• Sleep Medicine and Psychophysiology
• /
• v.12 no.1
• /
• pp.68-71
• /
• 2005

We report a case of obstructive sleep apnea syndrome, which occurred primarily during the REM sleep stage. A 55-year-old female patient who complained of chronic insomnia on the initial visit turned out to have obstructive sleep apnea syndrome of a mild degree (respiratory disturbance index (RDI) of 13.8/hour, %time spent below 90% of SaO2=5.0%) on nocturnal polysomnography. Interestingly, apnea episodes and desaturations mainly occurred during REM sleep stage. And RDI and destaturations during REM sleep stage were found to be severe enough to classify as a severe degree of obstructive sleep apnea syndrome. These findings suggest that severe obstructive sleep apnea syndrome might be masked under the symptom of chronic insomnia and that apneas can be predominantly localized within REM sleep epochs. In terms of treatment, "REM sleep-dependent" apneas may call for different methods of treatment, especially REM sleep-specific pharmacological intervention.

• Tuberculosis and Respiratory Diseases
• /
• v.49 no.6
• /
• pp.715-723
• /
• 2000

Background : Obstructive sleep apnea syndrome (OSAS) affects systemic blood pressure and cardiac function. The development of cardiovascular dysfunction including the changes of systemic blood pressure and cardiac rhythm, suggests that recurrent hypoxia and arousals from sleep may increase a sympathetic nervous system activity. Continuous positive airway pressure (CPAP) therapy has been found to be an effective treatment of OSAS. However, only a few studies have investigated the cardiovascular and sympathetic effects of CPAP therapy. We evaluated influences of nasal CPAP therapy on the cardiovascular system and the sympathetic activity in patients with OSAS. Methods : Thirteen patients with OSAS underwent CPAP therapy and were monitored using polysomnography, blood pressure, heart rate, presence of arrhythmia and the concentration of plasma catecholamines, before and with CPAP therapy. Results: The apnea-hypopnea index (AHI) was significant1y decreased (p<0.01) and the lowest arterial oxygen saturation level was elevated significantly after applying CPAP (p<0.01). Systolic blood pressure tended to decrease after CPAP but without statistical significance. Heart rates during sleep were not significantly different after CPAP. However, the frequency and number of types of arrhythmia decreased and sinus bradytachyarrhythmia disappeared after CPAP. Although there was no significant difference in the level of plasma epinephrine concentration, plasma norepinephrine concentration significantly decreased after CPAP (p<0.05). Conclusion : CPAP therapy decreased the apnea-hypopnea index, hypoxic episodes and plasma norepinephrine concentration. In addition, it decreased the incidence of arrhythmia and tended to decrease the systemic blood pressure. These results indicate that CPAP may play an important role in the prevention of cardiovascular complications in patients with OSAS.

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

• Sleep Medicine and Psychophysiology
• /
• v.11 no.2
• /
• pp.106-109
• /
• 2004

Adenotonsillar hypertrophy is the leading cause of childhood obstructive sleep apnea. Obstructive sleep apnea syndrome in childhood, however, can occur from various causes such as obesity or craniofacial abnormalities. Childhood obstructive sleep apnea syndrome can be accompanied by enuresis, parasomnias and behavior problems. For patients with the symptoms of snoring and apnea, obstructive sleep apnea should be suspected and diagnosed properly. In addition, the evaluation of complications and proper treatment are indispensable. When the cause of childhood obstructive sleep apnea is adenotonsillar hypertrophy, symptoms can be improved by surgical methods. If the cause is other than adenotonsillar hypertrophy, such as obesity, it should be treated with other therapeutic modalities, like nasal continuous positive airway pressure (nCPAP), weight reduction and modification of life style. This paper reports a case of nCPAP used to manage severe sleep apnea when it was not resolved after adenoidectomy and tonsillectomy. Differential diagnosis of narcolepsy in a case with excessive daytime sleepiness and reflections on accompanying enuresis and parasomnia were also described.

• Tuberculosis and Respiratory Diseases
• /
• v.40 no.5
• /
• pp.501-508
• /
• 1993

Background: Sleep apnea syndrome is a common disorder which is estimated to affect about 1~4% of adult male population. And if untreated, sleep apnea can cause significant sequelae, such as hypertension, nocturnal cardiac arrhythmia, daytime hypersomnolence, and cognitive impairment. Various kinds of treatment for obstructive sleep apnea (OSA) have been developed. Among them nasal CPAP, first introduced by Sullivan et al in 1981, has received widespread interest and acclaim as a treatment of OSA, and is currently recommended as first-line treatment for OSA. We evaluated the effect of nasal CPAP in OSA and the side effects of nasal CPAP hindering patients from using nasal CPAP. Methods: We performed sleep studies in 20 OSA patients at 2 consecutive nights; baseline night at first day and CPAP night at second day. We compared apnea index, lowest oxygen concentration during apnea, maximal apnea time, and total apnea duration per total sleep time before and after CPAP. We also evaluated the side effects of CPAP with inquiry to the patients. Results: 1) Apnea index was significantly decreased after CPAP in 17 out of 20 OSA patients (85%) and increased in 3 patients (15%). 2) Average apnea index was significantly decreased after CPAP ($34.1{\pm}18.9/h{\rightarrow}15.4{\pm}10.3/h$, p<0.01). 3) Total apnea duration per total sleep time was also significantly decreased after CPAP ($28.5{\pm}16.0%{\rightarrow}11.9{\pm}9.3%$, p<0.05). 4) The lowest oxygen satuation and maximal apnea time were not significantly changed after CPAP. 5) The most frequent side effect of nasal CPAP was mask discomfort (80%), and the next was drying of nasal passages (65%). Conclusion: Nasal CPAP is an effective treatment for OSA. Futher studies should be concentrated on long term follow up of nasal CPAP for its therapeutic effects and the study of methods to enhance patients' compliance.

