• Korean Journal of Biological Psychiatry
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• v.28 no.2
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• pp.58-69
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• 2021

Objectives The aim of this study was to examine the association between the sleep pattern, chronotype (midpoint of sleep on free days) and the depressive symptoms in adults aged 19 years and over in Korea. This study also investigated the mediating effect of perceived usual stress (PUS) and self-rated health (SRH) on the association between chronotype and depressive symptoms. Methods Among the subjects of the 7th Korea National Health and Nutrition Examination Survey (KNHANES) 2016 and 2018, 16142 adults aged 19 or over responded to the survey and finally 8604 were analyzed according to the exclusion conditions. Logistic regression analysis was conducted to see the risk of depressive symptoms, suicidal ideation over sleep pattern, chronotype. Finally, mediation analysis was performed in order to clarify how PUS and SRH are associated to chronoytpe and depression. Results After controlling for potential covariates, weekly sleep duration < 5 hours, ≥ 10 hours was associated with depressive symptoms. And late bed time sleeping after am 1:00 and later midpoints of sleep was associated with a higher level of depressive symptoms. Additionally, the PUS and SRH between chronotype and depressive symptoms showed a serial multiple mediation effect. Conclusions Short or long sleep duration, late bed time and later midpoints of sleep on free days are associated with depressive symptoms. Furthermore, the mechanism between chronotype and depressive symptoms needs to be further clarified by identifying the serial multiple mediation effects of PUS and SRH.

• Nutrition Research and Practice
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• v.15 no.3
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• pp.309-318
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• 2021

BACKGROUD/OBJECTIVES: Data regarding the effects of poly-γ-glutamic acid (γ-PGA) on sleep status are limited. This study aimed to test whether γ-PGA and vitamin B₆ (VitB6) supplements improve sleep duration and quality. SUBJECTS/METHODS: A factorial randomized, double-blinded, placebo-controlled crossover study included 47 adults (25 men and 22 women) who were free of chronic disease. Stratified randomized allocation considered age and gender for three interventions, group A (supplementation with γ-PGA 600 mg; n = 16), group B (supplementation with VitB6 100 mg; n = 14), and group C (dual supplementation of both γ-PGA 600 mg and VitB6 100 mg; n = 17). Participants underwent a 1-mon intervention period, followed by a 1-mon washout period, and then a second 1-mon intervention period. Differences (mean ± SD) in nighttime sleep status before and after supplementation were compared between the placebo and intervention groups using nonparametric tests. RESULTS: Significant changes in sleep duration (0.27 ± 0.98 h, P < 0.05) and the Pittsburgh Sleep Quality Index global score (-0.52 ± 1.58, P < 0.05) indicating improved sleep status were observed in the intervention compared with the placebo of group C while no significant changes were observed in groups A and B. No statistical significance was detected between the intervention and the placebo; however, there was a greater increase in the group C intervention (4.59 ± 38.5 ng/mL) in serum serotonin concentrations than the groups A and B interventions. No side effects were observed. CONCLUSIONS: On the basis of these findings, the dual supplementation of γ-PGA and VitB6 may be effective as functional food components to improve nighttime sleep status.

• Safety and Health at Work
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• v.6 no.2
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• pp.104-113
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• 2015

Background: Given the long hours on the road involving multiple and interacting work stressors (i.e., delivery pressures, irregular shifts, ergonomic hazards), commercial drivers face a plethora of health and safety risks. Researchers goal was to determine whether and to what extent long-haul trucker work schedules influence sleep duration and quality. Methods: Survey and biometric data collected from male long-haul truck drivers at a major truckstop in central North Carolina over a six month period. Results: Daily hours worked (mean = 11 hours, 55 minutes) and frequency of working over government-mandated daily HOS regulations (23.8% "frequently or always") were statistically significant predictors of sleep duration. Miles driven per week (mean = 2,812.61), irregular daily hours worked (63.8%), and frequency of working over the daily hour limit (23.8% "frequently or always") were statistically significant predictors of sleep quality. Conclusion: Implications of findings suggest a comprehensive review of the regulations and operational conditions for commercial motor vehicle drivers be undertaken.

