National Cancer Control Institute, National Cancer Center, Goyang, South Korea.
Department of Family Medicine, Seoul National University Hospital, Seoul, South Korea.
J Clin Endocrinol Metab. 2020 Aug 1;105(8). doi: 10.1210/clinem/dgaa338.
Although a significant relationship has been reported between air pollution and thyroid function in limited samples or regions, few studies have addressed this association in the general population.
Using a nationwide sample of Korean adults, we investigated the association between exposure to air pollution and thyroid function, and whether this association differed between subgroups stratified according to age or body mass index (BMI).
We included 4704 adults in the final analysis and used each person's annual average exposure to 4 air pollutants, namely, particulate matter with an aerodynamic diameter less than or equal to 10 μm (PM10), nitrogen dioxide (NO2), sulfur dioxide, and carbon monoxide (CO). We measured serum thyrotropin (TSH) and free thyroxine (FT4) concentrations as indicators of thyroid function according to age and BMI.
The annual average exposure to NO2 and CO was significantly associated with an elevated TSH and reduced FT4 concentration after adjusting for possible confounding factors (all P < .05). In men, in addition to these 2 pollutants, PM10 exposure was positively associated with TSH level (P = .03). Age-stratified analysis showed stronger effects of NO2 and CO exposure in older than in younger adults. Exposure to these air pollutants was related to serum TSH and FT4 concentrations in people with overweight or obesity but not in those of normal weight.
This study provides the first evidence that air pollution exposure is linked to thyroid function in the general population and that this association may be stronger in older or overweight or obese adults.
尽管在有限的样本或地区中已经报道了空气污染与甲状腺功能之间存在显著关系，但很少有研究在一般人群中探讨这种关联。
本研究使用韩国成年人的全国性样本，调查了暴露于空气污染与甲状腺功能之间的关系，以及这种关联是否在根据年龄或体重指数（BMI）分层的亚组之间存在差异。
我们最终纳入了 4704 名成年人进行分析，并使用每个人每年平均暴露于 4 种空气污染物（即，空气动力学直径小于或等于 10μm 的颗粒物（PM10）、二氧化氮（NO2）、二氧化硫和一氧化碳（CO））的情况来评估。我们根据年龄和 BMI 测量了血清促甲状腺激素（TSH）和游离甲状腺素（FT4）的浓度作为甲状腺功能的指标。
在调整了可能的混杂因素后，NO2 和 CO 的年平均暴露与 TSH 升高和 FT4 浓度降低显著相关（均 P <.05）。在男性中，除了这 2 种污染物之外，PM10 的暴露还与 TSH 水平呈正相关（P =.03）。年龄分层分析表明，NO2 和 CO 的暴露在老年人中比在年轻人中对 TSH 水平的影响更强。在超重或肥胖的人群中，这些空气污染物的暴露与血清 TSH 和 FT4 浓度有关，但在体重正常的人群中则没有。
本研究首次提供了证据表明，空气污染暴露与一般人群的甲状腺功能有关，这种关联在老年人或超重或肥胖成年人中可能更强。
