Gawon Ju

Effects of Sleep Apnea Syndrome on Delayed Memory and Executive Function in Elderly Adults

To identify differences in cognitive function between elderly adults with sleep apnea syndrome (SAS) and healthy controls.

The Prevalence of and Risk Factors for Sleep-Disordered Breathing in an Elderly Korean Population

Background: There are just a few epidemiological studies on sleep-disordered breathing (SDB) in the elderly, and the results are inconsistent. Study Objectives: We sought to investigate the prevalence of and risk factors for SDB in a representative elderly population with the use of attended nocturnal polysomnography (NPSG). Methods: Among 6,959 individuals aged ≥60 years living in Yongin City, Korea, 696 subjects were selected using random sampling. All the subjects were invited to visit a hospital for NPSG, and SDB was defined as an apnea-hypopnea index ≥15. Results: Of the 696 participants investigated, 348 participants completed the sleep study and clinical evaluation. SDB was observed in 127 of the 348 participants, and the prevalence of SDB was 36.5% (52.6% in males and 26.3% in females). A body mass index ≥25 was associated with SDB in both male and female subjects, particularly in males, whereas snoring was independently associated with SDB in female participants only. In male participants, SDB was a significant risk factor for hypertension (p = 0.025). Conclusions: SDB was found to be common among elderly Koreans, and it was more prevalent and severe in male than in female subjects. Health consequences of SDB in the elderly need to be further explored.

Modest Changes in Cerebral Glucose Metabolism in Patients with Sleep Apnea Syndrome after Continuous Positive Airway Pressure Treatment

Background: Decreased cerebral glucose metabolism has been reported in patients with sleep apnea syndrome (SAS), but it has yet to be decided whether cerebral glucose metabolism in SAS can be altered by continuous positive airway pressure (CPAP) treatment. Objective: The aim of this study was to evaluate cerebral glucose metabolism changes in patients with SAS after CPAP treatment. Methods: Thirteen middle-aged male patients with severe SAS [mean age 49.3 ± 7.2 years, mean apnea-hypopnea index (AHI) 60.4 ± 21.2] and 13 male controls (mean age 46.0 ± 9.4 years, mean AHI 4.1 ± 3.7) participated in the study. All 26 study subjects underwent fluorodeoxyglucose-positron emission tomography (FDG-PET), but SAS patients underwent FDG-PET twice, namely before and 3 months after acceptable CPAP usage. Results: Significant hypometabolism was observed in the bilateral prefrontal areas, left cuneus and left cingulate cortex of SAS patients before CPAP, and after CPAP, significant increases in cortical glucose metabolism were observed in the bilateral precentral gyri and left anterior cingulate cortex. However, these improvements in hypometabolism in both areas were insufficient to reach control levels, and hypometabolism in other regions persisted after CPAP treatment. Conclusions: Reduced cerebral glucose metabolism in the precentral gyrus and the cingulate cortex in patients with SAS was modestly improved by acceptable CPAP treatment. The findings of this study suggest that acceptable CPAP usage cannot completely reverse reduced cerebral glucose metabolism in SAS patients. Further studies are required to evaluate the long-term effects of CPAP treatment with total compliance.

Improvement of EEG slowing in OSAS after CPAP treatment.

OBJECTIVES This study was done to investigate change of electroencephalography (EEG) slowing and its relationship to daytime sleepiness and cognitive functions by continuous positive airway pressure (CPAP) in patients with obstructive sleep apnea syndrome (OSAS). METHODS We enrolled thirteen male subjects with severe OSAS, and all the subjects were treated with CPAP for 3 months. Quantitative EEG (QEEG) and neuropsychological tests were performed before and after CPAP treatment. RESULTS After CPAP treatment, delta absolute power decreased in the frontal, central, parietal and temporal regions and the slowing ratio was reduced in the frontal region. The Epworth Sleepiness Scale (ESS) score was reduced after CPAP treatment. Reduction in the ESS score was correlated with a decrease in delta absolute power in the frontal region (r=0.559) and a decrease in slowing ratio in frontal, central, parietal, and temporal regions (frontal, r=0.650; other regions, r=0.603). Results of neuropsychological tests assessing memory and attention were improved after CPAP treatment. CONCLUSIONS EEG slowing was decreased across all cerebral regions in patients with severe OSAS after CPAP treatment accompanied by improvement of cognitive functions involving several brain areas. These findings suggest that CPAP can induce improvement of cerebral function in OSAS without regional specificity.

