• Journal of Korean Biological Nursing Science
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• v.18 no.4
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• pp.203-212
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• 2016

Purpose: The purpose of this study was to identify the sleep patterns of nursing students using self-report questionnaire and physiologic measurement, to examine the factors influencing sleep patterns in based on Spielman's model. Methods: Participants were 119 nursing students who were in the clinical practice period. Self-report questionnaires and actigraphy were used to collect the data. Data were analyzed using descriptive statistics, correlation and regression by the SPSS/WIN 21.0 programs. Results: When sleep was measured by self-report questionnaire, 84 students (70.6%) showed poor sleep quality. The mean sleep efficiency was 82.6%, and 67 students(56.3%) showed low sleep efficiency (less than 85.0%). The factors affecting subjective sleep pattern measured by KMLSEQ were circadian sleep type (${\beta}=.28$, ${\rho}=.003$) and alcohol (${\beta}=.20$, ${\rho}=.031$). The factors affecting total sleep time were sedentary behavior (${\beta}=-.27$, ${\rho}=.003$) and daytime sleepiness (${\beta}=-.33$, ${\rho}$<.001). Conclusion: Many nursing students in their clinical practice period expressed sleep disturbance. Factors affecting the perceived sleep measured by the self-report questionnaire and objective sleep evaluated by physiologic measures were different. The evening type of students perceived poor sleep quality, however, sedentary life style and daytime sleepiness resulted in short sleep time. Therefore, more studies measuring the objective sleep characteristics are needed using subjective and objective characteristics.

• Annals of Occupational and Environmental Medicine
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• v.35
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• pp.30.1-30.13
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• 2023

Background: Dysmenorrhea and menstrual cycle changes occur in women working shifts. Circadian rhythm disruption and sleep disturbances associated with shift work leads to health problems. We identified chronotypes and the occurrence of insomnia among newly employed university hospital nurses and investigated the association of these factors with menstrual problems. Methods: We conducted pre-placement health examinations for shift workers using self-reported questionnaires between 2018 and 2020. A total of 463 nurses were included in the study. Sociodemographic data, shift work experience, and information on insomnia were collected from health examination data. In addition, details regarding chronotype, dysmenorrhea, irregular and abnormal menstrual cycles, amenorrhea, and contraceptive use were obtained from the questionnaire. Multiple logistic regression analysis was performed to study the association between chronotype, insomnia, and menstrual problems after controlling for age, body mass index, contraceptive use, amenorrhea, and prior shift work. Results: The prevalence rates of dysmenorrhea, irregular menstrual cycles, and longer menstrual cycles were 23.8%, 14.9%, and 4.1%, respectively. The risk of dysmenorrhea increased in the evening-type (odds ratio [OR]: 3.209; 95% confidence interval [CI]: 1.685-6.113) and those with insomnia (OR: 1.871; 95% CI: 1.074-3.261). Additionally, the risk of an irregular menstrual cycle (OR: 2.698; 95% CI: 1.167-6.237) increased in the evening-type, and the risk of a longer menstrual cycle (OR: 4.008; 95% CI: 1.354-11.864) increased in individuals with insomnia. Conclusions: Our findings suggest that dysmenorrhea is promoted in the evening-type and insomnia individuals. There may be an increased risk of irregular menstrual cycles among evening-type nurses and an increased risk of longer menstrual cycles among those with insomnia. Therefore, factors such as evening-type and insomnia should be considered for the prevention of menstrual problems in women performing shift work.

• Journal of Digital Convergence
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• v.16 no.9
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• pp.187-195
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• 2018

The purpose of this study is to measure quality of sleep (PSQI) and to investigate the affecting factors according to sex in college students. The participants in this study were 214 students from 4 universities. The data were analyzed by t-test, chi-square test and multiple regression using SPSS/WIN 24.0 program. The mean score of quality of sleep was 2.83, for male students are 2.70 and female students 3.06. In multiple regression analysis, physical stress, psychological stress and exercise were significant predictors and explained 25.4% of quality of sleep for male students. In female students, physical stress, psychological stress and drinking were significant predictors and explained 39.2% of quality of sleep. It is necessary to develop and apply education and counseling that can solve factors affecting the quality of sleep of college students.

