Monitoring and evaluation results of iodine deficiency disorders in Shanxi Province in the past 10 years since the implementation of the standard of "Iodine Content in Edible Salt" (GB 26878-2011) / 中华地方病学杂志

ABSTRACT

Objective:To learn about the status of iodine deficiency disorders (IDD) and iodine nutrition of residents in Shanxi Province since the implementation of the standard of "Iodine Content in Edible Salt" (GB 26878-2011), to evaluate the level of prevention and control of IDD, and to provide scientific basis for adjusting prevention and control strategies.Methods:The data of core indicators monitored by Shanxi Province in accordance with the requirements of the national iodized salt and IDD monitoring program for each year from 2012 to 2021 were comprehensively reviewed, and the change trends of the indicators such as coverage rate of iodized salt, consumption rate of qualified iodized salt, children's median urinary iodine and goiter rate, and pregnant women's median urinary iodine were analyzed; the evaluation of IDD elimination in counties (cities and districts, hereinafter referred to as counties) was analyzed.Results:From 2012 to 2021, the coverage rate of iodized salt in Shanxi Province was remained > 95%; from 2012 to 2014 (transition period between new and old standard iodized salt), the consumption rate of qualified iodized salt had an upward trend (χ 2trend = 2 703.32, P < 0.001), with a downward trend from 2015 to 2017 (before and after the reform of the salt industry system, χ 2trend = 122.18, P < 0.001), and with an upward trend from 2018 to 2021 (after the reform of the salt industry system, χ 2trend = 455.11, P < 0.001), from 2018, the consumption rate of qualified iodized salt remained > 90%; from 2015 to 2021, the average content of salt iodine was between 23 - 25 mg/kg, and the coefficient of variation of salt iodine was 15% - 18%. From 2014 to 2021, the median urinary iodine of children in Shanxi Province remained at 200 - 250 μg/L, the median urinary iodine of pregnant women remained at 150 - 200 μg/L, and the goiter rate of children remained below 5%. Every year, iodine nutrition of pregnant women in some counties was insufficient. In 2016, the proportion of counties with insufficient iodine nutrition of pregnant women was high, reached 30.0% (12/40); from 2018 to 2021, the proportion of counties with insufficient iodine nutrition of pregnant women had a downward trend (χ 2trend = 9.37, P = 0.002), which was 11.1% (13/117) in 2021. In 2020, 117 counties in the province reached the IDD elimination standard, with a compliance rate of 100.0%. Conclusions:Since the implementation of the current salt iodine content standard for 10 years, the consumption rate of qualified iodized salt has gradually stabilized and remained at a high level, which can ensure that IDD is in a sustainable state of elimination in Shanxi Province, and the iodine nutrition of school-age children and pregnant women is generally at a suitable level. However, there are a certain number of counties with insufficient iodine nutrition of pregnant women. It is recommended to guide pregnant women to supplement iodine or set the average standard of salt iodine for pregnant women separately.