Shift schedules and circadian preferences: the association with sleep and mood.

Object: We explored the circadian preferences of non-shift workers (non-SWs) and various types of shift workers (SWs), and the associations of these preferences with sleep and mood. Methods: In total, 4,561 SWs (2,419 women and 2,142 men aged 37.00 ± 9.80 years) and 2,093 non-SWs (1,094 women and 999 men aged 37.80 ± 9.73 years) completed an online survey. Of all SWs, 2,415 (1,079 women and 1,336 men aged 37.77 ± 9.96 years) reported regularly rotating or fixed schedules ("regular SWs"), and 2,146 (1,340 women and 806 men aged 36.12 ± 9.64 years) had irregular schedules ("irregular SWs"). Of the regular SWs, 2,040 had regularly rotating schedules, 212 had fixed evening schedules, and 163 had fixed night schedules. All participants completed the Morningness-Eveningness Questionnaire (MEQ) exploring circadian preferences, the short form of the Center for Epidemiological Studies-Depression Scale (CES-D) evaluating depression, the Insomnia Severity Index (ISI), and the Epworth Sleepiness Scale (ESS). Results: Compared to non-SWs, SWs had lower MEQ scores, i.e., more eveningness, after controlling for age, gender, income, occupation, and weekly work hours (F = 87.97, p < 0.001). Irregular SWs had lower MEQ scores than regular SWs (F = 50.89, p < 0.001). Among regular SWs, the MEQ scores of fixed evening and fixed night SWs were lower than those of regularly rotating SWs (F = 22.42, p < 0.001). An association between the MEQ and ESS scores was apparent in non-SWs (r = -0.85, p < 0.001) but not in SWs (r = 0.001, p = 0.92). Conclusion: SWs exhibited more eveningness than non-SWs; eveningness was particularly prominent in SWs with irregular or fixed evening/night shifts. Eveningness was associated with sleepiness only in non-SWs, but not in SWs.

Peripheral blood lipid and liver and kidney function test results in long-term night shift nurses: a cross-sectional study in South China.

Purpose: This study aimed to elucidate the effects of long-term day and night shifts on liver function and lipid metabolism in a group of nurses. Methods: This cross-sectional study in December 2019 was based on a group of nurses. A total of 1,253 physically healthy caregivers were included, including 1231 women and 22 men. A total of 886 nurses had long-term shift work (working in a rotating system for >1 year). The receiver operating characteristic (ROC) curve and logistic regression analyses were used to evaluate factors related to long-term shift work. Results: We observed differences in liver and kidney indicators between the non-night and night shift groups. The ROC curve revealed that CHO (AUC: 62.4%), LDLC (AUC: 62%), and GLUO (AUC: 61.5%) were more related to the night shift. Logistic regression analysis showed that night shift work was associated significantly with CREA (log (OR) = -0.02, 95% CI: -0.04 to -0.01), CHO (log (OR) = -0.38, 95% CI: -0.67 to -0.09), and GLUO (log (OR) = -0.35, 95% CI: -0.56 to -0.17). This correlation was observed only for CHO and LDHC (CHO: log (OR) = -0.55, 95% CI: -0.98 to -0.12; LDLC: log (OR) = 0.83, 95% CI: 0.32, 1.4) after age standardization. After using propensity score matching, we did not find evidence to support that the indicators differed between night and non-night shift groups. Conclusion: Our study observed an association of long-term night work with abnormal liver and kidney function and dyslipidemia, but the difference was not significant after strict age matching. Although these findings may support interventions for long-term night shift nurses, more detailed studies are needed to confirm.

Concurrent trajectories of self-rated health and working hour patterns in health care shift workers: A longitudinal analysis with 8-year follow-up.

