• Sleep Medicine and Psychophysiology
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• v.19 no.1
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• pp.22-26
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• 2012

Objectives: The percentage of positional sleep apnea in obstructive sleep apnea (OSA) varies in different reports from 9% to 60%. If there is a positional dependency in patients with OSA, positional therapy alone could be successful in treating about 50% of all OSA cases. The aim of this report is to compare anthropomorphic and polysomnographic data between the positional sleep apnea group and non-positional sleep apnea group with OSA whose conditions were diagnosed in our sleep clinic. Methods: This is a retrospective study of anthropomorphic and polysomnographic data of patients with OSA who was performed a nocturnal polysomnography. Positional sleep apnea was defined as having a supine apnea-hypopnea index (AHI) of twice or more compared to the AHI in the non-supine position. The patients were divided in the positional sleep apnea group and the non-positional sleep apnea group. Results: In 101 patients with OSA, 81 were male, and the mean age was $49.2{\pm}11.9$ years. Seventy-six (75.2%) were diagnosed as the positional sleep apnea. Waist to hip ratio and body mass index (BMI) were significantly higher in non-positional sleep apnea group. The frequency of severe OSA was significantly higher in this group. In the positional sleep apnea group, nocturnal sleep quality was better preserved, and consequently these patients were less sleepy during daytime. AHI was significantly lower and minimal arterial oxygen saturation during sleep was significantly higher in this group. Conclusion: The percentage of positional sleep apnea in OSA was 75.2%. AHI, BMI, and waist to hip ratio were lower in the positional sleep apnea group. These patients have less severe breathing abnormalities than the non-positional sleep apnea group in polysomnography.

• Sleep Medicine and Psychophysiology
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• v.21 no.1
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• pp.14-20
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• 2014

Objectives: Several studies suggest that nocturia may be related to obstructive sleep apnea syndrome (OSAS). The mechanism by which OSAS develops nocturia has not been determined. The present study aimed to determine the prevalence of nocturia among adults with OSAS and to identify factors that may be predictive in this regard. Methods: Retrospective review of clinical and polysomnographic data obtained from patients evaluated at the sleep clinics of the St. Paul's Hospital between 2009 and 2012. The urinary symptoms were assessed on the basis of the International Prostate Symptom Score (IPSS). Pathologic nocturia was defined as two or more urination events per night. OSAS was defined as apnea-hypopnea index (AHI) ${\geq}5$. A multivariate analysis using logistic regression was performed to examine the relationship between polysomnographic variables and the presence of pathologic nocturia, while controlling for confounding factor. Results: A total of 161 men >18 years of age (mean age $46.7{\pm}14.1$), who had been referred to a sleep laboratory, were included in the present study. Among these, 27 patients with primary snoring and 134 patients with obstructive sleep apnea were confirmed by polysomnography. Nocturia was found in 53 patients with OSAS (39.6%) and 8 patients with primary snoring (29.6%). The AHI was higher in patients with nocturia than in those without nocturia (p=0.001). OSAS patients with nocturia had higher arousal index (p=0.044), and lower nadir oxyhemoglobin saturation (p=0.001). Multiple regression analysis showed that age (${\beta}$=0.227, p=0.003), and AHI (${\beta}$=0.258, p=0.001) were associated with nocturia, and that the presence of pathologic nocturia was predicted by age (OR 1.04 ; p=0.004) and AHI (OR 1.02 ; p=0.001). Conclusion: Nocturia is common among patients with OSAS. The strongest predictors of nocturia are age and AHI in patients with OSAS.

• Proceedings of the Korea Contents Association Conference
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• 2015.05a
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• pp.145-146
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• 2015

폐쇄성수면무호흡증(Obstructive sleep apnea syndrome : OSAS)은 신경근육계, 호흡계, 심혈관계의 복합적인 질환으로서 사회적, 생리학적으로 심각한 문제를 발생시킬 수 있는 질병이다. 수술적치료를 결정하기에 앞서 환자의 증상 및 징후, 신체 상태와 습관 등을 정밀검사하고, 기도폐쇄가 일상생활 및 정신건강에 미치는 영향을 고려하여 수술여부를 결정하여야 한다. 폐쇄성수면무호흡증후군의 진단에 유용한 검사인 수면다원검사와 Videofluoroscopy의 검사결과를 바탕으로 수술소견을 비교분석하고자 하였다.

• Journal of the Korea Society of Computer and Information
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• v.25 no.7
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• pp.113-123
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• 2020

Obstructive sleep apnea (OSA) among sleep disorders is one of relatively common diseases. Patients can be checked for the disease through sleep polysomnography. However, as far as he diagnosis of OSA using polysomnography (PSG) is concerned, many practical problems such as an increasing number of patients, expensive testing cost, discomfort during examination, and the limited number of people for testing have been pointed out. Accordingly, for the purpose of substituting PSG researchers have been actively conducting studies on OSA diagnosis based on machine learning using bio signals. In this regard, we review a rich body of existing OSA diagnosis studies applying machine learning techniques based on bio-signal data. As a result, this paper presents a novel taxonomy of the reviewed studies and provides their comprehensive comparative analysis results. Also, we reveal various limitations of the studies using the bio signals and suggest several improvements about utilization of the used machine learning methods. Finally, this paper presents future research topics related to the application of machine learning techniques using bio signals.

