• Tuberculosis and Respiratory Diseases
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• v.43 no.4
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• pp.600-612
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• 1996

Background : Recent studies deported that untreated patients with obstructive sleep apnea syndrome had high long-term mortality rates, and cardiovascular complications of these patients clad a major effect on mortality. Several data indicates that obstructive sheep apnea syndrome contributes to the development of diurnal systemic hypertension. But the pathophysiological mechanism of the development of systemic hypertension in these patients is still uncertain. This study was performed to evaluate the possible role of sympathetic nervous system activity for the development of systemic hypertension in patients with obstructive sleep apnea syndrome. Method : 35 patients with obstructive sleep apnea syndrome(OSAS) and 13 Control subjects(control) were included in this study. 21 patients of OSAS were normotensives(OSAS-NBP), and 14 patients of OSAS were hypertensives(OSAS-HBP). Full night polysomnography was undertaken to all subjects. We measured plasma norepinephrine(NE) and epinephrine(EP) concentrations during waking and sleep, using high performance liquid chromatography, in all patients and control subjects. Results : In OSAS, OSAS-NBP and control, plasma NE and EP concentrations during sleep were lowed than during waking(p<0.01). But, in OSAS-HBP, these was no difference between during waking and sleep. Plasma NE concentrations during sleep of OSAS, OSAS-NBP and OSAS-HBP were higher than Control(p<0.05). In OSAS-HBP, daytime systolic blood pressure correlated with plasma NE concentration during sleep(r=0.7415, p<0.01), arid correlated inversely with mean arterial oxygen saturation(r=-0.6465, p<0.05) or arterial oxygen saturation nadir(r=-0.6) 14, p<0.05) during sleep. Conclusion : The sympathetic activity during sleep of obstructive sleep apnea syndrome patients was higher than control subjects. In obstructive sleep apnea syndrome patients with systemic hypertension, there was no diurnal variation of sympathetic activity, and there was correlation between daytime systolic blood pressure and sympathetic activity during sleep. These data suggests that chronic hyperactivity of sympathetic nervous system may contribute to the development of diurnal systemic hypertension in patients with obstructive sleep apnea syndrome.

• Korean Journal of Clinical Laboratory Science
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• v.40 no.2
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• pp.129-134
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• 2008

Obstructive sleep apnea syndrome (OSAS) is occurred by apnea by the obstruction of upper trachea while sleeping, followed by repetitive drop on arterial oxygen saturation ($SpO_2$). Therefore, the present study was focused on relation between $SpO_2$ of while having difficulty in breathing and clinical characteristics of OSAS while sleeping. The study took place at Ewha women university Mokdong hospital with 149 subjects (male 121, female 28) who were examined for polysomnography (PSG) from May 2007 to February 2008. All subjects were adhered to electrodes and sensors to measure electroencephalogram (EEG), electrooculogram (EOG), chin & leg electromyogram (EMG), airflow at nasal and oral cavities, breathing movement of chest and abdominal snoring sound and $SpO_2$. Lowest $SpO_2$ in male was meaningfully low with higher body mass index (BMI), louder snoring sound and thick neck circumference (p<0.01). While mean $SpO_2$ based on the degree of AHI did not show significant difference, lowest $SpO_2$ was significantly low with high AHI (p<0.001). Also, lowest $SpO_2$ was closely correlated with BMI (r=-00.343, p<0.001), snoring sound (r=0.177, p<0.05), apnea index (r=-0.589, p<0.001), hypopnea index (r=-0.336, p<0.001) and apnea-hypopnea index (r=-0.664, p<0.001). $SpO_2$ was closely related to clinical characteristics of OSAS, like male, BMI, snoring sound and neck circumference. Also, polysomnography accompanied by recent development of sleep study is considered as critical test to diagnose OSAS, decide the severity of illness, and evaluate the treatment plan.

