• Sleep Medicine and Psychophysiology
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• v.3 no.2
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• pp.18-31
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• 1996

Jet-lag can be defined as the cumulative physiological and psychological effects of rapid air travel across multiple time zones. Many reports have suggested that age-related changes in sleep reflect fundamental changes in the circadian system and in significant declines in slow wave sleep. Jet lag is a dramatic situation in which the changes of the phase of circadian process and homeostatic process of sleep occur. Thus the authors evaluatead the changes of sleep-wake cycle from jet lag by age. Thirty-eight healthy travellers were studied for 3 days before and 7 days after jet-flights across seven to ten time zone. They were aged 19-70, They trareled eastbound, Seoul to North America (USA, Canada). Sleep onset time, wake-up time, sleep latency, awakening frequency on night sleep, awakening duration on night sleep, sleepiness at wake-up and nap length were evaluated. Our results suggest that by the 7 to 10 time zone shift, the old age group was significantly influenced in sleep-wake cycles. The date on which subjective physical condition was recovered was $6.23{\pm}83$ day after arrivals for old age group, while for young and middle age group, $4.46{\pm}1.50$ day and $4.83{\pm}1.52$ day, respectively. In old age group, sleep onset time was later than baselines and could not recover untill 7th day. But in other groups, the recovery was within 5th day. Nap dura fion was longer in old age group through jet lag than younger age group. In other parameters, there was no definite difference among three age groups. Our results suggested that the old age was significantly influenced by the disharmony between internal body clock and sleep-wake cycle needed at the travel site. Thus we proved that recovery ability from jet lag was age-dependent as well as travelling direction-dependent. To demonstrate more definite evidence, EEG monitoring and staging of sleep were funthun encouraged.

• The Korean Journal of Physiology and Pharmacology
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• v.14 no.5
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• pp.291-297
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• 2010

The sleep homeostatic response significantly affects the state of anesthesia. In addition, sleep recovery may occur during anesthesia, either via a natural sleep-like process to occur or via a direct restorative effect. Little is known about the effects of isoflurane anesthesia on sleep homeostasis. We investigated whether 1) isoflurane anesthesia could provide a sleep-like process, and 2) the depth of anesthesia could differently affect the post-anesthesia sleep response. Nine rats were treated for 2 hours with $ad$ $libitum$ sleep (Control), sleep deprivation (SD), and isoflurane anesthesia with delta-wave- predominant state (ISO-1) or burst suppression pattern-predominant state (ISO-2) with at least a 1-week interval. Electroencephalogram and electromyogram were recorded and sleep-wake architecture was evaluated for 4 hours after each treatment. In the post-treatment period, the duration of transition to slow-wave-sleep decreased but slow wave sleep (SWS) increased in the SD group, but no sleep stages were significantly changed in ISO-1 and ISO-2 groups compared to Control. Different levels of anesthesia did not significantly affect the post-anesthesia sleep responses, but the deep level of anesthesia significantly delayed the latency to sleep compared to Control. The present results indicate that a natural sleep-like process likely occurs during isoflurane anesthesia and that the post-anesthesia sleep response occurs irrespective to the level of anesthesia.

• Korean Journal of Psychosomatic Medicine
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• v.18 no.1
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• pp.30-39
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• 2010

Objectives：Assessment of sleep disturbance is an essential part of the diagnostic criteria used for several psychiatric disorders. Change in sleep patterns over time may indicate response to treatment. In clinical practice, sleep is usually evaluated subjectively by patient self-report. This study was aimed to compare subjective sleep assessment with objective sleep measurement by actigraphy in psychiatric inpatients. Methods：A total of 32 psychiatric inpatients were studied. Patients were asked to wear a wrist actigraphy for three consecutive days and nights and to fill out a sleep log each morning. The severity of depression and anxiety was evaluated according to Beck Depression Inventory and State-Trait Anxiety Inventory on the first day of the study. The subjective level of satisfaction with quality of sleep was also evaluated according to visual analog scale. Nurses assessed sleep at one hour interval between 10:00 PM and 6:00 AM for three consecutive nights. Results：There was statistically significant difference of sleep latency between patient's sleep log and acti-graphic measurement. Nursing reports were more consistent with actigraphic measurement than sleep log. Interestingly, subjectively poor sleepers show no significant difference in sleep parameters compared with those of good sleepers. Subjectively poor sleepers report longer sleep latency than that of actigraphic assessment. The discrepancy between subjective and objective assessment of sleep latency was significantly correlated with scores of Beck Depression Inventory and State-Trait Anxiety Inventory. Conclusion：These results show that there are discrepancies between subjective and objective assessment of sleep. The discrepancy of sleep assessment could be influenced by severe depression and anxiety. Especially objective sleep measurement is needed to assess sleep in psychiatric inpatients with severe depression or anxiety and the subjectively poor sleepers for more reliable measurements.

