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<p><b>OBJECTIVE</b>The aim of this study was to evaluate the impact of the revised Chinese National Standard GB26878-2011 'Iodine Content in Edible Salt' on the iodine status among the Chinese population.</p><p><b>METHODS</b>In 2011 and 2014, the probability proportionate to size sampling (PPS) was used in each Chinese province to obtain the representative data. In each sampling unit, school children aged 8-10 years and pregnant women were selected. Key indicators included urinary iodine concentration (UIC), thyroid volume (TV), and the iodine content in edible household salt.</p><p><b>RESULTS</b>The median urinary iodine concentration (MUIC) decreased between 2011 and 2014 from 238.6 to 197.9 µg/L in school-age children. The number of provinces with iodine excess decreased to zero. The proportion of children whose UIC was > 300 µg/L was 18.8% and decreased to 11% compared with 29.8% in 2011. There was no significant difference in UIC < 50 µg/L between 2014 (4.3%) and 2011 (3.7%) (P > 0.05). The MUIC among pregnant women in 2014 was more concentrated between 110 and 230 µg/L. The goiter rate among children aged 8-10 years was unchanged, both the goiter rate of 2011 and 2014 remaining below 5%, in view of the sustainable elimination of iodine deficiency disorders.</p><p><b>CONCLUSION</b>The National Standard GB26878-2011 'Iodine Content in Edible Salt' that was introduced in March 2012 resulted in an overall improvement in iodine status, reducing the risk of excessive iodine intake in the Chinese population.</p>
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<p><b>OBJECTIVE</b>We aimed to evaluate goiter prevalence and iodine nutritional status in areas with high levels of water iodine; to monitor the prevalence of iodine deficiency disorders (IDD) in areas at high risk of IDD; and to compare the prevalence of goiter and urine iodine (UI) concentrations between children living in the two areas.</p><p><b>METHODS</b>Based on surveillance from 2012-2014, we analyzed the concentration of UI and prevalence of goiter in 8-10-year-old children from 12 high-risk IDD provinces, and from 8 provinces and municipalities with excessive water iodine. We calculated goiter prevalence for each UI level according to World Health Organization (WHO) standards and constructed predictive prevalence curves.</p><p><b>RESULTS</b>The goiter prevalence and median UI of children from areas with high water iodine were not optimal, being above the WHO standards (5% and 100-199 μg/L, respectively), whereas those in high-risk areas fell within the standard. UI and goiter prevalence exhibited a U-shaped relationship in high-risk endemic areas and a parabolic relationship in areas of iodine excess.</p><p><b>CONCLUSION</b>Iodine surplus in high-iodine areas leads to high goiter prevalence and UI. However, in high-risk areas, UI was optimal and goiter prevalence met the national criteria for IDD elimination.</p>
Subject(s)
Child , Female , Humans , Male , China , Epidemiology , Dose-Response Relationship, Drug , Goiter , Epidemiology , Iodine , Urine , Prevalence , Risk FactorsABSTRACT
<p><b>OBJECTIVE</b>To assess the effect of different levels of salt iodine content on thyroid volume (ThV) distribution using data from the 1999, 2011, and 2014 Chinese national iodine deficiency disorder (IDD) surveys.</p><p><b>METHODS</b>Probability proportion to size (PPS) sampling method was used to obtain a representative national sample of 34,547, 38,932, and 47,188 Chinese children aged 8-10 years in 1999, 2011, and 2014 Chinese national IDD surveys, respectively. The iodine content in household iodized salt and urinary iodine concentration were measured and thyroid ultrasound examination was performed. The data were analyzed by SAS software using histograms and box plots. The skewness and kurtosis were calculated for testing the normality of ThV.</p><p><b>RESULTS</b>The median iodine content in household iodized salt dropped from 42.30 mg/kg in 1999 to 25.00 mg/kg in 2014. The median urinary iodine concentration of children aged 8-10 years decreased from 306.0 μg/L in 1999 to 197.9 μg/L in 2014. The median and interquartile range (IQR) of ThV in 1999, 2011, and 2014 surveys were 3.44 mL and 1.50 mL, 2.60 mL and 1.37 mL, 2.63 mL and 1.25 mL, respectively. The skewness and kurtosis of ThV distribution in 1999, 2011, and 2014 surveys were 1.34 and 5.84, 0.98 and 3.54, 1.27 and 5.49, respectively.</p><p><b>CONCLUSION</b>With reduced salt iodization levels, the median urinary iodine concentration and median ThV of children decreased significantly, and the symmetry of the ThV distribution improved.</p>
Subject(s)
Child , Female , Humans , Male , China , Iodine , Nutritional Status , Sodium Chloride, Dietary , Thyroid Gland , Diagnostic Imaging , UltrasonographyABSTRACT
