• Genomics & Informatics
• /
• 제18권4호
• /
• pp.38.1-38.9
• /
• 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.

• 생물정신의학
• /
• 제28권2호
• /
• pp.58-69
• /
• 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.

• Journal of Korean Biological Nursing Science
• /
• 제21권1호
• /
• pp.70-76
• /
• 2019

Purpose: The aim of this study is to identify the influence of chronotype and self-efficacy on drinking problem in undergraduate students. Methods: A cross-sectional survey design was adopted for the 177 undergraduate students in D, G, and K city in 2017. The data was analyzed for descriptive statistics, t-test, ANOVA, Pearson's correlation coefficients and multiple regression analysis using the SPSS 18.0 program. Results: Chronotype (${\beta}=-.31$, p< .001), self-efficacy (${\beta}=27$, p< .001) and religion (${\beta}=-.19$, p= .005) were identified as the factors influencing drinking problem in the subjects. The model explained 19% of variance in drinking problem (F= 11.36, p< .001). Conclusion: It is necessary to develop and apply a program that would consider chronotype and self-efficacy factors to reduce the drinking problem in undergraduate students.

• 대한인간공학회지
• /
• 제19권3호
• /
• pp.1-12
• /
• 2000

The Korean version of the morningness-eveningness questionnaire (MEQ) and sleep habits inventory were administered to 1,038 Korean male daytime workers and were analyzed according to age and chronotype to determine what these factors reveal about sleep habits in view of phase difference of circadian rhythm. The mean and distribution of scores on the MEQ moved significantly toward the morning type with aging. Bedtimes and waking times were progressively later from the morning, intermediate, to evening types, and were also earlier with aging. Preferred bedtimes and waking times showed more distinct differences than did the habitual times in each chronotype. The percentage of subjects who answered that sleep length was 'short', mood upon waking was 'bad', and variabilities of bedtime and sleep length were 'large' were greater in the young and evening types than in the elder and morning types, respectively. These findings suggested that subjects were shifted toward the morning type and the phase of circadian rhythm had moved forward with aging. Preferred bedtime and waking time were a better reflection of individual circadian rhythms than habitual bedtime and waking time.

• 생물치료정신의학
• /
• 제24권3호
• /
• pp.194-201
• /
• 2018

Objectives : Some studies have reported that chronotypes, among several factors, could contribute to problematic drinking. However, there is little evidence confirming this relationship between chronotype and problematic drinking based on gender differences in mood disorder. This study is to investigate the difference of the relationship between chronotype and problematic drinking according to gender differences in mood disorder. Methods : Two hundred fifteen patients with mood disorder were recruited. Problematic drinking and chronotypes were assessed by the Alcohol Use Disorder Identification Test in Korea(AUDIT) and the Korean translation of composite scale of morningness(KtCS). We analyzed the correlation between KtCS and AUDIT using Pearson's correlation, and compared AUDIT scores according to chronotypes classified by KtCS between male and female patients using analysis of variance(ANOVA). Results : There was no significant difference in AUDIT scores between the male and female patients(t=0.91, p=0.183). In female patients, eveningness had significantly higher AUDIT scores than other chronotypes(F=0.199, p=0.033). Meanwhile, in male patients, there was no significant difference in AUDIT score among chronotypes(F=0.008, p=0.933). Conclusion : This study suggests that eveningness might be associated with problematic drinking in female patients who suffer from mood disorder. It also suggests that chronotherapeutical treatment might be able to help improve the course in female patients with mood disorder. In the future, a large-scale prospective study is needed to confirm these results.

• Journal of Korean Biological Nursing Science
• /
• 제23권3호
• /
• pp.227-236
• /
• 2021

Purpose: The purpose of this study was to investigate the sleep duration, social jetlag (SJL), and subjective sleep disturbance according to the individual chronotype in rotating shift nurses. Methods: A total of 344 rotating 3-shift nurses (mean age 28.67 years) were recruited at one university affiliated hospital. They completed the following questionnaires, which were used to assess their chronotype and sleep: the morningness-eveningness questionnaire (MEQ), self-reported sleep duration of work days (SDW_shift) and free days (SDF_shift) in each shift (day [D], evening [E], night [N]), and sleep disturbance (Insomnia severity index, ISI). SJL_shift was calculated as the difference in midsleep (MS=sleep onset+1/2 sleep duration) between work days (MSW) and free days (MSF). Results: Subjects were divided into 3 chronotype groups according to the MEQ; morning (MG, 4.4%) intermediate (IG, 57.8%), and evening groups (EG, 37.8%). SDW_D was shortest (4.68 hr) and SDF_E was longest (8.93 hr) in the EG. SJL_D was longest in the EG (3.77 hr), and SJL_N was longest in the MG (7.37 hr). The prevalence of sleep disturbance was 33.3% (MG), 29.6% (IG), and 40.0% (EG), respectively, without any statistical significance. Conclusion: In order to improve the sleep of shift workers, it is recommended that the evening chronotypes should reduce the day shifts and the morning chronotypes should reduce the night shifts. We also propose a study to determine whether these shift assignments can improve the sleep in shift nurses.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제14권1호
• /
• pp.148-167
• /
• 2020

