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Objective:To follow up the iodine nutrition and intellectual development of school children aged 8-10 years old in Nangqian County of Qinghai Province after 9 years of the implementation of iodine deficiency disorders intervention measures with iodine supplement as the main measure.Methods:In order to improve the iodine nutritional status of the population in Nangqian County, free iodized salt distribution, health education and other intervention measures for iodine deficiency disorders were implemented for 9 consecutive years since 2013. In May 2012 (before iodine supplementation) and September 2021 (after iodine supplementation), the same 5 townships (towns) were selected, and children aged 8-10 years old (half male and half female, age balanced) born locally in the central primary school of each township (town) were selected as the survey subjects. Household edible salt samples and random urine samples were collected for salt iodine and urinary iodine detection; the second revised version of the Chinese Combined Raven's Test (rural version) was used to assess the intelligence quotient (IQ) of children. The Flynn effect (FE) gain was used to adjust IQ, the corrected IQ = (IQ starting point value - current year's IQ value) - FE gain (calculated by 0.74/year). The differences of salt iodine and urinary iodine related indexes, IQ value and corrected IQ were compared before and after iodine supplementation.Results:After iodine supplementation, the coverage rate of iodized salt reached 100.00% (300/300), and the consumption rate of qualified iodized salt reached95.00% (285/300), the median urinary iodine increased to 157.20 μg/L, and all indexes met the elimination standard of iodine deficiency disorders. The IQ value of children aged 8-10 years old after iodine supplementation was 99.00 ± 14.90, significantly higher than that before iodine supplementation (82.00 ± 13.20, F = 156.82, P < 0.001). The FE gain in 9 years was 6.66, and the actual IQ gain of children aged 8-10 years old after iodine supplementation was 10.34. There were statistically significant differences in IQ value before and after iodine supplementation in male and female children ( F = 78.84, 78.88, P < 0.001). After iodine supplementation, there was a statistically significant difference in IQ value between children in the 8-year-old group and the 10-year-old group ( P = 0.010). There were statistically significant differences in IQ value before and after iodine supplementation in 8, 9 and 10 years old groups ( F = 55.23, 65.79, 36.85, P < 0.001). Conclusion:Intervention measures for iodine deficiency disorders, mainly iodine supplement, can significantly improve the iodine nutrition status of children aged 8-10 years old, and significantly promote the intellectual development of children.
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Objective:To understand the water iodine content in Qinghai Province and draw a distribution map of water iodine, so as to provide a basis for scientific supplementation of iodine and continuous elimination of iodine deficiency hazards.Methods:In 2017, in all counties (cities, districts) in Qinghai Province, with townships (towns, streets, referred to as townships) as the unit, the residents' drinking water samples were collected, water iodine content was tested, the median water iodine was calculated, and the water iodine distribution map of Qinghai Province was drew.Results:Totally 1 836 drinking water samples were collected in 392 townships, the median water iodine was 1.7 μg/L. Townships that had the median water iodine < 5 μg/L, in the range of 5 to 10 μg/L and > 10 μg/L accounted for 80.6% (316/392), 17.1% (67/392) and 2.3% (9/392), respectively. Among all townships, the highest of the median water iodine was 24.8 μg/L. Based on the results, water iodine distribution map of Qinghai Province, water iodine distribution map of Xining City and water iodine distribution map of Haidong City were compiled.Conclusions:Iodine deficiency is widespread throughout natural environment in Qinghai Province. Hence, salt iodization measures to prevent iodine deficiency disorders should be implemented continuously. According to the water iodine distribution map, the people should be guided to supplement iodine scientifically.
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Objective:To investigate the dietary iodine intake of people in different areas of Qinghai Province, and to provide the basis for scientific iodine supplementation and continuous elimination of iodine deficiency hazards.Methods:From 2018 to 2019, according to administrative division, natural geographical regions, population distribution and economic development level of Qinghai Province, a total of 14 survey sites were selected. One village was selected from each survey site, and 20 households were selected from each village, the salt samples and 24 h urine samples of all family members were collected to detect salt iodine and urinary iodine. One drinking water sample was collected at the five directions of east, west, south, north and middle of each village to detect water iodine. Salt iodine was detected by direct titration, urinary iodine and water iodine were detected by arsenic-cerium catalytic spectrophotometry. At the same time, the 3-day weighing method was used to investigate the diet, the daily dietary iodine intake per capita (the result was expressed as average) and the proportion of dietary iodine in urinary iodine were calculated, the daily dietary iodine intake per capita of different production modes (agricultural region and pastoral region), different geographical environment (Hehuang Valley, Qaidam Basin, Qilian Mountain and Qingnan Plateau), different nationalities (Han, Tibetan, Hui, Mongolian, Tu, Salar) and different economic levels (< 8 000, 8 000 -, 10 000 -, ≥12 000 Yuan) were compared.Results:A total of 999 people from 280 families were surveyed, including 511 males and 488 females. The median water iodine of each survey site was less than 10 μg/L, all of which were environmentally iodine-deficient areas. A total of 280 salt samples were collected, the median salt iodine was 26.0 mg/kg, and the consumption rate of qualified iodized salt was 100% (280/280). A total of 999 urine samples were tested, and the median urinary iodine of people was 192.5 μg/L, which was at an appropriate level of iodine. There was no statistically significant difference ( t =-1.599, P > 0.05) in the daily dietary iodine intake per capita (28.53, 33.44 μg) of people in agricultural region ( n = 643) and pastoral region ( n = 356). The daily dietary iodine intake per capita (25.38, 33.30, 32.98, 34.79 μg) of people in Hehuang Valley ( n = 448), Qaidam Basin ( n = 125), Qilian Mountain ( n = 157), and Qingnan Plateau ( n = 269) were compared, the difference was statistically significant ( F = 2.883, P < 0.05); among them, the daily dietary iodine intake per capita in Hehuang Valley was lower than that in Qingnan Plateau ( P < 0.05). The daily dietary iodine intake per capita of different nationalities were compared, the difference was statistically significant ( F = 3.647, P < 0.05), Salar ( n = 68) and Tibetan ( n = 239) were higher (37.21 and 32.21 μg). The daily dietary iodine intake per capita (38.97, 17.01, 30.86, 33.14 μg) of annual per capita disposable income < 8 000 ( n = 194), 8 000-( n = 221), 10 000-( n = 302), ≥12 000 Yuan ( n = 282) were compared, the difference was statistically significant ( F = 9.407, P < 0.05). The proportions of dietary iodine in urinary iodine of various population ranged from 5.35% to 15.54%. Conclusions:The iodine nutrition of people in Qinghai Province is suitable, the dietary iodine intake of people is closely related to geographical environment, nationality and economic level. But the proportion of dietary iodine in urinary iodine is relatively low, the consumption of iodized salt is still the main way for people to intake iodine, and it is also the main measure to continuously eliminate the harm of iodine deficiency in Qinghai Province.