Cross-sectional associations of weekly time, social context, and motivation of exercise with mental health among workers.

PURPOSE: Exercise is considered a strategy to promote mental health among workers. However, the optimal exercise conditions that promote mental health benefits for workers are still unclear. This study examined the cross-sectional associations of weekly exercise time duration, social context of exercise, and exercise motivation levels with the mental health among Japanese workers. METHODS: A web-based cross-sectional questionnaire survey was conducted among 18,902 workers, aged 20-59 years. The mental health variables (psychological distress, psychological stress reaction, physical stress reaction, job satisfaction, and work engagement), exercise participation (non-exercisers, exercisers), and demographic factors of all responders were measured. Weekly exercise time, social context of exercise (alone only, with others only, both alone and with others), and exercise motivation (non-regulation, external/introjected regulation, identified regulation, integrated regulation, and internal regulation) were also measured amongst exercisers. After adjusting for demographic factors, multiple regression analyses were conducted. RESULTS: Exercisers had significantly lower psychological distress, lower psychological and physical stress reactions, higher job satisfaction, and higher work engagement than non-exercisers. Among exercisers, while weekly exercise time duration and social context of exercise were not clearly and robustly associated with mental health variables, respondents with intrinsic regulation had significantly lower psychological distress, lower psychological and physical stress reaction, higher job satisfaction, and higher work engagement than those with lower self-determined motivations. CONCLUSIONS: This study found that more self-determined exercise motivation is closely associated with advantageous mental health variables, than the duration or the social context of exercise among Japanese workers.

Multifaceted ORganizational InterventiONs (M-ORION) project for prevention of depression and anxiety among workers: study protocol for a five-arm cluster randomized controlled trial.

BACKGROUND: Depression and anxiety are the most common mental health issues experienced by workers. Although organizational intervention has been extensively evaluated as a primary prevention of depression and anxiety, the corresponding scientific evidence remains limited because of the lack of cluster randomized controlled trials (cRCT) and failure to detect organizational-level effects. Therefore, the present study aims to assess the preventive effects of four types of interventions on depression and anxiety among workers in an open, five-arm, parallel-group cRCT. METHODS: Overall, 140 worksites and 18,200 nested employees will be recruited from September 2023. The eligible worksites will be randomly assigned to each of the five arms, and programs will be offered for 6-12 months. The five arms are 1) psychoeducation for workers, 2) psychoeducation for supervisors, 3) work environment improvement, 4) physical activity promotion, and 5) active control. The primary outcomes of interest are depression and anxiety. We will also assess psychosocial factors at work, work engagement, health-related quality of life, well-being, economic outcomes, physiological outcomes of health checkups, cortisol levels extracted from fingernails, and indices representing the process and implementation outcomes, including program completion rates. Follow-up surveys will be conducted at 6, 12, and 18 months from baseline, and the primary endpoint is set at the 6-month follow-up. Repeated-measures multi-level mixed modeling will be used to evaluate the effect of each intervention compared with the control. ETHICS AND DISSEMINATION: The study protocol was approved by the Research Ethics Committee of the Kitasato University Medical Ethics Organization (C22-082). The results and findings of this study will be published in a scientific journal and disseminated to companies that participate in the study. TRIAL REGISTRATION NUMBER: UMIN000050949.

Effects of work-related electronic communication during non-working hours after work from home and office on fatigue, psychomotor vigilance performance and actigraphic sleep: observational study on information technology workers.

OBJECTIVES: This study examined the effects of work-related electronic communication (WREC) during non-working hours in the work from home or office setting on health. METHODS: The study recruited 98 information technology workers in a 9-day observational study. They recorded work-life events (eg, work style (working mostly from home or the office) and duration of WREC during non-working hours) and subjective ratings (eg, current fatigue, sleepiness and depression) and wore a sleep actigraph to measure objective sleep variables before bedtime every day. They completed the Brief Psychomotor Vigilance Test (PVT-B) before bedtime for 4 days. RESULTS: The frequency of WREC was significantly higher when working mostly from home than in the office (p<0.01). In addition, the duration of WREC was longer when working mostly from home than in the office (p<0.001). Linear or generalised linear mixed model analysis for fatigue, depression and PVT lapse revealed significant interaction effects between work style and WREC (all p<0.05). Post hoc analysis showed that the longer the WREC, the worse the fatigue and depression and the lower the lapse on working mostly from the office (all p<0.05). CONCLUSIONS: Longer WREC is associated with worse fatigue and depression and lower lapse of PVT (higher alertness) before bedtime for working mostly from the office. Workers, especially those working from the office, should minimise WREC during non-working hours to maintain good health. Therefore, companies, managers and other relevant stakeholders should refrain from contacting workers during non-working hours.

