Objective:To investigate the iodine nutrition status of children aged 8 - 10 and pregnant women in Xining City, Qinghai Province.Methods:From 2019 to 2021, a stratified cluster sampling method was used to divide 7 counties (districts) under the jurisdiction of Xining City, Qinghai Province into 5 sampling areas according to east, west, south, north, and center each year. One township (town, street) was selected from each area. Forty non boarding students aged 8 to 10 from each primary school (half male and half female, age balanced) and 20 pregnant women from each township (town, street) location were selected to collect edible salt samples at home and a random urine sample to measure salt iodine and urinary iodine level. B-ultrasound was used to measure thyroid volume in children and the goiter rate was calculated.Results:A total of 6 534 samples of household edible salt were collected from children and pregnant women, with an average salt iodine concentration of 25.58 mg/kg. The coverage rate of iodized salt was 97.50% (6 371/6 534), and the qualified iodized salt consumption rate was 89.46% (5 845/6 534). A total of 4 362 urine samples were collected from children, with a median urinary iodine level of 183.10 μg/L. The difference between different years was statistically significant ( H = 20.27, P < 0.001). A total of 2 169 urine samples were collected from pregnant women, with a median urinary iodine level of 168.90 μg/L. The difference between different years was statistically significant ( H = 107.09, P < 0.001). A total of 3 336 cases of thyroid gland examination were conducted in children, including 33 cases of thyroid enlargement, with a goiter rate of 0.99%. There was a statistically significant difference between different years (χ 2 = 15.00, P < 0.001). Conclusion:From 2019 to 2021, children aged 8 to 10 and pregnant women in Xining City are at an appropriate level of iodine, and the achievements in prevention and treatment of iodine deficiency disorders still need to be continuously consolidated.

Objective:To investigate the iodine nutrition status of children aged 8 - 10 and pregnant women in Xining City, Qinghai Province.Methods:From 2019 to 2021, a stratified cluster sampling method was used to divide 7 counties (districts) under the jurisdiction of Xining City, Qinghai Province into 5 sampling areas according to east, west, south, north, and center each year. One township (town, street) was selected from each area. Forty non boarding students aged 8 to 10 from each primary school (half male and half female, age balanced) and 20 pregnant women from each township (town, street) location were selected to collect edible salt samples at home and a random urine sample to measure salt iodine and urinary iodine level. B-ultrasound was used to measure thyroid volume in children and the goiter rate was calculated.Results:A total of 6 534 samples of household edible salt were collected from children and pregnant women, with an average salt iodine concentration of 25.58 mg/kg. The coverage rate of iodized salt was 97.50% (6 371/6 534), and the qualified iodized salt consumption rate was 89.46% (5 845/6 534). A total of 4 362 urine samples were collected from children, with a median urinary iodine level of 183.10 μg/L. The difference between different years was statistically significant ( H = 20.27, P < 0.001). A total of 2 169 urine samples were collected from pregnant women, with a median urinary iodine level of 168.90 μg/L. The difference between different years was statistically significant ( H = 107.09, P < 0.001). A total of 3 336 cases of thyroid gland examination were conducted in children, including 33 cases of thyroid enlargement, with a goiter rate of 0.99%. There was a statistically significant difference between different years (χ 2 = 15.00, P < 0.001). Conclusion:From 2019 to 2021, children aged 8 to 10 and pregnant women in Xining City are at an appropriate level of iodine, and the achievements in prevention and treatment of iodine deficiency disorders still need to be continuously consolidated.

Objective:To observe the changes of serum C-terminal peptide of type Ⅰ collagen (CTX-1) and N-terminal lengthening peptide of type Ⅰ collagen (P1NP) in adult patients with skeletal fluorosis in the tea-drinking-borne endemic fluorosis area in Qinghai Province, and to find sensitive indicators for diagnosis of skeletal fluorosis.Methods:From April to August 2019, a case-control study was carried out in tea-drinking-borne endemic fluorosis area in Zhiduo County, Yushu Tibetan Autonomous Prefecture, and Gangcha County, Haibei Tibetan Autonomous Prefecture of Qinghai Province. According to the Diagnostic Standard for Endemic Skeletal Fluorosis (WS/T 192-2008), the clinical diagnosis and X-ray examination of skeletal fluorosis were carried out for permanent residents ≥25 years old and living for more than 10 years in the area, combined with face-to-face inquiry and investigation of past disease history, lifestyle and clinical manifestations. The patients with skeletal fluorosis and healthy people were selected as skeletal fluorosis group and control group, respectively. Randomized urine samples and fasting venous blood from the two groups were collected. The content of fluoride in urine was determined by ion selective electrode method, and the contents of CTX-1 and P1NP in serum were determined by enzyme-linked immunosorbent assay (ELISA).Results:A total of 127 people in the disease area were investigated, including 63 cases in skeletal fluorosis group and 64 cases in control group. There was no statistically significant difference in age and sex ratio between the two groups ( t = 0.42, χ 2 = 0.07, P > 0.05). The X-ray examination results showed that the patients with skeletal fluorosis were mainly mild, accounting for 71.43% (45/63); X-ray changes were mainly ossification of interosseous membrane and tendon. The urinary fluoride in control group and skeletal fluorosis group was 1.62 (1.12, 1.95) and 3.22 (2.38, 4.89) mg/L, respectively, with statistically significant difference between the two groups ( Z = 7.07, P < 0.001). The difference of serum CTX-1 and P1NP contents between the two groups was statistically significant ( Z = 2.00, 4.89, P < 0.05). Conclusions:The levels of serum CTX-1 and P1NP in patients with skeletal fluorosis are higher than those in healthy people. Serum CTX-1 and P1NP may be used as sensitive indicators for diagnosis of skeletal fluorosis.

