Objective To study the iodine nutritional status and thyroid function of adults in urban and rural areas of Wuwei City Gansu Province.Methods A cross-sectional survey was performed in 200 adults aged 18-45 who had lived more than six months in Wuwei City from April 2009 to January 2010.A random urine and fasting blood samples were collected.Urinary iodine content was measured with arsenic cerium catalytic spectrophotometry.The thyroid-stimulating hormone (TSH),free thyroid hormone (FT4) and three free triiodothyronine (FT3) were quantified by direct chemiluminescence immunoassay.Thyroglobulin antibodies (TGAb) and thyroid microsomal antibodies (TMAb) were detected by radioimmunoassay.Results A total of 99 and 98 copies of urine samples of urban and rural groups were tested,respectively.The median of urinary iodine of urban and rural groups was 189.0 and 258.2 μg/L,respectively,and rural group was higher than urban group (Z =-4.020,P ＜ 0.01).A total of 104 and 95 copies of blood samples of urban and rural groups were detected; mean value of FT4 in urban group [(16.8 ± 3.0)pmol/L] was higher than that of rural group [(15.4 ± 2.4)pmol/L,t =3.539,P ＜ 0.01].The positive rates of TGAb of urban and rural groups were 11.5％ (12/104) and 15.8％ (15/95),respectively; the positive rates of TMAb of urban and rural groups were 13.5％ (14/104) and 14.7％ (14/95),respectively; the positive rates of TGAb of male and female were 5.5％ (6/109) and 23.3％ (21/90),respectively; the positive rates of TMAb of male and female were 6.4％ (7/109) and 23.3％ (21/90),respectively.The positive rates of TGAb and TMAb were lower in male than in female (x2 =13.362,11.661,all P ＜ 0.01).The rates of thyroid function disorders of urban and rural groups were 16.3％ (17/104) and 8.4％ (8/95),of male and female 11.9％ (13/109) and 13.3％ (12/90),respectively.Subclinical hypothyroidism in all thyroid function disorders was the most common,which was 14.4％ (15/104) and 7.4％ (7/95) in urban and rural groups,11.0％ (12/109) and 11.1％ (10/90) in male and female,respectively.Conclusions Iodine nutrition level is appropriate for adults in urban areas,but in rural areas iodine nutrition is high or excessive; subclinical hypothyroidism in all thyroid function disorders is the most common; we should be concerned about the risk of iodine overdose,especially the risk of illness in women.

Objective To build a case database of endemic cretinism,investigate the distribution of existing cretinism,and provide suggestions for prevention of iodine deficiency disorders.Methods In 2011,an existing endemic cretinism case database was established in Gansu Province by verifying and registering the historical cases before 1985,and searching and diagnosing the cases between 1985-2011 in history cretinism areas and IDD high-risk areas according to endemic cretinism and endemic sub-clinical cretinism diagnosis (WS 104-104) and the IDD monitoring program of the central transfer fund at the same time,and analysis the distribution of existing cretinism.Results In 1985 and 2011,cretinism areas were 53 and 41 in Gansu Province,and the endemic cretinism cases werel9 696 and 4 715,respectively;18 cases of endemic cretinism were born between 1985 to1997,7 new cases were born after 1997;nerve cretinism,myxedematous and mixed types among existing cases were 58.8％ (2 766/4 708),9.8％ (461/4 708) and 31.4％ (1 481/4 708),males and females were 69.3％ (3 261/4 708)and 30.7％ (1 481/4 708),respectively.Cases older than 45 accounted for 73.2％ (3 444/4 708);the 7 new cases were all nerve cretinism and 5 cases distributed in ethnic minority areas.Conclusions There are potential dangers of endemic cretinism in the high-risk areas of iodine deficiency disorders due to multiple factors in Gansu Province;the nervous cretinism is the majority which is caused by insufficient iodine intake in early maternal pregnancy.To prevent new endemic cretinism,it is necessary to strengthen measures of emergency iodine supplementation for pregnant women and nursing mothers in the high-risk areas.

