• The Journal of the Korea Contents Association
• /
• v.15 no.12
• /
• pp.314-325
• /
• 2015

This study examines the impact of sleep duration on Korean adolescents' suicidal impulse. A gender-based analysis was conducted using binary logistic regression method. The major findings are as follows. First, weekday sleep duration had a significant effect only on male adolescents. Male adolescents who sleep less than seven hours on a weekday are likely to experience suicidal impulse by 1.9 times higher than the others. This effect remained significant even when other relevant variables were controlled. On the other hand, female adolescents who have less than seven hours of sleep on a weekday have about 1.3 times higher chances to experience suicidal impulse. However, this effect became insignificant when other variables such as stress were controlled. Meanwhile, weekend sleep duration did not have any significant effect on both male and female adolescents. By demonstrating the different effects between weekday/weekend sleep duration and male/female adolescents, this study supports the claim that it is necessary to take a social approach in studying sleep duration.

• Journal of Nutrition and Health
• /
• v.55 no.6
• /
• pp.656-669
• /
• 2022

Purpose: This study investigates the relationship between sleep duration, sleep quality, time use, and dietary quality of adolescents. Methods: A cross-sectional study was conducted, enrolling 423 high school students (112 male and 311 female students) in Chungnam using a questionnaire comprising general characteristics, sleep status, use of time, and Nutrition Quotient for Korean Adolescents (NQ-A). Results: On weekdays, male students reported getting 6.6 hours of sleep, which was significantly higher than the 5.8 hours reported by female students. The sleep quality score between male and female students was not significantly different on weekdays and weekends. Comparing the students categorized as getting 6 hours of sleep duration on weekdays and 8 hours on weekends, a significantly higher total NQ-A score was obtained for the long sleep duration group of female students on weekdays. In male students who reported increased screen time on weekdays and study time on weekends, there was a greater frequency of short sleep duration. Our data also revealed that the longer the sleep duration higher the NQ-A score. In addition, higher NQ-A scores were determined with shorter screen time and more prolonged exercise time. Conclusion: Our results suggest that intense study time and excessive use of smartphones have a negative effect on sleep in high school students. In addition, poor sleep quality and lack of sleep are likely to affect eating habits and nutritional status. Therefore, there is a need to provide nutritional education to adolescents imparting knowledge that associates desirable sleep habits and the correct use of time.

• Sleep Medicine and Psychophysiology
• /
• v.26 no.1
• /
• pp.16-22
• /
• 2019

Objectives: The objective of this study was to investigate the correlation between insufficient sleep and visuospatial memory in adolescents using a computerized neurocognitive function test. Methods: A total of 103 high school students (26 males and 77 females; mean age $17.11{\pm}8.50years$) without a serious psychiatric problem was recruited. All subjects were requested to complete a self-report questionnaire about weekday total sleep time and weekend total sleep time. The epworth sleepiness scale (ESS) and the beck depression inventory (BDI) were administered to measure daytime sleepiness and symptoms of depression. Seven subsets of the Cambridge Neuropsychological test automated battery were examined to assess visuospatial memory. Results: After controlling for age, sex, ESS, and BDI, longer weekend total sleep time was correlated with poor performance on delayed matching to sample (r = -0.312, p = 0.002) and immediate recall on pattern recognition memory (r = -0.225, p = 0.025). Increased weekend catch-up sleep time was correlated with poor performance of delayed matching to sample (r = -0.236, p = 0.018), immediate recall on pattern recognition memory (r = -0.220, p = 0.029), and delayed recall on pattern recognition memory (r = -0.211, p = 0.036) after controlling for age, sex, ESS, and BDI. Conclusion: This study showed that increased weekend catch-up sleep time reflecting insufficient weekday sleep were associated with poor performance in delayed recall tasks of visual memory. This finding suggests that insufficient sleep during adolescence might produce a decline of visuospatial memory.