Today, digital shoppers express increasingly complex buying behavior. They can use multiple channels for shopping and also they can switch from one to another channel almost effortlessly, in the result of engaging in omnichannel shopping behavior. A few years ago, consumers were using brick and mortar stores to make their purchases. However, nowadays, they possess different digital devices (mobile and/or desktop) to search for different alternatives and to make a better shopping choice. These devices (mobile and desktop) are different and offer unique benefits to consumers. However, there has been very little research that has treated mobile and desktop devices separately. Perhaps this study is the pioneer when it comes to investigating the effect of regulatory focus (prevention vs. promotion) and chronotype (morning and evening person) on a sample of university students using desktop and mobile channels for their shopping. The findings from a sample of 312 digital consumers (mobile and/or desktop) confirmed that the desktop channel provides a greater fit for morning-type respondents and that the mobile channel offers better value for evening-type respondents in e-retail. Furthermore, promotion-focused shoppers favor the mobile channel, and prevention-focused shoppers favor the desktop channel. The new insights and contributions of this study provide a better understanding of digital consumers to help sellers to develop a more effective e-retail strategy.

• 생물정신의학
• /
• 제21권1호
• /
• pp.14-20
• /
• 2014

Objectives The current study investigated the putative relationship between chronotype and suicidality or bipolarity in patients with major depressive disorder (MDD). Method Nineteen outpatients who met the criteria for MDD according to the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders-text revision were recruited for the current study. The subjects were divided into two subgroups based on their Basic Language Morningness (BALM) scores (dichotomized according to the median BALM score). The Loudness Dependence of Auditory Evoked Potentials (LDAEP) was evaluated by measuring the auditory event-related potentials before beginning medication with serotonergic agents. In addition, K-Mood Disorder Questionaire (K-MDQ), Beck Scale for Suicidal Ideation (BSS), Beck Hopelessness Scale (BHS), Barratt Impulsiveness Scale (BIS) were applied. Results The K-MDQ, BSS, BHS, BIS score was higher for the eveningness group than for the morningness group. However, the LDAEP, Hamilton Depression Rating Scale, Hamilton Anxiety Scale scores did not differ significantly between them. There were negative correlations between the total BALM score and the total K-MDQ, BSS, and BHS scores (r=-0.64 and p=0.0033, r=-0.61 and p=0.0055, and r=-0.72 and p=0.00056, respectively). Conclusions Depressed patients with eveningness are more vulnerable to the suicidality than those with morningness. Eveningness is also associated with bipolarity.

• 수면정신생리
• /
• 제26권1호
• /
• pp.5-15
• /
• 2019

일주기 유형의 차이는 다양한 관점에서 이해되어야 한다. 기존 연구결과들에 따르면 일주기 유형 중 아침형이 몇몇 정신장애의 보호요인인 반면 저녁형은 위험 요인으로 나타났다. 일반적으로 아침형에서 나타나는 습관들은 저녁형보다 더 건강하다. 성인의 생활양식을 형성하는 과정에 있는 청소년 시기와 생활습관과 관련된 건강 문제가 잦아지는 노년기에 일주기 유형의 중요성이 더욱 크다고 볼 수 있다. 따라서 일주기 유형을 생물-심리-사회적 건강 모델에 포함시켜 보다 효율적인 예방 및 치료적 접근을 설계하는 것이 중요하겠다. 정신장애 치료에서도 일주기 리듬을 고려해야 한다. 일반적으로 취침-기상, 식사, 그리고 일상 활동을 규칙적인 아침형 패턴으로 변화시키는 것이 도움이 될 수 있다. 광치료(light therapy)와 멜라토닌 주입(melatonin administration)과 같은 전략들도 정신장애의 치료 및 재발 방지에 효과적일 수 있다. 일주기 유형 기저의 유전학을 이해하는 것 또한 어떤 사람이 특정한 생활 양식이나 정신장애에 취약한지 구별하는데 도움이 될 수 있다.

• 수면정신생리
• /
• 제29권1호
• /
• pp.21-28
• /
• 2022

목적: 의과대학생들은 많은 스트레스를 받으며 점점 불안감이 높아지고 수면시간의 부족과 함께 수면양상도 불규칙 해진다. 따라서 의과대학생들의 일주기 유형, 수면의 질, 회복탄력성 그리고 불안이 어떠한 연관이 있는지 알아보고자 하였다. 방법: 경상국립대학교 의과대학생 본과 1학년 52명과 2년 후, 44명의 본과3학년 학생들을 대상으로 했다. 벡 우울 척도, 벡 불안 척도, 불면증 심각성 척도, 아침활동형 척도 그리고 코너-데이비드슨 탄력성 척도를 자기 설문지로 사용하였다. 각각의 상호 연관성을 알아보기 위하여 다중회귀 분석을 시행하였다. 결과: 본과 1학년 때의 불안이 높은 것은 2년 뒤인 3학년때 저녁형을 예측했고 본과 1학년때의 불안이 낮을수록 본과 3학년의 수면의 질이 좋았다. 본과 3학년의 수면의 질이 낮은 것은 저녁형 그리고 낮은 회복탄력성과 연관이 있었다. 또한, 본과 3학년의 우울감이 적은 것은 높은 회복탄 력성과 유의한 연관성을 보였다. 결론: 본 연구에서 의과대학생 본과 1학년 때의 불안의 정도가 2년 후 3학년 때의 수면의 질과 저녁형을 예측했다. 앞으로 1학년 학생들의 불안을 낮출 수 있는 방안을 고안하여 학생들의 수면의 질을 높이고 삶의 질을 향상시킬 필요가 있다.