Abstract: Background　Abnormal blood lipids show an increasing trend of prevalence in Chinese adults，among which elevated serum total cholesterol is a key risk factor for atherosclerotic cardiovascular disease. Currently，there is no consistency regarding the association of shift work and dyslipidemia. The number of Chinese shift workers is growing，but the association of shift work and unhealthy lifestyle with hypercholesterolemia has been rarely studied. Objective　To explore the association of shift length and unhealthy lifestyle with hypercholesterolemia. Methods　By use of a cluster sampling，the workers of a steel mill attending the 2017 occupational medical examination were selected. A survey was used to collect their demographics（sex，age，height，weight，family medicalhistory，and so on），shift situation（shift time，age for initiating shifts，and so on），and lifestyle（diet，physical activity，smoking，drinking，and so on） using a self-developed Health Assessment Questionnaire. Restricted cubic spline（RCS） was used to analyze the dose-response relationship between shift length and hypercholesterolemia. RCS regression line with knots was used to divide the participants by shift length. Multivariate Logistic regression model was used to analyze the relationship between shift and unhealthy lifestyle with hypercholesterolemia. The additive interaction between shift work and unhealthy lifestyle was estimated using relative excess risk due to interaction（RERI） and proportion attributable to interaction（AP）. Results　The analysis with Logistic regression models with shift length（0，greater than 0 but less than 23.8 years，and equal to or greater than 23.80 years） incorporated as independent variables，and hypercholesterolemia as the dependent variable，indicated that the risk of hypercholesterolemia increased with the prolongation of shift length in groups with shift length greater than 0 in two models（P<0.05）. But hypercholesterolemia had no significant association with either physical activity or DASH diet scoreafter adjusting for age，sex，hypertension，diabetes，family medical history and other variables（P>0.05）. Given all factors，workers with three or more unhealthy lifestyles were 1.703 times more likely to have hypercholesterolemia than those with no or only one unhealthy lifestyle. Workers with more than three unhealthy lifestyles who worked shifts within 23.8 years were 2.527 times more likely to develop hypercholesterolemia than those who never worked shifts and had no or only one unhealthy lifestyle. Among those who worked shifts for 23.8 years or less，it was found that there was an obvious additive interaction between shift shifts and unhealthy lifestyles，in which RERI was 1.559（0.186，2.928） and AP was 46.26（4.36，88.17）. Conclusion　Both shift work and unhealthy lifestyle can increase the risk of hypercholesterolemia in workers，and they have an additive effect.
 

Key words: Hypercholesterolemia, Shift, Unhealthy lifestyle, Life style, Additive effect, Steel workers

摘要： 背景　我国成人血脂异常患病率不断提高，血清总胆固醇升高是动脉粥样硬化性心血管疾病的重要危险因素。同时，我国倒班工人数量逐渐增加，目前对于倒班与血脂异常关系的研究结果并不相同，并且也较少有研究探讨倒班、不良生活方式与人群高胆固醇血症的关系。目的　探究倒班及不良生活方式对钢铁工人高胆固醇血症的联合作用。方法　采用整群抽样选择某钢厂2017年职业体检的员工，采用自行设计的《健康评估调查表》收集个人基本信息（性别、年龄、身高、体质量、家族史等）、倒班情况（倒班时间、倒班开始年龄等）、个人生活方式（饮食、体力活动、吸烟、饮酒等 ）；采用限制性立方样条（RCS）模型分析倒班年限与高胆固醇血症的剂量-反应关系；根据RCS结果，对倒班年限进行分组，使用多因素Logistic回归模型分析倒班和不良生活方式与高胆固醇血症的关系。通过计算超额相对危险度（RERI）、交互作用归因比（AP）来评价倒班与不良生活方式的相加交互作用。结果　根据RCS结果分为0 年、>0~年、23.8~年 3组，以是否患有高胆固醇血症为因变量，采用Logistic回归分析倒班与高胆固醇血症的关系，结果显示，在>0~年倒班年限中，倒班与高胆固醇血症呈正相关（P<0.05）。吸烟、饮酒、BMI均与高胆固醇血症呈正相关（P<0.05）。体力活动与DASH饮食评分在调整年龄、性别、高血压、糖尿病、家族史等变量后与高胆固醇血症无明显相关性（P>0.05）。当综合考虑时，不良生活方式评分3分及以上组合的工人患高胆固醇血症是不良生活方式评分1分及以下工人的1.703倍。倒班年限在23.8年内且不良生活方式评分3分及以上的工人发生高胆固醇血症的危险是从不倒班、不良生活方式评分1分及以下工人的2.527倍。仅研究倒班年限在23.8年以内的工人时，发现倒班与不良生活方式有明显的交互作用，其中RERI为1.559（0.186，2.928），AP为46.26（4.36，88.17）。结论　倒班与不良生活方式均会使工人患高胆固醇血症的风险增高，并且倒班与不良生活方式具有交互作用。

关键词: 高胆固醇血症, 倒班, 不良生活方式, 生活方式, 相加作用, 钢铁工人