• 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.

• Korean Journal of Clinical Laboratory Science
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• v.39 no.3
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• pp.264-270
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• 2007

Obstructive sleep apnea syndrome (OSAS) is defined by sleep apnea with decreased oxygen saturation, excessive snoring with daytime sleepiness, and frequent awakening during the night time sleep. The present study was performed to investigate how apnea-hypopnea, that possibly causes breathing disturbance during sleep, can affect sleep pattern in patients with OSAS. We included 115 patients (92 men, 23 women) who underwent a polysomnography from January 2006 to May 2007. As the frequency of sleep apnea-hypopnea increases, the proportion of non-rapid eye movement (REM) sleep (p<0.001), and stage I sleep (p<0.001) increased, while that of stage II sleep (p<0.001), stage III and IV sleep (p<0.01), and REM sleep (p<0.05) decreased. Furthermore, sleep apnea-hypopnea was closely correlated with REM sleep (r=0.314, p<0.001), stage I sleep (r=0.719, p<0.001), stage II sleep (p=-0.342, p<0.05), stage III and IV sleep (r=-0.414, p<0.001), and REM sleep (r=-0.342, p<0.05). Stage I sleep could account for the 51% of the variance of apnea-hyponea. Our study shows sleep apnea-hypopnea affects sleep pattern in pattern with OSAS significantly, and the change of stage I sleep is the most important factor in estimating the disturbance of sleep pattern.

• Sleep Medicine and Psychophysiology
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• v.2 no.2
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• pp.146-155
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• 1995

Jet lag can be defined as the cumulative physiological and psychological effects of rapid air travel across multiple time zone. The consequences of jet lag include fatigue, general malaise, sleep disturbances, and reductions of cognitive and psychomotor performance, all of which have been documented in experimental biological and air crew personnel studies. Thus authors tried to study the jet lag of natural travellers by modified self reporting sleep log. Total 61 healthy travellers was studied for 3 days before and 7 days after jet-flights across seven to ten time zone. The eastbound travelling group was 38 persons, aged 19 -70 and westbound travelling group was 23 persons, aged 13 - 69. 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 suggested that the 7 to 10 time zone shift gave significant influence to traveller's sleep-wake cycles. The date which subjective physical condition was recovered on was $5.16{\pm}1.50$ day after arrivals for eastbound, while for westbound, $4.91{\pm}1.62$ day. In eastbound travelling, sleep onset time became later than baselines and could not recover until 7th day. But in westbound, it became earlier than baseline and could recover until 6th day. The mean score of 24-hour sleepiness was greater in eastboumd than westbound. Therefore the eastbound travelling caused more sleep-wake cycle disturbance and daytime dysfunction than westbound travelling. In other parameters, there was no definite difference between east and westbound. From our results, it was suggested that the symptom severity of jet lag was dependent on the travelling direction. To demonstrate more definite evidence, large sized data collections and comparision by age difference were needed.

• Sleep Medicine and Psychophysiology
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• v.10 no.2
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• pp.77-83
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• 2003

Industrialization has brought great changes in human life. Human sleep patterns have also been much influenced by industrialization and the invention of electricity and the light bulb. Insufficient sleep is a common problem with considerable health, social, and economical impacts on modern society. In this review, we will outline the present state of insufficient sleep in our society, especially catastrophic accidents related with chronic sleep insufficiency. We will discuss the effect of sleep deprivation on human performance by reviewing the literature. We will also emphasize the role of sleep specialists in this issue and highlight the areas in which the principles of sleep medicine can constructively improve public policy and public health.

• Journal of Yeungnam Medical Science
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• v.38 no.4
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• pp.282-288
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• 2021

Medication alone is not sufficient to treat insomnia. In addition, the side effects of sleep medications themselves cannot be ignored during treatment. Insomnia begins with poor sleep quality and discomfort, but as it continues, patients fall into a vicious circle of insomnia with negative thoughts and dysfunctional and distorted perceptions related to sleep. Mindfulness-based intervention for insomnia corrects these sequential cognitive and behavioral processes. The mindfulness technique basically recognizes all the thoughts, feelings, and experiences that occur to us as they are, nonjudgmentally, and then trains them to return to the senses of our body. In this way, while noticing all the processes of the sequential vicious cycle and training them to return to our bodies (e.g., breathing), mindfulness determines whether we are really sleepy or just fatigued. This mindfulness-based intervention can be a useful nonpharmaceutical intervention for insomnia, and its stability and efficacy has been proven by many studies.

