Objective:To learn about the current status of iodine nutrition of key populations in Shiyan City, Hubei Province, and to provide basis for guiding key populations to supplement iodine scientifically.Methods:According to the requirements of the "National Iodine Deficiency Disorders Surveillance Program (2016 Edition)", pregnant women and school-age children aged 8 - 10 (age balanced, half male and half female) in 8 counties (cities, districts) under the jurisdiction of Shiyan City, Hubei Province were selected from 2017 to 2020. Their household edible salt samples and urine samples were collected to detect salt iodine and urinary iodine contents, respectively. At the same time, the thyroid gland of children was examined by B-ultrasonic and the goiter rate was calculated.Results:In total, 3 198 household edible salt samples of pregnant women were tested, the median salt iodine was 23.7 mg/kg, the coverage rate of iodized salt was 99.9% (3 196/3 198), the qualified rate of iodized salt was 96.0% (3 068/3 196), and the consumption rate of qualified iodized salt was 95.9% (3 068/3 198). Totally 2 898 urine samples of pregnant women were tested, and the median urinary iodine was 198.2 μg/L. In total, 6 363 household edible salt samples of children were tested, the median salt iodine was 23.8 mg/kg, the coverage rate of iodized salt was 99.8% (6 352/6 363), the qualified rate of iodized salt was 95.5% (6 067/6 352), and the consumption rate of qualified iodized salt was 95.3% (6 067/6 363). Totally 5 764 urine samples of children were tested, and the median urinary iodine was 259.8 μg/L. Totally 2 188 children were examined, and the goiter rate was 0.4% (9/2 188).Conclusions:From 2017 to 2020, the coverage rates of iodized salt (≥95%), consumption rates of qualified iodized salt ( > 90%) of key populations and the goiter rate of children ( < 5%) in Shiyan City of Hubei Province are in line with the national standards for eliminating iodine deficiency disorders. Pregnant women are generally at an appropriate level of iodine (150 - 249 μg/L) and children are generally at the super appropriate level of iodine (200 - 299 μg/L). It is necessary to continue to strengthen the monitoring of iodine nutrition in key populations and implement the strategy of "adjusting measures to local conditions, classified guidance and scientific iodine supplementation".

Objective:To study the iodine nutrition status and influencing factors of thyroid volume of children aged 8 - 10 years in Shiyan City, Hubei Province.Methods:From June 2019 to October 2020, in 8 counties (cities, districts) under the jurisdiction of Shiyan City, Hubei Province, each county (city, district) was divided into 5 districts according to the east, west, south, north, and center. One township (street) was selected in each district, and 40 children aged 8 to 10 years from one primary school (age balanced, half male and half female), were selected in each township (street), and their home salt samples and once random urine sample were taken to detect salt iodine and urinary iodine levels. At the same time, thyroid volume measurements and physical examination were performed.Results:A total of 3 172 salt samples were collected from children's homes, with a salt iodine content of 23.68 mg/kg. The iodine salt coverage rate was 99.81% (3 166/3 172), and the qualified iodine salt consumption rate was 96.72% (3 068/3 172). A total of 3 172 urine samples were collected from children, with a median urinary iodine level of 241.87 μg/L, indicating that iodine nutrition was at a super optimal level. There were statistically significant differences in the median urinary iodine among children of different genders and regions ( Z = - 3.63, H = 160.83, P < 0.001). The thyroid of 1 191 children was examined, and the goiter rate was 0.67% (8/1 191), and there were statistically significant differences in the goiter rate of children of different ages and regions (χ 2 = 6.41, 11.91, P = 0.040, 0.002). The correlation analysis results showed that there was a negative correlation between urinary iodine and thyroid volume in children ( r = - 0.08, P = 0.025); according to age stratification, there were positive correlation between height, weight, body surface area, and thyroid volume in children aged 8, 9 and 10 years ( P < 0.05). Conclusions:The iodine nutrition of 8 - 10 years old children in Shiyan City is in an over appropriate level, and the goiter rate is low. Urinary iodine, height, weight, and body surface area of children are all factors influencing thyroid volume.