The impact of night-shift work on platelet function in healthy medical staff

Endothelial Dysfunction and Hemostatic System Activation in Relation to Shift Workers, Social Jetlag, and Chronotype in Female Nurses

Circadian misalignment, due to shiftwork and/or individual chronotype and/or social jetlag (SJL), quantified as the difference between internal and social timing, may contribute to cardiovascular disease. Markers of endothelial dysfunction and activation of the coagulation system may predict cardiovascular pathology. The present study aim was to investigate the effects of shift work, SJL, and chronotype on endothelial function and coagulation parameters. One hundred female nurses underwent endothelial function testing using the EndoPAT and blood sampling for coagulation markers, repeated at 06:00-9:00 and 18:00-21:00. We found that compared with day workers, endothelial function and fibrinogen levels were lower (p = 0.001, p = 0.005, respectively) and the procoagulant parameters of plasminogen activator inhibitor-1 (PAI-1) and heparanase level and activity were higher amongst shift workers (p = 0.009, p = 0.03, p = 0.029, respectively). High SJL was associated with lower endothelial function (p = 0.002) and higher PAI-1, heparanase procoagulant activity, heparanase level, and D-Dimer level (p = 0.004, p = 0.003, p = 0.021, p = 0.006, respectively). In the late chronotype, PAI-1 and heparanase procoagulant activity were higher than in the early chronotype (p = 0.009, p = 0.007, respectively). Diurnal variation was found for PAI-1, von-Willebrand factor (vWF), heparanase, and heparan-sulfate with higher levels in the mornings. The correlation between shift/day workers and SJL or chronotype was moderately strong, indicating that SJL and chronotype are independent factors. In conclusion, findings suggest endothelial impairment and increased thrombotic risk in nurses working in shifts or with high SJL or late chronotype. The thrombotic risk is increased in the morning independent of circadian misalignment cause. These findings strengthen the importance of the alliance to the biological daily rhythm in daily life. Further research is needed to evaluate inhibitors of heparanase to attenuate the thrombotic risk in individuals with circadian misalignment.

Adverse Associations of Long-Term Exposure to PM2.5 and Its Components with Platelet Traits among Subway Shift-Workers without Air Purifier Use

Air purifier use, shift work, and long-term exposure to fine particulate matter (PM2.5) are linked to platelet abnormality. However, the role of air purifier use and shift work in the individual or joint associations of PM2.5 and its components with platelet indices are largely unknown. A total of 8772 participants were recruited from a population of subway workers in China. PM2.5 and its component data were obtained from the Tracking Air Pollution in China dataset. The role of air purifier use and shift work in the association between PM2.5 and its components and platelet indices were analyzed. Among shift workers without air purifier use, positive associations of PM2.5 and each component in PM2.5 with the mean platelet volume (MPV) or platelet counts (PLT) were observed, whereas negative associations of PM2.5 and each component in PM2.5 with the platelet distribution width (PDW) were observed. Furthermore, estimated changes (95%CIs) in PLT, MPV, and PDW in response to each 10th percentile increment in the mixture of PM2.5 and its components were 0.8657 (0.2496, 1.4819), 0.0192 (0.0054, 0.0329), and -0.0648 (-0.0945, -0.0351), respectively, and sulfate in PM2.5 was the major contributor to those associations. Long-term exposure to PM2.5 and its components was related to increased platelet disorders among shift workers without air purifier use, and those associations were mainly attributed to sulfate in PM2.5.

Molecular-Level Dysregulation of Insulin Pathways and Inflammatory Processes in Peripheral Blood Mononuclear Cells by Circadian Misalignment

Circadian misalignment due to night work has been associated with an elevated risk for chronic diseases. We investigated the effects of circadian misalignment using shotgun protein profiling of peripheral blood mononuclear cells taken from healthy humans during a constant routine protocol, which was conducted immediately after participants had been subjected to a 3-day simulated night shift schedule or a 3-day simulated day shift schedule. By comparing proteomic profiles between the simulated shift conditions, we identified proteins and pathways that are associated with the effects of circadian misalignment and observed that insulin regulation pathways and inflammation-related proteins displayed markedly different temporal patterns after simulated night shift. Further, by integrating the proteomic profiles with previously assessed metabolomic profiles in a network-based approach, we found key associations between circadian dysregulation of protein-level pathways and metabolites of interest in the context of chronic metabolic diseases. Endogenous circadian rhythms in circulating glucose and insulin differed between the simulated shift conditions. Overall, our results suggest that circadian misalignment is associated with a tug of war between central clock mechanisms controlling insulin secretion and peripheral clock mechanisms regulating insulin sensitivity, which may lead to adverse long-term outcomes such as diabetes and obesity. Our study provides a molecular-level mechanism linking circadian misalignment and adverse long-term health consequences of night work.