Association of childhood maltreatment history with salivary interleukin-6 diurnal patterns and C-reactive protein in healthy adults.

Childhood maltreatment has been associated with increased inflammation, as indicated by elevated levels of proinflammatory markers such as interleukin-6 (IL-6) and C-reactive protein (CRP). Studies in humans show that secretion of IL-6 follows a clear circadian rhythm, implying that its disturbed rhythm represents an important aspect of dysregulated inflammatory system. However, possible alterations in diurnal secretion patterns of IL-6 associated with childhood maltreatment have not been studied. Here we investigated this association in 116 healthy adults. Diurnal levels of IL-6 were examined using saliva samples collected at 5 times a day across 2 consecutive days. Salivary CRP levels were also determined by averaging measurements at 2 times a day for 2 days. Different types of childhood maltreatment were assessed with the Childhood Trauma Questionnaire (CTQ). CTQ total and emotional abuse scores were significantly correlated with smaller IL-6 diurnal variation as indexed by lower standard deviation across the measurement times (p = 0.024 and p = 0.008, respectively). Individuals with emotional abuse, as defined by a cut-off score of CTQ, showed flatter IL-6 rhythm than those without (p = 0.031). These results, both correlation and group comparison, remained significant after controlling for age, sex, and body mass index. Childhood maltreatment was not associated with total output of IL-6 or CRP. Our findings indicate that childhood trauma can have a long-term negative effect on the circadian rhythm of inflammatory system. The findings are consistent with those of previous studies on adulthood trauma, suggesting that the disrupted IL-6 rhythmicity may be associated with a broad range of trauma-related conditions.

A validation study on fingernail cortisol: correlations with one-month cortisol levels estimated by hair and saliva samples.

Several studies have focused on the cortisol levels in fingernail samples as a possible index of cumulative hormone production; however, the biological validity of fingernail cortisol has not been fully established. We investigated the association between cortisol levels in fingernail samples and other biological specimens, including hair and saliva samples, in healthy young adults to determine whether fingernail cortisol was associated with past cumulative hormone production. Participants were 23 adults (14 men and 9 women; mean age = 22.7 ± 2.8 years). Saliva samples were collected three times per day for 30 days, and hair samples (1 cm) from participants' scalps were obtained. Fingernail samples were repeatedly collected for 8 months, considering growth rate of fingernail and time lag for fingernails to fully extend from the nail matrix. Cortisol levels in hair samples were significantly associated with the levels in fingernail samples that were obtained 3 months after hair collection (r = .48, p < .05). The 30-day integrated area under the curve, based on salivary cortisol levels at awakening and bedtime, were significantly associated with cortisol levels in fingernail samples that were collected 2-5 months after saliva collection. This finding was especially significant after adjusting for the awakening time when the saliva was collected. This study provided evidence that fingernail cortisol was associated with cumulative hormone levels measured several months before but not those in the present. The samples may be useful for endocrinological evaluation in the investigation of chronic stress, cortisol levels, and health; moreover, the use of fingernail samples would permit larger-scale studies.

Shorter sleep duration is associated with potential risks for overwork-related death among Japanese truck drivers: use of the Karoshi prodromes from worker's compensation cases.

PURPOSE: We aimed to cross-sectionally investigate how work and sleep conditions could be associated with excessive fatigue symptoms as an early sign of Karoshi (overwork-related cerebrovascular and cardiovascular diseases; CCVDs). METHODS: We distributed a questionnaire regarding work, sleep, and excessive fatigue symptoms to 5410 truck drivers, as the riskiest occupation for overwork-related CCVDs, and collected 1992 total samples (response rate: 36.8%). The research team collected 1564 investigation reports required for compensation for Karoshi. Of them, 190 reports listed the prodromes of Karoshi, which were used to develop the new excessive fatigue symptoms inventory. RESULTS: One-way analyses of variance showed that the excessive fatigue symptoms differed significantly by monthly overtime hours (p < 0.001), daily working time (p < 0.001), work schedule (p = 0.025), waiting time on-site (p = 0.049), number of night shifts (p = 0.011), and sleep duration on workdays (p < 0.001). Multivariate mixed-model regression analyses revealed shorter sleep duration as the most effective parameter for predicting excessive fatigue symptoms. Multiple logistic regression analysis confirmed that the occurrences of CCVDs were significantly higher in the middle [adjusted ORs = 3.56 (1.28-9.94)] and high-score groups [3.55 (1.24-10.21)] than in the low-score group. CONCLUSION: The findings suggested that shorter sleep duration was associated more closely with a marked increase in fatigue, as compared with the other work and sleep factors. Hence, ensuring sleep opportunities could be targeted for reducing the potential risks of Karoshi among truck drivers.

