Balachandar Rakesh, Viramgami Ankit, Bagepally Bhavani Shankara, Upadhyay Kuldip
ICMR-National Institute of Occupational Health, Meghaninagar, Ahmedabad, 380016 India.
ICMR-National Institute of Epidemiology, Ayapakkam, Chennai, 600077 India.
Indian J Clin Biochem. 2023 Oct;38(4):426-436. doi: 10.1007/s12291-023-01113-8. Epub 2023 Jan 26.
Chronic Lead (Pb) exposure is associated with disrupting certain endocrine levels and is referred to as an endocrine disruptor. Thyroid hormones, involved in regulating numerous physiological functions, are reported with conflicting associations with chronic Pb exposure. This study broadly evaluated the association between long-term lead exposure and thyroid function parameters. In this systematic review, the observational studies documenting the changes in thyroid function parameters between the chronically Pb-exposed and controls were systematically identified from PubMed-Medline, Scopus, and Embase digital databases from the beginning to March 31, 2022. The protocol was previously registered with PROSPERO (ID: CRD42022315520) and executed following PRISMA 2020 guidelines. The random-effects model was used to analyze the mean differences in thyroid function parameters between groups. The classical statistic was applied to assess heterogeneity, while the Newcastle Ottawa Scale was used to assess the risk of various biases. Where data allowed, sub-group, sensitivity, and meta-regression analyses were carried out. The current systematic review included fifteen observational studies. The Pb-exposed have a higher mean blood Pb level [i.e. 28.07 (95% CI 21.43-34.72) µg/dl], significantly higher free T [(i.e. 0.48 pg/dl (95% CI 0.05-0.95)] and trend of higher T. T, FT, and TSH levels than controls with high heterogeneity ( > 85%). Considering the important role of thyroid hormone in multiple biological functions, the present findings emphasize the requisite for high-quality studies to investigate the association between levels of thyroid function parameters among individuals known for cumulative exposure to Pb.
The online version contains supplementary material available at 10.1007/s12291-023-01113-8.
长期接触铅（Pb）与某些内分泌水平紊乱有关，被称为内分泌干扰物。甲状腺激素参与调节多种生理功能，据报道，其与长期铅接触的关联存在矛盾。本研究广泛评估了长期铅暴露与甲状腺功能参数之间的关联。在这项系统评价中，从PubMed-Medline、Scopus和Embase数字数据库中系统地识别了记录长期铅暴露组与对照组甲状腺功能参数变化的观察性研究，检索时间从建库至2022年3月31日。该方案先前已在PROSPERO注册（ID：CRD42022315520），并按照PRISMA 2020指南执行。采用随机效应模型分析各组甲状腺功能参数的平均差异。应用经典统计量评估异质性，同时使用纽卡斯尔渥太华量表评估各种偏倚的风险。在数据允许的情况下，进行了亚组分析、敏感性分析和Meta回归分析。当前的系统评价纳入了15项观察性研究。铅暴露组的平均血铅水平较高[即28.07（95%CI 21.43 - 34.72）μg/dl]，游离T4显著更高[即0.48 pg/dl（95%CI 0.05 - 0.95）]，且T4、FT4和TSH水平有高于对照组的趋势，异质性较高（>85%）。考虑到甲状腺激素在多种生物学功能中的重要作用，本研究结果强调需要高质量的研究来调查累积接触铅的个体中甲状腺功能参数水平之间的关联。
在线版本包含可在10.1007/s12291-023-01113-8获取的补充材料。