Objective To assess iodine nutritional status of lactating women and infants (0-2 years old) in six ecological regions of Gansu Province,and to provide a scientific basis for iodine supplementation of target people.Methods According to different topography and climate conditions,Gansu Province was divided into six ecological regions:the desert region,the Gobi region of Hexi Corridor,the hills and valleys region of Loess Plateau,the Zhongshan Valley of Qinling Mountains,the grassland meadow area of Gannan plateau and the Loess Plateaugully region.Totally 5 counties were selected from each ecological region,and each county was divided into five geographic locations (east,south,west,north and center).In each location,one township was identified and ten samples of lactating women and infants (0-2 years old) were selected randomly and 60 salt samples of residents were collected to determine iodine content.At the same time salt intake of 20 residents was surveyed in three townships as mentioned above.The water samples of all the centralized water supply projects were collected in each county,and one water sample of the decentralized water supply in ten townships with the largest population of each county from east,south,west,north and center locations was collected to determine iodine content.One soil sample was collected to determine iodine content in east,south,west,north and center townships of each county.The urinary iodine and water iodine levels were measured with the method for determination of iodine in urine by As3+-Ce4+ catalytic spectrophotometry (WS/T 107-2006).The direct titration method among thegeneric methods for iodide testing in salt production industry (GB/T 13025.7-2012) was used to determine the salt iodine level,and the arbitration method was adopted for quantitative determination in the case of Sichuan salt or other special salts and the salt intake was estimated based on three day weighed food record.The soil iodine was determined using the amplified colorimetric method.Results Totally 1 476 and 1 461 urine samples of lactating women and infants were collected,and the total urine iodine medians of lactating women and infants (0-2 years old) were 149.05 and 151.34 μg/L,respectively,the urine iodine median of lactating women and infants in each ecological region was at the 100-199 μg/L appropriate level.Not weaning infants urine iodine (155.32 μg/L) was higher than that of the weaning infants (146.30 μg/L),the difference was significant statistically (Z =-2.808,P ＜ 0.05).There was a correlation between urine iodine of not weaning infants aged 0-2 years old and breastfeeding women (r =0.133,P ＜ 0.01),and there was no correlation between weaning infants and breastfeeding women (r =0.045,P ＞ 0.05).About 9 008 salt samples were collected,and the rates of qualified iodized salt intake in the six ecological regions were all higher than 93％.The daily salt intake per person ranged from 4.5 g to 12.6 g,in which the Loess Plateaugully region was the highest with 12.6 g and the grassland meadow area of Gannan plateau was the lowest with 4.5 g.The water iodine median of 1 513 water samples was 3.3 μg/L.The water iodine medians of the rest 4 ecological regions were all less than 5 μg/L except for the desert region (42.4 μg/L) and the Loess Plateau-gully region (30.0 μg/L) of which the median of water iodine was higher than 20 μg/L.The soil iodine median of 155 soil samples was 127 μg/kg,in which the desert region was the lowest with 78 μg/kg and the grassland meadow area of Gannan plateau was the highest with 218 μg/kg.Conclusion Lactating women and infants are in good iodine nutritional status and the present iodized salt concentration can meet the demand of iodine nutrition of lactating women and infants well.

Objective:To evaluate the iodine level of drinking water in different ecological regions in Gansu Province, and to provide a basis for preventing iodine deficiency disorders in accordance with local conditions.Methods:In May to July 2017, according to different topography, landforms and climatic conditions, Gansu Province was divided into six ecological regions: desert area, Hexi Corridor gobi area, Loess Plateau hilly area, Qinling Zhongshan gorge area, Gannan Plateau grassland and meadow area, and Loess Plateau gully area. One county was selected from each of the five districts in the east, west, south, north, and central areas in each ecological regions. Drinking water samples were collected in each county based on the township, and the water iodine content was determined by arsenic-cerium catalytic spectrophotometry.Results:A total of 4 037 water samples were collected in 527 townships of six ecological regions, the water iodine range was 0.10 - 97.60 μg/L, with a median of 2.10 μg/L. Among them, the medians water iodine of the six ecological regions were less than 40 μg/L, the difference between different ecological regions was statistically significant ( H = 1 007.440, P < 0.01); the unified centralized, partially centralized and dispersed water supply water samples were 157, 2 263 and 1 617, and the medians water iodine were 1.61, 2.42, and 1.83 μg/L, respectively, and there was statistically significant difference among different water supply methods ( H = 37.164, P < 0.01). Stratified by water supply method, the differences in water iodine between different ecological regions of the same water supply method were statistically significant ( H = 32.628, 580.630, 391.070, P < 0.01); stratified by ecological region type, the differences of different water supply methods in desert area, Hexi Corridor gobi area, Qinling Zhongshan gorge area, Gannan Plateau grassland and meadow area were statistically significant ( Z = - 2.770, H = 6.369, 9.936, 12.666, P < 0.05). Conclusions:The six ecological regions in Gansu Province are all iodine-deficient areas. The water iodine content varies among different ecological region types and different water supply methods. Surveys on water iodine content and the operating status of water supply facilities should be carried out regularly, and measures should be adjusted in time to prevent and control iodine deficiency disorders in accordance with local conditions.

