Department of Occupational and Environmental Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
PLoS One. 2021 Jul 23;16(7):e0255118. doi: 10.1371/journal.pone.0255118. eCollection 2021.
Non-alcoholic fatty liver disease (NAFLD), a common chronic liver disease, may progress to fibrosis, cirrhosis, hepatocellular carcinoma, and liver failure. But only a few cross-sectional studies have reported an association of NAFLD with working hours. This cohort study further examined the association between working hours and the development of NAFLD.
We included 79,048 Korean adults without NAFLD at baseline who underwent a comprehensive health examination and categorized weekly working hours into 35-40, 41-52, 53-60, and >60 hours. NAFLD was defined as the presence of fatty liver, in the absence of excessive alcohol use, as observed by ultrasound.
During a median follow-up of 6.6 years, 15,095 participants developed new-onset NAFLD (incidence rate, 5.55 per 100 person-years). After adjustment for confounders, the hazard ratios (95% confidence interval) for the development of NAFLD in 41-52, 53-60, and >60 working hours compared with that in 35-40 working hours were 1.07 (1.02-1.13), 1.06 (1.00-1.13), and 1.13 (1.05-1.23), respectively. Furthermore, the association remained significant after confounders were treated as time-varying covariates.
In this large-scale cohort, long working hours, especially >60 working hours a week, were independently associated with incident NAFLD. Our findings indicate that long working hours are a risk factor for NAFLD.
非酒精性脂肪性肝病（NAFLD）是一种常见的慢性肝病，可能会进展为纤维化、肝硬化、肝细胞癌和肝功能衰竭。但只有少数横断面研究报道了 NAFLD 与工作时间之间的关联。本队列研究进一步探讨了工作时间与 NAFLD 发展之间的关系。
我们纳入了 79048 名基线时无 NAFLD 的韩国成年人，他们接受了全面的健康检查，并将每周工作时间分为 35-40、41-52、53-60 和>60 小时。NAFLD 的定义为超声检查未发现过量饮酒情况下存在脂肪肝。
在中位随访 6.6 年期间，有 15095 名参与者新诊断出 NAFLD（发病率为 5.55/100 人年）。在调整混杂因素后，与每周工作 35-40 小时相比，每周工作 41-52、53-60 和>60 小时发生 NAFLD 的风险比（95%置信区间）分别为 1.07（1.02-1.13）、1.06（1.00-1.13）和 1.13（1.05-1.23）。此外，在将混杂因素视为时变协变量后，这种关联仍然显著。
在这项大规模队列研究中，长时间工作，尤其是每周工作>60 小时，与新发 NAFLD 独立相关。我们的研究结果表明，长时间工作是 NAFLD 的一个危险因素。