• Perspectives in Nursing Science
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• v.2 no.1
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• pp.37-47
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• 2005

Biobehavioral nursing research is focused on generating knowledge that examines relations among biological, behavioral, and social dimensions of health to improve outcomes. In this paper we review the findings of a biobehavioral nursing study of individuals with fibromyalgia (FM) that was framed from the perspective of an individual human response model, the FM literature, and our previous studies in midlife women. We were particularly interested in the studying the role of 'arousal' secondary to pain or to dysregulated hypothalamic-pituitary-adrenal (HPA) axis hormones during sleep and the impact on symptom expression. Unexpectedly, we did not find evidence of, arousal' or abnormal amounts of HPA axis hormones but we did find reduced amounts of growth hormone (GH) and prolactin (PRL) and of sleep spindle activity, a biomarker of sleep maintenance. We discuss these new findings and how our thinking was re-shaped to better understand the role that disturbed sleep plays in symptom expression in FM. It is argued that disturbed sleep maintenance mechanisms coupled with dysregulated somatotrophic-growth hormone axis and sleep-related PRL render individuals vulnerable to the development of or exacerbations of FM symptoms.

• Journal of the Korea Society of Computer and Information
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• v.22 no.11
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• pp.17-23
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• 2017

In this paper, we implemented a respiration measurement system consisting of piezoelectric sensor, respiration signal processing device, and a viewer on a notebook. We tried an experiment for measuring respiration and detecting sleep apnea syndrome when a subject lay on a bed. We applied the respiration measurement algorithm to sensor data obtained from four subjects. In order to get a good graph shape, data manipulation methods such as moving averages and maximum values were applied. The window size for moving average was chosen as N=70, and the threshold value for each subject was customized. In this case, the proposed system showed 96.0% accuracy. When the maximum value among 90 data was applied instead of moving average, our system achieved 95.1% accuracy. In an experiment for detecting sleep apnea syndrome, the system showed that sleep apnea occurred correctly and calculated the average interval of sleep apnea. While infants or the elderly as well as patients with sleep apnea syndrome are lying down on a bed, our results are also expected to be able to cope with some accidental emergency situation by observing their respiration and detecting sleep apnea.

• 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.

• 한국노년학
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• v.36 no.3
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• pp.633-648
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• 2016

This study focuses on the sleep pattern of the elderly people living in the community and its relationship to the occurrences of the depression and deterioration of the cognitive function. Our primary data is the raw data gathered by the Korean Ministry of Health and Welfare in 2008 in the National Senior Living Conditions and Well-being Needs Assessment Survey. The survey contained data from 12,087 people over 65 years of age living in the community. We have used the secondary data analysis method on this raw data to see if there exists correlation between age, gender, soundness of the sleep, total sleep time and the depression and the cognitive difficulties. Our study finds that the older a person is, the more trouble she has in sleeping. It also shows that too much sleep (in excess of 9 hours) and too little sleep (less than 6 hours) can both be linked to more occurrence of depression. Lack of restful sleep could also be linked to more frequent occurrence of depression and cognitive difficulties. Changes in the sleep pattern is not always pathological in elderly people. However, our study shows that it is important the primary health-care givers understand the role of sleep in elderly person's daily life. They should examine the elderly person's sleep pattern focusing on the quantity and the quality of sleep and develop programs suited for individuals to prevent and intervene sleep disorder.

• Journal of the Korean Society of Food Culture
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• v.28 no.5
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• pp.539-546
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• 2013

The aim of this study was to investigate the effect of sleep duration on dietary habits and body composition of university students. Sleep duration has recently been added to the list of risk factors for obesity. However, studies on this topic are fairly limited particularly in Korea. We studied the relationship between the duration of sleep and obesity principally based on body mass index and %body fat in university students. For this purpose, a survey was conducted on a total of 312 university students. The subjects enrolled for this study were divided into two groups: (1) those with sleep duration of <7 hours (148 students) and (2) those with sleep duration of >7 hours (164 students). Based on a self-reporting method, the participants filled up the questionnaires for more than 20 minutes. Based on the overall data obtained, we observed that most students (52.88%) skipped breakfast. This was mainly due to shortage of time (60.58%). We also observed that self-reporting dietary preferences included eating irregular meals (49.04%), overeating (19.55%), imbalanced diet (16.35%), and skipping meals (9.94%). It was found that cookies were the favorite snacks in the majority of the participants (50%). Our data reveal that the body mass index, fat mass, visceral fat, and subcutaneous fat, respectively of the shorter sleep duration group (<7 h/day) were 23.78 $kg/m^2$, 19.13 kg, 2.23 kg, and 11.15 kg. In contrast, in those of the control group (7 h/day), these values were found to be 21.84 $kg/m^2$, 13.88 kg, 1.56 kg, and 12.11 kg. We also observed that there were significant correlations of sleep duration with body mass index (p<0.05), fat mass (p<0.01), visceral fat (p<0.01), and beck depression score (p<0.01). Our data suggest that the body mass index in the shorter sleep duration group was higher than that of the control group; however, %fat, visceral fat, and subcutaneous fat in the shorter sleep duration group were found to be higher than those of the control group. The data obtained through our study suggest that short sleep duration is clearly associated with a modest increase in general and abdominal obesity particularly in university students.