Objective To understand the iodine nutrition and thyroid function of different population in urban and rural areas of Gansu province and provide evidence for iodine supplementation.Methods A cross-sectional survey was performed in urban and rural children,adults,pregnant women and breastfeeding women in Wuwei from April 2009 to January 2010.Urine and fasting blood samples were collected from the subjects.Urine iodine content was measured with arsenic cerium catalytic spectrophatometry.The thyroid-stimulating hormone (TSH),free thyroid hormone (FT4) and three free triiodothyronine (FT3) were detected by using direct chemiluminescence immunoassy.Non parametric test was used to compare the urinary iodine and TSH group.t test was used to compare FT4,FT3.x2 test was used to compare the rate.Results The medians of urinary iodine level (μg/L) were 358.6,189.0,255.4 and 239.5 in urban children,adults,pregnant women and breastfeeding women and 387.6,258.5,172.8 and 215.3 in rural children,adults,pregnant women and breastfeeding women respectively.The median of urinary iodine of urban adults was significantly lower than that in rural adults (Z=-4.020,P=0.000) and the medians of urinary iodine level of urban pregnant women was higher than that in rural pregnant women (Z=1.424,P=0.035).The mean valuc of FT3 in rural pregnant women and breastfeeding women were higher than that in urban groups (t=-3.933,P=0.000;t=-2.259,P=0.026).The mean value of FT4 in urban adults was higher than that in rural adults (t=3.539,P=0.001).The positive rate of TGAb and TMAb in rural pregnant women and breastfeeding women were 43.6％,56.4％ and 33.3％,35.6％,respectively,which were higher than those in urban groups.Subclinical hypothyroidism in all thyroid function disorders was common in all the groups.No statistical significant difference in all thyroid function disorders were found in different population.Conclusion The iodine nutrition were in good status in both urban population and rural population,the children' s iodine nutrition was surplus.Statistical differences existed in iodine nutrition status or thyroid hormone level between urban and rural adults,pregnant women and breastfeeding women.

Objective To master the situation of iodine deficiency disorders (IDD) and the people's iodine nutritional status after implementation of the new salt iodine standard in Gansu Province in 2012.Methods Totally 30 counties (cities) were selected in Gansu Province by population proportionate to size sampling (PPS) method in 2014,and one primary school was selected in each counties (cities).In each selected school,50 children aged 8-10 years old were selected for thyroid examination by B-ultrasound,urine samples were collected for iodine determination,and salt samples were collected for iodine determination from a subset of children included in the study.Totally 20 pregnant women were selected from the towns with the sampled schools and urine samples were collected for iodine determination.Arsenic and cerium catalysis spectrophotometry (WS/T 107-2006) was used to detect urinary iodine content;direct titration (GB/T 13025.7-2012) was used to detect edible salt iodine content.Urinary iodine of children and pregnant women were compared with 2011 (before implementation of the new salt iodine standard).Results The median of salt iodine was 26.6 mg/kg,the iodized salt coverage rate was 99.5％ (1 492/1 500),the qualified rate of iodized salt was 89.3％ (1 333/1 492),and the consumption rate of qualified iodized salt was 88.9％ (1 333/1 500).The thyroid goiter rate of children was 3.2％ (48/1 500);a total of 1 499 urine samples of children were detected,the urinary iodine median was 169.8 μg/L,it was significantly lower than that in 2011 (216.0 μg/L,Z =-6.813,P ＜ 0.05).A total of 600 urine samples of pregnant women were detected,the urinary iodine median was 161.8 μg/L,it was significantly lower than that in 2011 (168.6 μg/L,Z =-3.590,P ＜ 0.05).Conclusion IDD has been controlled after implementation of the new standard of iodized salt and iodine nutrition condition is good.

