[Mediation effect of inflammatory biomarkers on the association between blood lead levels and blood pressure changes in Chinese adults].

Objective: To investigate the role of inflammatory biomarkers in the relationship between blood lead levels and blood pressure changes. Methods: A total of 9 910 people aged 18-79 years who participated in the China National Human Biomonitoring in 2017-2018 were included in this study. A self-made questionnaire was used to collect demographic characteristics, lifestyle and other information, and the data including height, weight and blood pressure were determined through physical examination. Blood and urinary samples were collected for the detection of blood lead and cadmium levels, urinary arsenic levels, white blood cells, neutrophils, lymphocytes, and hypersensitive C-reactive protein (hs-CRP). Weighted linear regression models were used to evaluate the associations between blood lead, inflammatory biomarkers and blood pressure. Mediation analysis was performed to investigate the role of inflammation in the relationship between blood lead levels and blood pressure changes. Results: The median (Q1, Q3) age of all participants was 45.4 (33.8, 58.4)years, including 4 984 males accounting for 50.3%. Multivariate logistic regression model analysis showed that after adjusting for age, gender, residence area, BMI, education level, smoking and drinking status, family history of hypertension, consumption frequency of rice, vegetables, and red meat, fasting blood glucose, total cholesterol, triglycerides, blood cadmium and urinary arsenic levels, there was a positive association between blood lead levels, inflammatory biomarkers and blood pressure (P<0.05). Each 2.71 μg/L (log-transformed) increase of the lead was associated with a 2.05 (95%CI: 0.58, 3.53) mmHg elevation in systolic blood pressure (SBP), 2.24 (95%CI: 1.34, 3.14) mmHg elevation in diastolic blood pressure (DBP), 0.25 (95%CI: 0.05, 0.46) mg/L elevation in hs-CRP, 0.16 (95%CI: 0.03, 0.29)×109/L elevation in white blood cells, and 0.11 (95%CI: 0.02, 0.21)×109/L elevation in lymphocytes, respectively. Mediation analysis showed that the levels of hs-CRP significantly mediated the association of blood lead with SBP, with a proportion about 3.88% (95%CI: 0.45%, 7.32%). The analysis also found that the levels of hs-CRP and neutrophils significantly mediated the association of blood lead with SBP, with a proportion about 4.10% (95%CI: 1.11%, 7.10%) and 2.42% (95%CI: 0.07%, 4.76%), respectively. Conclusion: This study suggests that inflammatory biomarkers could significantly mediate the association of blood lead levels and blood pressure changes.目的： 探索炎症生物标志物在成年人血铅暴露与血压水平变化间的中介效应。 方法： 以2017—2018年参与国家人体生物监测研究的9 910名18~79岁的成年人为对象，采用自制问卷收集人口学特征和生活方式等资料，通过体格检查测定身高、体重及血压等指标。采集调查对象的空腹静脉血及尿液，检测全血中铅、镉水平、炎症生物标志物如白细胞、中性粒细胞及淋巴细胞，血清中超敏C反应蛋白（hs-CRP）水平以及尿液中砷暴露水平。采用加权线性回归模型分析血铅、炎症生物标志物及血压变化之间的相互关联。采用中介效应模型分析炎症生物标志物在血铅暴露与血压水平变化间的中介效应。 结果： 9 910名对象的年龄［M（Q1，Q3）］为45.4（33.8，58.4）岁，其中男性4 984名，占50.3%。多因素logistic回归模型分析显示，调整年龄、性别、城乡、体质指数、教育程度、吸烟情况、饮酒情况、高血压家族史、大米摄入频率、蔬菜摄入频率、肉类摄入频率、空腹血糖、总胆固醇、甘油三酯、血镉和尿砷水平等因素后，血铅水平与血压、炎症生物标志物均存在正向关联（P<0.05），血铅水平每升高2.71 μg/L，收缩压、舒张压、hs-CRP、白细胞计数和淋巴细胞计数分别增加2.05（95%CI：0.58，3.53）mmHg、2.24（95%CI：1.34，3.14）mmHg、0.25（95%CI：0.05，0.46）mg/L、0.16（95%CI：0.03，0.29）×109/L和0.11（95%CI：0.02，0.21）×109/L。中介效应分析显示：hs-CRP、白细胞和中性粒细胞在血铅暴露导致SBP升高中的中介效应占比（95%CI）分别为3.88%（0.45%，7.32%）、4.10%（1.11%，7.10%）和2.42%（95%CI：0.07%，4.76%）。 结论： 炎症生物标志物在血铅暴露与血压水平变化的关联中存在中介效应。.