• Sleep Medicine and Psychophysiology
• /
• v.20 no.2
• /
• pp.69-74
• /
• 2013

Introduction: Although it is well known that medical students are not getting an adequate amount of sleep, there have been only a few studies on the sleep patterns of medical students and the related factors. Therefore, the present study aimed to investigate the medical students' sleep patterns and the related factors. Methods: A questionnaire package was administered to the $1^{st}$ to $4^{th}$ year medical students at one medical school. It consisted of questions asking about their lifestyles as well as Pittsburgh sleep quality index (PSQI), Epworth sleepiness scale (ESS), global assessment of recent stress scale (GASS), the center for epidemiologic studies-depression scale (CES-D), and Moudsley obsessive-compulsive inventory (MOCI). A total of 352 students (206 males and 146 females) responded to the survey and the result was analyzed using the independent t-test, the chi-square test, the paired t-test, Pearson's correlation and ANOVA. p-values of less than 0.05 were considered statistically significant in analyses. Results: The weekend bedtime was significantly delayed (0 : 49 on weekday ; 1 : 34 on weekend ; t=-5.23, p<0.001), the weekend rise time was delayed (6 : 58 on weekday ; 9 : 30 on weekend ; t=-24.48, p<0.001) and the total sleep time was increased on weekends (5 : 36 on weekday ; 7 : 39 on weekend ; t=15.94, p<0.001). The PSQI score of all subjects was 6.43{\pm}2.64. PSQI was positively correlated with ESS (r=0.383, p<0.001), GASS (r=0.326, p<0.001), CES-D (r=0.393, p< 0.001), and MOCI (r=0.247, p<0.001), but not with GPA (r=0.072, p=0.228. The more senior students had lower PSQI, GASS, CES-D, and MOCI score (p<0.05). Conclusion: Medical students were experiencing a lack of sleep during weekdays as they have a later bedtime and earlier rise time, and consequently had more hours of sleep on weekends. Overall, the medical students were experiencing poor sleep quality and sleep deprivation. Poor sleep quality is associated with psychological problems (daytime sleepiness, stress, depression, and obsessive tendency).

• Sleep Medicine and Psychophysiology
• /
• v.7 no.1
• /
• pp.51-59
• /
• 2000

Objectives: It is been reported that sleep patterns change significantly during the adolescent years. In Korea, the sleep patterns of adolescents have not been investigated systematically. The authors performed preliminary study about sleep patterns of middle and high school students in Seoul before nationwide study. Methods: The authors selected one of middle and high schools located in typical middle class area in Seoul. The study was performed during the periods when examination or vacation did not affect the sleep cycle. Fifty to one hundred male and female students were selected from one school year each. One of investigators explained the purposes and methods of this study to the students and gave additional explanation to the teachers in charge. We designed a questionnaire for subjects to describe the nap time, bedtime, sleep latency, total sleep time, rise time and sleep efficiency, and the students recorded sleep logs for seven days including weekend. Eight hundred three students answered the questionnaires. Among them, we selected the subjects who recorded sleep logs at least three days and filled up the questionnaires completely. Finally, seven hundred seventy one subjects were included in this study. Weekend was defined as the time from Saturday morning to Sunday morning, and Sunday sleep patterns were treated separately. Results: Across the six school years, school-night bedtimes were delayed one hundred twenty four minutes and school-ight rise times were advanced by thirty five minutes. School-night total sleep times were decreased by one hundred fifty eight minutes, and weekend bedtimes were delayed by one hundred twenty five minutes. The students tended to oversleep on weekends, and the mean of weekend oversleep was ninety six minutes. But, bedtime in weekends was not delayed. Daytime sleep, sleep latency and sleep efficiency were not changed greatly across six school years. Total sleep time of female students was decreased significantly between third middle school year and first high school year, but time of male students was decreased between first and second high school year. Conclusion: It is supposed that sleep deficiency of middle and high school students in Seoul was due to delayed bedtimes and advanced rise times across the school years.

• Journal of Digital Convergence
• /
• v.17 no.12
• /
• pp.435-444
• /
• 2019

The purpose of this study was to investigate the relationship between sleep duration and muscle strength in Korean adults aged 19 years and older. The cross-sectional analysis was conducted using the 2016 National Health and Nutrition Examination Survey data and Chi square test and multiple regression analysis were used. As a result of the analysis, the grip strength of those with more than weekday average sleep duration of 9 hours was found to be -1.267kg compared with those with weekday average sleep duration of 7 hours. The grip strength of those with more than weekend average sleep duration of 9 hours was found to be -0.879kg compared with those with weekend average sleep duration of 7 hours. In model simultaneously adjusting for both the average weekday and weekend average sleep duration, weekday average sleep duration of 9 hours was found to be -1.034kg compared with those with weekday average sleep duration of 7 hours. Therefore, careful observation will be required in light of the fact that both sleep duration and grip strength can predict future health conditions.

• Journal of Digital Convergence
• /
• v.18 no.4
• /
• pp.263-272
• /
• 2020

The purpose of this study was to identify the relationships between sleep time and depression and suicidal ideation in middle aged women. The subjects of this study were 1,617 women aged 40-64 years who participated in the Seventh Korea National Health and Nutrition Examination Survey (KNHANES VII-2), 2017. Data were downloaded from the KNHANES website and were analysed through complex sampling design data analysis using IBM SPSS 21.0 program. Suicidal ideation is 3.65 times higher in women who sleeps for five hours or less in weekend than in women who sleeps more than seven hours and less than nine hours in weekend. These result indicate that suicide prevention program for middle aged women should include strategies for maintaining proper sleep times and women who sleeps for five hours or less should be considered as a priority intervention case. In additions, further studies on the relationship between sleep times and depression of middle aged women should be conducted.

