• Sleep Medicine and Psychophysiology
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• v.7 no.1
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• pp.34-42
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• 2000

Objectives: Periodic limb movements in sleep(PLMS) is a moderately prevalent disorder, of which pathophysiology remains largely unknown. PLMS has been reported to be common in patients with obstructive sleep apnea syndrome(OSAS), but reports on their relationship have been inconsistent in previous studies. Inconsistency of results may be attributable to insufficient number of the study subjects. We attempted to explore the influence of OSAS on PLMS in a large number of subjects. Methods: Three hundred and twenty subjects(M : F=192:128) with PLMS, as identified by the nocturnal polysomnography, were studied. Sample mean age was 53.1(SD=15.1) years and their mean periodic limb movement index(PLMI) is 25.2/hr (SD=24.8). PLMS subjects were divided into two groups, based on the presence or absence of OSAS. Periodic limb movement indices and sleep parameters between two groups were analyzed to evaluate the effects of OSAS on PLMS. Results: Each of PLMI and PLMI with arousal(PLMAI) correlated positively with age. PLMI of men was larger than that of women (p<0.01). The presence of comorbid OSAS independently had influence on PLMI(t=-2.20, p<0.05), but not PLMAI. There were no significant differences between the two groups in their PLMI, PLMAI and sleep parameters. However, the two groups differed in PLMI-correlated sleep parameters. In PLMS subjects with comorbid OSAS, PLMI was negatively correlated with each of slow wave sleep time and REM sleep time. In subjects without comorbid OSAS, PLMI was negatively correlated with sleep efficiency. Conclusion: PLMS patients with OSAS turned out to have increased PLMI than those without OSAS We suggest that OSAS patients may have subtle autonomic arousals and these arousals could, in part, express themselves as PLM.

• Sleep Medicine and Psychophysiology
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• v.7 no.1
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• pp.18-26
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• 2000

Objectives: To investigate the airway narrowing patterns by multi-level airway pressure(MAP) monitoring during sleep and to evaluate the value of CT scan taken during waking and sleep apneic periods to identify the level of airway narrowing(LAN) in patients with obstructive sleep apnea syndrome(OSAS). Methods: Eleven patients with OSAS underwent a night polysomnography with continuous MAP monitoring by 4-sensor(placed at nasopharynx, caudal-uvula, hypopharynx, esophagus) or 2-sensor(placed at caudal-uvula and esophagus) catheter. All patients had cine CT at five levels of high retro and alatal, low retropalatal, retroglossal, epiglottis and hypopharynx during awake and sleep periods. In each patient, LAN determined by CT scan($LAN_{CT}$) during sleep apnea was compared with LAN by MAP monitoring($LAN_{MAP}$). Results: MAP monitoring showed that four patients(36%) had a single pattern of LAN while the other seven patients(64%) showed two or more different LANs in different apneic episodes. Velopharynx was the most common level of frequently observed airway narrowing during sleep apnea(63.6%). However, a single pattern of airway narrowing was more frequent(72.7%) in airway CT during sleep apnea. Velopharynx was the most common narrowest level also in apneic CT(66%). In comparing $LAN_{CT}$ with $LAN_{MAP}$, the $LAN_{CT}$ of five patients(45.5%) were high-concordant, those of another five(45.5%) low-concordant, and that of one(9%) discordant with $LAN_{MAP}$. Conclusions: Cine CT scan during the awake state or sleep apnea may not reflect the LAN correctly in OSAS because most patients showed two or more different airway narrowing patterns during different episodes of sleep apnea in each patient.

• Sleep Medicine and Psychophysiology
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• v.17 no.1
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• pp.21-27
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• 2010

Objectives: It is well established that primary insomnia affects the activity of autonomic nervous system. We tried to know how the activity of autonomic nervous system during night sleep changes by analyzing correlation between heart rate variability (HRV) index and the variables related with sleep structure in primary insomnia. Methods: Thirty three subjects (mean age: $36.2{\pm}14.2$ years, male:female=15:18) who were diagnosed with primary insomnia were selected for the study. Nocturnal polysomnography (NPSG) was carried out on each subject and correlation was analyzed between high frequency/low frequency ratio (LF/HF ratio), one of HRV indices and the variables related with sleep structure which were calculated from NPSG. Results: When age and sex were controlled, LF/HF ratio showed negative correlations with slow wave sleep and stage 2 sleep, respectively ($r_p$=-0.43, p=0.01; $r_p$=-0.37, p=0.04). On the other hands LF/HF ratio showed a positive correlation with arousal index ($r_p$=0.65, p<0.001). The activity of autonomic nervous system responded differentially depending on the change of sleep structure in primary insomnia. Especially the increase of arousal index and the decrease of slow wave sleep and stage 2 sleep which are the components of non-REM sleep provoked hyperactivity of sympathetic nervous system. Conclusion: This study suggests that the typical change of sleep structure in primary insomnia can negatively impact on cardiovascular system.

