摘要目的:探讨医务工作者近5年内夜班总数对其BMI的影响。方法:本研究为横断面研究。采用便利抽样法，于2016年1月—2020年12月抽取济宁医学院附属医院医务工作者的资料，医务工作者的体检数据来源于体检中心的电子信息系统，医务工作者的夜班数量及基本情况从人力资源管理部门提取。本研究中的协变量包括分类变量与连续变量2种，其中分类型变量包括性别、职称、工作类型，连续型变量包括年龄、工作年限、收缩压、舒张压、白细胞、红细胞、血红蛋白、平均血红蛋白量、血小板、ALT、总胆红素、总蛋白、白蛋白、尿素、肌酐、尿酸、三酰甘油、总胆固醇、HDL-C、LDL-C、葡萄糖。使用广义加法模型和平滑曲线拟合处理夜班数量与BMI的关系。结果:最终选择908名医务工作者的数据进行分析。908名医务工作者5年内平均夜班数量为（339.0±30.8）个，平均BMI为（22.88±2.08）kg/m 2。调整混杂因素后，夜班数量与BMI呈非线性关系，拐点为634个。在拐点左侧，夜班数量与BMI间无显著关系（ P=0.829）。拐点右侧两者之间关系显著，效应大小和95%可信区间分别为0.02和0.01～0.03。 结论:医务工作者近5年夜班数量>634个后，随着夜班数量增加，其BMI值显著增加。医院管理者可对每年夜班数量进行测算和规划，以降低轮值夜班对医务工作者健康的影响。

abstractsObjective:To explore effects of the total number of night shifts on BMI of medical workers in recent 5 years.Methods:This study was a cross-sectional study. Using the convenient sampling method, data of medical workers in Affiliated Hospital of Jining Medical University were collected from January 2016 to December 2020. The medical examination data of medical workers were obtained from the electronic information system of medical examination center, and the number of night shift and basic information of medical workers are extracted from the human resource management department. The covariates in this study included categorical variables and continuous variables. Categorical variables included gender, job title and job type. Continuous variables included age, working years, systolic blood pressure, diastolic blood pressure, white blood cells, red blood cells, hemoglobin, average hemoglobin volume, platelets, ALT, total bilirubin, total protein, albumin, urea, creatinine, uric acid, triacylglycerol, Total cholesterol, HDL-C, LDL-C and glucose. The relationship between the number of night shift and BMI was processed by generalized addition model and smoothing curve fitting.Results:Finally, a total of 908 medical workers were selected for data analysis. The average number of night shifts for 908 medical workers in 5 years was (339.0±30.8) , and the average BMI was (22.88±2.08) kg/m 2. After adjusting for confounding factors, the number of night shift showed a non-linear relationship with BMI, and the number of inflection points was 634. On the left of the inflection point, there was no significant relationship between the number of night shifts and BMI ( P=0.829) . The relationship between the two on the right side of the inflection point was significant, the effect size and 95% confidence interval were 0.02 and 0.01-0.03, respectively. Conclusions:BMI value of medical workers increases significantly with the increase of night shift number when the number of night shift is more than 634 in recent 5 years. Hospital managers can calculate and plan the number of night shifts per year to reduce the effect of night shifts on the health of medical workers.