• Sleep Medicine and Psychophysiology
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• v.9 no.2
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• pp.106-114
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• 2002

Objectives: Daytime sleepiness is a common symptom and is associated with sleep behavior, sleep deprivation, and night shift, etc. It is also one of the most important symptoms of sleep disorders like obstructive sleep apnea (OSA). According to our survey on Korean literature, a few studies have dealt with daytime sleepiness, and we have not been able to locate any study comparing normal subjects with polysomnography-proven sleep disorder patients regarding daytime sleepiness. We aimed at comparing daytime sleepiness among normal healthy daytime workers, medical students being expected to have daytime sleepiness due to chronic sleep deprivation, and patients having sleep disorders diagnosed with polysomnography. We also studied the association between subjective daytime sleepiness and objective polysomnographic findings in patients with sleep disorders. Methods: One hundred three hospital workers, 137 medical students, and patients with sleep disorders were studied. Sleep disorders included OSA, periodic limb movements in sleep (PLMS), insomnia, and narcolepsy. The degree of subjective sleepiness in each group was measured by the Korean version of Epworth sleepiness scale and compared. The relationship between polysomnographic findings reflecting severity of sleep disorder in each patient group and subjective sleepiness was analyzed. As for patients with narcolepsy, the relationship between the mean sleep latency and subjective sleepiness was studied. Results: There was a significant difference of ESS score (F=68.190, dF=5.752, p<0.001) among daytime workers, medical students, and sleep disorder patients. In OSA patient group, the degree of the sleepiness had no significant correlation either with mean O2 satuaration (p=0.062) or with RDI (p=0.807). In PLMS patient group, there was no correlation between periodic limb movement index (PLMI) and subjective sleepiness (p=0.761). In narcolepsy patient group, the subjective sleepiness had no correlation with mean sleep latency measured with MSLT (p=0.055). Conclusion: We found a significant difference of subjective sleepiness among daytime workers, medical students, and patients with sleep disorders. However, no consistent correlation was found between severity of subjective sleepiness and objective polysomnographic findings reflecting severity of each sleep disorder. This research confirms that the evaluation of subjective sleepiness is important clinically, but it cannot substitute the objective measures such as nocturnal polysomnography and MSLT.

• Sleep Medicine and Psychophysiology
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• v.12 no.2
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• pp.117-121
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• 2005

Objectives: The purpose of this study was to assess the difference of subjective daytime sleepiness level between primary insomnia patients and healthy control subjects. We also investigated the relationship between subjective daytime sleepiness level and variables of nocturnal polysomnograghic sleep architecture of insomnia patients. Method: Total subjects were 87 patients with primary insomnia diagnosed with polysomnography and 88 normal controls. The daytime sleepiness level in each group was measured by Korean version of Epworth Sleepiness Scale (ESS). The correlations of ESS score and nocturnal polysomnographic variables were calculated in the patient group. Results: Patients with insomnia had the lower ESS scores than the control group. In patients group, the ESS score showed significant negative correlations with total sleep time, sleep efficiency%, and stage 2 sleep time%. The ESS score also showed significant positive correlations with number of awakenings, number of awakenings more than 2 minutes, and wake after sleep onset time. Conclusions: Insomnia patients showed lower level of subjective daytime sleepiness that may indicate their higher alertness comparing to control subjects. Daytime sleepiness of patients with insomnia was associated with polysomnographic variables including total sleep time, sleep efficiency%, stage 2 sleep time% and disrupted continuity of nocturnal sleep.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.121-130
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• 2020

This study identified the differences and relationships between clinical practice stress, sleep quality, and daytime sleep disorder before and after clinical practice of college nursing students. The subjects were 130 students in the third year of nursing science. The results showed that the average clinical stress of the study subjects was 3.15 out of 5 points. Out of the external factors for clinical practice stress, the score for the task was 3.64. There was a significant difference in gender (t=-3.88, p<).001), subjective health status (F=5.78, p=.004), residence (F=3.20, p=.026). Nursing students showed lower sleep quality (80.0% before practice, 70.0% after practice), and those with daytime sleepiness (26.9% before practice, 42.3% after practice) were more than those of general college students. There was a difference between sleep quality (χ²=4.06, p=.004) and daytime sleepiness (χ²=6.08, p=.009) before and after clinical practice. There was also a negative correlation between daytime sleepiness and sleep quality (r=-.259, p<0.01). Therefore, strategies to reduce clinical practice stress and improve the quality of sleep are needed for the physical and mental health of nursing college students. The quality of nursing can be improved in the future by helping nursing students adapt to the clinical practice of changing nursing education field.

