Shifting Rhythms: A Systematic Review Exploring the Multifaceted Effects of Shift Work and Circadian Disruption on...

Shift work has long been studied as a contributing risk factor for cardiovascular disease. This study aims to provide a comprehensive summary of data regarding shiftwork and its impact on the cardiovascular system from the last decade. It explores the association of shift schedules with multiple aspects of cardiovascular disease and the physiological processes that lead up to it. It also identifies gaps in current knowledge regarding the topic. Two hundred and sixty-eight articles were gathered from PubMed, Google Scholar, and Science Direct using relevant medical subject headings (MeSH) strategy and advanced search using keywords including 'Shift work,' 'Night shift,' 'Occupational health,' 'Circadian rhythm,' 'Cardiovascular disease,' 'Cardiovascular health.' The search was conducted in April and completed in May 2023. Systemic reviews, meta-analysis, cohort and cross-sectional studies from the last 10 years were included, and assessment of multiple systematic reviews (AMSTAR), Newcastle Ottawa, and Joanna Briggs Institute (JBI) tools were used, respectively, for quality assessment. A total of 14 articles were included in our review, including five systematic reviews and meta-analyses, six prospective cohort studies, and three cross-sectional studies. Each study reported a significant association between shift work with some aspect of cardiovascular disease. An increase in the risk of myocardial infarction, coronary heart disease, hypertension, atherosclerosis, and metabolic syndrome is reported. Circadian disruption, unhealthy diet, and emotional and physiological stress contribute to these effects. Oxidative damage and inflammatory biomarkers appear to play a role in this process, but more research is warranted for a deeper understanding of these changes. Despite an abundance of evidence pointing towards the short-term and long-term harm to shift workers' cardiovascular health, there is limited research regarding the policies that are needed to better monitor cardiovascular damage in employees. The focus needs to shift toward prevention-based policies and their efficacy in workplace settings.