Relationships between sleep disturbances and gastroesophageal reflux disease in Asian sleep clinic referrals

OBJECTIVE Studies on the association between gastroesophageal reflux disease (GERD) and sleep apnea syndrome (SAS) have reported conflicting results, and attention has not been paid to the relationship between GERD and other sleep disorders. The aim of the study was to evaluate the relationship between GERD and various aspects of sleep disturbances. METHODS A total of 564 subjects who were referred to a sleep laboratory were enrolled in the study. They underwent nocturnal polysomnography (NPSG), and they were asked to complete a GERD questionnaire. The questionnaire consisted of 14 items, and included questions on seven reflux symptoms, namely, heartburn, acid regurgitation, chest pain, hoarseness, globus sensation, coughing and epigastric soreness. Subjects reporting heartburn or acid regurgitation at least once a week were classified as having GERD. RESULTS Among 564 participants, 51 subjects (9.0%) were diagnosed as having GERD. GERD patients had higher scores in Beck depression inventory (p<.01), Epworth sleepiness scale (p=.03), Pittsburg sleep quality index (p<.01), more spontaneous arousals in NPSG, and more alcohol consumption than non-GERD patients. There was no association between presence of GERD, SAS-related variables, and body mass index (BMI). GERD was significantly associated with poor sleep quality (adjusted OR, 3.5; 95% CI, 1.3-9.3) and depressed mood (adjusted OR, 2.8; 95% CI, 1.5-5.3). CONCLUSION Poor subjective sleep and depressive symptoms are associated with the presence of GERD with no association between SAS, BMI and GERD. In managing patients with GERD, psychiatric and sleep symptoms need to be evaluated and appropriately treated.

Characteristics of methods of suicide attempts in Korea: Korea National Suicide Survey (KNSS).

BACKGROUND Because the method used for a suicide attempt is an important determinant of outcome, these methods should be explored. The present study was a nationwide investigation of suicide attempts and the characteristics of suicidal behavior. AIMS To compare the suicide methods used in attempted suicides with those used in completed suicides and to examine the factors associated with each phenomenon. METHODS The present study reviewed the medical charts of subjects who had attempted suicide and subsequently visited the emergency rooms of 17 medical centers from May 1, 2013 to November 7, 2013. All subjects completed a full psychiatric interview conducted by trained psychiatric residents. Suicide-attempt methods were divided into the following six categories: drug poisoning, pesticide poisoning, gassing, cutting, hanging, and others. The associations among demographic variables, related psychiatric variables, and suicide-attempt methods were analyzed using a multinomial regression analysis. RESULTS Of the 1359 suicide attempts or instrumental suicide-related behaviors with/without injuries and the 14,160 completed suicides, drug poisoning and cutting were the most common suicidal behaviors with/without injuries, but they were the least frequent method of completed suicides. In contrast, hanging and jumping from a height were less common among failed suicide attempts but resulted in a higher percentage of fatalities. Being male, age, and area of residence were associated with pesticide poisoning, whereas previous suicide attempts were associated with cutting, pesticide poisoning, and gassing. CONCLUSION A previous suicide attempt is a risk factor for suicide; thus, assessing the characteristics of suicide attempts or instrumental suicide-related behaviors with/without injuries is necessary to prevent these attempts. The present findings showed that the methods of suicide used by individuals who only attempted suicide differed from those used by individuals who completed. Of the suicide methods, pesticide poisoning was related to age, residential area (urban), and a history of previous suicide attempts.

Prevalence and clinical characteristics of insomnia and its subtypes in the Korean elderly

BACKGROUND Insomnia is known to be associated with psychiatric disorders, other sleep disorders and medical conditions, but the prevalence of insomnia diagnosis has never been estimated according to its subtypes. We studied the prevalence and clinical characteristics of insomnia diagnosis and its subtypes in the Korean elderly population. METHODS Among 1423 sampled elderly individuals aged 60 years or older, 881 subjects participated in this study. The Athens Insomnia Scale was applied to detect insomnia symptoms, and insomnia diagnosis was finally evaluated using the international classification of sleep disorders, 2nd edition. To define insomnia subtypes, the DSM-IV-based interview, detailed history on sleep disorders and semi-structured interview for medical conditions were performed. Subsyndromal depression was defined when depressive symptoms did not meet the criteria for depressive disorders. RESULTS The prevalence of insomnia disorder was 32.8% in all subjects, with the prevalence being significantly higher in women than in men (37.9% vs. 25.2%; p<0.001). The prevalence of insomnia subtypes was as follows; psychophysiological insomnia (PI), 20.5%; insomnia due to mental disorder 7.2%; insomnia due to general medical conditions 2.9%; insomnia in other sleep disorders 2.2%, and insomnia due to substance use 0.2%. Among subjects with PI, subsyndromal depression was diagnosed in 53.7%. CONCLUSIONS Nearly one third of Korean elderly individuals suffer from insomnia and insomnia patients showed diverse comorbid conditions, especially depressive symptoms. By establishing insomnia subtypes, we can plan to treat comorbid conditions as well as insomnia itself.