• Sleep Medicine and Psychophysiology
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• v.14 no.2
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• pp.92-98
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• 2007

Objectives: Obstructive sleep apnea syndrome (OSAS) is the most common form of sleep-disordered breathing and often presents with comorbid depressive symptoms. In this study, we evaluated the relationship between depressive symptoms and sleep parameters as measured by nocturnal polysomnography (NPSG) and simultaneous wrist actigraphy. Methods: Two hundred sixty-four subjects with clinically suspected cases of OSAS underwent one-night polysomnography, while simultaneously wearing a wrist actigraphy device. They also completed two questionnaires；the Epworth Sleepiness Scale-Korean version (ESS-K) and the Beck Depression Inventory (BDI). Of the cases studied, 105 subjects were proven by NSPG to have OSAS without other sleep disorders. NPSG and wrist actigraphy data from the subjects were analyzed. Pearson correlation and paired t-test were used in order to evaluate the relationship between depressive symptoms and sleep-parameters. Results: Mean age of the subjects was $46.1{\pm}13.1$ years. Means of the ESS-K score and BDI scores were $10.9{\pm}4.7$ and $12.8{\pm}8.1$, respectively. NPSG sleep parameters significantly differed from those of wrist actigraphy. There was no correlation found between subjects' respiratory disturbance index (RDI) and BDI scores. When directly comparing sleep parameters between subjects who were more depressed versus subjects who were less depressed, both total sleep time and sleep efficiency were decreased in the more depressed. A correlation between RDI and ESS-K scores was also found in the more depressed group. Conclusions: Although our findings suggest that there is no relationship between RDI and depressive symptoms, there are other significant differences in the sleep parameters between subjects who are more depressed versus those without depression. We recommend that patients with depression should also be evaluated for clinical symptoms of OSAS.

• Sleep Medicine and Psychophysiology
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• v.13 no.2
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• pp.52-58
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• 2006

Objectives: Continuous positive airway pressure (CPAP) is effective in the treatment of obstructive sleep apnea syndrome (OSAS), but the major limitation of CPAP may be poor compliance. The aims of the study were to investigate the compliance and side effects of CPAP, and to evaluate the efficacy of CPAP in patients with OSAS. Methods: This study enrolled 106 patients with OSAS who took the CPAP treatment. The severity of daytime sleepiness was measured using Epworth Sleepiness Scale (ESS), and sleep quality and depressive symptoms were assessed by Pittsburgh Sleep Quality Index (PSQI) and Beck Depression Inventory (BDI), respectively. Results: During 29 months of the study period, 41.5% of patients were using CPAP and 38.7% of patients stopped using it. Compared to non-compliant patients, compliant patients had a higher PSQI score and obstructive apnea index. Among non-compliant patients, 51.2% of them stopped using CPAP within 1months. 85.7% of non-compliant patients were discomforted by the CPAP, but much more nasopharyngeal symptoms were reported in the compliant group. ESS (p<0.01), PSQI (p<0.01) and BMI (p<0.01) were reduced significantly after CPAP treatment but not BDI (p=0.86). Conclusions: We concluded that CPAP can reduce the daytime sleepiness, nocturnal sleep disturbance, and body mass index. To increase the compliance of CPAP, we suggest that some education and support are needed at the early stage of the CPAP treatment.

• Sleep Medicine and Psychophysiology
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• v.12 no.2
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• pp.133-138
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• 2005

Objectives: Narcolepsy is characterized by excessive sleepiness, cataplexy, sleep paralysis and hypnagogic hallucination. As there have been few researches on narcolepsy symptomatology in adolescents, we examined gender differences and prevalence of narcolepsy tetrad among students attending high school. Methods: Total 20,407 subjects, ages 14-19 years filled out Ullanlinna Narcolepsy Scale (UNS). Subjects whose UNS scores were equal to or more than 14 were interviewed by telephone using semi-structured questionnaire. Variables included questions to evaluate tetrad of narcolepsy. Results: UNS scores were higher in female than male ($11.1{\pm}5.2$ vs. $9.6{\pm}4.5$, p<0.001). Subjects scoring the UNS equal to or more than 14 were 4,535 (22.2% of all the participants), more frequently observed in female than in male (p<0.001). Excessive daytime sleepiness, cataplexy-like symptoms, sleep paralysis and hypnagogic hallucination in subjects of UNS ${\geq}14$ were significantly higher in female subjects than male ones. However, no significant gender difference was observed in the frequencies of severe sleep attack and cataplexy-like symptoms. Sleep paralysis was most frequently reported during sleep. There was significant correlation between sleep paralysis and hypnagogic hallucination (r=0.235, p<0.01). Conclusions: Our findings were that female adolescents complained more frequently narcolepsy symptoms than male subjects. Female adolescents might be more sensitive than male ones to physical complaints such as sleepiness or muscle weakness.