• Sleep Medicine and Psychophysiology
• /
• v.22 no.2
• /
• pp.64-69
• /
• 2015

Objectives: We investigated whether sleep behaviors, severity of insomnia and circadian typology are associated with quality of life among Gyeongsang National University (GNU) medical students. Methods: Questionnaires were distributed to 46 fourth-year students of GNU Medical School. The hospital anxiety-depression scale, insomnia severity index (ISI), morningness-eveningness questionnaire (MEQ) and WHO Quality of Life-BREF (WHOQOL-BREF) were used. Results: Quality of life in terms of physical health was associated with age, weekday total sleep time (TST), weekend TST, catch up sleep, depression, ISI score, and MEQ score. Quality of life in terms of psychological health was correlated to weekday and weekend TST, anxiety, ISI score and MEQ score. Sex, weekday TST, depression, and ISI score were revealed to influence the social aspect of quality of life, and weekday and weekend TST, and ISI score were associated with quality of life in terms of environment. Multiple regression analysis showed that better sleep quality predicted to a higher quality of life in terms of physical, psychological and environmental health, and eveningness was associated with a better quality of life in terms of physical and psychological health. Conclusion: It is concluded that physical, psychological, and environmental aspects of quality of life were associated with quality of sleep and that physical and psychological aspects of quality of life were related to eveningness in GNU medical students. Therefore, it is equally important to treat emotional problem as well as improve sleep quality.

• The Journal of Korean society of community based occupational therapy
• /
• v.4 no.1
• /
• pp.11-21
• /
• 2014

Objective : This study was aimed to survey the correlation between time usage and hope in 20s and 30s the disabled. Methods : From November to December 2012, 52 the disabled who have therapy in rehabilitation hospital in Busan and Gyeongnam, being diagnosed with spinal cord injury and stroke, were chosen. Semi-structured interview was carried out using a questionnaire involved time usage and hope. Results : The followings are the results of this study. First, the participants spent most time sleeping (10:47) and using media (3:41) on weekends. In additions, they spent most time sleeping (9:43) and health management (5:12) on weekdays. Second, doing household chores were positive correlation (.688) between time usage and hope (p<.05). However, no significant differences in time usage and hope. Conclusion : The results of this study would contribute to propose various activities for 20s and 30s the disabled.

• Sleep Medicine and Psychophysiology
• /
• v.10 no.2
• /
• pp.93-99
• /
• 2003

Objectives：Sleep loss and excessive daytime sleepiness may have serious consequences, including traffic and industrial accidents, decreased productivity, learning disabilities and interpersonal problems. Yet despite these adverse effects, there are few epidemiological studies on sleep loss and daytime sleepiness in the general population of Korea. This study investigates the number of people who suffer from sleep insufficiency, how much recovery sleep occurs on weekends, and the relationship between the amount of recovery sleep and daytime sleepiness. Methods：A total 164 volunteers, aged 20 and over, were recruited by advertisement. The subjects were workers and college students living in Seoul, Korea. Subjects were excluded if they were aged over 60；if they had medical, neurological, psychiatric or sleep disorders that could cause insomnia or daytime sleepiness；if they were not following a regular sleep schedule；if they traveled abroad during the study；or if they did not leave home to work or were shift workers. They were interviewed and given a sleep log to complete on each of 14 consecutive mornings. They also completed the Epworth Sleepiness Scale (ESS) at noontime on the last day of the second week. All statistical data were analyzed by t-test, $X^2$-test or ANOVA, using SPSS/PC+. Results：The results showed that the subjects woke up at 6：50 (${\pm}1$：16) on weekdays, 7：09 (${\pm}1$：29) on Saturdays, and 8：12 (${\pm}1$：39) on Sundays and holidays. They took more frequent and longer naps on Sundays than on weekdays and Saturdays. The mean sleep duration was 6h 35 min. on week nights, with a mean increase of about 1h on weekends. Only 9.1% of the subjects spent more than 8h in bed on week nights, with 67% spending less than 7h, and 49.4% reported recovery sleep of more than 1h on Sundays. The subjects who reported recovery sleep of more than 2h on Sundays, showed significantly more excessive daytime sleepiness than those who reported less than 30 min (F=2.62, p<.05). Conclusions：These findings suggest that sleep insufficiency and excessive daytime sleepiness are relatively common in Korea, and that the people who get insufficient sleep on weekdays try to compensate for sleep loss with oversleeping and daytime napping on Sundays and holidays. It appeared that daily sleep insufficiency had a cumulative effect and increased daytime sleepiness.