Irregular Schedules Research Articles

Abstract 007: Actigraphy-Measured Sleep Regularity and Risk of Incident Cardiovascular Disease: The Multi-Ethnic Study of Atherosclerosis

Background: Prior studies have linked rotating night shift work to increased risk of cardiovascular disease (CVD). Irregular sleep schedules, characterized by high day-to-day variability in sleep duration or timing, represent possibly milder but much more common/chronic disruption of circadian rhythms in the general population. However, no prospective study to date has examined the association between sleep regularity and CVD outcomes. Methods: In the Multi-Ethnic Study of Atherosclerosis, 1,993 participants who were free of CVD completed 7-day wrist actigraphy at home for objective monitoring of sleep duration and quality between 2010 and 2013, and were prospectively followed through 2015. We assessed sleep regularity using the standard deviation (SD) of actigraphy-measured sleep duration and sleep onset timing across 7 days. Incident CVD was defined as total cardiovascular events including coronary heart disease, stroke, congestive heart failure, and cardiovascular death. Cox proportional hazards model was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for incident CVD according to SD of sleep duration and timing, adjusted for traditional CVD risk factors (e.g., sociodemographic factors, lifestyles and CVD biomarkers) and other sleep-related factors (e.g., average sleep duration, insomnia symptoms, daytime sleepiness, sleep-disordered breathing, chronotype and work schedules). Results: During a median follow-up of 4.0 years, 95 participants developed CVD events. Compared to participants with a 7-day sleep duration SD ≤60 min, the multivariable-adjusted HR (95% CI) for CVD was 1.12 (0.61, 2.07) for 61-90 min, 1.71 (0.94, 3.09) for 91-120 min, and 2.20 (1.22, 3.96) for >120 min. Every 1-hour increase in sleep duration SD was associated with 23% higher CVD risk (95% CI: 1.05, 1.45; p-trend=0.01). In contrast to this linear association with sleep duration variability, there appeared to be a threshold pattern for the association with SD of sleep onset timing. Compared to participants with a sleep timing SD ≤30 min, the multivariable-adjusted HR (95% CI) for CVD was 1.13 (0.60, 2.13) for 31-60 min, 1.15 (0.58, 2.31) for 61-90 min, and 2.07 (1.09, 3.94) for >90 min. CVD risk was 87% higher comparing sleep timing SD >90 min versus ≤90 min (95% CI: 1.19, 2.96; p=0.007). These associations did not differ significantly by age, sex, race/ethnicity, sleep duration or work schedules. Exclusion of current shift workers yielded similar results. Conclusion: Irregular sleep duration and timing may be novel risk factors for CVD, independent of traditional CVD risk factors and sleep quantity/quality. Given the increased prevalence of irregular sleep (e.g., due to mobile device use), our findings have important public health implications for CVD prevention and suggest value in evaluating the impact of sleep hygiene interventions aimed at improving sleep pattern consistency.

The effects of amplitude and stability of circadian rhythm and occupational stress on burnout syndrome and job dissatisfaction among irregular shift working nurses.

To investigate the relation between the circadian rhythm amplitude and stability, and occupational stress with burnout syndrome and job dissatisfaction among shift working nurses. Irregular shift working nurses are prone to burnout syndrome (BS) and job dissatisfaction (JD). circadian rhythm difference and occupational stress might be effective in causing burnout syndrome and dissatisfaction. In total, 684 nurses who worked in four teaching hospitals were selected by stratified random sampling in a cross-sectional design based on STROBE guidelines. The data were collected by the Circadian Type Inventory, Job Content Questionnaire, Minnesota Satisfaction Questionnaire and the Maslach Burnout Inventory. Multiple linear regression, one-way ANOVA and independent t test were used for statistical analysis by SPSS v24. About 15% of the nurses suffered from high levels of burnout syndrome. Psychological demand (β=0.022, CI 95%=0.003-0.047 and β=0.016, CI 95%=0.001-0.032) and workplace support (β=-0.043, CI 95%=-0.097-0.003 and β=-0.025, CI 95%=-0.046-0.006) were significant predictors of BS and JD. Male nurses reported lower BS and higher JD compared to female nurses. Irregular shift working schedule was also related to a significantly higher odd of BS (p=0.009) and JD (p=0.011). Nurses classified as languid experienced significantly more BS and JD than vigorous nurses. This study shows that BS and JD were strongly associated with psychological demand and workplace support; and vigorous nurses were less prone to BS and JD, and were more suitable for irregular shift work. In order to reduce burnout syndrome and job dissatisfaction among irregular shift working nurses, we need to identify the effect of risk factors such as individual differences on the circadian rhythm and job demand which can affect nurses who work in irregular schedules.