• Sleep Medicine and Psychophysiology
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• v.18 no.2
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• pp.82-86
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• 2011

Objectives: The Berlin Questionnaire (BQ) has been used to help identify patients at high risk of having sleep apnea in primary care. But it has not been validated in a sleep clinic for Korean patients. The aim of this study is to evaluate the usefulness of the BQ as a screening tool for obstructive sleep apnea (OSA) for Korean patients in a sleep clinic. Methods: The BQ was prospectively applied to 121 subjects with OSA suspicion who visited to our sleep clinic. All subjects performed overnight polysomnography. OSA was defined as an apnea-hypopnea index (AHI) ${\geq}5$. We investigated the sensitivity, specificity, positive and negative predictive values of the BQ according to severity by AHI. Results: In 121 subjects, 73.6% were males, with a mean age of $48.8{\pm}13.0$ years. Twenty-five (20.6%) patients did not have OSA (AHI<5), 30 (25%) patients had mild OSA ($AHI{\geq}5$ and <15), 26 (21.4%) had moderate ($AHI{\geq}15$ and <30), and 40 (33%) had severe OSA ($AHI{\geq}30$). The BQ identified 69.4% of the patients as being at high risk for having OSA. The sensitivity and specificity of the BQ were 71.9% and 40%, for $AHI{\geq}5$, 75.8% and 38.2% for $AHI{\geq}15$, 77.5% and 34.6% for $AHI{\geq}30$, respectively. The positive and negative predictive values of the BQ were 82.1% and 27.0% for $AHI{\geq}5$, respectively. Positive and negative likelihood ratios were 1.2 and 0.7, and the overall diagnostic accuracy of the BQ was 65.3%, using an AHI cut-off of 5. Conclusion: Due to modest sensitivity and low specificity, the BQ does not seem to be an appropriate tool for identifying patients with obstructive sleep apnea in a sleep clinic population.

• Sleep Medicine and Psychophysiology
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• v.18 no.1
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• pp.29-34
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• 2011

Objectives: The purposes of this study were to estimate the effect of mandibular advancement device (MAD) and to evaluate the influence of the advancement amount of mandible in the application of MAD for obstructive sleep apnea (OSA) patients. Methods: From the patients who were diagnosed as OSA by polysomnographic study at Seoul National University Bundang Hospital from January 2007 to February 2009, the patients who chose MAD as treatment option were included in this study. All the patients’ data including clinical records and polysomnographic studies (both pre- and post-treatment) were reviewed and analyzed. Results: Successful results were obtained in 65 patients of 86 patients (75.6%). In the follow-up period, mild discomfort of anterior teeth or temporomandibular joint (TMJ) were described in 28 patients, especially in the cases the amount of mandibular advancement were more than 7.0 mm. There was no direct relationship between the amount of mandibular advancement and clinical outcome. Conclusion: MAD was effective treatment option for the OSA patients regardless of severity. For the prevention of potential dental complications, the amount of mandibular advancement should be considered at the time of MAD treatment.

• Sleep Medicine and Psychophysiology
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• v.12 no.2
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• pp.98-104
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• 2005

Approximately 1% to 3% of all children have obstructive sleep apnea syndrome (OSAS). OSAS in children can lead to a variety of symptoms and sequalae; impairment of development and quality of life, behavioral and personality disturbance, learning problem, cor pulmonale and hypertension. Diagnosis and treatment of OASA for children are different from those for adults in many respects. Adenotonsillar hypertrophy is major cause of childhood OSAS. Overnight polysomnography in a sleep laboratory is the gold standard for diagnosing childhood OSAS. However, because full polysomnography in children may be difficult to obtain, expensive, and inconvenient, other methods to diagnose OSAS have been investigated. Adenotonsillectomy is the most common surgical treatment of childhood OSAS. But if residual symptoms remained after adenotonsillectomy, it should be considered to additional treatment such as weight control, sleep positional change, and continuous positive airway pressure (CPAP).

• Sleep Medicine and Psychophysiology
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• v.23 no.2
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• pp.93-96
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• 2016

Obstructive sleep apnea syndrome (OSAS) has negative effects on health, including increased mortality, risk of cardiovascular disease, and neurocognitive difficulties. OSAS is common in obese patients and obesity is an important risk factor of OSAS. A 41-year-old female OSAS patient with severe obesity (body mass index [BMI] ${\geq}35$) who failed dietary weight loss underwent bariatric surgery. After surgery, there were improvements in BMI (from 36.9 to $31.7kg/m^2$) and polysomnographic data, including the apnea-hypopnea index (from 25.1 to 11.2 events/hr) and minimum SaO2 (from 69 to 82%). This case demonstrates that bariatric surgery may be an effective therapeutic option to reduce sleep-disordered breathing in severely obese patients with moderate OSAS. Bariatric surgery as a treatment option for OSAS should be considered in OSAS patients with severe obesity who failed dietary weight loss.

• Sleep Medicine and Psychophysiology
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• v.23 no.2
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• pp.97-99
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• 2016

Positive airway pressure (PAP) is currently recommended as a primary treatment for obstructive sleep apnea syndrome (OSAS) and positively affects various subjective and objective parameters related to OSAS, such as the apnea-hypopnea index, excessive daytime sleepiness, and blood pressure. However, PAP also exhibits various adverse effects, including skin breakdown, pressure intolerance, claustrophobia, unintentional mask removal, mouth leaks, and dryness. Especially, unintentional mask removal due to nasal obstruction may result in poor PAP compliance. A 47-year-old male patient with severe OSAS who had low PAP compliance due to nasal obstruction underwent nasal surgery. After the surgery, nasal obstruction was corrected and the patient experienced improved PAP compliance (from 30.4% to 86.7%). This case demonstrates that nasal surgery may be useful for improving PAP compliance in OSAS patients with nasal obstruction.

• 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.