• Tuberculosis and Respiratory Diseases
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• v.47 no.2
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• pp.218-230
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• 1999

Background: Craniofacial anatomic abnormalities related to structural narrowing of the upper airway have been reported in patients with obstructive sleep apnea syndrome. In this study, we evaluated the craniofacial anatomic characteristics of Korean patients with obstructive sleep apnea syndrome, and the role of cephalometric analysis in the prediction of abnormal breathing during sleep. Methods: Thirty-nine patients with obstructive sleep apnea syndrome(OSAS), 39 simple snorers(simple snorers) and 20 controls(control) had cephalometric analysis using the technique of Riley et al, and underwent standardized polysomnographic recordings. Different variables, including sex, body mass index, cephalometric and polysomnographic data, were statistically analyzed. Results: Pm-UPW and V-LPW distances were significantly shorter in OSAS when compared with simple snorers or control. PAS in simple snorers was shorter than in control. ANS-Gn distance in OSAS was significantly longer than in control. PNS-P distance in OSAS or simple snorers was significantly longer than in control. MP-H distance in OSAS was significantly longer than in simple snorers or control and MP-H distance in simple snorers was also longer than in control. NL/Pm-P angle in OSAS was lesser than in control. MP-H distance in OSAS or in the combined groups of OSAS and simple snorers was significantly correlated with apneahypopnea index(AHI). PNS-P distance in the combined groups of OSAS and simple snorers was correlated with AHI. In male of all subjects, body mass index was significantly correlated with PNS-P or MP-H distance. Conclusion: Cephalometric analysis can be useful tool in determining the craniofacial anatomic abnormalities in patients with obstructive sleep apnea syndrome. Cephalometric parameters, especially MP-H distance, can be useful for predicting frequency of narrowing or obstruction of upper airway during sleep.

• Tuberculosis and Respiratory Diseases
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• v.47 no.2
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• pp.231-238
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• 1999

Background: Nocturnal hypoxemia occurs in patients with chronic obstructive pulmonary disease(COPD) and the detection and treatment of nocturnal hypoxemia should be part of the management of COPD patients. We performed this study to evaluate the factors influencing to sleep related arterial oxygen desaturation($SaO_2$) in patients with COPD. Methods: Resting and exercise cardiopulmonary function test, polysomnography, and $SaO_2$ during resting, exercise and sleep were measured in 12 patients with COPD. Results: The $SaO_2$ fell twice as much during sleep as during maximal exercise($13.1{\pm}9.3%$ fall in nocturnal $SaO_2$ vs. $6.4{\pm}3.3%$, p<0.05). Fall in nocturnal $SaO_2$ was well correlated with mean exercise $SaO_2$(r=-0.78, p<0.05), minimum exercise $SaO_2$(r=-0.90, p<0.01), and resting $SaO_2$(Cr=-0.82, p<0.05). Lowest sleep $SaO_2$ was well correlated with mean exercise $SaO_2$(r=0.80, p<0.05), lowest exercise $SaO_2$(r=0.90, p<0.01), and resting $SaO_2$(r=0.84, p<0.05). Conclusion: Resting and exercise $SaO_2$ was well correlated with nocturnal $SaO_2$, but exercise study add no additional information to predicting the nocturnal oxygen desaturation in patients with COPD.

• Sleep Medicine and Psychophysiology
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• v.10 no.2
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• pp.100-107
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• 2003

Objectives: Periodic leg movements in sleep (PLMS) might be subdivided based upon whether or not they are associated with visible EEG microarousals (MA). MA is considered to be responsible for nonrestorative sleep and daytime fatigue. The American Sleep Disorders Association's (ASDA) scoring rules for MA based on visual analysis of the EEG changes suggest that MA should last more than 3 seconds. However, it has been suggested that visual analysis may not detect some changes in EEG activity. This study is aimed at measuring changes in EEG spectra during PLMS without MA in order to better understand the arousing response of PLMS. Methods: Ten drug-free patients (three men and seven women) diagnosed with PLMS by polysomnography were studied. Spectral analysis of the EEG was performed in each patient on 30 episodes of PLMS without MA, chosen randomly across the night in stage 2 non-REM sleep. We applied stricter criteria for MA compared to ASDA, by defining it as a return to alpha and theta frequency lasting at least 1 second. Results: The mean PLMS index was $16.7{\pm}10.0$. The mean PLMS duration was $1.3{\pm}0.7$ seconds. Comparison of 4-second EEG activity both before and after the onset of PLMS without MA using independent t-test showed that the movements were associated with significant increase of relative activity in the delta band (p=0.000) and significant decrease of activity in the alpha (p=0.01) and sigma (p=0.000) bands. No significant decrease in the theta (p=0.05), beta (p=0.129), or gamma (p=0.062) bands was found. Conclusion: PLMS without MA was found to be associated with EEG change characterized by increase in the delta frequency band. This finding seems to be compatible with the hypothesis of an integrative hierarchy of arousal responses of Sforza's. Considering that the subjects had lower PLMS index and shorter PLMS duration than those of the previous study, it is suggested that an even less severe form of PLMS without MA could induce neurophysiologic change, which may potentially be of clinical significance.

