Department of Health and Safety Convergence Science, Graduate School at Korea University, Seoul, Republic of Korea.
Environmental Health Research Division, National Institute of Environmental Research, Ministry of Environment, Incheon, Republic of Korea.
PLoS One. 2020 Dec 31;15(12):e0244821. doi: 10.1371/journal.pone.0244821. eCollection 2020.
Imbalances in thyroid-stimulating hormone (TSH) levels are associated with metabolic syndrome (MetS), and the underlying mechanism is partly in alignment with that of lead exposure causing MetS. Many studies have reported the association between lead exposure and MetS, but no study has considered the possibility of TSH mediating lead's effect on MetS. Therefore, we aimed to examine the association between lead exposure and MetS considering TSH as a partial mediator. The data of 1,688 adults (age ≥19 years) from the Korea National Health and Nutrition Examination Survey in 2013 were analyzed. The prevalence of MetS in the Korean population was 21.9%, and the geometric mean of blood lead and serum TSH levels were 1.96 μg/dL and 2.17 μIU/mL, respectively. The associations between blood lead levels, serum TSH levels, and MetS were determined through a multiple logistic regression analysis. Blood lead levels were positively associated with high TSH levels (upper 25%) with an odds ratio (OR) and 95% confidence interval (CI) of 1.79 (1.24, 2.58) per doubled lead levels. The increase in blood lead and serum TSH levels both positively increased the odds of developing MetS. The OR of MetS per doubling of blood lead level was 1.53 (1.00, 2.35), and was not attenuated after adjusting for TSH levels. These findings suggest that higher levels of blood lead are positively associated with serum TSH levels and MetS. By exploring the role of TSH as a partial mediator between lead and MetS, we verified that lead exposure has an independent relationship with MetS, regardless of TSH levels.
促甲状腺激素（TSH）水平失衡与代谢综合征（MetS）有关，其潜在机制与铅暴露导致 MetS 的部分机制一致。许多研究报告了铅暴露与 MetS 之间的关联，但没有研究考虑 TSH 是否介导铅对 MetS 的影响。因此，我们旨在研究 TSH 作为部分介导物时，铅暴露与 MetS 之间的关联。对 2013 年韩国国家健康和营养调查的 1688 名成年人（年龄≥19 岁）的数据进行了分析。韩国人口 MetS 的患病率为 21.9%，血液铅和血清 TSH 水平的几何平均值分别为 1.96μg/dL 和 2.17μIU/mL。通过多因素逻辑回归分析确定了血液铅水平、血清 TSH 水平与 MetS 之间的关系。血液铅水平与高 TSH 水平（上 25%）呈正相关，OR（优势比）和 95%CI（置信区间）分别为每增加两倍铅水平的 1.79（1.24，2.58）。血液铅和血清 TSH 水平的升高均增加了患 MetS 的几率。血液铅水平每增加一倍，患 MetS 的 OR 为 1.53（1.00，2.35），调整 TSH 水平后并未减弱。这些发现表明，血液铅水平升高与血清 TSH 水平和 MetS 呈正相关。通过探索 TSH 作为铅与 MetS 之间部分介导物的作用，我们验证了铅暴露与 MetS 之间存在独立关系，而与 TSH 水平无关。