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.

Objective:To analyze the external quality control assessment results of urinary iodine, salt iodine and water iodine in iodine deficiency disorders laboratories in Qinghai Province, to evaluate the testing capacity of provincial, municipal and county-level laboratories and the operation of external quality control network, so as to provide quality assurance for consolidating and eliminating iodine deficiency disorders.Methods:In 2021, 1 provincial, 8 municipal, and 43 county-level laboratories in Qinghai Province had participated in the assessment of urinary iodine and salt iodine, while 1 provincial and 8 municipal-level laboratories had participated in the assessment of water iodine. The assessment results were evaluated using the method of reference value ± uncertainty of external quality control samples.Results:All laboratories that participated in the assessment had provided feedback. One provincial-level laboratory passed the assessment of urinary iodine, salt iodine, and water iodine. Among 8 municipal-level laboratories, 2 laboratories failed the urinary iodine assessment, with a pass rate of 6/8; the assessment of salt iodine and water iodine in 8 laboratories were all qualified. Among 43 county-level laboratories, 7 laboratories failed the urinary iodine assessment, with a pass rate of 83.7% (36/43); the assessment of salt iodine in 43 laboratories were all qualified.Conclusions:The external quality control network of iodine deficiency disorders laboratories in Qinghai Province has fully covered all municipal and county-level laboratories. The testing capability of provincial-level laboratory is stable and maintains a high level; the testing quality of some municipal and county-level laboratories is still unstable and needs to be further strengthened.

Objective:To investigate the molecular mechanism of excessive iodine induced experimental autoimmune thyroiditis (EAT) in mice.Methods:Sixty female non-obese diabetic (NOD) mice were selected and divided into 5 groups according to body weight [(25 ± 3) g] via the random number table method, with 12 mice in each group: control group (group A), 10-fold high iodine group (group B), 100-fold high iodine group (group C), 1 000-fold high iodine group (group D) and 1 000-fold high iodine combined with polyinosinic acid-polycytidylic acid [Poly (I:C)] group (group E). The experiment period was 16 weeks. Mice in each group drank purified water with sodium iodine (NaI) content of 0.000, 0.005, 0.050, 0.500 and 0.500 mg/L, respectively; mice in group E were intraperitoneally injected with Poly (I:C) at week 7 and week 15, respectively. At the end of the 16th week, mice were dissected and blood samples and thyroid tissue were taken. The levels of serum thyroid function indexes [thyroid stimulating hormone (TSH), free triiodothyronine (FT 3), free thyroxine (FT 4), and thyroid peroxidase antibody (TPOAb)] were detected by enzyme-linked immunosorbent assay (ELISA); the pathological changes of thyroid tissue were observed after hematoxylin-eosin (HE) staining; differentially expressed genes in thyroid tissue were detected by RNA-sequencing (RNA-seq), and analyzed by KEGG pathway; mRNA and protein levels of p38, intercellular adhesion molecule-1 (ICAM-1) and chemokine 10 (CXCL10) in thyroid tissue were detected by real-time fluorescence quantitative PCR (qPCR) and Western blotting, respectively. Results:There were statistically significant differences in serum levels of TSH (ng/ml: 6.53 ± 0.86, 6.61 ± 0.82, 7.68 ± 0.55, 7.93 ± 0.60, 8.73 ± 1.60), FT 3 (pg/ml: 59.35 ± 10.16, 53.73 ± 10.96, 46.19 ± 8.03, 41.01 ± 8.67, 34.21 ± 11.75), FT 4 (pg/ml: 136.74 ± 10.06, 124.33 ± 14.34, 101.80 ± 6.78, 91.37 ± 6.75, 73.29 ± 17.31), and TPOAb (U/ml: 130.81 ± 24.53, 145.47 ± 28.89, 166.52 ± 41.59, 199.78 ± 42.19, 201.99 ± 44.03) among the 5 groups of mice ( F = 4.77, 4.96, 23.12, 3.68, P < 0.05). Compared with group A, the serum TSH levels of mice in groups C, D and E were higher, the levels of FT 3 and FT 4 in groups B, C, D and E were lower, and the levels of TPOAb in groups D and E were higher, and the differences were statistically significant ( P < 0.05). HE staining showed that the thyroid follicle lesion in groups D and E was serious, and the EAT phenotype appeared in both groups. The differentially expressed genes were analyzed by KEGG pathway. Compared with group A, 8 metabolic pathways related to thyroid autoimmunity and inflammation were found in groups B, C, D and E. Further analysis found that 3 genes appeared in multiple pathways, namely p38, ICAM-1 and CXCL10. There were significant differences in the mRNA levels of p38, ICAM-1 and CXCL10 in thyroid tissue of the 5 groups of mice ( F = 14.77, 12.76, 16.39, P < 0.05); compared with group A, the mRNA levels of p38 in groups B, C, D and E were higher, and the mRNA levels of ICAM-1 and CXCL10 in groups C, D and E were higher ( P < 0.05). There were significant differences in the protein levels of p38, ICAM-1 and CXCL10 in thyroid tissue of the 5 groups of mice ( F = 7.97, 73.86, 18.02, P < 0.05); compared with group A, the protein levels of ICAM-1 and CXCL10 in groups B, C, D and E were higher ( P < 0.05). Conclusion:Excessive iodine promotes the occurrence and development of EAT in mice by up-regulating the expressions of p38 and ICAM-1 genes that are closely related to thyroid autoimmune and inflammatory responses.

