1 Institute and Department of Endocrinology and Metabolism, Shanghai Ninth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine , Shanghai, China .
2 Shanghai Changning Center for Disease Control and Prevention , Shanghai, China .
Thyroid. 2017 Dec;27(12):1566-1573. doi: 10.1089/thy.2017.0385.
Whether iodized salt increases the risk of thyroid disease has been strongly debated in China, especially in the urban areas of coastal regions, in recent years. This study aimed to investigate the status of iodized salt in terms of urinary and serum iodine concentration in urban coastal areas, and to explore further whether consumption of iodized salt or non-iodized salt is associated with autoimmune thyroid disease (AITD).
The data source was SPECT-China, a cross-sectional study in East China. A total of 1678 subjects were enrolled from 12 communities in downtown Shanghai. The type of salt consumed, the urinary iodine concentration (UIC), serum iodine, thyroid peroxidase antibodies (TPOAb), and thyroglobulin antibodies (TgAb) levels were obtained. AITD was defined as serum TPOAb and/or TgAb >60 kIU/L (TPO/TgAb [+]).
The prevalence of AITD was 10.5% in men and 21.4% in women. The median UIC and serum iodine concentration were 106.4 μg/L and 60.9 μg/L, respectively. Among all the subjects, 46.4% consumed non-iodized salt; the prevalence of iodine deficiency among those subjects was significantly higher than that of the subjects who consumed iodized salt (54.2% vs. 40.1%; p < 0.001). Consumption of non-iodized salt was positively associated with AITD in all participants (odds ratio [OR] = 1.49 [confidence interval (CI) 1.15-1.95]; p = 0.003) and in women (OR = 1.63 [CI 1.20-2.21]; p < 0.01) after multivariable adjustment. Additionally, the association between low UIC and AITD was observed among all subjects (OR = 1.50 [CI 1.10-2.05]; p = 0.01) and in women (OR = 1.45 [CI 1.02-2.07]; p = 0.038).
In coastal areas, which are believed to be rich in iodine, consuming non-iodized salt still led to lower UIC levels and a higher prevalence of iodine deficiency. The consumption of non-iodized salt and low UICs might be a risk factor for AITD, especially for women, which should be further confirmed by longitudinal studies.
近年来，在中国，尤其是沿海地区的城市，碘化盐是否会增加患甲状腺疾病的风险一直存在激烈的争论。本研究旨在调查城市沿海地区尿碘和血清碘浓度的碘化盐状况，并进一步探讨食用碘化盐或非碘化盐是否与自身免疫性甲状腺疾病（AITD）有关。
资料来源于中国 SPECT 研究，这是一项在华东地区进行的横断面研究。共纳入上海市市中心 12 个社区的 1678 名研究对象。获取了他们所食用盐的类型、尿碘浓度（UIC）、血清碘、甲状腺过氧化物酶抗体（TPOAb）和甲状腺球蛋白抗体（TgAb）水平。将血清 TPOAb 和/或 TgAb>60 kIU/L（TPO/TgAb[+]）定义为 AITD。
男性 AITD 的患病率为 10.5%，女性为 21.4%。UIC 和血清碘浓度的中位数分别为 106.4μg/L 和 60.9μg/L。在所有研究对象中，46.4%食用非碘盐；与食用碘盐者相比，食用非碘盐者碘缺乏的患病率显著更高（54.2%比 40.1%；p<0.001）。在所有参与者中，食用非碘盐与 AITD 呈正相关（OR=1.49[95%CI 1.15-1.95]；p=0.003），在女性中也呈正相关（OR=1.63[95%CI 1.20-2.21]；p<0.01），校正多变量后依然如此。另外，在所有研究对象中（OR=1.50[95%CI 1.10-2.05]；p=0.01）和女性中（OR=1.45[95%CI 1.02-2.07]；p=0.038），UIC 降低与 AITD 之间存在相关性。
在被认为富含碘的沿海地区，食用非碘盐仍会导致 UIC 水平降低和碘缺乏症患病率升高。食用非碘盐和 UIC 降低可能是 AITD 的一个危险因素，尤其是对女性而言，这需要进一步通过纵向研究来证实。
