ABSTRACT
Objective:To understand the iodine nutrition status of children aged 8 to 10 years in Yantai City, Shandong Province, and to provide evidence for making prevention and control strategies in the future.Methods:From 2016 to 2018, a multi-stage stratified simple random sampling method was used in Yantai City, 5 to 7 counties (cities, districts) were selected each year in the east, west, south, north, and middle directions. Each county (city, district) was divided into 5 locations of east, west, south, north, and middle, and one township (town, street) was selected in each location. One village primary school was selected from each township (town, street), if there was no village primary school, the township central primary school was selected. For each primary school, 40 children aged 8 to 10 years (half male half female) were selected. Random urine samples and edible salt samples were collected, and urinary iodine and salt iodine contents were measured, while thyroid volume was examined by B-ultrasound.Results:From 2016 to 2018, the medians iodine contents of edible salt (1 000, 1 400, 1 200 samples) in the households of children aged 8 to 10 years were 21.02, 21.50 and 21.15 mg/kg, respectively; the qualified iodized salt consumption rates were all < 90%; the qualified rate of iodized salt had decreased year by year, and the difference was statistically significant (χ 2=85.92, P < 0.01). From 2016 to 2018, 1 000, 1 400, and 1 200 urine samples of children aged 8 to 10 years were tested, and the medians urinary iodine were 190.05, 148.20, and 145.00 μg/L, and there was no correlation between children's salt iodine contents and their own urinary iodine levels ( r=- 0.036, P > 0.05). From 2016 to 2018, the overall goiter rate for children aged 8 to 10 years was 3.61% (130/3 600), and there was no correlation between urinary iodine levels and thyroid volume in children ( r=0.108, P > 0.05). From 2016 to 2018, the number of children who consumed non-iodine salt accounted for 19.50% (702/3 600), the median urinary iodine was 155.00 μg/L, and the goiter rate was 3.70% (26/702). Conclusion:Although the qualified iodized salt consumption rate in children in Yantai City is less than 90%, the urinary iodine level and goiter rate of children have reached the standards for elimination of iodine deficiency disorders, indicating that children's dietary nutrition level and salt iodine content can meet the children iodine requirement.
ABSTRACT
Objective To investigate the iodine nutritional status in the key populations before and after the adjustment of salt iodine content in Yantai of Shandong.Methods In 2010 (the pre-adjustment period) and 2014,2015 (the post-adjustment period),the changes in the residents' iodized salt,the goiter prevalence and urinary iodine of children aged 8-10,the urinary iodine of pregnant women,and the iodine content of drinking water before and after the adjustment were analyzed.Results The coverage rate of iodized salt and the edible rate of qualified iodized salt were 98.27％ and 97.28％,respectively before the adjustment of salt iodine content,and 97.44％ and 96.14％ after the adjustment.The mean of salt iodine after the adjustment (21.96 mg/kg) was significantly lower than that of 2010 (31.45 mg/kg,t =66.29,P ＜ 0.05).The goiter prevalence of children aged 8-10 by thyroid palpation was 0.92％ in 2010,while it was 1.89％ by ultrasonic in 2014,2015.There was significant difference in the iodine nutritional status of children in 2010 (191.0 μg/L) and in 2014,2015 (173.0 μg/L,Z =3.56,P ＜ 0.05).The difference of iodine nutritional status in pregnant women between pre-adjustment (154.0 μg/L) and post-adjustment (130.4 μg/L) was also significant (Z =5.54,P ＜ 0.05).The median of water iodine was 5.4 μg/L after the adjustment.There were 52 towns with medians of water iodine below 10 μg/L.Conclusions The coverage rate of iodized salt and the edible rate of qualified iodized salt have all met the national standard before and after the adjustment of salt iodine content.The mean of salt iodine during 2014,2015 is significantly lower than that of 2010.Before and after the adjustment,the goiter rates of children aged 8-10 are all below 5％.The adjustment of salt iodine content is more suitable to children aged 8-10 than to pregnant women currently.It is suggested that pregnant women eat more foods rich in iodine.