Night shift work was associated with functional outcomes in acute ischemic stroke patients treated with endovascular thrombectomy

Objective

This study aimed to explore the impact of late night shift work on the functional outcomes of patients with acute ischemic stroke (AIS) treated with endovascular thrombectomy (EVT).

Methods

Consecutive AIS patients who underwent EVT between June 2019 and June 2021 were enrolled and divided into non-night shift work and night shift work groups based on their occupational histories. The primary outcome was the modified Rankin Scale score defined 3-month functional outcome. The secondary outcomes were 3-month mortality, symptomatic intracerebral hemorrhage (sICH), ICH and early recanalization.

Results

A total of 285 patients were enrolled, 35 patients (12.3%) were night shift workers, who were younger (P < 0.001) and had a significantly higher prevalence of smoking (P < 0.001), hyperlipidemia (P = 0.002), coronary heart disease (P = 0.031), and atrial fibrillation (P < 0.001). The 3-month favorable outcomes were achieved in 44.8% and 25.7% of patients in the non-night shift work and night shift work groups, respectively (adjusted odds ratio [OR]: 0.24, 95% CI: 0.10-0.57; adjusted P = 0.001). No difference was found in 3-month mortality (adjusted OR: 0.43; 95% CI: 0.14-1.25, adjusted P = 0.121), rates of ICH (adjusted OR: 0.73; 95% CI: 0.33-1.60; adjusted P = 0.430), sICH (adjusted OR: 0.75; 95% CI: 0.34-1.67; adjusted P = 0.487), or early successful recanalization (adjusted OR: 0.42; 95% CI: 0.12-1.56; adjusted P = 0.197). These results were consistent after PSM analysis.

Conclusion

Our findings suggest that late night shift work is significantly associated with unfavorable outcomes in patients with AIS after EVT.

The Impact of Shift Work on Occupational Health Indicators among Professionally Active Adults: A Comparative Study

The analysis of the impact of shift work on occupational health still needs further contributions. Therefore, we developed this research with the purpose of assessing the impact of shift work on occupational health indicators, namely burnout, work-engagement, occupational self-efficacy, and mental health functioning (symptoms of depression and anxiety), by comparing workers who did shift work (44.2% of participants) with workers who did not (55.8% of participants). A total of 695 Portuguese professionally active adults between 18 and 73 years of age (M_age = 37.71; SD = 12.64) participated in this study and completed a survey containing a sociodemographic questionnaire and four occupational health measures: The Burnout Assessment Tool, The Work-Engagement questionnaire (UWES), The Occupational Self-Efficacy Questionnaire, and the BSI-18 for mental health symptoms. Results showed statistically significant differences (p < 0.05) for all indicators, demonstrating that participants who worked shifts presented lower scores of work-engagement and occupational self-efficacy, and higher scores of burnout, depression, and anxiety when compared to participants who did not work shifts. Linear regressions showed that shift work explained significant but low percentages of anxiety symptoms, low work-engagement, depression symptoms, low occupational self-efficacy, and burnout. We concluded that non-standard working hours (by shifts) are detrimental to employee occupational health, by increasing the risk of anxiety and depression levels, and burnout, and by reducing work-engagement (as a well-being indicator) and occupational self-efficacy perceptions.

Acute Myocardial Infarction and Daylight Saving Time Transitions: Is There a Risk?

Available evidence on the risk of acute myocardial infarction (AMI) in the days after the spring daylight saving time (DST) transition suggests either a modest increase or no risk increase. Partial sleep deprivation and enhanced circadian clock misalignment have been implicated as the underlying mechanisms for increased AMI risk, probably via enhanced thrombo-inflammatory processes and activation of the sympathetic nervous system. Most of the studies, as we suggest as a perspective here, have used potentially inappropriate control periods, including the two post-transitional weeks, because adjustment after the spring DST transition lasts at least four weeks for all chronotypes and probably even beyond this period for late chronotypes. The most plausible conclusions, at the moment, for the risk of AMI after the spring DST transition are: (1) the risk is increased, (2) a relatively modest risk increase could be currently underestimated or in some studies undetected, (3) late chronotypes and/or individuals with high levels of social jetlag (a proxy for circadian clock misalignment) could be more affected by the phenomenon, and (4) underlying pathophysiological mechanisms should be further explored. As a significant part of world's population continues to be affected by the biannual clock change, the question of increased AMI risk in the post-transitional period remains an intriguing public health issue.