• Korean Journal of Psychosomatic Medicine
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• v.31 no.2
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• pp.173-175
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• 2023

Enuresis nocturia is more prevalent in children than in adults. Using polysomnography (PSG), we investigated the causes of adult enuresis nocturia in a 20-year-old female patient with nighttime bedwetting. In spite of normal urological examinations, her detailed medical history disclosed frequent sleep paralysis and urination during dreams. During PSG, two electromyograms were attached to her anus to assess the tone of her bladder's sphincter while she slept. During REM sleep, the EMG tone of the mandible decreased, but the anal and bladder sphincter tones did not. The polysomnogram revealed moderate obstructive sleep apnea. Consequently, she was diagnosed with adult parasomnia (nocturnal enuresis) overlap syndrome with OSA. This study demonstrates the value of PSG with simultaneous anal tone EMG for diagnosing NREM parasomnia and nocturnal enuresis.

• Journal of Korean Biological Nursing Science
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• v.18 no.3
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• pp.135-143
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• 2016

Purpose: This study was conducted to identify the factors associated with obstructive sleep apnea (OSA) risk in patients with metabolic syndrome (MS). Methods: Patients with MS between 30 and 74 years of age were recruited in an outpatient clinic of a cardiovascular center in Seoul, South Korea. MS and the risk of OSA were evaluated by Berlin questionnaire survey, the medical records of the participants were reviewed and a comprehensive lifestyle survey was performed. SPSS WIN 21.0 was used for statistical analysis. Results: BMI (OR: 1.31, CI: 1.14-1.51, p<.001) and lifestyle score (OR: 0.96, CI: 0.93-0.99, p=.028) were associated with the risk of OSA. Physical activity, weight control and diet were specifically associated with the risk of OSA after controlling for age, gender and BMI. Conclusion: This study demonstrated that lifestyle was an important factor associated with OSA risk in patients with MS.

• Clinical and Experimental Pediatrics
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• v.53 no.10
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• pp.863-871
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• 2010

The prevalence of pediatric obstructive sleep apnea syndrome (OSAS) is approximately 3% in children. Adenotonsillar hypertrophy is the most common cause of OSAS in children, and obesity, hypotonic neuromuscular diseases, and craniofacial anomalies are other major risk factors. Snoring is the most common presenting complaint in children with OSAS, but the clinical presentation varies according to age. Agitated sleep with frequent postural changes, excessive sweating, or abnormal sleep positions such as hyperextension of neck or abnormal prone position may suggest a sleep-disordered breathing. Night terror, sleepwalking, and enuresis are frequently associated, during slow-wave sleep, with sleep-disordered breathing. Excessive daytime sleepiness becomes apparent in older children, whereas hyperactivity or inattention is usually predominant in younger children. Morning headache and poor appetite may also be present. As the cortical arousal threshold is higher in children, arousals are not easily developed and their sleep architectures are usually more conserved than those of adults. Untreated OSAS in children may result in various problems such as cognitive deficits, attention deficit/hyperactivity disorder, poor academic achievement, and emotional instability. Mild pulmonary hypertension is not uncommon. Rarely, cardiovascular complications such as cor pulmonale, heart failure, and systemic hypertension may develop in untreated cases. Failure to thrive and delayed development are serious problems in younger children with OSAS. Diagnosis of pediatric OSAS should be based on snoring, relevant history of sleep disruption, findings of any narrow or collapsible portions of upper airway, and confirmed by polysomnography. Early diagnosis of pediatric OSAS is critical to prevent complications with appropriate interventions.

• Korean Journal of Clinical Laboratory Science
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• v.43 no.2
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• pp.82-88
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• 2011

Mandibular advancement devices (MAD) are therapeutic options for obstructive sleep apnea (OSA). The aim of study was to investigate treatment outcomes of before and after insertion of MAD in OSA patients. We retrospectively selected a total of 13 patients who were diagnosed with OSA syndrome. All sleep-related parameters including apnea-hypopnea index (AHI), oxygen desaturation index (ODI), wake after sleep onset (WASO), total arousal were measured by before and after MAD. The use of MAD proves to be efficient in reducing snoring, apnea-hypopne index ($17.2{\pm}14.6$ vs $20.9{\pm}14.6$), WASO ($27.4{\pm}28.8$ vs $47.9{\pm}43.6$), oxygen desaturation index ($9.0{\pm}11.6$ vs $16.4{\pm}11.7$), stage N3 ($54.8{\pm}45.2$ vs $36.6{\pm}22.0$), REM sleep times ($73.3{\pm}19.4$ vs $66.0{\pm}31.0$) and increases sleep efficiency ($92.6{\pm}6.6$ vs $87.2{\pm}11.2$). The decreases in apnea index based on a reduction in the overall and supine AHI values after MAD therapy were significantly greater for the positional OSA than nonpositional OSA patients. The use of MAD proves to be efficient in snoring, WASO, sleep efficiency, reduced AHI and associated with good compliance of patients.

