Shift Work Increases the Risk of Circadian Syndrome Rather than Metabolic Syndrome: A Cross-Sectional Study of NHANES 2005–2010

<b><i>Introduction:</i></b> Shift work disrupts sleep-wake cycles and may lead to adverse health outcomes, including cardiovascular disease and metabolic disorders. This study examines the association between shift work and the risks of metabolic syndrome (MetS) and circadian syndrome (CircS) in U.S. workers. <b><i>Methods:</i></b> We analyzed data from 4173 participants aged 18 and above from the National Health and Nutrition Examination Survey (NHANES) spanning 2005-2010. Shift work status was determined based on work hours, and MetS and CircS were defined using established criteria. Statistical analyses included weighted multivariate logistic regression models, weighted multivariate linear regression models, and inverse probability weighted propensity score matching to ensure accurate comparison between shift and nonshift workers. <b><i>Results:</i></b> The study found no significant association between shift work and the prevalence of MetS. However, shift workers exhibited a higher prevalence of CircS compared with nonshift workers. This association was more pronounced in specific subgroups, including those under 60 years of age and various ethnicities. The study highlights the heightened risk of CircS among shift workers, underscoring the potential impact of shift work on circadian rhythm disruptions. <b><i>Conclusion:</i></b> Shift work is associated with an increased risk of CircS but not MetS, according to NHANES 2005-2010 data.