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.

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.

Objective:To observe and evaluate the effect of health education on drinking brick-tea type fluorosis in Zhiduo County, Qinghai Province, so as to provide basis for further formulating health education strategies.Methods:From April 2019 to April 2020, according to the historical prevalence of drinking brick-tea type fluorosis in Zhiduo County, Qinghai Province, 3 townships (towns) were selected to carry out the health education activities on drinking brick-tea type fluorosis for students of grade 4 - 6, village doctors, adults and monks in each township (town). We carried out a one-year publicity on the prevention and treatment of drinking brick-tea type fluorosis, distributed health education materials and organized health education activities. Before and after the intervention, we conducted a questionnaire survey on health education among the target population (grade 4 - 6 students, village doctors, adults and monks), to evaluate the awareness rate and behavior formation rate of fluorosis prevention and control, and to evaluate the intervention effect.Results:A total of 86 students of grade 4 - 6, 40 village doctors, 42 adults and 20 monks were investigated, after the intervention, the awareness rates of prevention and treatment of drinking brick-tea type fluorosis in grade 4 - 6 students, village doctors, adults and monks were 87.98% (227/258), 96.67% (116/120), 81.75% (103/126), 83.33% (50/60), respectively, which were significantly higher than those before the intervention [38.38% (76/198), 83.33% (100/120), 15.45% (19/123), 28.89% (13/45), P < 0.05]. After the intervention, the behavior formation rates of prevention and treatment of the drinking brick-tea type fluorosis in grade 4 - 6 students, village doctors, adults and monks were 74.42% (128/172), 72.50% (58/80), 52.38% (44/84), 60.00% (24/40), respectively, which were significantly higher than those before the intervention [14.39% (19/132), 38.75% (31/80), 3.66% (3/82), 0(0/28), P < 0.05]. Conclusion:The comprehensive intervention measures based on health education can significantly improve the knowledge of local residents, and improve their bad drinking habits of drinking tea, which is of great significance to the prevention and treatment of drinking brick-tea type fluorosis.

Objective:To analyze the assessment results of the external quality control in iodine deficiency disorders laboratories at all levels in Qinghai Province so as to provide quality assurance for monitoring and control effect evaluation of iodine deficiency disorders.Methods:The results of urinary iodine, salt iodine, and water iodine quality control assessments at the provincial, city (state) and county-level iodine deficiency disorders laboratories were analyzed in Qinghai Province from 2013 to 2018 (sourced from the annual evaluation results issued by National Reference Laboratory for Iodine Deficiency Disorders). Among them, there were 1 provincial, 8 city (state) and 43 county-level (2017, 2018) laboratories participated in the urinary iodine assessment; 1 provincial, 8 city (state) and 30 county-level (43 in 2017 and 2018) laboratories participated in the salt iodine assessment; 1 provincial and 8 city (state)-level laboratories participated in the water iodine assessment.Results:From 2013 to 2018, the feedback rates and qualified rates of provincial and city (state)-level laboratories participated in the urinary iodine external quality control assessment were 100.0%; the feedback rates of 43 county-level laboratories (2017 and 2018) were 100.0%, and the qualified rates were 93.0%(40/43) and 88.4%(38/43), respectively. The feedback rates and qualified rates for salt iodine assessment in provincial and city (state)-level laboratories were 100.0%; the county-level laboratories feedback rates were 100.0%, and the qualified rates were > 90.0% except for 2014. And the feedback rates of provincial and city (state)-level laboratories for water iodine assessment were 100.0%; the qualified rate of provincial-level laboratory was 100.0%, and the city (state)-level laboratories were 100.0% except 2016 (7/8).Conclusions:The quality control network of Qinghai Province's iodine deficiency disorders laboratories has fully covered all city (state) and county-level laboratories. Provincial, city (state)-level laboratories have stable and reliable levels of urinary iodine, salt iodine, and water iodine; some individual county-level laboratories testing capabilities still need to be improved.