• Sleep Medicine and Psychophysiology
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• v.26 no.2
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• pp.67-74
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• 2019

Anger is a multi-dimensional concept ranging from feeling irritable to violent aggression. A growing body of literature suggests the relevance of sleep in regard to anger. The current study aims to review previous studies on the association between anger and diverse aspects of sleep including sleep disruption, chronotype, sleep disorders and sleep deprivation. An association between sleep and anger has been observed starting in the early stage of life, with sleep of infants or toddlers affecting emotional and behavioral aspects of anger. However, the association between anger and sleep is not clear in adolescents and might be due to the effects of psychosocial factors on both sleep and anger during adolescence. Subjective but not objective sleep disturbances of adults have been also associated with anger. Evening types showed more anger, which might be mediated by psychological characteristics or social jet lag of evening people. Increased anger has also been found in those with insomnia, sleep apnea, or experimental sleep-deprivation. Previous studies have reported that diverse sleep disturbances are related to anger. Future study assessing the various sleep or circadian indices and considering the multidimensional aspects of anger are needed.

• BMB Reports
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• v.48 no.4
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• pp.209-216
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• 2015

Stress is now recognized as a universal premorbid factor associated with many risk factors of various chronic diseases. Acute stress may induce an individual's adaptive response to environmental demands. However, chronic, excessive stress causes cumulative negative impacts on health outcomes through "allostatic load". Thus, monitoring the quantified levels of long-term stress mediators would provide a timely opportunity for prevention or earlier intervention of stressrelated chronic illnesses. Although either acute or chronic stress could be quantified through measurement of changes in physiological parameters such as heart rate, blood pressure, and levels of various metabolic hormones, it is still elusive to interpret whether the changes in circulating levels of stress mediators such as cortisol can reflect the acute, chronic, or diurnal variations. Both serum and salivary cortisol levels reveal acute changes at a single point in time, but the overall long-term systemic cortisol exposure is difficult to evaluate due to circadian variations and its protein-binding capacity. Scalp hair has a fairy predictable growth rate of approximately 1 cm/month, and the most 1 cm segment approximates the last month's cortisol production as the mean value. The analysis of cortisol in hair is a highly promising technique for the retrospective assessment of chronic stress. [BMB Reports 2015; 48(4): 209-216]

• Sleep Medicine and Psychophysiology
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• v.8 no.1
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• pp.5-10
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• 2001

The prevalence of insomnia and the degree of impairment due to insomnia is greater than in the of young. The cause for insomnia in the elderly are various factors among the elderly is known to be high including medical, psychiatric, drug issues, circadian rhythm changes, sleep disorders, and psychosocial. So the careful evaluation to find the cause of insomnia is needed for the eldery. Treatment options for insomnia include behavior modification and pharmacotherapy. Outcome data from previous studies indicate that behavioral approaches produce reliable and durable therapeutic benefits, as evidenced by improved sleep efficiency and continuity and enhanced satisfaction with sleep patterns. Treatment methods such as stimulus control and sleep restriction, which target maladaptive sleep habits, are especially beneficial for older insomniacs, whereas relaxation-based interventions aimed at decreasing arousal, produce more limited effects. Cognitive and educational interventions are instrumental in altering age-related dysfunctional beliefs and attitudes about sleep. The choice of hypnotics is based on matching the nature of the insomnia to the hypnotic agent. The ideal agent has rapid onset, duration of action that lasts through the night but no residual daytime effects, and no adverse effects. The key for the healthcare professional is finding the appropriate treatment or treatment combination, including behavioral modification and pharmacotherapy. When hypnotics are indicated, the most appropriate short-acting agent should be considered.

• Sleep Medicine and Psychophysiology
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• v.9 no.2
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• pp.81-85
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• 2002

There are several factors which are more likely to have sleep disorders in fertile women with menstruation than adult men. Menstrual cycle plays an important role in them. We describe herein the overview about the association of menstrual cycle and sleep disorders by viewing the interactions of menstrual cycle and circadian rhythm. We review how menstrual cycle affects sleep-wake cycle by reviewing menstrual cycle and estrous cycle to understand these interactions. Menstrual cycle and estrous cycle are mainly affected by hormonal cycle and light-dark cycle, respectively and they are generally determined in monthly rhythm and annual rhythm, respectively. The determination of estrous cycle is also affected by cyclic changes of hormones besides light-dark cycle. Although sleep-wake cycle almost alternates according to estrous cycle in non-primate mammals, it is hardly affected by menstrual cycle in primate mammals as compared with estrous cycle. But menstrual cycle affects sleep-wake cycle via desynchronization of sleep-wake cycle and temperature rhythm. The decrease of amplitude and phasic change during luteal phase in the daily fluctuation of body core temperature can partially contribute to the induction of sleep disorders in fertile women. In addition to this, premenstrual syndrome which nearly happens during luteal phase commonly have sleep problems. Therefore, we suggest that menstrual cycle and PMS can partially contribute the increase of sleep disorders in fertile women.