Development of Tandem Mass Tag Labeling Method for Lipid Molecules Containing Carboxy and Phosphate Groups, and Their Stability in Human Serum

In clinical lipidomics, it is a challenge to measure a large number of samples and to reproduce the quantitative results. We expanded the range of application of the tandem mass tag (TMT) method, which is widely used in proteomics, to lipidomic fields. There are various types of lipid molecule, for example, eicosanoids have a carboxyl group and phosphatidic acid has a phosphate group. We modified these functional groups simultaneously with TMT. This approach allows for a single analysis by mixing six samples and using one of the six samples as a bridging sample; the quantitative data can be easily normalized even if the number of measurements increases. To accommodate a large number of samples, we utilize a pooled serum sample of 300 individuals as a bridging sample. The stability of these lipid molecules in serum was examined as an analytical validation for the simultaneous TMT labeling. It was found that the stability of these lipid molecules in serum differs greatly depending on the lipid species. These findings reaffirmed the importance of proper sample preparation and storage to obtain reliable data. The TMT labeling method is expected to be a useful method for lipidomics with high-throughput and reliable reproducibility.

Shift Workers at Risk for Metabolic Syndrome

In this highly digitalized era, sleep disorders are becoming more common and are associated with an increased burden of chronic disease. Shift workers are at an increased risk for both sleep disorders and metabolic syndrome. In this article, the authors outline the connection between circadian discordance, hormonal imbalance, and the development of metabolic syndrome in shift workers. Based on a literature review of animal model studies, observational studies, and clinical trials conducted between August and October of 2018, the authors offer several clinical interventions, including work schedules, light therapy, medications, and dietary habits to improve the circadian synchronicity of shift workers and reduce their risk of morbidity and mortality. It is important for physicians to be familiar with the consequences of shift work and ways to mitigate the risks for this patient population.

Chronobiological Influence Over Cardiovascular Function: The Good, the Bad, and the Ugly

Essentially all biological processes fluctuate over the course of the day, observed at cellular (eg, transcription, translation, and signaling), organ (eg, contractility and metabolism), and whole-body (eg, physical activity and appetite) levels. It is, therefore, not surprising that both cardiovascular physiology (eg, heart rate and blood pressure) and pathophysiology (eg, onset of adverse cardiovascular events) oscillate during the 24-hour day. Chronobiological influence over biological processes involves a complex interaction of factors that are extrinsic (eg, neurohumoral factors) and intrinsic (eg, circadian clocks) to cells. Here, we focus on circadian governance of 6 fundamentally important processes: metabolism, signaling, electrophysiology, extracellular matrix, clotting, and inflammation. In each case, we discuss (1) the physiological significance for circadian regulation of these processes (ie, the good); (2) the pathological consequence of circadian governance impairment (ie, the bad); and (3) whether persistence/augmentation of circadian influences contribute to pathogenesis during distinct disease states (ie, the ugly). Finally, the translational impact of chronobiology on cardiovascular disease is highlighted.

Sleep in the United States Military

The military lifestyle often includes continuous operations whether in training or deployed environments. These stressful environments present unique challenges for service members attempting to achieve consolidated, restorative sleep. The significant mental and physical derangements caused by degraded metabolic, cardiovascular, skeletomuscular, and cognitive health often result from insufficient sleep and/or circadian misalignment. Insufficient sleep and resulting fatigue compromises personal safety, mission success, and even national security. In the long-term, chronic insufficient sleep and circadian rhythm disorders have been associated with other sleep disorders (e.g., insomnia, obstructive sleep apnea, and parasomnias). Other physiologic and psychologic diagnoses such as post-traumatic stress disorder, cardiovascular disease, and dementia have also been associated with chronic, insufficient sleep. Increased co-morbidity and mortality are compounded by traumatic brain injury resulting from blunt trauma, blast exposure, and highly physically demanding tasks under load. We present the current state of science in human and animal models specific to service members during- and post-military career. We focus on mission requirements of night shift work, sustained operations, and rapid re-entrainment to time zones. We then propose targeted pharmacological and non-pharmacological countermeasures to optimize performance that are mission- and symptom-specific. We recognize a critical gap in research involving service members, but provide tailored interventions for military health care providers based on the large body of research in health care and public service workers.