Working Time Society consensus statements: Psychosocial stressors relevant to the health and wellbeing of night and shift workers

This consensus report summarizes the negative impact of work-related psychosocial factors and job stressors on the health and wellbeing of shift workers. Psychosocial factors may (a) directly affect work schedules or (b) mediate or moderate relationships between work schedules, circadian factors, and health. In this paper, prominent psychosocial models (e.g. Job Strain and Effort-Reward Imbalance) are used to help assess detrimental effects, including pathophysiologic outcomes. Several studies indicate the psychosocial environment can be more problematic for shift workers compared to regular day workers. This is likely due to shift worker’s experiencing greater risks of low job control, high physical work demands, lower support from supervisors, and greater levels of over-commitment. Workplace violence is another frequently encountered psychosocial stressor for shift workers more likely to be in regular contact with the general public, such as police officers, security personnel, professional drivers, and other service employees being at elevated risk. A large body of literature confirms night and irregular shift schedules increase risk for injury. Non-diurnal schedules can trigger and worsen such incidents, especially under unsafe conditions. The problem of workplace violence for shift workers, in terms of severity and consequences, is probably underestimated, especially when present among other occupational stressors. Practical considerations and recommendations for action to mitigate the detrimental effects of psychosocial stressors on night and shift workers are presented.

Risk Factor Analysis of Recurrent Acute Coronary Syndrome

Background: Acute coronary syndrome (ACS) is a form of life-threatening coronary heart disease. Interestingly, this entity has the possibility to recurrence with prevalence reaches 21-30% in a year. Purpose: This study aims to analyse risk factors associated with recurrent ACS incident. Methods: The analytic observation research with the case-control design was applied in this present study. Furthermore, this research was conducted at the Dr. Mohamad Soewandhie General Hospital, Surabaya. This study carried from February to July 2018. The samples used in this study cover 43 cases and 43 controls in the consecutive admission to the ACS patients who came to the cardiac clinic of the Dr. Mohamad Soewandhie General Hospital, Surabaya that meets the research criteria. On the other hand, bivariable analysis was performed using simple logistic regression and multivariable analysis was performed using multiple logistic regression. This study showed that the most influential risk factor for ACS recurrent. Results: incident were including control of Low-Density Lipoprotein Cholesterol (LDL-C) ≥ 100 mg/dL (p= 0.03; adjusted OR= 3.35; 95% CI= 1.16 < OR < 9.68), irregular exercise schedule (p < 0.01; adjusted OR= 9.15; 95% CI= 2.83 <OR <29.58), and smoking history (p= 0.02; adjusted OR= 4.07; 95% CI= 1.29 <OR <12.84). Conclusion: The control of LDL Cholesterol levels below 100 mg/dL, regular exercise, and avoid smoking are beneficial for people with ACS to reduce the risk of recurrent ACS incident.

Team Retreats for Interprofessional Trainees and Clinic Staff: Accelerating the Development of High-Functioning Teams.

Teams are critical to managing the health care needs of patients with part-time trainee providers. High-functioning teams require trusting relationships among trainees and staff and opportunities to learn and practice skills together. Irregular trainee schedules, time-limited training programs, and lack of protected time for team development during clinic can hinder development of high-functioning teams. To provide time for team development, we created an annual half-day team retreat for interprofessional trainees and staff at three San Francisco Veterans Affairs primary care clinics. We used principles of high-functioning teams and relationship-centered communication to develop retreat content, then trained interprofessional faculty members to facilitate and role-model this content. Retreat objectives and content focused on building relationships, establishing team goals, clarifying roles, and learning communication skills. Postretreat surveys and qualitative content analysis of comments and team goals evaluated retreat objectives and opportunities for improvement. Between 2011 and 2017, 16 team retreats were attended by 232 interprofessional trainees and 77 unique staff (some attended multiple times). Thirty-seven faculty facilitated. Most participants strongly agreed that they knew their team members better personally and professionally after the retreat (M = 4.7 out of 5, n = 368); 78% of teams (n = 65) submitted SMART goals addressing high-functioning teams. Participants' comments consistently reflected the benefits of protected time for team building. This team retreat supports team development among trainees and staff on primary care teams by promoting relationship building, role clarity, communication, and team processes. It can be valuable for all interprofessional participants.