Imbalance Between Salivary Cortisol and DHEA Responses Is Associated with Social Cost and Self-perception to Social Evaluative Threat in Japanese Healthy Young Adults.

BACKGROUND: Social evaluative threat activates the HPA-axis system, namely cortisol and dehydroepiandrosterone (DHEA) responses. Additionally, cognitive and behavioral models in social anxiety, which is aroused anxiety symptoms in social situations, indicate that negative cognitions have a role in the maintenance of symptoms. Thus, the present study examined the relationship between HPA-axis activity and cognitive features in social situations. METHOD: We conducted the Trier Social Stress Test (TSST) with 44 male participants and assessed HPA-axis responses, fear of negative evaluation, the estimated social cost, and self-perceptions of their speech performance, which are core negative cognitions in social situations. RESULTS: Results revealed that the cortisol-DHEA ratio significantly correlated with self-perceptions of participants' speech performance (r = .30, p = .044) and the discrepancy between self-ratings and others' ratings of the speech (r = .44, p = .003). After controlling for depressive symptoms, significant correlations remained (r = .39, p = .01 and r = .50, p = .001, respectively). In addition, the estimated social cost, assessed before the speech task, significantly correlated with both the AUCg cortisol (r = .38, p = .011) and cortisol-DHEA ratios (r = .40, p = .007). CONCLUSION: These results suggest that estimating social costs in social situations, as well as distorted self-perceptions of that stressor, is related to dysfunctional endocrine regulation.

Psychosocial correlates of cortisol levels in fingernails among middle-aged workers.

It was recently suggested that cortisol levels in fingernails reflect cumulative hormone exposure over a relatively long period. This exploratory study cross-sectionally investigated the relationships between fingernail cortisol level and psychosocial stress in a sample of middle-aged workers (94 men and 29 women). The participants were asked to grow their fingernails for ∼2 weeks and then provide fingernail samples from every digit by using nail clippers. Further, they completed questionnaires for assessment of exposure to psychosocial stress in the past (stressful life events in the workplace in the previous year; e.g. change to a different line of work) and in the present (job stress and perceived stress). Results of a regression analysis adjusting for the effects of demographic variables showed that experience of stressful life events, but not job stress and perceived stress, was associated with elevated fingernail cortisol level. These findings indicate the potential of fingernail samples to retrospectively reflect individual differences in cortisol levels related to past psychosocial stress.

Effort-reward imbalance, cortisol secretion, and inflammatory activity in police officers with 24-h work shifts.

PURPOSE: Accumulating evidence shows that effort-reward imbalance (ERI) at work can cause various health problems. However, few studies have investigated the biological pathways linking ERI and health outcomes, and their findings have been inconsistent. In this study, we investigated the associations between ERI, the hypothalamic-pituitary-adrenocortical axis, and inflammation in a sample of police officers. METHODS: One hundred forty-two male police officers that were engaged in a working system of 24-h shifts were followed up during the work shift as well as during the two subsequent work-free days. Throughout this period, the participants provided two saliva samples each day for the 3-day period, and we measured the concentrations of cortisol and C-reactive protein (CRP) in the saliva. The police officers also completed the Japanese short version of the Effort-Reward Imbalance Questionnaire. RESULTS: The results of linear mixed model analyses controlled for possible confounding variables indicated that higher effort scores (p = 0.031) as well as effort-reward ratio (p = 0.080) were associated with lower cortisol levels, and the effect of effort was strengthened in the younger police officers (p = 0.017). Furthermore, higher effort scores were associated with higher CRP levels in younger police officers (p = 0.037). CONCLUSIONS: Our results indicate that effort, a component of ERI, has physiological effects in younger police officers, which possibly contribute to the development of stress-related diseases.

Stress Underestimation and Mental Health Outcomes in Male Japanese Workers: a 1-Year Prospective Study.