Volume of hippocampal subfields in patients with alcohol dependence

Alcohol-induced hippocampal atrophy has been well documented in many studies and is known to affect various subfields. Given the functional heterogeneity of these subfields, we investigated the precise effects of alcohol-induced damage in these areas. Twenty-six male patients with alcohol dependence (alcohol group) and twenty-six age-matched male healthy social drinkers were recruited from a mental health hospital and the community respectively, with the aim of comparing the hippocampal subfields between groups. Each participant underwent a 3T MRI scan. Hippocampal subfield volumes were estimated using an automated procedure and drinking history recorded using Lifetime Drinking History, Alcohol Use Disorder Identification Test, and the Brief Michigan Alcoholism Screening Test. The alcohol group showed a lower total hippocampus volume, specifically in the left presubiculum, fimbria, and bilateral subiculum. Regression analysis assessing the influence of age and group showed that group was a more significant factor than age in most subfields. Our findings suggest that alcohol dependence alters hippocampal subfield volumes. Further longitudinal studies on the interaction of structural and neurocognitive changes would improve our understanding of brain structural changes resulting from long-term alcohol consumption.

A Study of Covert Narcissism in Adolescent Internet Addiction : Relationship to Anonymity, Presence, Interactivity, and Achievement Motivation

Objectives:This study compared covert narcissistic propensity in adolescents with internet addiction tendency to normal adolescents. Further, we investigated the correlation between such propensities and anonymity in cyberspace, presence feeling and interactivity in internet gaming, and achievement motivation in adolescents with internet addiction tendencies. Methods:Male middle school students with internet addiction tendencies (Addiction Tendency Group, N=27) and normal stu- dents (Control Group, N=29) were recruited. The scale of internet use, Covert Narcissism Scale, scale of achievement motiva- tion, scale of anonymity in cyberspace, scale of presence feeling in internet games, and the scale of interactivity in internet games were administered. A comparison of the average scores and correlation analyses were performed. Results:1) Compared with Control Group, the Addiction Tendency Group showed significantly higher scores on all subscales of the Covert Narcissism Scale, and both the scale of presence feeling and that of interactivity in internet games. Further, the score on the scale of achievement motivation for the Addiction Tendency Group was significantly lower than that of the Control Group. 2) In the Addiction Tendency Group, the scores on several subscales of the Covert Narcissism Scale were significantly positively correlated with the scores on the scale of presence feeling in internet games, anonymity in cyberspace, and interac- tivity in internet games. However, in the Control Group, the scores of several subscales on the Covert Narcissism Scale were sig- nificantly negatively correlated with the score on the scale of achievement motivation, and was significantly positively correlat - ed with the score on the scale of interactivity in internet games. There were no other significant correlations between the scores on the subscales of the Covert Narcissism Scale and the scores of either presence feeling in internet games or anonymity in cy- berspace.

An fMRI Study Investigating Adolescent Brain Activation by Rewards and Feedback

Objective This study aimed to investigate the adolescent brain activation patterns in response to performance feedback (PF), social reward (SR) and monetary reward (MR) and their association with psychological factors. Methods Functional magnetic resonance imaging (fMRI) was performed while middle school boys (n=15) performed tests pertained to PF, SR and MR. The brain activation pattern in each condition was investigated, and the extent of brain activation in each of the three conditions was compared at once. Results The caudate and the dorsal prefrontal area were activated in all three conditions. Furthermore, the cuneus showed significantly greater activation in the PF condition than the SR or MR condition. And the self - related areas, such as the right precentral gyrus and paracenral lobule, were more activated in the SR condition than the PF or MR condition. The left middle frontal gyrus was more activated in the MR condition than the PF or SR condition. Conclusion Not only various reward stimuli but also feedback stimulus might commonly activate dorsal prefrontal and subcortical area in adolescents. Moreover, several different brain activation patterns were also observed in each condition. The results of this study could be applied to planning of learning and teaching strategy for adolescents in various ways.