Prebiotic, Immunomodulating, and Antifatigue Effects of Konjac Oligosaccharide

Irregular and long time work schedules not only makes people feel fatigue, but also brings great risks of diseases, due to gastrointestinal disorder and immune dysfunction. Therefore, it has positive significance to help challenged people stay energetic and healthy with food supplement. Konjac oligosaccharide has shown various physiological benefits and been recommended in the fortification of functional foods. However, there have been few reports on its application aimed to simultaneously relieve physical fatigue and keep body healthy. In this paper, the potential prebiotic, immunoregulatory, and antifatigue activities of konjac oligosaccharide were evaluated in vitro and in vivo. The results showed that konjac oligosaccharide could promote probiotics growth and short chain fatty acids production in mice cecum. At the concentration of 50 to 200 μg/mL, konjac oligosaccharide could activate murine macrophage RAW 264.7 to secret NO and cytokines of IL-10 and IL-6. Moreover, this oligosaccharide could alleviate physical fatigue by prolonging exhaustive time, improving the level of superoxide dismutases and glutathione peroxidase, increasing the content of blood glucose, and decreasing the content of blood urea nitrogen. The results suggested that konjac oligosaccharide had prebiotic, immunoregulatory, and antifatigue effects, providing its application potential in functional food aimed at people with irregular and long time work.

Passenger demand oriented train scheduling and rolling stock circulation planning for an urban rail transit line

We study the integration of train scheduling and rolling stock circulation planning under time-varying passenger demand for an urban rail transit line, where the practical train operation constraints, e.g., the capacity of trains, the number of available rolling stocks, and the entering/exiting depot operations, are considered. Three solution approaches are proposed to solve the resulting multi-objective mixed-integer nonlinear programming (MINLP) problem to deliver both an irregular train schedule (i.e., departure and arrival times of all train services) and a rolling stock circulation plan (including entering/exiting depot operations of rolling stocks and connections between train services) simultaneously. We first present an iterative nonlinear programming (INP) approach, where the solutions of the original MINLP problem are obtained by solving a nonlinear programming problem and a mixed integer linear programming (MILP) problem iteratively. Moreover, an equivalent MILP formulation of the original MINLP model is developed and an approximated MILP approach is proposed to reduce the number of constraints introduced by passenger demand. A case study is conducted based on the practical data of the Beijing Yizhuang line, where the three proposed approaches are compared with a state-of-the-art approach and a practical method used by the traffic planners. This comparison shows the effectiveness and efficiency of the three proposed approaches.

Human Resting Energy Expenditure Varies with Circadian Phase

There is emerging evidence that circadian misalignment may alter energy expenditure, leading to obesity risk among those with irregular schedules [1-5]. It has been reported that energy expenditure is affected by the timing of sleep, exercise, and meals [6]. However, it is unclear whether the circadian system also modulates energy expenditure, independent of behavioral state and food intake. Here, we used a forced desynchrony protocol to examine whether fasted resting energy expenditure (REE) varies with circadian phase in seven participants. This protocol allowed us to uncouple sleep-wake and activity-related effects from the endogenous circadian rhythm, demonstrating that REE varies by circadian phase. REE is lowest at circadian phase ∼0°, corresponding to the endogenous core body temperature (CBT) nadir in the late biological night, and highest at circadian phase ∼180° in the biological afternoon and evening. Furthermore, we found that respiratory quotient (RQ), reflecting macronutrient utilization, also varies by circadian phase. RQ is lowest at circadian phase ∼240° and highest at circadian phase ∼60°, which corresponds to biological morning. This is the first characterization of a circadian profile in fasted resting energy expenditure and fasted respiratory quotient (with rhythmic profiles in both carbohydrate and lipid oxidation), decoupled from effects of activity, sleep-wake cycle, and diet in humans. The rhythm in energy expenditure and macronutrient metabolism may contribute to greater weight gain in shift workers and others with irregular schedules.

A first look at parental work schedules and children’s well-being in contemporary China

ABSTRACTThis article examines the association between parental work schedules and children’s well-being using a 2014 sample of first-graders in Shanghai, China (N = 2282), a society undergoing rapid economic and social changes. Approximately one-third of the sampled parents worked nonstandard hours in 2014. Propensity score matching analysis results show that children whose fathers worked evening and night schedules had worse internalizing behavior than those whose fathers worked a at standard daytime schedule. In addition, children whose fathers worked nights or irregular schedules displayed poorer academic performance than their peers whose fathers worked a standard daytime schedule. Maternal nonstandard work schedules were associated with worse academic performance but better behavioral outcomes. These associations were particularly pronounced for families with rural residential status and families in the bottom-third of the income distribution.

