Abstract
Objectives: This study aimed to investigate group differences in demographic, clinical, and polysomnographic characteristics based on the presence or absence of excessive daytime sleepiness (EDS) and insomnia symptoms.Methods: In this retrospective study, patients were divided into five groups based on their Epworth Sleepiness Scale and Insomnia Severity Index scores. The participants’ demographics, sleep-related symptoms, questionnaires, and polysomnography findings were used in the analysis.Results: The study found that patients in the group with EDS were younger, were mostly males, and had higher body mass index (BMI) than other groups. They also reported obstructive sleep apnea symptoms. The patients in the group with both EDS and insomnia were younger and had a higher BMI than other groups. They reported higher levels of fatigue and depression, as well as insomnia, rapid eye movement sleep behavior disorder and restless legs syndrome symptoms. The patients in the group with only insomnia had a higher proportion of females, were older, and had a lower BMI than other groups. Most characteristics of the patients in the threshold insomnia group were similar to those of the patients in the EDS-insomnia group. The normal group had a higher proportion of males and a higher prevalence of obstructive sleep apnea; however, they reported lower sleep-related symptoms. Furthermore, the polysomnography showed differences among the five groups in total sleep time, sleep latency, sleep efficiency, total arousal index, and spontaneous arousal. Total apnea-hypopnea index was significantly lower in the insomnia group than that in other groups.Conclusions: This study demonstrated the clinical and polysomnographic characteristics of the five groups through self-reported questionnaires. The findings provided evidence to help assess patients’ sleep problems and the possibility of sleep disorders.