Objective:To study the iodine nutritional status and thyroid function of adult males in iodine nutrition appropriate rural areas of Gansu Province.Methods:In 2017, Liangzhou District and Linze County of Gansu Province with suitable children iodine nutrition were selected as the study areas and 52 males aged 20 - 49 years old were investigated in each study area. One random urine sample was collected to determine urinary iodine. Fasting blood samples were collected to determine serum thyroid-stimulating hormone (TSH), free triiodothyronine (FT 3), free thyroxin (FT 4), thyroglobulin antibody (TgAb) and thyroid microsomal antibody (TMAb). At the same time, thyroid examination was performed by B-ultrasound. Results:The median urinary iodine of adult males in Liangzhou District and Linze County was 180.2 and 161.0 μg/L, respectively, and the difference was statistically significant ( P < 0.05). There was no goiter in adult males in Liangzhou District and Linze County. The serum TSH (median), FT 3 and FT 4 (mean value) of adult males in Liangzhou District and Linze County were 1.85, 1.61 mU/L, 5.19, 5.16 pmol/L and 16.58, 16.30 pmol/L, respectively. There were no significant differences between the two areas ( P > 0.05). The overall abnormal rate of thyroid function in the two areas was 6.7% (7/104), mainly subclinical hypothyroidism (6/7). The incidences of thyroid dysfunction in Liangzhou District and Linze County were 5.8% (3/52) and 7.7% (4/52), respectively, with no statistical difference between the two areas ( P > 0.05). The total positive rate of antibody was 12.5% (13/104). The positive rates of antibody in Liangzhou District and Linze County were 13.5% (7/52) and 11.5% (6/52), respectively, with no statistical difference between the two areas ( P > 0.05). Both TgAb and TMAb were positive in 9/13 of antibody positive persons, of which the proportion of antibody positive persons in Liangzhou District and Linze County were 7/7 and 2/6, respectively. The 11/13 of the total antibody positive persons were simple antibody positive without thyroid hormone and TSH abnormalities. Conclusion:The iodine nutrition of adult males in iodine nutrition appropriate rural areas of Gansu Province is suitable, but there is a potential risk of thyroid disease in this population, which should be paid attention to and checked regularly.

Objective:To comprehensively investigate the epidemic scope, geographic features and threatened population of tea drinking type endemic fluorosis in Gansu Province.Methods:From June 2019 to December 2020, according to the "2019 Investigation Plan on the Epidemic Situation of Tea Drinking Type Endemic Fluorosis" and the relevant information about the living habits of residents in cities (prefectures) in Gansu Province, 12 counties (cities) in 4 cities (prefectures) of Gannan, Wuwei, Jiuquan and Zhangye, which had the habit of drinking border-sale tea, were selected as the survey sites. The survey contents included temperature, altitude, the number of townships (towns), the number of administrative villages (residents' committees, referred to as villages), the total population under its jurisdiction, ethnic composition, production methods, drinking condition of border-sale tea, fluoride content of tea, etc. The fluoride content of tea was tested according to "The Fluoride Content of Brick Tea" (GB 19965-2005), and the evaluation of whether the fluoride content exceeded the standard (> 300 mg/kg) was carried out.Results:The annual average temperature of the survey sites ranged from 0.2 to 12.7 ℃, except for Zhouqu County, the annual average temperature of the other 11 counties (cities) was < 10 °C; the average altitude ranged from 1 200 to 4 874 m, and there were 6 counties (Maqu, Tianzhu, Subei, Sunan, Aksay and Luqu) with an altitude > 3 000 m. The total population of the 12 counties (cities) was 1 051 843, of which 492 597 (46.83%) were ethnic minorities who had the habit of drinking border-sale tea; among them, there were 474 620 Tibetans, 10 152 Yugurs, 4 660 Mongolians and 3 165 Kazaks. In 860 villages of 125 townships (towns), a survey was conducted on drinking condition of border-sale tea, and the survey rate was 79.48% (860/1 082); the drinking border-sale tea rates of villages and families were 57.67% (496/860) and 42.41% (3 658/8 625), respectively. From the perspective of production methods, the drinking border-sale tea rates of villages and families in the pastoral counties such as Aksay, Subei, Maqu, Luqu and Sunan, as well as in the semi-agricultural and semi-pastoral county of Tianzhu, were all > 95%. A total of 3 664 tea samples were tested, with an average fluoride content of 481.33 mg/kg. There were 2 588 tea samples with a fluoride content > 300 mg/kg, accounting for 70.63% (2 588/3 664).Conclusions:There are still a large number of populations who drink border-sale tea in Gansu Province, mainly distributes in the low-temperature and high-altitude pastoral counties such as Aksay, Subei, Maqu, Luqu and Sunan. The ethnic group most threatened by tea drinking type endemic fluorosis is Tibetans.

