TY - JOUR T1 - Night shift work and abnormal liver function: is non-alcohol fatty liver a necessary mediator? JF - Occupational and Environmental Medicine JO - Occup Environ Med SP - 83 LP - 89 DO - 10.1136/oemed-2018-105273 VL - 76 IS - 2 AU - Feng Wang AU - Liuzhuo Zhang AU - Suyang Wu AU - Wentao Li AU - Miaomiao Sun AU - Wenting Feng AU - Ding Ding AU - Samuel Yeung-shan Wong AU - Peng Zhu AU - Greg J Evans AU - Yun Kwok Wing AU - Jihui Zhang AU - Jelle J Vlaanderen AU - Roel C H Vermeulen AU - Yanfang Zhang AU - Emily Ying-yang Chan AU - Zhimin Li AU - Lap Ah Tse Y1 - 2019/02/01 UR - http://oem.bmj.com/content/76/2/83.abstract N2 - Objectives Accumulated evidence implies that night shift work may trigger liver dysfunction. Non-alcoholic fatty liver (NAFL) is suggested to be a necessary mediator in this process. This study aimed to examine the relationship between night shift work and elevated level of alanine transaminase (e-ALT) of workers and investigate the potential mediation effect of NAFL.Methods This study included all male workers from the baseline survey of a cohort of night shift workers. Information on demographics, lifestyle and lifetime working schedule was collected by face-to-face interview. Liver sonography was used to identify NAFL cases. Serum ALT level was detected by an automatic biochemical analyser. e-ALT was defined as ALT >40 U/L. Logistic regression models were used to evaluate ORs, and mediation analysis was employed to examine the mediation effect.Results Among 4740 male workers, 39.5% were night shift workers. Night shift workers had an increased risk of e-ALT (OR, 1.19, 95% CI 1.00 to 1.42). With the increase in night shift years, the OR of e-ALT increased from 1.03 (95% CI 0.77 to 1.36) to 1.60 (95% CI 1.08 to 2.39) among workers without NAFL. A similar trend was not found among workers with NAFL. In addition, no significant mediation effect of NAFL in the association between night shift work and e-ALT was found.Conclusions Night shift work is positively associated with abnormal liver function, in particular among workers without NAFL. Shift work involving circadian disruption is likely to exert a direct effect on liver dysfunction rather than rely on the mediation effect of NAFL. ER -