scholarly journals Effects of 2-hour nighttime nap on melatonin concentration and alertness during 12-hour simulated night work

2021 ◽  
Author(s):  
Sang-il LEE ◽  
Takeshi NISHI ◽  
Masaya TAKAHASHI ◽  
Shigekazu HIGUCHI
Keyword(s):  
Night Work ◽  
Melatonin Concentration

scholarly journals 0261 The effects of night work and light exposure on salivary melatonin concentration during work days and days off

2017 ◽  
Author(s):  
Stine Daugaard ◽  
Anne Helene Garde ◽  
Jens Peter Bonde ◽  
Jens Christoffersen ◽  
Aase Marie Hansen ◽  
...  
Keyword(s):  
Light Exposure ◽  
Night Work ◽  
Melatonin Concentration ◽  
Salivary Melatonin

The risks of night work

2011 ◽  
Author(s):  
Michael Price
Keyword(s):  
Night Work

scholarly journals Impact of Shift Work and Long Working Hours on Worker Cognitive Functions: Current Evidence and Future Research Needs

2021 ◽  
Vol 18 (12) ◽  
pp. 6540
Author(s):  
Veruscka Leso ◽  
Luca Fontana ◽  
Angela Caturano ◽  
Ilaria Vetrani ◽  
Mauro Fedele ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Cognitive Impairment ◽  
Sleep Disturbances ◽  
Working Hours ◽  
Night Work ◽  
Current Evidence ◽  
Future Research ◽  
Negative Effects ◽  
Long Working Hours ◽  
Main Determinants

Particular working conditions and/or organization of working time may cause important sleep disturbances that have been proposed to be predictive of cognitive decline. In this regard, circadian rhythm misalignment induced by exposure to night work or long working hours would be responsible for cognitive impairment. Nevertheless, evidence supporting this correlation is limited and several issues still need to be elucidated. In this regard, we conducted a systematic review to evaluate the association between shift/night work and cognitive impairment and address its main determinants. Information provided by the reviewed studies suggested that night work might have serious immediate negative effects especially on cognitive domains related to attention, memory and response inhibition. Furthermore, cognitive performance would progressively worsen over consecutive night shifts or following exposure to very long work shifts. Otherwise, conflicting results emerged regarding the possible etiological role that night work chronic exposure would have on cognitive impairment. Therefore, circadian rhythm desynchronization, lack of sleep and fatigue resulting from night work may negatively impact worker’s cognitive efficiency. However, in light of the considerable methodological variability of the reviewed studies, we proposed to develop a standardized research and evaluation strategy in order to obtain a better and comprehensive understanding of this topic.

scholarly journals Effects of circadian clock and light on melatonin concentration in Hypericum perforatum L. (St. John’s Wort)

2020 ◽  
Vol 61 (1) ◽  
Author(s):  
Ming-Hsiu Chung ◽  
Tzu-Shing Deng
Keyword(s):  
High Performance ◽  
Hypericum Perforatum ◽  
Fresh Weight ◽  
Melatonin Concentration ◽  
Long Day ◽  
Spatiotemporal Regulation ◽  
Circadian Time ◽  
Hypericum Perforatum L ◽  
Pharmaceutical Industries ◽  
Oriented Research

Abstract Background Melatonin acts as a signaling hormone and entraining agent in many organisms. We studied the spatiotemporal regulation and influence of light (photoperiods, intensities, and spectral qualities) on melatonin concentration in the medicinal herb Hypericum perforatum L. Furthermore, melatonin concentrations in the leaves of eight species of the Hypericum genus were compared and analyzed using high-performance liquid chromatography. Results Melatonin concentration was found to be the highest in its flowers and leaves. The leaves exhibited a rhythmic variation in melatonin concentration of approximately 24 h under both light–dark entrained (Zeitgeber time) and constant light [circadian time (CT)] conditions, with melatonin concentration peaking at approximately CT6 in the middle of the subjective day. Melatonin concentration was influenced significantly by not only photoperiods but also applied light’s wavelength and intensity. It was approximately six times higher under long-day conditions (18-h light:6-h dark) than under short-day photoperiods (10-h light:14-h dark) and was the highest (131 μg/g fresh weight [FW]) under treatment with blue light at an intensity of 45 µmol·m2/s of photons. The melatonin concentration of the two examined Hypericum spp., namely H. kouytchense Lev. and H. coris L., were approximately twice that of H. perforatum L. Conclusion Our findings provide first insights on melatonin-related functions and mechanisms in the circadian system of H. perforatum and useful resources for further melatonin-oriented research and possible applications in agriculture and pharmaceutical industries.

scholarly journals Implications of Lifestyle and Occupational Factors on the Risk of Breast Cancer in Shiftwork Nurses

Healthcare ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 649
Author(s):  
Javier Fagundo-Rivera ◽  
Regina Allande-Cussó ◽  
Mónica Ortega-Moreno ◽  
Juan Jesús García-Iglesias ◽  
Adolfo Romero ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Shift Work ◽  
Regression Tree ◽  
Night Work ◽  
Circadian Disruption ◽  
Classification And Regression Tree ◽  
Baseline Risk ◽  
Unhealthy Lifestyle ◽  
Cross Sectional ◽  
Occupational Factors

