The workers and employees in various institutions are subjected to different shifts and work schedules. The employees work not only at daytime but also during odd hours at night. The biological clock of an individual is often altered during night shifts. This affects the psychosocial well-being and circadian nutritional intake of the worker. Disturbance in circadian rhythm results in the development of metabolic disorders such as hypertension, dyslipidemia, dysglycemia, and abdominal obesity. In the present review, we discuss the nature of shift work, sleep/wake cycle of an individual, chrononutrition, dietary habits, and meal changes with regard to timing and frequency, related to shift work. We also discuss the relationship between nutritional intake and psychosocial well-being among shift workers. The review may be beneficial for prevention of metabolic disorders and maintaining sound psychological condition in shift workers.
The synthesis and secretion of cortisol are controlled by the hypothalamic-pituitary-adrenal axis. Cortisol exhibits a proper 24-h circadian rhythm that affects the brain, the autonomic nervous system, the heart, and the vasculature that prepares the cardiovascular system for optimal function during these anticipated behavioral cycles. A literature search was conducted using databases such as Google Scholar, PubMed, and Scopus. Relevant search terms included "circadian rhythm and cardiovascular", "cortisol", "cortisol and acute coronary syndrome", "cortisol and arrhythmias", "cortisol and sudden cardiac death", "cortisol and stroke", and "cardioprotective agents". A total of 120 articles were obtained on the basis of the above search. Lower levels of cortisol were seen at the beginning of sleep, while there was a rise towards the end of sleep, with the highest level reached at the moment the individual wakes up. In the present review, we discuss the role of 11β-hydroxysteroid dehydrogenase (11β-HSD1), which is a novel molecular target of interest for treating metabolic syndrome and type-2 diabetes mellitus. 11β-HSD1 is the major determinant of cortisol excess, and its inhibition alleviates metabolic abnormalities. The present review highlights the role of cortisol, which controls the circadian rhythm, and describes its effect on the cardiovascular system. The review provides a platform for future potential cardioprotective therapeutic agents.
In several regions of the world, the recent Coronavirus Disease-2019 (COVID-19) pandemic outbreak increased morbidity and mortality. The pandemic situation disrupted many workers' previously established lifestyles. The main aim of the present review was to describe the circadian disruption and occupational toxicant exposure affecting the immunity of shift workers during the SARS CoV-2 pandemic. We retrieved pertinent published literature from the Google Scholar, PubMed, and Scopus databases. In the present review, we discuss the circadian rhythm involving the hypothalamic-pituitary-adrenal (HPA) axis at the molecular level, its disruption, occupational toxicant exposure causing immunomodulatory effects, and the role of immunity during the SARS CoV-2 pandemic. The severity of the progression of the viral infection depends on multiple factors affecting immunity. Hence, shift workers may need to be aware of those factors such as circadian rhythm disruption as well as occupational toxicant exposure. The timing of shift workers' energy intake is also important concerning the shift of the workers. The information in the present review may be important for all workers who are at risk during the pandemic. In the absence of any published literature related to association of circadian rhythm disruption with occupational toxicant exposure, the present review may have greater importance.