• Journal of Rhinology
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• v.25 no.2
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• pp.69-74
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• 2018

Background and Objectives: Sleep disturbances and excessive daytime sleepiness (EDS) are the major symptoms of obstructive sleep apnea (OSA). This study aimed to investigate clinical implications of insomnia and EDS in patients with OSA using the Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS). Materials and Method: We evaluated 131 subjects with suspected OSA who were undergoing polysomnography (PSG) and performing the PSQI and ESS surveys. OSA was diagnosed when the apnea-hypopnea index was five or more. EDS was defined when ESS score was 11 points or higher. Detailed history and questionnaire were used to categorize insomnia. We compared clinical variables and PSG results in subgroups with or without insomnia and EDS. Results: There were no significant differences of PSQI and ESS score between controls and OSA. OSA with insomnia had significantly increased total score (p<0.001) and decreased total sleep time (p=0.001) and sleep efficiency (p=0.001) on the PSQI compared to those without insomnia. OSA with EDS showed significantly increased PSQI score (p=0.022) and decreased total sleep time (p=0.018) on PSG compared to those without EDS. Neither PSQI nor ESS score had a correlation with respiratory variables such as AHI and oxygen saturation. Total sleep time had a significant effect on both insomnia and EDS in patients with OSA. Conclusion: Decreased total sleep time had important effects on subjective symptoms of OSA and comorbid insomnia. Therefore, restoration of decreased sleep time is important in the management of OSA.

• Sleep Medicine and Psychophysiology
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• v.13 no.1
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• pp.27-32
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• 2006

Objectives: Nasal continuous positive airway pressure (nCPAP) is the treatment of choice and has been shown to reduce the frequency of nocturnal respiratory events, improve sleep architecture, and decrease daytime sleepiness in patients with obstructive sleep apnea syndrome (OSAS). However, little is known about the compliance of nCPAP treatment in Korea. Our objective was to look into the nCPAP compliance and examine the factors influencing it. Methods: We reviewed the records of one hundred and twenty consecutive patients with OSAS referred for nocturnal polysomnography with nCPAP pressure titration during the period of January 1995 through April 1999 to the Seoul National University Hospital. We performed a telephone interview and obtained data from eighty-three patients. Results: In sixty patients who had accepted nCPAP treatment, twenty-six patients (43.3%) were still using nCPAP device, while thirty-four patients (56.7%) stopped using it. Fifteen patients (25%) were using nCPAP device everyday. In thirty-four patients who discontinued nCPAP use, twenty-five patients (73.5%) did within the first three months, and thirty-one (91.2%) within the first year. Significant predictor of long-term nCPAP use was the presence of subjective daytime sleepiness before nCPAP application. Conclusions: Long-term compliance with nCPAP treatment appears to be associated with the presence of subjective daytime sleepiness before nCPAP application. Long-term compliance with nCPAP may be mostly predicted from the usage pattern within the first three months of use.

• Sleep Medicine and Psychophysiology
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• v.4 no.2
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• pp.140-146
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• 1997

Sleep-related breathing disorders, especially sleep apnea syndrome are complicated by neuropsychiatric dysfunction such as excessive daytime sleepiness, cognitive dysfunction, and depression. As the determinants of daytime sleepiness, sleep fragmentation is more influential than nocturnal hypoxia. Daytime sleepiness can be improved by continuous positive airway pressure (CPAP) or surgery in up to 95% of the treated subjects. Both sleepiness and nocturnal hypoxia would cause cognitive dysfunction. While impairments in attention and verbal memory are more related with sleepiness and prominent in mild to moderate sleep apnea syndrome (SAS), impairments in general intellectual function and executive function are more related with nocturnal hypoxia and prominent in severe SAS. Several cognitive deficits related with nocturnal hypoxia may be irreversible despite CPAP or surgical treatments. So, early detection and early appropriate treatment of SAS would prevent sleepiness and cognitive deterioration.

• Journal of the Korea Convergence Society
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• v.10 no.12
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• pp.465-476
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• 2019

This study was convergence study to determine sleep and its factors in university students on the basis of Spielman's 3P model. The participants were 191 graduate and undergraduate students who were scheduled to take the exam after 1~2 weeks. The related variables of quality of sleep were self-control, stress, test anxiety, smartphone dependence, and daytime sleepiness. Chi-square test and t-test were used to make a comparison of the quality of sleep between the good and the bad sleep quality group. Pearson's coefficient correlation analysis was performed for correlation between the quality of sleep and the general characteristics, self-control, stress, test anxiety, smartphone dependence, and daytime sleepiness. Stress and test anxiety as precipitating factors for sleep disturbance, smartphone dependency as a perpetuating factor for sleep disorder, and daytime sleepiness as a sleep-related factor were correlated with the quality of sleep; no statistically significant correlation was found with self-control as a predisposing factor in the biopsychological area. It is necessary to solve such problems with mental health as stress and test anxiety, which are factors for sleep disturbance, and smartphone dependency as a perpetuating factor for sleep disorder, in pursuit of higher quality of sleep for university students.