Shift work that involves circadian disruption has been highlighted as a likely carcinogenic factor for breast cancer in humans. Also, unhealthy lifestyle habits observed in night work nurses could be causally related to an increase in the incidence of estrogen-positive breast tumours in this population. Assessing baseline risk of breast cancer in nurses is essential. The objective of this study was to analyze the risk of breast cancer that nurses had in relation to their lifestyle and labour factors related to shift work. A cross-sectional descriptive study through a questionnaire about sociodemographic variables, self-perception of health, and working life was designed. The sample consisted of 966 nurses. The relationship between variables was tested. A binary logistic regression and a classification and regression tree were performed. The most significant labour variables in relation to the risk of breast cancer were the number of years worked (more than 16 years; p < 0.01; OR = 8.733, 95% CI = 2.811, 27.134) and the total years performing more than 3 nights per month (10 or more years; p < 0.05; OR = 2.294, 95% CI = 1.008, 5.220). Also, the nights worked throughout life (over 500; OR = 4.190, 95% CI = 2.118, 8.287) were significant in the analysis. Nurses who had or ever had breast cancer valued their self-perceived health more negatively (p < 0.001) and referred a lower quality of sleep (p < 0.001) than the non-cases nurses. The occupational factors derived from night work could have several impacts on nurses’ health and their family-work balance. Promoting healthy lifestyles, informing about shift work risks, and adjusting shift work schedules are critical methods to decrease the possible effects of circadian disruption in nurses.

scholarly journals Effect of work schedule on prospective antidepressant prescriptions in Sweden: a 2-year sex-stratified analysis using national drug registry data

BMJ Open ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. e023247 ◽  
Author(s):  
Amy L Hall ◽  
Göran Kecklund ◽  
Constanze Leineweber ◽  
Philip Tucker
Keyword(s):  
Shift Work ◽  
Anatomical Therapeutic Chemical ◽  
Night Shift ◽  
Primary Outcome Measure ◽  
Night Work ◽  
Registry Data ◽  
Chemical System ◽  
Future Research ◽  
Work Schedule ◽  
Drug Register

IntroductionDepression-related mood disorders affect millions of people worldwide and contribute to substantial morbidity and disability, yet little is known about the effects of work scheduling on depression. This study used a large Swedish survey to prospectively examine the effects of work schedule on registry-based antidepressant prescriptions in females and males over a 2-year period.MethodsThe study was based on an approximately representative sample (n=3980 males, 4663 females) of gainfully employed participants in the Swedish Longitudinal Occupational Survey of Health. Sex-stratified analyses were conducted using logistic regression. For exposure, eight categories described work schedule in 2008: ‘regular days’ (three categories of night work history: none, ≤3 years, 4+ years), ‘night shift work’, ‘regular shift work (no nights)’, ‘rostered work (no nights)’, ‘flexible/non-regulated hours’ and ‘other’. For the primary outcome measure, all prescriptions coded N06A according to the Anatomical Therapeutic Chemical System were obtained from the Swedish National Prescribed Drug Register and dichotomised into ‘any’ or ‘no’ prescriptions between 2008 and 2010. Estimates were adjusted for potential sociodemographic, health and work confounders, and for prior depressive symptoms.ResultsIn 2008, 22% of females versus 19% of males worked outside of regular daytime schedule. Registered antidepressant prescription rates in the postsurvey period were 11.4% for females versus 5.8% for males. In fully adjusted models, females in ‘flexible/non-regulated’ schedules showed an increased OR for prospective antidepressant prescriptions (OR=2.01, 95% CI=1.08 to 3.76). In males, odds ratios were most increased in those working ‘other’ schedules (OR=1.72, 95% CI=0.75 to 3.94) and ‘Regular days with four or more years’ history of night work’ (OR=1.54, 95% CI=0.93 to 2.56).ConclusionsThis study’s findings support a relationship between work schedule and prospective antidepressant prescriptions in the Swedish workforce. Future research should continue to assess sex-stratified relationships, using detailed shift work exposure categories and objective registry data where possible.

The Autonomy Paradox: How Night Work Undermines Subjective Well-Being of Internet-Based Freelancers

ILR Review ◽  
2018 ◽  
Vol 72 (1) ◽  
pp. 75-100 ◽  
Author(s):  
Andrey Shevchuk ◽  
Denis Strebkov ◽  
Shannon N. Davis
Keyword(s):  
New Economy ◽  
Well Being ◽  
Russian Language ◽  
Night Work ◽  
Subjective Well Being ◽  
Unique Data ◽  
Flexible Schedule ◽  
Partnership Status ◽  
Online Labor ◽  
Nonstandard Work Schedules

Nonstandard work schedules have important consequences for workers in the new economy. Using unique data on the work times of Internet-based freelancers, specifically, self-employed professionals participating in a Russian-language online labor market ( N = 4,280), the authors find that working at night has adverse effects on workers’ subjective well-being as measured by satisfaction with work–life balance, life satisfaction, and emotional exhaustion. Night work has differential effects on freelancers’ well-being based on gender, partnership status, and caregiving responsibilities. Highlighting the autonomy paradox, the authors’ findings document how freelancers’ discretionary application of a flexible schedule to work at night consequently undermines their well-being.

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