Nitrate intake and the risk of thyroid cancer and thyroid disease.
Nitrate intake and the risk of thyroid cancer and thyroid disease.
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DOI：
10.1097/ede.0b013e3181d6201d
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发表时间：
2010-05
期刊：
影响因子：
--
通讯作者：
Cerhan JR
中科院分区：
文献类型：
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作者：
Ward MH;Kilfoy BA;Weyer PJ;Anderson KE;Folsom AR;Cerhan JR
硝酸盐是农业区饮用水中的一种污染物，在一些蔬菜中含量很高。硝酸盐与甲状腺对碘的摄取竞争，因此可能影响甲状腺功能。我们调查了从公共供水和饮食中摄取的硝酸盐与患甲状腺癌、自我报告的甲状腺功能减退和甲亢的风险之间的关系，研究对象是1986年在爱荷华州登记的21,977名老年妇女，她们使用相同的供水系统长达10年。我们使用硝酸盐测量的公共数据库(1955-1988)估计了饮用水中的硝酸盐摄入量。膳食硝酸盐摄入量是使用食物频率调查问卷和已发表文献中的水平来估计的。癌症发病率是在2004年确定的。我们发现，公共供水中的平均硝酸盐水平越高，以及用水量超过5 mg/L硝酸盐-N的时间越长，患甲状腺癌的风险就越高(≤在5 mg/L工作5年，相对风险[RR]=2.6[95%可信区间=1.1-6.2])。我们没有观察到与甲状腺功能减退症或甲状腺机能亢进症的患病率有关联。增加膳食硝酸盐摄入量与患甲状腺癌的风险增加(最高与最低四分位数，RR=2.9[1.0-8.1]；趋势P=0.046)和甲状腺功能减退症(优势比=1.2[95%CI=1.1-1.4])相关，但与甲状腺功能亢进症无关。硝酸盐可能在甲状腺癌的病因学中起作用，值得进一步研究。
Nitrate is a contaminant of drinking water in agricultural areas and is found at high levels in some vegetables. Nitrate competes with uptake of iodide by the thyroid, thus potentially affecting thyroid function. We investigated the association of nitrate intake from public water supplies and diet with the risk of thyroid cancer and self-reported hypothyroidism and hyperthyroidism in a cohort of 21,977 older women in Iowa who were enrolled in 1986 and who had used the same water supply for >10 years. We estimated nitrate ingestion from drinking water using a public database of nitrate measurements (1955–1988). Dietary nitrate intake was estimated using a food frequency questionnaire and levels from the published literature. Cancer incidence was determined through 2004. We found an increased risk of thyroid cancer with higher average nitrate levels in public water supplies and with longer consumption of water exceeding 5 mg/L nitrate-N (for ≤5 years at >5 mg/L, relative risk [RR] = 2.6 [95% confidence interval (CI) = 1.1–6.2]). We observed no association with prevalence of hypothyroidism or hyperthyroidism. Increasing intake of dietary nitrate was associated with an increased risk of thyroid cancer (highest vs. lowest quartile, RR = 2.9 [1.0–8.1]; P for trend = 0.046) and with the prevalence of hypothyroidism (odds ratio = 1.2 [95% CI = 1.1–1.4]), but not hyperthyroidism. Nitrate may play a role in the etiology of thyroid cancer and warrants further study.