• Sleep Medicine and Psychophysiology
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• v.9 no.1
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• pp.48-55
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• 2002

Objective: Stress is known to be a common cause of short-term insomnia and insomniacs often complain that stress induces sleep problems. However, previous studies on the correlation between stress and sleep do not show consistent results. We aimed to investigate the effects of minor stressful events on sleep among college students. Method: Physically and mentally healthy college student volunteers filled out a self-assessment questionnaire to evaluate their stress and sleep. To find out the status of average stress and sleep, the volunteers filled out K-DSI and daily sleep assessments on three consecutive days. In addition, we surveyed the amount of caffeine beverage intake and assessed the degree of depression and anxiety. Results: The total number of students participating in this study was 202, 101 men and 101 women. Minor stress turned out to significantly affect non-restorative sleep and secondary symptoms of insomnia (awakening difficulty, displeasure, feeling of dissatisfaction with sleep, physical uneasiness or pain at awakening, daytime sleepiness, depressive moods, tiredness and concentration difficulty). However, global PSQI score, self-reported sleeping hours, sleep latency, awakening frequency, frequency and duration of napping, were not explained by stress scores. Conclusion: In this study, minor stresses seemed to affect sleep, especially secondary symptoms caused by non-restorative sleep. We can thus infer that minor stresses impair the restorative effects of sleep by inducing arousal, and the direct relationship the two can be confirmed by polysomnogram.

• Tuberculosis and Respiratory Diseases
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• v.59 no.3
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• pp.298-305
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• 2005

Background : Obstructive sleep apnea syndrome (OSAS) is believed to have multifactorial causes. The major risk factors for OSAS are obesity, narrowed upper airways, and abnormal cranial-facial structures. A genetic basis for OSAS has been also suggested by reports of families with many members affected. This study analyzed the HLA typing in patients with OSAS to determine the possible role of genetics in OSAS. Methods : Twenty-five Korean patients with OSAS (1 woman and 24 men; age range 30-66 years) were enrolled in this study. A diagnosis of OSAS was made using full-night polysomnography. The control group consisted of 200 healthy Korean people. Serologic typing of the HLA-A and B alleles was performed in all patients using a standard lymphocyte microcytotoxicity test. Analysis of the polymorphic second exons of the HLA-DRB1 gene was performed using a polymerase chain reaction-sequence specific oligonucleotide probe. Results : The allele frequency of HLA-A11 was significantly lower in patients with OSAS compared with the controls (p<0.05). The HLA-B allele frequencies in the patients and controls had a similar distribution. Analysis of the HLADRB1 gene polymorphisms showed an increased frequency of DRB1*09 in the OSA patients compared with the controls (p<0.05). When the analysis was performed after dividing the OSAS patients according to the severity of apnea, the allele frequency of HLA-DRB1*08 was significantly higher in the severe OSA patients (apnea index >45) than in the controls (p<0.05). Conclusion : This study revealed an association between OSAS and the HLA-A11 and DRB1*09 alleles as well as association between the disease severity and the HLA-DRB1*08 allele in Korean patients. These results suggest that genetics plays an important role in both the development and the disease severity of OSAS.

• Journal of Life Science
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• v.28 no.1
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• pp.26-36
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• 2018

This study was performed to identify the antioxidant and ${\alpha}$-glucosidase inhibitory activities of water and 70% ethanol extracts of the three following herbs: G. procumbens, M. charantia, and C. longa. In addition, the antioxidant and antidiabetic activities of five types of Jerusalem artichoke composites (JA1 - 5), which were prepared by adding ethanol extracts of several herbs to Jerusalem artichoke concentrate, were studied and compared. The results showed that the total phenol and flavonoid contents of the ethanol extracts were higher than those of the water extracts. The DPPH and ABTS radical scavenging activities and reducing power depended on the total phenol and flavonoid contents. The antioxidant activities of ethanol extracts from G. procumbens and C. longa were comparable. Moreover, the ${\alpha}$-glucosidase inhibitory activity of the ethanol extracts ($2,000{\mu}g/ml$) from each herb was found to be over 50%. In contrast, the five types of JA composites showed higher total phenol and flavonoid contents than those of JA concentrate. In addition, increased antioxidant and ${\alpha}$-glucosidase inhibitory activities were observed, with that of JA1 being the highest. However, all concentrations ($1{\sim}100{\mu}g/ml$) of JA tested did not affect the cell viability of Chang cells. In addition, JA induced the activation of AMP-activated protein kinase (AMPK) in Chang cells and significantly increased the glucose uptake in C2C12 cells. Therefore, it could be concluded that the JA composites (JA1 - 5) mixed with G. procumbens, M. charantia, and C. longa extracts were effective in increasing the extracts' antioxidant and antidiabetic activities.

• 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.