• Sleep Medicine and Psychophysiology
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• v.22 no.1
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• pp.11-19
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• 2015

Objectives: Whether daytime sleepiness is proportional to the severity of sleep apnea in obstructive sleep apnea syndrome (OSAS) is controversial. In this study we investigated how insomnia severity affects the association between daytime sleepiness and sleep apnea severity in OSAS. Methods: The present study included 235 male subjects who were diagnosed with OSAS based on clinical history and nocturnal polysomnography. Pearson's correlation analysis was conducted among sleep and mood-related self-reported data, polysomnographic data and demographic data of all subjects. Based on Pittsburgh Sleep Quality Index (PSQI), the subjects were divided into 2 groups; group A (n = 75; $PSQI{\leq}5$) and group B (n = 160; PSQI > 5). Partial correlation analysis was performed between the Epworth Sleepiness Scale (ESS) and other data in both groups. Multiple linear regression analysis was conducted to investigate the factors which affected the ESS in group A. Results: Pearson's correlation analysis showed weak or non-existent correlations between ESS and apnea severity data such as apnea-hypopnea index (AHI) (r = 0.148, p = 0.023), apnea index (AI) (r = 0.137, p = 0.036), hypopnea index (HI) (r = 0.058, p = 0.377), oxygen desaturation index (ODI) (r = 0.149, p = 0.022) and arousal total index (ATI) (r = 0.129, p = 0.048). Positive correlations between ESS and apnea severity data such as AHI ($r_p=0.313$, p = 0.008), AI ($r_p=0.339$, p = 0.004), ODI ($r_p=0.289$, p = 0.015) and ATI ($r_p=0.256$, p = 0.031) were observed only in group A. Multiple regression analysis showed that AI (t = 2.996, p = 0.004) and BAI (t = 2.721, p = 0.008) were associated with ESS in group A. Conclusion: The correlation between daytime sleepiness and sleep apnea severity was shown only in group A. This result suggests that associations between daytime sleepiness in OSAS and sleep apnea severity will become prominent when controlling for insomnia-related variables.

• Sleep Medicine and Psychophysiology
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• v.6 no.1
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• pp.19-25
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• 1999

Sleep alters both breathing pattern and the ventilatory responses to external stimuli. These changes during sleep permit the development or aggravation of sleep-related hypoxemia in patients with respiratory disease and contribute to the pathogenesis of apneas in patients with the sleep apnea syndrome. Fundamental effects of sleep on the ventilatory control system are 1) removal of wakefulness input to the upper airway leading to the increase in upper airway resistance, 2) loss of wakefulness drive to the respiratory pump, 3) compromise of protective respiratory reflexes, and 4) additional sleep-induced compromise of ventilatory control initiated by reduced functional residual capacity on supine position assumed in sleep, decreased $CO_2$ production during sleep, and increased cerebral blood flow in especially rapid eye movement(REM) sleep. These effects resulted in periodic breathing during unsteady non-rapid eye movement(NREM) sleep even in normal subjects, regular but low ventilation during steady NREM sleep, and irregular breathing during REM sleep. Sleep-induced breathing instabilities are divided due primarily to transient increase in upper airway resistance and those that involve overshoots and undershoots in neural feedback mechanisms regulating the timing and/or amplitude of respiratory output. Following ventilatory overshoots, breathing stability will be maintained if excitatory short-term potentiation is the prevailing influence. On the other hand, apnea and hypopnea will occur if inhibitory mechanisms dominate following the ventilatory overshoot. These inhibitory mechanisms include 1) hypocapnia, 2) inhibitory effect from lung stretch, 3) baroreceptor stimulation, 4) upper airway mechanoreceptor reflexes, 5) central depression by hypoxia, and 6) central system inertia. While the respiratory control system functions well during wakefulness, the control of breathing is commonly disrupted during sleep. These changes in respiratory control resulting in breathing instability during sleep are related with the pathophysiologic mechanisms of obstructive and/or central apnea, and have the therapeutic implications for nocturnal hypoventilation in patients with chronic obstructive pulmonary disease or alveolar hypoventilation syndrome.