• Sleep Medicine and Psychophysiology
• /
• v.15 no.2
• /
• pp.67-70
• /
• 2008

Overlap syndrome can be defined as a coexistence of chronic obstructive pulmonary disease (COPD) and sleep apnea-hypopnea syndrome (SAHS). The association of COPD and SAHS has been suspected because of the frequency of both diseases. Prevalence of COPD and SAHS is respectively 10 and 5% of the adult population over 40 years of age. However, a recent study has shown that the prevalence of SAHS is not higher in COPD than in the general population. The coexistence of the two diseases is only due to chance. SAHS does not affect the pathophysiology of COPD and vice versa. Prevalence of overlap syndrome is expected to occur in about 0.5% of the adult population over 40 years of age. Patients with overlap syndrome have a more profound hypoxemia, hypercapnia, and pulmonary hypertension when compared with patients with SAHS alone or usual COPD patients without SAHS. To treat the overlap syndrome, nocturnal noninvasive ventilation (NIV) or nasal continuous positive airway pressure (nCPAP) can be applied with or without nocturnal oxygen supplement.

• Tuberculosis and Respiratory Diseases
• /
• v.42 no.2
• /
• pp.206-217
• /
• 1995

Background: In patients with obstructive sleep apnea syndrome(OSAS), there are several factors increasing upper airway resistance and there is a predisposition to compromised respiratory function during waking and sleep related to constitutional factors including a tendency to obesity. Several recent studies have suggested a possible relationship between sleep apnea(SA) and systemic hypertension. But the possible pathophysiologic link between SA and hypertension is still unclear. In this study, we have examined the relationship among age, body mass index(BMI), pulmonary function parameters and polysomnographic data in patients with OSAS. And also we tried to know the difference among these parameters between hypertensive OSAS and normotensive OSAS patients. Methods: Patients underwent a full night of polysomnography and measured pulmonary function during waking. OSAS was diagnosed if patients had more than 5 apneas per hour(apnea index, AI). A careful history of previously known or present hypertension was obtained from each patient, and patients with systolic blood pressure $\geq$ 160mmHg and/or diastolic blood pressure $\geq$ 95mmHg were classified as hypertensives. Results: The noctural nadir of arterial oxygen saturation($SaO_2$ nadir) was negatively related to AI and respiratory disturbance index(RDI), and the degree of noctural oxygen desaturation(DOD) was positively related to AI and RDI. BMI contributed to AI, RDI, $SaO_2$ nadir and DOD values. And also BMI contributed to $FEV_1,\;FEV_1/FVC$ and DLco values. There was a correlation between airway resistance(Raw) and AI, and there was a inverse correlation between DLco and DOD. But there was no difference among these parameters between hypertensive OSAS and normotensive OSAS patients. Conclusion: The obesity contributed to the compromised respiratory function and the severity of OSAS. AI and RDI were important factors in the severity of hypoxia during sleep. The measurement of pulmonary function parameters including Raw and DLco may be helpful in the prediction and assessment of OSAS patients. But we could not find clear difference between hypertensive and normotensive OSAS patients.

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

• Sleep Medicine and Psychophysiology
• /
• v.18 no.2
• /
• pp.63-66
• /
• 2011

It has been controversial whether upper airway resistance syndrome (UARS) is a distinct syndrome or not since it was reported in 1993. The International Classification of Sleep Disorders classified UARS under obstructive sleep apnea syndrome (OSAS) in 2005. UARS can be diagnosed when the apnea-hypopnea index (AHI) is fewer than 5 events per hour, the simultaneously calculated respiratory disturbance index (RDI) is more than 5 events per hour due to abnormal non-apneic non-hypopneic respiratory events accompanying respiratory effort related arousals (RERAs), and oxygen saturation is greater than 92% at termination of an abnormal breathing event. Although esophageal pressure measurement remains the gold standard for detecting subtle breathing abnormality other than hypopnea and apnea, nasal pressure transducer has been most commonly used. RERAs include phase A2 of cyclical alternating patterns (CAPs) associated with EEG changes. Symptoms of OSAS can overlap with UARS, but chronic insomnia tends to be more common in UARS than in OSAS and clinical symptoms similar with functional somatic syndrome are also more common in UARS. In this journal, diagnostic and clinical differences between UARS and OSAS are reviewed.

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