Background: The association between health and working hours is hypothesized to be reciprocal, but few longitudinal studies have examined changes in both health and working hour patterns over time. We examined combined trajectories of self-related health and two working hour patterns (working <35 h/week and working night shifts) and the extent to which these trajectories were predicted by employees' lifestyle and mental health. Methods: Participants of this cohort study with a 8-year follow-up were 5,947 health care shift workers. We linked self-reports of health from three repeated surveys with objective pay-roll based data on working hours. Using group-based multi-trajectory analysis we identified concurrent trajectories for self-rated health and working hour patterns. We examined their associations with baseline lifestyle-related factors (smoking, at-risk alcohol use, obesity, and physical inactivity) and mental health (sleep problems and psychological distress) using multinomial regression analysis. Results: Three combined trajectories of self-rated health and working <35 h/week and four combined trajectories of self-rated health and night work were identified. Unhealthy lifestyle and poor mental health were associated with trajectories of moderate and declining health. Sleep problems were linked with working <35 h/week. Younger age and good mental health were associated with a combined trajectory of good health and continued night shift work. Conclusion: Trajectories of suboptimal and declining health are associated with trajectories of reducing working hours and leaving night work, and are more common in employees with unhealthy lifestyle, sleep problems, and psychological distress.

Night Shift Among Women: Is It Associated With Difficulty Conceiving a First Birth?

Background: Asynchrony in circadian processes alters many physiological systems, including female reproduction. Thus, there are possible reproductive consequences of night shift work for women including menstrual irregularity, endometriosis, and prolonged time to conception. This study examined whether women who worked night shift were more likely than those who did not to require fertility treatment to conceive a first birth, whether they had specific infertility diagnoses, and if such relationships were age-specific. Methods: In a retrospective data linkage study of 128,852 primiparous women, fertility treatment data were linked to the state perinatal registry for South Australia (1986-2002). Potential exposure to night shift work was assessed using a job-exposure matrix. First, the association between night shift work and fertility treatment was assessed among (1) all women, then (2) women in paid employment, using logistic regression. Interactions between age and shift work status were also examined. Secondly, among women who conceived with fertility treatment, we assessed associations between night shift work and type of infertility diagnosis. Potential confounders were considered in all analyses. Results: Among women ≤35 years, night shift workers were more likely to require fertility treatment (all: OR = 1.40, 95% CI 1.19-1.64; in paid employment: OR = 1.27, 95% CI 1.08-1.50). There were no associations among women >35 years. Ethnicity, socioeconomic status and smoking did not affect these results. Among women who underwent fertility treatment, night shift workers were more likely than day workers to have menstrual irregularity (OR = 1.42, 95% CI 1.05-1.91) or endometriosis (OR = 1.34, 95% CI 1.00-1.80). Conclusions: Night shift work may contribute to increased need for fertility treatment in younger women. This increased risk may reflect young women's vulnerability in terms of poor tolerance of night shift work, and/or lack of control and choice about shift schedule.

Aspectos en la responsabilidad legal y laboral en el síndrome de apnea-hipopnea obstructiva del sueño (SAHOS) / Legal and labor responsibility aspects related to obstructive sleep apnea-hypopnea syndrome (OSAHS)

Resumen La apnea del sueño y la somnolencia diurna excesiva (SDE) constituyen un gran riesgo para el desarrollo de actividades laborales, en especial las que se pueden considerar peligrosas y que implican responsabilidad legal; entre estas se encuentra la conducción de vehículos de transporte público, de carga y de maquinaria pesada. El trabajar por turnos y privarse de horas de sueño es también causa del aumento de accidentes laborales; este riesgo aumenta cuando los trabajadores y sus familiares no comprenden la dimensión real de este tipo de vida laboral y, por tanto, no actúan con responsabilidad respecto a su salud. Algunos autores consideran que la apnea del sueño y la SDE constituyen problemas de salud pública debido a su elevada prevalencia y a los altos costos que origina. Es importante que el Estado colombiano reglamente, por un lado, los aspectos de responsabilidad legal de los pacientes que desempeñan tareas riesgosas y están afectados por esta enfermedad y síntoma específico y, por el otro, las condiciones ocupacionales de los trabajadores que en la actualidad laboran por turnos y ven su salud afectada.

Abstract Sleep apnea and excessive daytime sleepiness (EDS) represent a major risk when developing working activities, especially those that are considered dangerous and involve legal responsibility, including handling public transport vehicles, cargo and heavy machinery. Shift work and sleep deprivation are also causes of increased work-related accidents; this risk increases when workers and their families do not understand the real dimension of this type of work life and, therefore, are not responsible for their health. Some authors think that sleep apnea and EDS are public health issues due to their high prevalence and economic burden. It is important that the Colombian State regulates, on the one hand, aspects of legal responsibility of patients who carry out hazardous tasks and are affected by this disease and specific symptoms and, on the other hand, the occupational conditions of the workers who work shifts and whose health is affected.