Sex, Gender Dynamics, Differential Exposure, and Work–Family Conflict

This study tested a differential exposure explanation of the association between sex categories and work–family conflict. It addresses the question of why men and women may experience similar or dissimilar levels of work–family conflict and tests whether differences are due to their different gendered demands and resources. Drawing from a sample of 1,751 employed adults from 63 workplaces, the results suggest that women spend less time in paid employment than do men; a gendered response that is associated with lower work-to-family conflict, but higher family-to-work conflict. Women were also found to be less involved in irregular work schedules, which is associated with lower work-to-family conflict. The differential exposure explanation was also supported by indirect effects involving commute time, family income, and social support outside work.

Digital Gaming to Improve Adherence Among Adolescents and Young Adults Living With HIV: Mixed-Methods Study to Test Feasibility and Acceptability.

BackgroundAn estimated 50% of adolescents and young adults (AYA) living with HIV are failing to adhere to prescribed antiretroviral treatment (ART). Digital games are effective in chronic disease management; however, research on gaming to improve ART adherence among AYA is limited.ObjectiveWe assessed the feasibility and acceptability of video gaming to improve AYA ART adherence.MethodsFocus group discussions and surveys were administered to health care providers and AYA aged 13 to 24 years living with HIV at a pediatric HIV program in Washington, DC. During focus group discussions, AYA viewed demonstrations of 3 game prototypes linked to portable Wisepill medication dispensers. Content analysis strategies and thematic coding were used to identify adherence themes and gaming acceptance and feasibility. Likert scale and descriptive statistics were used to summarize response frequencies.ResultsProviders (n=10) identified common adherence barriers and strategies, including use of gaming analogies to improve AYA ART adherence. Providers supported exploration of digital gaming as an adherence intervention. In 6 focus group discussions, 12 AYA participants identified disclosure of HIV status and irregular daily schedules as major barriers to ART and use of alarms and pillboxes as reminders. Most AYA were very or somewhat likely to use the demonstrated game prototypes to help with ART adherence and desired challenging, individually tailored, user-friendly games with in-game incentives. Game prototypes were modified accordingly.ConclusionsAYA and their providers supported the use of digital games for ART adherence support. Individualization and in-game incentives were preferable and informed the design of an interactive technology-based adherence intervention among AYA living with HIV.

Circadian misalignment has differential effects on affective behavior following exposure to controllable or uncontrollable stress

In modern 24 h society, circadian disruption is pervasive, arising from night shift work, air travel across multiple time zones, irregular sleep schedules, and exposure to artificial light at night. Disruption of the circadian system is associated with many adverse health consequences, including mood disorders. Here we investigate whether inducing circadian misalignment using a phase advance protocol interferes with the ability to cope with a stressor, thereby increasing susceptibility to the negative consequences of stress. Male rats were maintained on a standard 12:12 light: dark (LD) cycle or subjected to a chronic phase advance (CPA) protocol involving 4 weekly 6 h phase shifts (earlier light onset) of the LD cycle. Rats were then exposed to escapable stress (ES), inescapable stress (IS), or no stress (home cage control; HC) and performance on juvenile social exploration and active escape learning in the two-way shuttlebox test was assessed 24 h and 48 h following stress, respectively. CPA alone had no effect on pre-stress juvenile social exploration, and it also did not interfere with the protective effect of ES on the stress-induced reduction in juvenile social exploration. In contrast, CPA impaired escape learning in the two-way shuttlebox to the same extent as IS in all subjects, regardless of stress history. Additionally, CPA produced somatic alterations that included increased body mass, increased epididymal adiposity, and decreased adrenal mass. These data indicate that CPA differentially modulated the stress-protective effects of behavioral control depending on the type of affective behavior examined.

