Nocturnal sweating in obstructive sleep apnoea and its association with sleep parameters

Objective: Nocturnal sweating is a condition frequently encountered in obstructive sleep apnoea (OSA) patients. This study aimed to examine the relationship between nocturnal sweating and sleep parameters in patients with and without OSA. Methods: A total of 355 patients were included in this study. The patients were separated into two groups: group 1, consisting of patients with OSA and group 2, the control group, which contained patients without OSA. The presence of nocturnal sweating and its effect on sleep parameters were obtained by polysomnography and examined. Results: In patients from group 1 that had nocturnal sweating, the rapid eye movement (REM) sleep percentage (12.80%, min-max: 0.40-29.60 vs 14.00%, min-max: 1.10-29.40; p=0.034), and REM episode (3, min-max: 1-6 vs 4, min-max: 1-6; p=0.002) were significantly lower, and the apnoea-hypopnoea index (AHI) (26.70, min-max: 0-107.80 vs 17.40, min-max: 0-108.40; p=0.04) during the REM period was significantly higher compared to the patients from group 2 without nocturnal sweating. There was no difference in nocturnal sweating between group 1 and group 2. Conclusion: This study indicates that the REM sleep period may be suppressed due to high sympathetic activity in relation to nocturnal sweating. Moreover, the high AHI detected during the REM sleep period also indicates the association between increased respiratory events and nocturnal sweating during this period.