28°C. The subjective sleep latency was longer at 32°C than at 30°C. The number of respondents that selected sleep environment (including temperature) as the cause of sleep dissatisfaction was greater at higher temperatures. Participants felt that the mattress temperature was the least cool when they woke up at 32° than 30°C. Furthermore, they reported that the sleep latency at 32°C was longer than the other temperatures compared to usual sleep, and that they had more frequent awakenings at 32°C than at 28°C. The nPSG results showed that the proportion of rapid eye movement (REM) sleep was lower at 28°C than at 30°C.Conclusion: A high microclimate temperature caused by a high mattress temperature was associated with poor subjective sleep quality. Mattress temperature was also related to the objective proportion of REM sleep; however, the results are inconsistent with previous findings. Additional large-scale studies that evaluate a wider temperature range are required.