Association between pregnant women’s experience of stress and partners’ fly-in-fly-out work

BackgroundIt is relatively common in Western Australia for men to commute long distances and work away from home for extended periods of time, often referred to as fly-in-fly-out work. Women are particularly susceptible to the effects of stress during pregnancy, and the absence of a partner due to working away could be an additional risk to their wellbeing. While there is little published fly-in-fly-out literature, there is evidence that working non-standard hours, more generally, has a negative impact on health and well-being of workers and their families. AimTo determine if there is an association between pregnant women’s report of stress and their partners working fly-in-fly-out, and if so, is there is a differential impact that is dependent on family socioeconomic status. MethodsData from a Western Australian pregnancy cohort study were analysed (n=394 families). Couples completed self-report ratings of anxiety, depression, stress, family functioning, and stressful life events. Comparisons were made between three groups: fly-in-fly-out workers, non-fly-in-fly-out regular schedule workers, and non-fly-in-fly-out irregular schedule workers. ResultsAfter controlling for a range of variables, women’s stress was significantly associated (p<.05) with their partners working fly-in-fly-out. Neither women’s education, partners’ occupation nor an interaction between partners’ fly-in-fly-out work and partners’ occupation were significantly associated with women’s stress. ConclusionThere is some evidence that the pregnant partners of fly-in-fly-out workers perceive their lives to be more stressful than women whose partner works non-fly-in-fly-out regular schedules.

Does part-time employment status really reduce time pressure?

Part-time employment rates are increasing in Australia, for both women and men. However, gendered patterns in part-time employment status are typically associated with mothers’, rather than fathers’, transition to parenthood. This study uses data from the 2006 Negotiating the Life Course survey to investigate whether part-time employment reduces time pressure for women compared to men, when temporal job quality is considered. Our results show that women employed in shorter part-time hours had better time pressure outcomes, overall and at work, than women employed in longer part-time hours. Yet findings show that a lack of access to temporal flexibility and irregular work schedules negatively impact time pressure outcomes for both men and women. We conclude that time pressure benefits gained from being employed part-time, may be diminished when there is poor temporal job quality.

Work stress, personality traits, and cortisol secretion: Testing a model for job burnout.

Job stressors can cause a salivary cortisol secretion dysregulation which in turn can lead to burnout. However, job stressors do not induce the same cortisol secretion dysregulation and psychic consequences systematically to all workers. Personality traits may influence job stressor's adaptation. The objectives of this study were (a) to verify the mediating effect cortisol has on the relationship between work conditions and burnout, and (b) to identify the moderate mediation effects that personality traits have on the relationship between work conditions and salivary cortisol secretion. Multilevel regression analyses were carried out on a sample of 352 employees in 34 Québec firms. Saliva samples were collected five times a day (on awakening, 30 minutes after awakening, at 2 p.m., 4 p.m., and bedtime) on three days (1 day off, 2 work days). Work conditions variables comprised skill utilization, decision authority, psychological demands, physical demands, job insecurity, irregular schedules, number of working hours, and social support. Personality traits included self-esteem, locus of control, and the Big Five. Both work conditions and personality traits were assessed with a psychosocial questionnaire. The level of salivary cortisol secretion was negatively associated with burnout. Certain workplace and personality variables had a significant effect on emotional exhaustion (psychological demands was positively associated, social support from supervisors was negatively associated) and on cortisol levels (job insecurity was negatively associated). Cortisol did not play any mediating role in the relationship between work conditions and burnout, which is moderated by personality traits. We conclude that work conditions (skill utilization, decision authority, psychological demands, physical demands, job insecurity, irregular schedules, number of working hours, and social support) and the interaction of personality traits with work conditions have no indirect effects on burnout.

Can starlings use a reliable cue of future food deprivation to adaptively modify foraging and fat reserves?

Regulation of mass in small birds is based on simultaneously minimizing starvation and predation risk, but the mechanisms birds use to assess starvation risk are still debated. While we know that birds anticipate periods of unpredictable food availability/energy expenditure (e.g. the winter and night) by increasing their fat reserves, we do not know whether this anticipation involves learning. This study investigated whether birds could learn to use a light cue that predicted a period of food unavailability, to adaptively regulate their foraging and/or body weight. Sixteen captive starlings, Sturnus vulgaris, were subjected to 42 days of an irregular schedule of food deprivation that involved depriving them of food for 5 h on 20 pseudorandomly chosen days. Birds were randomly allocated to two treatment groups for which a 30 min period of reduced ambient light either provided perfect information (Predictable) or no information (Unpredictable) about upcoming food deprivation. Both groups of birds increased their dawn body mass over the period of the experiment, consistent with a response to unpredictable food deprivation. However, no differences in either foraging behaviour or dawn body mass emerged between the groups, suggesting that the Predictable birds were unable to learn to use the light cue to initiate anticipatory foraging ahead of food deprivation. Furthermore, both groups immediately decreased their foraging behaviour in response to the onset of the light cue, suggesting that starlings do not have an evolved anticipatory foraging response to low light levels. Further work is needed to test alternative cues and designs before any general conclusions can be drawn regarding the flexibility of anticipatory foraging.

