Zimmermann Michael B, Aeberli Isabelle, Torresani Toni, Bürgi Hans
Laboratory for Human Nutrition, Institute for Food Science and Nutrition, Swiss Federal Institute of Technology, Zürich, Switzerland.
Am J Clin Nutr. 2005 Aug;82(2):388-92. doi: 10.1093/ajcn.82.2.388.
Many industrialized countries struggle to maintain adequate iodine intake because of changes in dietary habits and the food supply. In Switzerland, because of declining iodine intakes in children and pregnant women, the iodine concentration in table salt was increased from 15 to 20 mg/kg.
We evaluated Swiss iodine nutrition after the 1999 increase in the salt iodine concentration.
In 1999 and 2004, a 3-stage probability proportionate-to-size cluster sampling was done to obtain a representative national sample of primary schoolchildren and pregnant women. Urine and household salt were collected for iodine measurement. The frequency of elevated thyrotropin concentrations found in the newborn screening program was evaluated before and after the increase.
In 1999, median urinary iodine (UI) concentrations among children (n = 610) and pregnant women (n = 511) were 115 microg/L (range: 5-413 microg/L) and 138 microg/L (range: 5-1881 microg/L), respectively, which indicated marginal iodine status. In 2004, median UI concentrations among children (n = 386) and pregnant women (n = 279) were 141 microg/L (range: 0-516 microg/L) and 249 microg/L (range: 8-995 microg/L), respectively (P < 0.01). Newborn thyrotropin concentrations >5 mU/L decreased from 2.9% in 1992-1998 (n = 259 035) to 1.7% in 1999-2004 (n = 218 665) (P < 0.0001).
A 25% increase in iodine concentration in iodized table salt markedly improved iodine status in Switzerland, which showed the value of monitoring and adjusting iodine concentrations in national salt programs. The frequency of newborn thyrotropin concentrations >5 mU/L appears to be a sensitive indicator of iodine nutrition during pregnancy.
由于饮食习惯和食物供应的变化，许多工业化国家难以维持充足的碘摄入量。在瑞士，由于儿童和孕妇碘摄入量下降，碘盐中的碘浓度从15毫克/千克提高到了20毫克/千克。
我们评估了1999年盐碘浓度提高后瑞士的碘营养状况。
1999年和2004年，采用三阶段概率规模成比例整群抽样方法，以获取具有代表性的全国小学生和孕妇样本。收集尿液和家庭食盐用于碘含量测定。评估了碘浓度提高前后新生儿筛查项目中促甲状腺素浓度升高的频率。
1999年，儿童（n = 610）和孕妇（n = 511）的尿碘中位数分别为115微克/升（范围：5 - 413微克/升）和138微克/升（范围：5 - 1881微克/升），表明碘营养状况处于边缘水平。2004年，儿童（n = 386）和孕妇（n = 279）的尿碘中位数分别为141微克/升（范围：0 - 516微克/升）和249微克/升（范围：8 - 995微克/升）（P < 0.01）。新生儿促甲状腺素浓度>5 mU/L的比例从1992 - 1998年的2.9%（n = 259 035）降至1999 - 2004年的1.7%（n = 218 665）（P < 0.0001）。
碘盐中碘浓度提高25%显著改善了瑞士的碘营养状况，这显示了在国家盐项目中监测和调整碘浓度的价值。新生儿促甲状腺素浓度>5 mU/L的频率似乎是孕期碘营养的一个敏感指标。
