甘肃省不同生态类型区哺乳妇女和0～2岁婴幼儿碘营养状况调查

An investigation on iodine nutritional status of lactating women and infants （0 - 2 years old） in different ecological regions of Gansu Province

目的评估甘肃省6个生态类型区哺乳妇女及其0～2岁子女碘营养状况，为重点人群科学补碘提供依据。方法根据不同的地形地貌及气候条件，将甘肃省划分为荒漠区、河西走廊戈壁区、黄土高原丘陵区、秦岭中山峡谷区、甘南高原草原草甸区、黄土高原沟壑区6大生态类型区，2014年在每个生态类型区抽取5个县．每个县按照东、西、南、北、中5个方位各抽取1个乡镇，每个乡镇分别抽取哺乳妇女及其0～2岁子女各10名，采集尿样进行尿碘测定。每个乡镇采集居民户食用盐60份进行盐碘检测，再在其中3个乡镇，每个乡镇各抽取20户居民进行食盐摄入量调查。每个调查县采集所有集中式供水工程水样，同时每个县在覆盖人口最多的10个乡镇（不足10个的全选）按东、南、西、北、中5个方位采集分散式供水水样各1份，进行水碘检测。每个县按东、西、南、北、中5个方位选择1个监测乡镇，每个乡镇选择一块耕地，采集土壤样品1份，进行土壤碘测定。尿碘、水碘检测采用砷铈催化分光光度测定法（WS／T107—2006）；盐碘检测采用直接滴定法，川盐及其他强化食用盐检测采用仲裁法（GB／T13025．7-2012）；食盐摄入量采用313称量法进行测算；土壤碘检测采用放大比色法。结果6个生态类型区共采集哺乳妇女尿样1476份，总体尿碘中位数为149．05μg／L，各生态区哺乳妇女尿碘中位数均在100～199μg／L。共采集0—2岁婴幼儿尿样1461份，总体尿碘中位数为151．34μg／L，各生态区婴幼儿尿碘中位数均在100～199μg／L，其中未断乳婴幼儿尿碘（155．32μg／L）高于断乳婴幼儿（146．30μg／L），两者比较差异有统计学意义（Z=-2．808，P〈0．05）。已断乳0—2岁婴幼儿与哺乳妇女尿碘之间不存在相关性（r=0．045，P〉0．05）；未断乳的0—2岁婴幼儿与哺乳妇女尿碘之间存在相关性（r=0．133，P〈0．01）。共采集食盐样本9008份，6个生态类型区合格碘盐食用率均在93％以上。13人均摄盐量在4．5～12．6g．黄土高原沟壑区最高为12．6g，甘南高原草原草甸区最低为4．5g。共采集水样1513份，水碘总体中位数为3．3Ixg／L，除荒漠区（42．4μg／L）和黄土高原沟壑区（30．0μg／L）水碘〉20μg／L外，其余4个生态区水碘中位数均〈5μg／L。共采集土壤样本155份，土壤碘含量总体中位数为127μg／kg，荒漠区最低为78μg／b，甘南高原草原草甸区最高为218μg／kg。结论甘肃省6个生态区哺乳妇女和婴幼儿碘营养状况良好，现行盐碘含量可以满足各生态类型区哺乳妇女和0～2岁婴幼儿碘营养需求。

Objective To assess iodine nutritional status of lactating women and infants （0 - 2 years old） in six ecological regions of Gansu Province, and to provide a scientific basis for iodine supplementation of target people. Methods According to different topography and climate conditions, Gansu Province was divided into six ecological regions： the desert region, the Gobi region of Hexi Corridor, the hills and valleys region of Loess Plateau, the Zhongshan Valley of Qinling Mountains, the grassland meadow area of Gannan plateau and the Loess Plateau- gully region. Totally 5 counties were selected from each ecological region, and each county was divided into five geographic locations （east, south, west, north and center）. In each location, one township was identified and ten samples of lactating women and infants （0 - 2 years old） were selected randomly and 60 salt samples of residents were collected to determine iodine content. At the same time salt intake of 20 residents was surveyed in three townships as mentioned above. The water samples of all the centralized water supply projects were collected in each county, and one water sample of the decentralized water supply in ten townships with the largest population of each county from east, south, west, north and center locations was collected to determine iodine content. One soil sample was collected to determine iodine content in east, south, west, north and center townships of each county. The urinary iodine and water iodine levels were measured with the method for determination of iodine in urine by As3＋- Ce4＋ catalytic spectrophotometry （WS/T 107-2006）. The direct titration method among the generic methods for iodide testing in salt production industry （GB/T 13025.7-2012） was used to determine the salt iodine level, and the arbitration method was adopted for quantitative determination in the case of Sichuan salt or other special salts and the salt intake was estimated based on three day weighed food record. The soil iodine was determined using the amplified colorimetric method. Results Totally 1 476 and 1 461 urine samples of lactating women and infants were collected, and the total urine iodine medians of lactating women and infants （0 - 2 years old） were 149.05 and 151.34 μg/L, respectively, the urine iodine median of lactating women and infants in each ecological region was at the 100 - 199 trg/L appropriate level. Not weaning infants urine iodine （155.32 μg/L） was higher than that of the weaning infants （146.30 μg/L）, the difference was significant statistically （Z = - 2.808,P 〈 0.05）. There was a correlation between urine iodine of not weaning infants aged 0 - 2 years old and breastfeeding women （r = 0.133, P 〈 0.01）, and there was no correlation between weaning infants and breastfeeding women （r = 0.045, P 〉 0.05）. About 9 008 salt samples were collected,and the rates of qualified iodized salt intake in the six ecological regions were all higher than 93%. The daily salt intake per person ranged from 4.5 g to 12.6 g, in which the Loess Plateaugully region was the highest with 12.6 g and the grassland meadow area of Gannan plateau was the lowest with 4.5 g. The water iodine median of 1 513 water samples was 3.3 μg/L. The water iodine medians of the rest 4 ecological regions were all less than 5 μg/L except for the desert region （42.4 μg/L） and the Loess Plateau-gully region （30.0 μg/L） of which the median of water iodine was higher than 20 μg/L. The soil iodine median of 155 soil samples was 127 μg/kg, in which the desert region was the lowest with 78 μg/kg and the grassland meadow area of Gannan plateau was the highest with 218 μg/kg. Conclusion Lactating women and infants are in good iodine nutritional status and the present iodized salt concentration can meet the demand of iodine nutrition of lactating women and infants well.