• Journal of Sasang Constitutional Medicine
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• v.36 no.2
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• pp.27-38
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• 2024

Objectives The purpose of this study was to compare sleep quality and chronotype by Sasang constitution and examine the relationship with nutritional status. Methods This study used 672 follow-up data from the Korean Medicine Daejeon Citizen Cohort study (KDCC). Demographic, Sasang constitution, sleep quality, chronotype, and nutritional status evaluation were conducted based on questionnaires. Multiple linear regression analysis was used to confirm the relationship between sleep quality and chronotype according to Sasang constitution and nutritional status. Results The relationship between sleep quality and chronotype by Sasang constitution and nutritional status is that Taeeum nutritional index is related to sleep quality (adj. B = -0.46, 95% CI = -0.79 ~ -0.12) and chronotype (adj. B = 0.38, 95% CI = 0.24 ~ 0.52), and Soeum and Soyang showed an association between nutritional indices only in chronotype (adj. B = 0.43, 95% CI = 0.23 ~ 0.63 in SE, adj. B = 0.55, 95% CI = 0.38 to 0.73 in SY). Conclusions This study confirmed the relationship between sleep quality and chronotype and healthy eating habits. For a balanced nutritional status, overall sleep management is necessary. Based on the results of this study, we intend to use it as basic data on the impact of the relationship between nutritional status and chronotype by Sasang constitution on health.

• Sleep Medicine and Psychophysiology
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• v.16 no.1
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• pp.5-9
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• 2009

Relatively little is known about the neurobiology of insomnia, despite its wide prevalence and broad medical impact. Although much is still to be learned about the pathophysiology of the disorder, identification, systematic assessment, and appropriate treatment are clearly beneficial to patients. Recent research, using quantitative EEG, polysomnography (PSG), multiple sleep latency test (MSLT) and neuroimaging techniques, suggests that some broad areas can be identified as possible pathophysiological models. Sleep-wake homeostat model hypothesizes a failure in homeostatic regulation of sleep, an attenuated increase in sleep drive with time awake, and/or defective sensing of sleep need. Circadian clock model hypothesizes a dysfunctional circadian clock, resulting in changes in the timing of sleep-wake propensity that are incompatible with normal sleep. Intrinsic sleep-wake state mechanism model suggests that abnormal function of insomnia comprises the systems responsible for expression of the sleep states themselves. Extrinsic over-ride mechanism (stress-response) model suggests that insomnia reflects the consequences of overactivity of one of the systems considered "extrinsic" to normal sleep-wake control. Many current therapies for insomnia are based on these physiological models. Several attempts have been made to create a physiological model that would explain this disorder and could be used as a foundation for treatment. However, it appeared that no model can fully explain and clarify all aspects of insomnia. Future research should be necessary to expand our knowledge on the biological dimensions of insomnia.

• Sleep Medicine and Psychophysiology
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• v.12 no.2
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• pp.87-92
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• 2005

Cytokines are the main regulatory molecules of not only immune system but also sleep system. Research on the role of cytokines on sleep has greatly been expanding since the first report of sleep-promoting effects of interleukin-1, the first cytokine molecule. Interleukin-1 and tumor necrosis factor are most widely studied among various cytokines. Studies over about twenty years demonstrate that most cytokines promote sleep but several cytokines inhibit sleep. Slow wave sleep is the main part that cytokines have effects on. Besides normal sleep physiology, cytokines have more major roles on pathophysiology of various sleep disorders. Obstructive sleep apnea is the representative sleep disorder that shows how deeply cytokines are involved in their pathophysiologic mechanisms of sleep disorders. Though there are many controversial issues on this topic, more mysterious part of normal sleep physiology and sleep disorders will be revealed in near future through thorough studies on sleep and cytokine.

• Sleep Medicine and Psychophysiology
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• v.2 no.2
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• pp.133-137
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• 1995