• Tuberculosis and Respiratory Diseases
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• v.45 no.1
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• pp.153-168
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• 1998

Background: The existing data indicate that obstructive sleep apnea syndrome contributes to the development of cardiovascular dysfunction such as systemic hypertension and cardiac arrhythmias, and the cardiovascular dysfunction has a major effect on high long-term mortality rate in obstructive sleep apnea syndrome patients. To a large extent the various studies have helped to clarify the pathophysiology of obstructive sleep apnea, but many basic questions still remain unanswered. Methods: In this study, the influence of obstructive sleep apnea on systemic blood pressure, cardiac rhythm and urinary catecholamines concentration was evaluated. Over-night polysomnography, 24-hour ambulatory blood pressure and ECG monitoring, and measurement of urinary catecholamines, norepinephrine (UNE) and epinephrine (UEP), during waking and sleep were undertaken in obstructive sleep apnea syndrome patients group (OSAS, n=29) and control group (Control, n=25). Results: 1) In OSAS and Control, UNE and UEP concentrations during sleep were significantly lower than during waking (P<0.01). In UNE concentrations during sleep, OSAS showed higher levels compare to Control (P<0.05). 2) In OSAS, there was a increasing tendency of the number of non-dipper of nocturnal blood pressure compare to Control (P=0.089). 3) In both group (n=54), mean systolic blood pressure during waking and sleep showed significant correlation with polysomnographic data including apnea index (AI), apnea-hypopnea index (AHI), arterial oxygen saturation nadir ($SaO_2$ nadir) and degree of oxygen desaturation (DOD). And UNE concentrations during sleep were correlated with AI, AHI, $SaO_2$ nadir, DOD and mean diastolic blood pressure during sleep. 4) In OSAS with AI>20 (n==14), there was a significant difference of heart rates before, during and after apneic events (P<0.01), and these changes of heart rates were correlated with the duration of apnea (P<0.01). The difference of heart rates between apneic and postapneic period (${\Delta}HR$) was significantly correlated with the difference of arterial oxygen saturation between before and after apneic event (${\Delta}SaO_2$) (r=0.223, P<0.001). 5) There was no significant difference in the incidence of cardiac arrhythmias between OSAS and Control In Control, the incidence of ventricular ectopy during sleep was significantly lower than during waking. But in OSAS, there was no difference between during waking and sleep. Conclusion : These results suggested that recurrent hypoxia and arousals from sleep in patients with obstructive sleep apnea syndrome may increase sympathetic nervous system activity, and recurrent hypoxia and increased sympathetic nervous system activity could contribute to the development of cardiovascular dysfunction including the changes of systemic blood pressure and cardiac function.

• Sleep Medicine and Psychophysiology
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• v.29 no.2
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• pp.29-34
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• 2022

Coronavirus disease 2019 (COVID-19), which was a global pandemic caused by severe acute respiratory syndrome corona virus 2 (SARS-CoV-2), is still a serious public health problem. COVID-19 causes various symptoms not only in the respiratory system but also in various parts of the body and has a significant effect on sleep. Insomnia and poor sleep quality were observed at high rates in patients with COVID-19 as well as in the uninfected general population. Obstructive sleep apnea is also considered a risk factor in patients with severe COVID-19. Virus-induced central nervous system damage is likely to be the cause of many sleep disorders in COVID-19, but psychosocial influences also seem to have played a significant role. Sleep problems persisted at high rates for a considerable period after the infection phase was over. More attention and research on the effect of COVID-19 on sleep is needed in the future.