PURPOSE: Being appropriately aware of the extent of stress experienced in daily life is essential in motivating stress management behaviours. Excessive stress underestimation obstructs this process, which is expected to exert adverse effects on health. We prospectively examined associations between stress underestimation and mental health outcomes in Japanese workers. METHODS: Web-based surveys were conducted twice with an interval of 1 year on 2359 Japanese male workers. Participants were asked to complete survey items concerning stress underestimation, depressive symptoms, sickness absence, and antidepressant use. RESULTS: Multiple logistic regression analysis revealed that high baseline levels of 'overgeneralization of stress' and 'insensitivity to stress' were significantly associated with new-onset depressive symptoms (OR = 2.66 [95 % CI, 1.54-4.59], p < .01) and antidepressant use (OR = 4.91 [95 % CI, 1.22-19.74], p < .05), respectively, during the 1-year follow-up period. CONCLUSIONS: This study clearly demonstrated that stress underestimation, including stress insensitivity and the overgeneralization of stress, could exert adverse effects on mental health.

Occupational exposure levels of static magnetic field during routine MRI examination in 3T MR system.

Occupational exposure to the high static magnetic fields (SMFs) during magnetic resonance imaging (MRI) examinations raises concerns of adverse health effects. In this study, personal exposure monitoring of the magnetic fields during routine examinations in two 3 T MRI systems was carried out. A three-axis Hall magnetometer was attached to a subject's chest during monitoring. Data acquisition started every time the subject entered the scanner room and ended when the subject exited the room. Four radiologic technologists from two different institutes participated in this study. The maximum exposed field ranged from 0 to 1250 mT and the average peak magnetic field (B) was 428 ± 231 mT (mean ± standard deviation (SD): number of samples (N) = 103). Then, the relationship between exposure levels and work duties was analyzed. The MRI examination of the head or neck showed the highest average peak B among four work categories. These results provide information of real exposure levels for 3 T MRI system operators and can also improve the current practical training advice for preventing extra occupational field exposure.

Psychosocial characteristics of workers with irritable bowel syndrome and its relationship with abdominal symptoms and work productivity.

OBJECTIVES: This study aimed to validate the psychosocial characteristics and work-related challenges faced by workers exhibiting symptoms of irritable bowel syndrome (IBS) and to clarify the factors that exacerbate abdominal symptoms or hinder work productivity by focusing on IBS-related cognitive-behavioral factors and job-related stressors. METHODS: An online survey was conducted from October 5 to October 20, 2023, among workers in Japan aged 20-49 years with more than 30 hours of work per week, excluding managers and the self-employed. The data were obtained from 1062 participants (including 551 women and 329 individuals with IBS). RESULTS: The levels of depression in the IBS group were significantly higher than those in the Non-IBS group (P < .05). Cognitive-behavioral variables associated with abdominal symptoms were positively correlated with work productivity (r = 0.367-0.483, P < .001). Hierarchical multiple regression analysis with IBS symptoms and work productivity as dependent variables revealed a significant effect of the interaction between maladaptive cognition related to abdominal symptoms and job control on IBS symptoms (ß = -.164, P = .002). The association between maladaptive cognition and IBS symptoms was more pronounced when job control was lower. Additionally, IBS symptoms (ß = .130-.214, P < .05), maladaptive cognition (ß = .196-.233, P < .01), and job overload (ß = .106-.108, P < .05) significantly influenced work productivity. CONCLUSIONS: Maladaptive cognition regarding abdominal symptoms may lead to more severe abdominal symptoms in situations with a low sense of work control. Beyond cognitive-behavioral interventions for IBS, enhancing the sense of control over work environments is expected to contribute to alleviating abdominal symptoms and, consequently, enhancing work productivity.

Time-course changes in fingernail cortisol levels during pregnancy and postpartum.

The cortisol level in fingernails can reflect the cumulative hormones produced in the body several months prior. However, previous studies have only demonstrated the cross-sectional associations of fingernail cortisol with salivary or hair cortisol, and not longitudinal changes in fingernail cortisol in situations where cortisol levels in the body could be expected to change. Therefore, this study focused on pregnancy as a model for changes in cortisol levels over a prolonged period of time, and investigating the time courses of fingernail cortisol during pregnancy and the postpartum period. We collected nail samples from 30 healthy women during pregnancy and 12 months postpartum to measure the cortisol levels in the nail. Results showed that cortisol levels in fingernail clippings increased from 1 month before childbirth to 4 months postpartum, with the levels peaking at 2 months postpartum. Additionally, we found higher cortisol levels in fingernail clippings in primiparas than in those of multiparas. The time course of fingernail cortisol levels could replicate the longitudinal changes in cortisol in the body, and differences between multiparas and primiparas seemed to be biologically plausible, which could support the concept of fingernail cortisol as a retrospective index of hormone production.