• Journal of dental hygiene science
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• v.17 no.1
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• pp.38-45
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• 2017

We evaluated the association between sleep duration, dental caries, and periodontitis by using representative nationwide data. We examined 8,356 subjects aged ${\geq}19$ years who participated in the sixth Korea National Health and Nutrition Examination Survey (2013~2014). Sleep duration were grouped into ${\leq}5$, 6, 7, 8, and ${\geq}9$ hours. Presence of dental caries was defined as caries in ${\geq}1$ permanent tooth on dental examination. Periodontal status was assessed by using the community periodontal index (CPI), and a CPI code of ${\geq}3$ was defined as periodontitis. A chi-square test and multiple logistic regression analysis were used to determine statistical significance. Model 1 was adjusted for age and sex, model 2 for household income, educational level, and marital status plus model 1, and model 3 for smoking status, alcohol consumption, blood pressure level, fasting blood glucose level, total cholesterol level, and body mass index plus model 2. The prevalence of dental caries according to sleep duration showed a U-shaped curve of 33.4%, 29.4%, 28.4%, 29.4%, and 31.8% with ${\leq}5$, 6, 7, 8, and ${\geq}9$ hours of sleep, respectively. In the fully adjusted model 3, the risk of developing dental caries was significantly higher with ${\leq}5$ than with 7 hours of sleep (odds ratio, 1.23; 95% confidence interval, 1.06~1.43). The prevalence of periodontitis according to sleep duration showed a U-shaped curve of 34.4%, 28.6%, 28.1%, 31.3%, and 32.5%, respectively. The risk of periodontitis was significantly higher with ${\geq}9$ than with 7 hours of sleep in models 1 and 2, whereas the significant association disappeared in model 3. In a nationally representative sample, sleep duration was significantly associated with dental caries formation and weakly associated with periodontitis. Adequate sleep is required to prevent oral diseases such as dental caries and periodontitis.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.22 no.4
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• pp.433-441
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• 2015

Purposes: This study was done to identify factors associated with uncontrolled hemoglobin A1c among patient with diabetes mellitus. Method: The sample was 412 Koreans with diagnosed diabetes aged 40 years or older who participated in the Fifth Korea Health and Nutrition Examination survey, which was a nationwide, cross-sectional survey. Data was analyzed using logistic regression. Uncontrolled hemoglobin A1c rate was 55%. Results: There was a difference between controlled and uncontrolled group in hemoglobin A1c as follows: duration of diabetes, BMI(Body Mass Index), hypertriglyceridemia, vitamin D, sleep duration. After adjusting for confounding factor, longer duration of diabetes (>7 years vs. ${\leq}7$)(Adjusted OR=2.277, 95% CI [1.277-4.060]), presence of hypertriglyceridemia (Adjusted OR=4.019, 95% CI [1.871-8.634]), lower vitamin D level (<20ng/mL vs. ${\geq}20$)(Adjusted OR=2.487, 95% CI[1.411-4.381]), longer sleep duration (6-8 hours vs >8 hours)(Adjusted OR=6.831, 95% CI [1.877-24.855]) were significantly associated with increased odds of uncontrolled hemoglobin A1c. Conclusions: Results show that duration of diabetes, hypertriglyceridemia, vitamin D and sleep duration are significantly related to hemoglobin A1c. Therefore, considering these factors it would be helpful to develop strategies to improve blood glucose control in patients with diabetes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.652-662
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• 2019

This study demonstrates the association between total sleep duration of adolescents, and its effects on their physical and mental health. Chi-square test and the multiple logistic regression model were applied to analyze the data collected in 2018 by the Korean Youth Health Behavior Survey (n = 52,928), conducted by the Korea Centers for Disease Control & Prevention. Our analysis indicates increased suicidal ideation with insufficient total sleep duration as per the recommended amount and grade (OR: 1.17, 95% CI: 1.06-1.29, p-value: 0.00]. Especially, insufficient sleep among adolescent girls significantly increases the risk of suicidal thoughts (OR: 1.22, 95% CI: 1.06-1.41, p-value: 0.01). Sufficient sleep showed reduced risk of suicidal ideation among boys (OR: 0.83, 95% CI: 0.71-0.96, p-value: 0.02). We propose that to reduce the risk of suicide among teenagers, policy considerations are required to ensure sufficient sleep.

