Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, USA.
Wadsworth Center, New York State Department of Health, Albany, NY, USA.
J Nutr. 2020 Sep 1;150(9):2429-2434. doi: 10.1093/jn/nxaa178.
Severe iodine deficiency or excess during pregnancy can cause congenital hypothyroidism (CH). Iodine deficiency is common in pregnant women in the United States.
We conducted a nested case-control study in a cohort of ∼2.5 million births in California to determine whether iodine status is related to CH in a US population.
Dried blood spots from 907 newborns with CH identified by newborn screening and 909 unaffected controls matched by month of birth were obtained from the California Newborn Screening Program to measure whole-blood iodine concentration. Iodine status was compared between cases and controls, and logistic regression was used to assess the association between CH status and blood iodine concentrations. Iodine status was also compared between cases and controls among infants treated in a neonatal intensive care unit (NICU) because CH has been reported in infants exposed to high levels of iodine in the NICU.
Blood iodine concentrations did not differ significantly between cases (median: 20.0 ng/mL; IQR: 12.1-29.8 ng/mL) and controls (median: 20.3 ng/mL; IQR: 12.5-30.9 ng/mL; P = 0.59). Neither extremely high nor extremely low blood iodine concentrations (1st, 5th, 95th, and 99th percentiles of the distribution) were more common in cases. Among infants treated in NICUs, however, cases had significantly (P = 0.01) higher iodine (median: 22.7 ng/mL; IQR: 16.4-32.1 ng/mL) compared with controls (median: 17.3 ng/mL; IQR: 8.3-26.6 ng/mL).
CH cases did not have significantly higher or lower iodine in this population, which is reassuring given that maternal iodine deficiency is common in the United States. Among newborns in the NICU, CH cases had higher blood iodine concentrations compared with controls, suggesting that excess iodine exposure in the NICU could be causing CH. It may be beneficial to monitor iodine exposure from surgical procedures, imaging, and iodine-containing disinfectants and to consider non-iodine alternatives.
孕妇碘缺乏或碘过量可导致先天性甲状腺功能减退症（CH）。美国孕妇碘缺乏较为常见。
我们在加利福尼亚州约 250 万例出生队列中进行了一项巢式病例对照研究，以确定美国人群中碘状况与 CH 是否相关。
从加利福尼亚州新生儿筛查计划中获得了 907 例经新生儿筛查确定为 CH 的新生儿和 909 例未受影响的对照者的干血斑，以测量全血碘浓度。比较病例组和对照组之间的碘状态，并使用逻辑回归评估 CH 状态与血液碘浓度之间的关系。还比较了在新生儿重症监护病房（NICU）接受治疗的病例和对照组婴儿之间的碘状态，因为据报道，在 NICU 中接触高碘水平的婴儿会出现 CH。
病例组（中位数：20.0ng/mL；IQR：12.1-29.8ng/mL）和对照组（中位数：20.3ng/mL；IQR：12.5-30.9ng/mL；P=0.59）的血液碘浓度无显著差异。分布的第 1 百分位数、第 5 百分位数、第 95 百分位数和第 99 百分位数也没有极高或极低的血液碘浓度更常见于病例组。然而，在接受 NICU 治疗的婴儿中，病例组的碘水平明显高于对照组（P=0.01）（中位数：22.7ng/mL；IQR：16.4-32.1ng/mL 与中位数：17.3ng/mL；IQR：8.3-26.6ng/mL）。
在该人群中，CH 病例的碘含量没有明显升高或降低，这令人放心，因为美国普遍存在孕妇碘缺乏的情况。与对照组相比，NICU 中的 CH 病例血液碘浓度更高，这表明 NICU 中过量的碘暴露可能导致 CH。监测手术、影像学和含碘消毒剂的碘暴露，并考虑使用非碘替代品可能会有所帮助。