Protocol for a web-based study on the work environment and daily lifestyle of Japanese employees.

Mental health problems are prevalent among the working population and must be resolved. We conducted a web-based large-scale study of workers, including a baseline survey and two follow-up surveys, to investigate the associations between self-care behaviors in daily life (e.g., stress coping, sleep, diet, and exercise), work environment improvements, and mental health among Japanese employees from various industries. In this protocol, we demonstrate the study design and demographic data of the participants in the baseline survey. Invitations to participate in this study were sent to 421,825 internet monitor registrants in February 2022. Overall, 20,000 registrants who met the inclusion criteria participated in the survey. There were large variations in occupations and working styles (e.g., physical work, night work, and teleworking) among the participants, and we also found significant differences between male and female participants in the demographic data. An overview of the survey data suggests that the demographic characteristics of the participants in this study are comparable to those reported in previous studies on Japanese employees. We plan to use these survey data in the future to examine the associations of daily lifestyles and work environments with the mental health of Japanese employees.

The diurnal patterns of salivary interleukin-6 and C-reactive protein in healthy young adults.

In recent years, salivary inflammatory markers, such as interleukin-6 (IL-6) and C-reactive protein (CRP), have been investigated regarding their relationships with psychosocial stress and stress-related diseases. This study investigated the diurnal patterns of salivary IL-6 and CRP in healthy young adults. Twenty-seven students (11 males and 16 females) participated in this study. The participants were instructed to provide saliva samples 8 times a day (at 0700, 0730, 1000, 1300, 1600, 1900, 2200, and 0100 h). For the duration of study, they were asked to wake up at 0700 h and go to bed after 0100 h. Twelve of the participants were asked to repeat this sampling procedure on two consecutive days to test the stability of the diurnal patterns. The salivary IL-6 levels peaked at awakening, gradually declined from morning to noon, and peaked again at midnight, before the participants went to sleep. The salivary CRP levels peaked at awakening, and they were lower during the daytime. The salivary IL-6 and CRP levels exhibited moderate to high stability over 2 days of sample collection. This study revealed that the salivary inflammatory markers had distinctive diurnal patterns.

[Development of a measure to assess stress underestimation beliefs].

Stress estimation is involved in the production of stress management behavior. Stress underestimation could hinder efforts to adequately manage stress. This study developed a measure to assess stress underestimation beliefs. Questionnaire surveys were conducted by mail twice on 2,340 adults aged from 20 to 65 years. The data from the surveys were subject to factor analysis, from which we developed a 12-item scale to assess stress underestimation beliefs (SUB). The SUB included four subscales: "Excessive self-efficacy for managing stress," "Insensitivity to stress," "Overgeneralization of stress," and "Evasive attitude towards stress." The SUB had adequate internal consistency. Higher SUB scores were associated with being in the precontemplation stage of change in terms of stress management behaviors, working long overtime hours (more than 81 hours per month), and having fewer self-reported stress symptoms. The SUB is potentially useful for assessing stress underestimation in the context of stress management.

Impaired self-monitoring ability on reaction times of psychomotor vigilance task of nurses after a night shift.

The cognitive ability to self-monitor one's current performance is important for hospital nurses to maintain safety and health. However, studies on the effects of rotating shift work on self-monitoring ability are insufficient. We examined the differences in self-monitoring accuracy across shifts in a rotating three-shift system among 30 female ward nurses (mean age 28.2 years). Their self-monitoring ability was calculated by subtracting the predicted reaction times of the psychomotor vigilance task performed just before exiting the workplace from the actual reaction times. A mixed-effect model was employed to assess the effects of shift, awake hours, and prior sleep duration on self-monitoring ability. We observed impaired self-monitoring ability in nurses, particularly after the night shift. Although actual performance remained high across all shifts, their self-predictions on reaction times became pessimistic in the night shift, resulting in a difference of approximately-100 msec. The effect of the shift on self-monitoring was obvious even after adjusting for sleep duration and hours awake. Our findings indicate that the misalignment between their working hours and circadian rhythms may affect even professional nurses. Occupational management that emphasizes maintaining circadian rhythms will improve the safety and health of nurses.