• Journal of Preventive Medicine and Public Health
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• v.55 no.6
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• pp.520-528
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• 2022

Objectives: Thiamine is thought to modify sleeping patterns, while alcohol use diminishes internal thiamine levels. We investigated the association between thiamine intake and sleep duration and explored possible heterogeneity in the effect according to alcohol use. Methods: In total, 15 384 participants aged 19-64 were obtained from the Korea National Health and Nutrition Examination Survey 2012-2016. Nutrient intake, including thiamine, was measured using a food frequency questionnaire. Sleep duration was measured by a self-reported questionnaire. The highest thiamine intake quartile was set as the reference group. Participants were divided into 3 groups, with 7-8 hours of daily sleep as a reference group and those who slept more or less than that as "oversleeping" and "insufficient sleeping," respectively. Multivariate logistic regression was used, adjusting for socioeconomic, medical, and nutritional factors. Additionally, participants were stratified according to high-risk alcohol use defined by the World Health Organization standards on alcohol use. Results: Low thiamine intake was associated with oversleeping (Q3: odds ratio [OR], 1.06; 95% confidence interval [CI], 0.86 to 1.32; Q2: OR, 1.24; 95% CI, 0.99 to 1.55; Q1: OR, 1.49; 95% CI, 1.16 to 1.91) and showed a significant trend for higher ORs at lower intake levels (p-trend<0.001). The effect was stronger in the high-risk alcohol use group (Q1: OR, 1.78; 95% CI, 1.28 to 2.49). Conclusions: Low thiamine intake was associated with oversleeping, and alcohol use intensified that association. These results were found in a context where overt clinical symptoms due to thiamine deficiency are considered rare. More awareness of the potential relationship of thiamine intake with oversleeping and its related risks should be considered.

• Journal of East-West Nursing Research
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• v.11 no.1
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• pp.42-50
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• 2005

Purpose: The purpose this research was to provide with basic data in the control of the fatiguer found in the patients with fibromyalgia by analysing the factors that predict that. Method: At three university medical center, appointed 245 out-patients diagnosed of fibromyalgia according to the conditions by American College of Rheumatology (1990). The research instruments used in this study were graphic rating scale(Anxiety, sleep disturbance, pain, joint stiffness and depression), physical activity, the number of tender points, life satisfaction and Self-efficacy scale. In data analysis, SPSS 12.0 program was utilized and data were analyzed using descriptive statistics, Pearson's correlation coefficient and multiple regression. Result: The factors that predict the fatigue of patients with fibromyalgia were sleep disturbance, life satisfaction, pain, joint stiffness, illness duration, and anxiety which explained 50.1% of the fatigue. Conclusion: It has been confirmed that the regression equation model of this research may serve as a fatigue prediction factors in patients with fibromyalgia.

• Sleep Medicine and Psychophysiology
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• v.5 no.2
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• pp.202-209
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• 1998

Authors report the findings of nocturnal polysomnography and multiple sleep latency test(MSLT) before and after morning light treatment in a winter depressive patient with hypersomnia. On polysomnographic recordings, the sleep pattern of this case before light treatment was similar to that of narcolepsy exhibited, sleep onset REM period(SOREMP). After treatment, the shortened REM latency changed to normal condition, but, deep sleep percentage did not changed, and stage 4 sleep percentage was decreased. Depressive symptoms were improved on clinical interview with Hamilton Depressive Rating Scale. Sleep log showed shortened sleep latency and reduced sleep duration. These findings suggest that although light treatment could alter the sleep structure in seasonal affective disorder with hypersomnia, it does not necessarily imply that antidepressant response of light treatment is result of change of sleep structure.

• Women's Health Nursing
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• v.15 no.2
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• pp.108-120
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• 2009

Purpose: This study aimed to explore the subjective sleep quality of depressed and non-depressed mothers in the late postpartum period and to determine the relationship with their health promoting behaviors, family functioning, parenting stress. Method: A non-probability sample of 128 mothers completed a self-administered questionnaires at 4-6weeks postpartum. The Edinburgh postnatal Depression Scale (EPDS) and Pittsburgh Sleep Quality Index were used to measure mother's experiences of depression symptoms and sleep. Related factors of sleep quality were measured by the Korean Family Functioning Scale, Health Promoting Lifestyle Profile, and Parenting Stress Index. The data was analysed using t-test, one-way ANOVA, and the Pearson's correlation coefficients. Result: The results indicated that the depressed mothers (EPDS$\geq$ 10) had poorer sleep quality than the non-depressed mothers(EPDS < 10), reported shortened sleep duration, and experienced more daytime dysfunctions. Depressed mothers who had no job, did not drink coffee, and were primipara tended to report poorer sleep quality. There were significant correlation between poorer sleep quality and lower health promoting behaviors, higher family intimacy and lower family communication, and higher parenting stress among depressed mothers. Conclusion: Our findings support the view that depressed mothers' experiences of poor sleep are much higher than non-depressed mothers and multi-faced. Nurse professionals should screen for sleep problems in the depressed mothers with a different biopsychosocial and behavioral aspect from the non-depressed mothers in the late postpartum period.