Objective To investigate the scope and distribution of water iodine in centralized water supply projects,and provide a basis for taking appropriate control measures in Gansu Province.Methods Collected 2 copies of water samples of all the different water supply of centralized water supply project water in the province's 87 counties (cities,districts),the source water iodine of all centralized water supply projects was tested by the method of cerium sulfate catalytic spectrophotometry.The relationship between different water types and different iodine levels in deep well water were analyzed.Results Of the total 1 563 centralized water supply projects,the median of water iodine was 6.38 μg/L,the range was 0.00-182.10 μg/L,the rates were 62.0％ (969/1 563),30.1％ (471/1 563),6.9％ (108/1 563),0.5％ (7/1 563) and 0.5％ (8/1 563) in water iodine level of ＜ 10,10-＜ 50,50-＜ 100,100-＜ 150 and ≥ 150 μg/L.The surface water was 26.7％ (418/1 563),the median of water iodine was 4.42 μg/L,the groundwater was 73.3％(1 145/1 563),the median of water iodine was 8.10 μg/L,the iodine content of surface water was lower than that of the groundwater (Z =-10.089,P ＜ 0.01);in surface water,the rate of river,lake,reservoir and other water source was 55.7％ (233/418),7.7％ (32/418),21.5％ (90/418) and 15.1％ (63/418),and the median was 2.52,31.10,6.65 and 5.40 μg/L,the iodine content between surface water and water sources of different water sources was significant different (x2 =179.976,P ＜ 0.01);in the groundwater,the rate of deep well,shallow well and spring was 55.5％ (635/1 145),41.3％ (473/1 145) and 3.2％ (37/1 145),and the median was 17.90,3.66 and 4.18 μg/L,the iodine content in groundwater from different sources was significant different (x2 =357.346,P ＜ 0.01).Iodine content of different well depth was significantly different (x2 =288.959,P ＜ 0.01),there was a positive correlation between iodine content and well depth (r =0.364,P ＜ 0.01).Conclusions Iodine content of the surface water is generally lower in many water types in Gansu,iodine content is higher in deep well,and there is high iodine deep well water in local areas.It is recommended that water iodine be included in the population iodine nutrition assessment index.

Objective To explore the iodine nutritional status of all people after the practice of new standard of edible iodized salt, to assess whether the new standard of edible iodized salt can satisfy the iodine nutrition need in different populations, and to provide a scientific basis for supplementation of iodine. Methods Before and after the implementation of new salt iodine concentration, in 2009 and 2015, a contrastive study was performed in 1 243 people(including 402 children aged 8 to 10 years,408 adults aged 18 to 45 years,211 pregnant women and 222 lactating women) who lived in urban and rural areas of Wuwei City. Random urine samples were collected to measure the urinary iodine in all populations and household salt samples were collected. Urinary iodine was detected by arsenic cerium catalytic spectrophotometry(WS/T 107-2006).The iodine level in salt was determined by direct titration(GB/T 13025.7-2012).Results Before and after the implementation of new iodine salt standard, the coverage of adequately iodized salt was consistently higher than 94%, the qualified rate of iodized salt was consistently higher than 96%,the median of iodized salt was reduced from 31.0 mg/kg to 26.9 mg/kg;the medians of urinary iodine of children aged 8 to 10 years, adults, pregnant and breastfeeding women were reduced from 290.84, 225.52,200.42 and 180.65 μg/L to 187.37,174.96,159.99 and 152.88 μg/L;the ratios of urinary iodine which was less than 100 μg/L in children aged 8 to 10 years, adults and breastfeeding women were risen from 5.15% (10/194), 12.57% (24/191) and 16.19% (17/105) to 10.58% (22/208), 15.81% (34/215) and 33.33% (39/117); the ratio of urinary iodine which was less than 150 μg/L in pregnant women was risen from 39.78%(37/93)to 43.22%(51/118);the ratios of urinary iodine between 100 and 200 μg/L in children aged 8 to 10 years and adults were risen from 15.46% (30/194) and 30.37% (58/191) to 44.23% (92/208) and 43.26% (93/215); the ratios of urinary iodine greater than 300 μg/L in children aged 8 - 10, adults, pregnant and breastfeeding women were reduced from 47.94%(93/194),34.55%(66/191),29.76%(26/93)and 28.57% (30/105) to 17.31% (36/208), 19.07% (41/215), 16.95% (20/118) and 11.97% (14/117). Conclusion After the implementation of new salt iodine concentration standard,the iodine nutrition level has decreased in all groups and better suited for children aged 8 to 10 years and adults,but the risk of iodine deficiency is increased in pregnant and breastfeeding women.