Blunted diurnal interleukin-6 rhythm is associated with amygdala emotional hyporeactivity and depression: a modulating role of gene-stressor interactions.

Background: The immune system has major roles in the brain and related psychopathology. Disrupted interleukin-6 secretion and aberrant amygdala emotional reactivity are well-documented in stress-related mental disorders. The amygdala regulates psychosocial stress-related interleukin-6 affected by related genes. These led us to comprehensively examine the relationship between interleukin-6, amygdala activity, and stress-related mental symptoms under gene-stressor interactions. Methods: One hundred eight nonclinical participants with various levels of anxiety/depression underwent magnetic resonance imaging scans during an emotional face task for amygdala activity and saliva collection (at 10-time points across 2 days) for the total output and diurnal patterns of interleukin-6. Gene-stressor interactions between rs1800796 (C/G) and rs2228145 (C/A) and stressful life events for the biobehavioral measures were explored. Results: The blunting of interleukin-6 diurnal pattern was associated with hypoactivation of the basolateral amygdala in response to fearful (vs. neutral) faces (t = 3.67, FWE-corrected p = 0.003), and was predominantly observed in individuals with rs1800796 C-allele homozygotes and negative life changes in the past year (F = 19.71, p < 0.001). When considered in a comprehensive model, the diminished diurnal pattern predicted greater depressive symptoms (ß = -0.40), modulated by the amygdala hypoactivity (ß = 0.36) and rs1800796-stressor interactions (ß = -0.41; all p < 0.001). Conclusion: Here we show that the blunted interleukin-6 diurnal rhythm predicts depressive symptoms, modulated by amygdala emotional hyporeactivity and gene-stressor interactions. These findings indicate a potential mechanism underlying vulnerability to depressive disorders, suggesting their early detection, prevention, and treatment through the understanding of immune system dysregulation.

Conversation time and mental health during the COVID-19 pandemic: A web-based cross-sectional survey of Japanese employees.

OBJECTIVE: During the Coronavirus disease 2019 (COVID-19) pandemic, social isolation and impaired social interaction could be the factors that cause mental health problems. This study investigated the association between conversation time in daily life and mental health among Japanese employees. METHODS: In August 2021, a web-based cross-sectional survey was conducted with 1000 Japanese employees. Weekly conversation time was assessed in four domains (family members, friends, someone in the workplace, and others), and mental health was assessed using the Japanese version of the Kessler Psychological Distress Scale (K6 scale). Weekly total conversation time was calculated, and participants were assigned to one of the four conversation time categories based on quantile values to investigate the associations with poor mental health (K6 ≥ 13). RESULTS: The logistic regression analyses revealed that participants with short conversation times (<3.5 h per week) had poorer mental health compared to those with long conversation times (> 21.0 h per week), even after adjusting for confounders (OR = 2.48 [95% CI 1.31-4.71]). For the exploratory analyses of conversation time for each domain, the associations of short conversation time in the workplace with poor mental health was most robust (OR =2.02 [95% CI 1.13-3.63]). CONCLUSIONS: Japanese employees with conversation time of <3.5 h per week (i.e., 30 min per day) had poor mental health. During the COVID-19 pandemic, people have largely limited opportunities to have conversations with others, but a certain level of conversation time might be required to maintain mental health.

Effects of short sleep duration on hemodynamic and psychological responses under long working hours in healthy middle-aged men: an experimental study.

This study examined the effects of short sleep duration (SSD) on hemodynamic and psychological responses under long working hours (LWH) in a laboratory experiment. Sixteen subjects participated in a crossover design experiment consisting of two conditions: normal (7-hours) sleep and short (5-hours) sleep. In each condition, participants engaged in simulated LWH (13 hours a day), comprising 12 task sessions. Hemodynamic and psychological responses were measured in each session. Results showed that there were significant main effects of condition and session but no interaction for hemodynamic and psychological responses. Systolic blood pressure and fatigue were higher in the later sessions than the first one. Stroke volume, sleepiness, fatigue, and stress were higher in the 5-hour than the 7-hour sleep condition (all p<0.05). These results suggest that although the combined effect of LWH and SSD was not significant, both LWH and SSD caused a hemodynamic and psychological burden.