The author reviews current knowledge about what REM sleep is and where and how it is generated. REM sleep is the state in which our most vivid dreams occur. REM sleep is identified by the simultaneous presence of a desynchronized cortical EEG, an absence of activity in the antigravity muscles(atonia), and periodic bursts of rapid eye movements. Another characteristic phenomena of REM sleep are the highly synchronized hippocampal EEG of theta frequency and the ponto-geniculo-occipital(PGO) spike. All these phenomena can be explained in terms of changes in neuronal activity. Transection studies have determined that the pons is sufficient for generating REM sleep. Lesion studies have identified a small region in the lateral pontine tegmentum corresponding to lateral portions of the nucleus reticularis pontis oralis(RPO) and the region immediately ventral to the locus coeruleus, which is required for REM sleep. Unit recording studies have found a population of cells within this region that is selectively active in REM sleep. Cholinergic neurons of the giant cell field of pontine tegmentum(ETG), which is 'REM a sleep-on cells', has shown to be critically involved in the generation of REM sleep. Noradrenergic neurons of the locus coeruleus and serotonergic neurons of the dorsal raphe, which are called 'REM sleep-off cells', appear to act in a reciprocal manner to the cholinergic neurons. It is proposed that the periodic cessations of discharge of 'REM sleep-off cells' during REM sleep might be significant for the prevention of the desensitization of receptors of these neurons.

• Journal of Society of Preventive Korean Medicine
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• v.26 no.1
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• pp.59-74
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• 2022

Objectives : Evidence supporting the cold-heat symptom and sasang constitution type, which are diagnostic items of traditional Korean medicine, is needed to manage sleep disturbances, which is a typical symptom of mibyeong (subhealth). This study examined the association between each cold-heat symptom and sleep disturbances according to each sasang constitution type. Methods : This research was a cross-sectional study of 5,793 subjects from the Korean Medicine Data Center (KDC) community cohort survey. The association between each cold-heat symptom and sleep disturbances was analyzed by logistic regression analysis adjusted for several demographic variables. Subgroup analysis was then performed for each type of sasang constitution. Results : The soeum and soyang types were 1.53 and 1.26 times more likely to have sleep disturbances than the taeum type. Sleep disturbances were associated with 'coldness of the abdomen', 'watery mouth' in the cold domain items, and 'body feverishness', 'flushed face and eye', 'thirst', and 'scanty dark urine' in the heat domain items. The soeum and soyang types were 1.55 and 1.39 times more likely to sleep less than five hours per night than the taeeum type. In addition, the associations of those showed a different pattern for each sasang constitution type. Conclusions : Sleep disturbances are associated with specific cold-heat symptoms, and the associated cold-heat symptoms differ according to the sasang constitution type. These results may help traditional medicine specialists select customized interventions for patients with sleep disturbances.

• Journal of Trauma and Injury
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• v.35 no.3
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• pp.202-208
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• 2022

Purpose: There is limited research on the effects of neuropathic pain (NP) on quality of life, depression levels, and sleep quality in patients with combat-related extremity injuries. This study evaluated whether patients with combat-related extremity injuries with and without NP had differences in quality of life, sleep quality, and depression levels. Methods: A total of 98 patients with combat-related extremity injuries, 52 with NP and 46 without, were included in this cross-sectional study. The presence of NP was determined using the Leeds Assessment of Neuropathic Symptoms and Signs questionnaire. The outcome measures were a visual analogue scale (VAS), the 36-Item Short Form Survey, the Beck Depression Inventory, and the Pittsburgh Sleep Quality Index (PSQI). Results: The VAS subparameter scores for pain (all P<0.05), PSQI sleep dur ation subscale scores (P=0.025), PSQI sleep disturbance subscale scores (P=0.016), and PSQI total scores (P=0.020) were significantly higher in patients with NP than those without. Logistic regression analysis showed that VAS scores of 5 and above for average pain during the previous 4 weeks contributed independently to the prediction of NP. Conclusions: Patients with combat-related extremity injuries with NP had more pain and poorer sleep quality than those without NP. Sleep quality should be evaluated as part of the diagnostic work-up in patients with combat-related extremity injury with NP, and interventions to improve sleep quality may help manage NP in this patient group.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.20 no.3
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• pp.146-151
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• 2009

Objectives : We conducted this study to investigate the relationship between sleep duration and body mass index (BMI), in Korean children. Methods : We performed a cross-sectional analysis of data collected on 3,639 boys and girls (aged 7-12) in Daegu, Korea. The data included each child's age, sex, weight, height, extracurricular activities, bedtime, wake-up time, sleep latency, total sleep duration, parents' occupations, and parents' educational levels. The relationship between sleep duration and each variable was examined via analysis of variance (ANOVA). Results : The analysis showed an association between short sleep duration and high BMI. Boys showed a graded inverse relationship between sleep duration and BMI. However, there was no significant corresponding result for girls. In the total sample, hours of computer use, time when the computer was turned off, time when the television was turned off, mother's bedtime, and hours of extracurricular activity were associated with longer sleep duration. No association was found between sleep duration and hours of watching television, child's wake-up time, or educational level of the parents. Conclusion : The results of this study show an inverse relationship between a child's sleep duration and BMI；thus, children with shorter sleep duration tend to have higher BMIs.