Relationship Between Shift Work and Lipid Profiles: A Prospective Cohort Study with Application of Ordinal Multilevel Modeling

Introduction:A very limited evidences are available that considered the relationship between Shift Work (SW) and lipid variables. Objectives: As the importance of this subject, this prospectively cohort study examines the association between SW and Body Mass Index (BMI) and lipid profiles among male workers using multilevel ordinal model Methods: This five years prospective cohort study has been conducted in random selected workers (using cluster sampling) who work in Esfahan’s Mobarakeh Steel Company (EMSC) (Iran) between 2011 and 2015. Results: The study sample included 1626 male workers (mean age=41.5). Among these subjects, 652 (40.01%), 183 (11.3%) and 791 (48.6%) were day workers, weekly rotating shift workers and routinely rotating. After controlling for several confounding variables, except HDL and Cholesterol, the odds ratio for high HDL was decreased by 26% (OR=0.74, P<0.001) and increased for TG by 36% in weekly rotating shift workers compared to day workers. Conclusion: Since weekly rotating shift workers had higher mean value of TG in their serum compared to day workers, they should limit eating high-fat diets in order to decrease risk of CVD.