• The Korean Journal of Nuclear Medicine
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• v.33 no.4
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• pp.341-351
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• 1999

Biochemical markers of bone turnover has received increasing attention over the past few years, because of the need for sensitive and specific tool in the clinical investigation of osteoporosis. Bone markers should be unique to bone, reflect changes of bone loss, and should be correlated with radiocalcium kinetics, histomorphometry, or changes in bone mass. The markers also should be useful in monitoring treatment efficacy. Although no bone marker has been established to meet all these criteria, currently osteocalcin and pyridinium crosslinks are the most efficient markers to assess the level of bone turnover in the menopausal and senile osteoporosis. Recently, N-terminal telopeptide (NTX), C-terminal telopeptide (CTX) and bone specific alkaline phosphatase are considered as new valid markers of bone turnover. Recent data suggest that CTX and free deoxypyridinoline could predict the subsequent risk of hiP fracture of elderly women. Treatment of postmenopausal women with estrogen, calcitonin and bisphosphonates demonstrated rapid decrease of the levels of bone markers that correlated with the long-term increase of bone mass. Factors such as circadian rhythms, diet, age, sex, bone mass and renal function affect the results of biochemical markers and should be appropriately adjusted whenever possible. Each biochemical markers of bone turnover may have its own specific advantages and limitations. Recent advances in research will provide more sensitive and specific assays.

• Genomics & Informatics
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• v.18 no.4
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• pp.38.1-38.9
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• 2020

Chronotype is an important moderator of psychiatric illnesses, which seems to be controlled in some part by genetic factors. Clock genes are the most relevant genes for chronotype. In addition to the roles of individual genes, gene-gene interactions of clock genes substantially contribute to chronotype. We investigated genetic associations and gene-gene interactions of the clock genes BHLHB2, CLOCK, CSNK1E, NR1D1, PER1, PER2, PER3, and TIMELESS for chronotype in 1,293 healthy Korean individuals. Regression analysis was conducted to find associations between single nucleotide polymorphism (SNP) and chronotype. For gene-gene interaction analyses, the quantitative multifactor dimensionality reduction (QMDR) method, a nonparametric model-free method for quantitative phenotypes, were performed. No individual SNP or haplotype showed a significant association with chronotype by both regression analysis and single-locus model of QMDR. QMDR analysis identified NR1D1 rs2314339 and TIMELESS rs4630333 as the best SNP pairs among two-locus interaction models associated with chronotype (cross-validation consistency [CVC] = 8/10, p = 0.041). For the three-locus interaction model, the SNP combination of NR1D1 rs2314339, TIMELESS rs4630333, and PER3 rs228669 showed the best results (CVC = 4/10, p < 0.001). However, because the mean differences between genotype combinations were minor, the clinical roles of clock gene interactions are unlikely to be critical.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.6
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• pp.415-425
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• 2022

Memory formation in the hippocampus is formed and maintained by circadian clock genes during sleep. Sleep deprivation (SD) can lead to memory impairment and neuroinflammation, and there remains no effective pharmacological treatment for these effects. Myricetin (MYR) is a common natural flavonoid that has various pharmacological activities. In this study, we investigated the effects of MYR on memory impairment, neuroinflammation, and neurotrophic factors in sleep-deprived rats. We analyzed SD-induced cognitive and spatial memory, as well as pro-inflammatory cytokine levels during SD. SD model rats were intraperitoneally injected with 10 and 20 mg/kg/day MYR for 14 days. MYR administration significantly ameliorated SD-induced cognitive and spatial memory deficits; it also attenuated the SD-induced inflammatory response associated with nuclear factor kappa B activation in the hippocampus. In addition, MYR enhanced the mRNA expression of brain-derived neurotropic factor (BDNF) in the hippocampus. Our results showed that MYR improved memory impairment by means of anti-inflammatory activity and appropriate regulation of BDNF expression. Our findings suggest that MYR is a potential functional ingredient that protects cognitive function from SD.