Impact of shift work schedules on actigraphy-based measures of sleep in Hispanic workers: results from the Hispanic Community Health Study/Study of Latinos ancillary Sueño study.

To describe sleep characteristics of shift workers compared with day workers from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) Sueño ancillary study and test the hypothesis that shift work is associated with shorter sleep duration, worse sleep quality, greater sleep variability, and other sleep/health-related factors. Employed adults (N = 1253, mean age 46.3 years, 36.3% male) from the Sueño study were included. Measures of sleep duration, timing, regularity, and continuity were calculated from 7 days of wrist-activity monitoring. Participants provided information on demographics, employment, work schedule (day, afternoon, night, split, irregular, and rotating), sleepiness, depressive symptoms, medications, caffeine, and alcohol use. Survey linear regression adjusting for age, sex, background, site, number of jobs, and work hours was used. In age and sex-adjusted models, all shift work schedules were associated with delayed sleep timing. Night and irregular schedules were associated with shorter sleep duration, greater napping, and greater variability of sleep. Afternoon and rotating shifts were associated with lower sleep regularity. In fully adjusted models, night and irregular schedules remained associated with shorter sleep duration, later sleep midpoint, and greater variability in sleep measures compared with day schedules. Split schedules were associated with, less time in bed, less sleep fragmentation, and less wake during the sleep period than day schedules. Work schedule significantly affects sleep-wake with substantial differences between day work and other types of schedule. Detailed assessment of work schedule type not just night shift should be considered as an important covariate when examining the association between sleep and health outcomes.

Are sleep hygiene practices related to the incidence, persistence and remission of insomnia? Findings from a prospective community study

The purpose was to examine whether sleep hygiene practices are associated with the course of insomnia (incidence, persistence and remission) over 1 year in the general population. This longitudinal study was carried out in the general population. After excluding anyone with other primary sleep disorder than insomnia, 1638 participants returned a baseline and a 1-year follow-up survey. Questions regarding sleep hygiene practices were administered at baseline, and the status of insomnia was assessed at baseline (T1) and at the 1-year follow-up (T2). Age, gender, mental ill-health, and pain were used as covariates in the analyses. Nicotine use, mental ill-health and pain were independently associated with an increased risk for concurrent insomnia at T1, while mental ill-health was the only risk factor for incident insomnia at T2. Relative to not reporting insomnia at the two time-points, nicotine use, light or noise disturbance, mental ill-health, and pain significantly increased the risk for persistent insomnia over 1 year. In comparison with those whose insomnia had remitted at the follow-up, reporting an irregular sleep schedule was a significant risk factor for persistent insomnia. Of the nine sleep hygiene practices examined in this study, only three were independently linked to concurrent and future insomnia, respectively; using nicotine late in the evening, light or noise disturbance, and having an irregular sleep schedule. This may have implications for the conceptualization and management of insomnia as well as for future research.

Shedding Light on Our Economic and Financial Lives

In November and December of 2017, we interviewed over 12,000 individuals, representative of all adults in the United States, about their economic and financial lives. Here we discuss the responses on three important economic issues: the role of economic conditions in the opioid epidemic; jobs with irregular schedules and varying income as a potential barrier to full employment; and how low rates of geographic mobility may relate to family support networks.

P-383 - Circadian clock and oxidative Stress: functional cross-talk in skin homeostasis

Ozone (O3) is among the most reactive chemical to which living organisms are routinely exposed and due to its critical location, the skin is one of the most susceptible tissues to environmental stressors. It is well known a significant role of the circadian system in the regulation of protein involved in the cellular response to oxidative stress. In this work, we investigated a possible protective role of the circadian system to O3 induced damage in human keratinocytes evaluating the cross-talk between defensive and inflammatory pathway. Synchronized keratinocytes exhibited a faster cellular response, with a more efficient interplay among these two important pathways, compared to the arrhythmic after O3 exposure. Analysis of clock gene expression in rhythmic cells reveals a more rapid induction of the cardinal clock gene Bmal1. Taken together these data suggest that an adequate coordination of the circadian system and antioxidant/inflammatory pathway might be essential to maintain the skin homeostasis. Alteration of metabolic pathways as occurs in many diseases or simply irregular schedule of life activity (shift work, transcontinental journey) could negatively influence tissue gene expression programs and associated organ physiology via its effect on the circadian system.