Department of Pharmacology, Pediatrics and Organic Chemistry, Miguel Hernández University, San Juan de Alicante, Alicante, Spain.
Department of Clinical Medicine, Miguel Hernández University, San Juan de Alicante, Alicante, Spain.
PLoS One. 2019 Jul 18;14(7):e0220040. doi: 10.1371/journal.pone.0220040. eCollection 2019.
Maternal iodine deficiency is related to high neonatal thyroid-stimulating hormone (TSH) values, with the threshold of 5 mIU/L recommended as an indicator of iodine nutrition status. The objective of this study was to analyse possible risk factors for increased TSH that could distort its validity as a marker of iodine status. The clinical relevance of this research question is that if the factors associated with iodine deficiency are known, iodine supplementation can be introduced in risk groups, both during pregnancy and in newborns.
A case-control study was carried out in a sample of 46,622 newborns in 2002-2015 in Spain. Of these, 45,326 had a neonatal TSH value ≥5 mIU/L. The main variable was having TSH ≥5 mIU/L and the secondary variables were: sex, gestational age, day of sample extraction and maternal origin. Associated factors were analysed through a logistic regression model, calculating the odds ratio (OR).
The factors associated with this outcome were: male sex (OR = 1.34, 95% CI: 1.20-1.50, p<0.001), originating from an Asian/Oceanic country (OR = 0.80, 95% CI: 0.54-1.20, p = 0.536) or Europe (OR = 0.80, 95% CI: 0.66-0.96, p = 0.285) (including Spain, OR = 1) [p<0.001 for America (OR = 0.54, 95% CI: 0.44-0.68) and p = 0.025 for Africa (OR = 0.78, 95% CI: 0.62-0.97)] and fewer days from birth to sampling (OR = 0.80, 95% CI: 0.77-0.82, p<0.001).
The risk of high neonatal TSH without congenital hypothyroidism is higher in males, decreases with a greater number of days from birth to extraction, and is dependent on maternal ethnicity but not on gestational age.
母体碘缺乏与新生儿促甲状腺激素（TSH）值升高有关，推荐 5mIU/L 作为碘营养状况的指标。本研究旨在分析可能导致 TSH 升高的危险因素，因为这会影响其作为碘状态标志物的有效性。该研究问题的临床意义在于，如果知道与碘缺乏相关的因素，可以在高危人群中，包括孕妇和新生儿，补充碘。
本研究为 2002 年至 2015 年间在西班牙进行的 46622 例新生儿的病例对照研究。其中 45326 例新生儿的 TSH 值≥5mIU/L。主要变量为 TSH≥5mIU/L，次要变量为：性别、胎龄、采血日和母亲籍贯。通过逻辑回归模型分析相关因素，计算比值比（OR）。
与该结果相关的因素包括：男性（OR=1.34，95%CI：1.20-1.50，p<0.001）、原籍为亚洲/大洋洲国家（OR=0.80，95%CI：0.54-1.20，p=0.536）或欧洲（OR=0.80，95%CI：0.66-0.96，p=0.285）（包括西班牙，OR=1）[美洲国家（OR=0.54，95%CI：0.44-0.68），p<0.001；非洲国家（OR=0.78，95%CI：0.62-0.97），p=0.025]和距出生到采血日的天数较少（OR=0.80，95%CI：0.77-0.82，p<0.001）。
无先天性甲状腺功能减退的新生儿 TSH 升高的风险在男性中更高，随着距出生到采血日的天数增加而降低，与母亲种族有关，但与胎龄无关。