Objective To investigate the iodine content of food in six provinces of China,to add the results of this survey to the food iodine content database,and to provide a scientific basis for iodine supplementation in different parts of China.Methods A total of 8 categories and 39 species common food produced locally in the six provinces of Fujian,Chongqing,Shandong,Anhui,Gansu and Jilin were collected.Samples of cereals,beans and other dry samples were crushed into powder; samples of fresh fruits and vegetables were washed and dried to constant weight,and crushed into powder; poultry,meat and fish samples were washed and then their edible parts were crushed into meat paste,bake dried to constant weight,and crushed into powder.Iodine content in the above-mentioned food was determined by catalytic spectrophotometry,and the wavelength was 405 nm.Data processing and statistical analysis were carried out by using SPSS 13.0 statistical software.The results of total iodine content of the various types of food were expressed as median(P50) and interquartile range(P25 and P75).Results The iodine content of the cereal in Fujian,Chongqing,Shandong,Anhui,Gansu and Jilin were 11.9,12.0,48.0,95.1,13.0and 3.1 μg/kg,respectively; of the potato were 53.9,26.3,74.9,43.7,76.8 and 38.5 μg/kg,respectively; of the meat and the eggs were 56.0,30.4,78.6,124.6,47.7 and 34.8 μg/kg,respectively; of the aquatic products were 319.3,144.7,186.6,241.3,155.4 and 213.3 μg/kg,respectively; of the vegetables were 166.6,145.1,131.7,218.0,205.4 and 98.1 μg/kg,respectively; of the fruits were 105.5,17.8,80.9,1.7,76.7 and 10.3 μg/kg,respectively; of the kelp and laver were 36.0 × 103,1292.0 × 103,2810.0 × 103,48.0 × 103,75.0 × 103 and 120.0 × 103 μg/kg,respectively; of the Chinese pickled vegetables were 640.4,4163.5,3073.7,2635.3,1540.9 and 492.0 μg/kg,respectively.ConclusionsThe iodine content of different types of food,and same kind of food from different provinces are different.The results are a complement to the 2004 Chinese food composition database.
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Objective To investigate iodine deficiency disorders(IDD) in Chongqing and Linzhi, and to provide scientific basis for IDD control and prevention. Methods According to the national program developed in 2007, investigation was conducted in Chengkou and Wuxi county in Chongqing municipality, and Linzhi, Bomi,Milin and Langxian county in Linzhi prefecture. Five towns were sampled in Linzhi county, and 3 in other counties.In each town, one township primary school and two village primary schools were selected to inspect thyroid by B ultrasound and palpation, and urinary iodine of children aged 8 to 10 years was tested in these schools. Meanwhile,2 villages were selected in each town for test of salt iodine level and urinary iodine of childbearing age women and search cretin cases. Results Three hundred and forty families in Chongqing and 915 families in Linzhi were investigated. The coverage of iodized salt in Chongqing was 98.82%(336/340), which was significantly higher than that in Linzhi[66.34%(607/905), x2 = 139.56, P ＜ 0.01]. Goiter rate of children in Chongqing was 9.27%(89/960) by palpation and 8.34% (61/731) by B ultrasound, while goiter rate of children in Linzhi was 7.80%(102/1308) by palpation and 5.53% (69/1248) by B ultrasound. The difference of goiter rate by palpation between Chongqing and Linzhi was not statistically significant (x2 = 1.37, P ＞ 0.05 ). But goiter rate of children by B ultrasound in Chongqing was higher than that in Linzhi (x2= 5.51, P ＜ 0.05). In Chongqing, the median urinary iodine was 319.15 μg/L, and 345.75 μg/L in Chengkou county and 281.39 μg/L in Wuxi county. In Linzhi prefecture, the median urinary iodine was 189.81 μg/L, and 207.81 μg/L in Linzhi county, 161.12 μg/L in Bomi county, 131.83 μg/L in Milin county and 334.60 μg/L in Langxian county. The median urinary iodine in childbearing women were 248.42 μg/L in Chongqing and 121.25 μg/L in Linzhi. The median urinary iodine in Chongqing both in children and women were higher than those in Linzhi. No new cretin case was found in these two areas. Conclusions Goiter rate in high risk areas of IDD in Chongqing and Linzhi has decreased to less than 10%.No new cretin case is found in these areas. It can be concluded that the work of control and prevention is effective.There is excess iodine in Chongqing. In Linzhi county and Langxian county, iodine is excess in children and deficient in women. Further investigation should be conducted to find out the reason. Population iodine is excess in Bomi and Milin counties. The concentration of salt iodine should be decreased in Chongqing. In Linzhi prefecture,adding iodine measures should be adjusted based on further investigation.
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Objective To observe the effects of casein on iodine metabolism in blood,urine and thyroid of mice under excessive iodine.Methods A 2 by 3 factorial design was used in the experiment.The levels of iodine and casein were 50 and 600 μg/L in drinking water and 0( Ⅰ ),10％( Ⅱ ),20％( m ) in food,respectively.After six and twelve months,iodine content in serum,thyroid gland and urine was determined by arsenic-cerium catalyzed spectrophotometry.Results In six months,the levels of serum iodine in 50 Ⅰ,50 Ⅱ,50Ⅲ,600 Ⅰ,600 Ⅱ,and 600Ⅲ groups were (85.59 ± 8.78),(64.59 ± 9.06),(72.53 ± 11.69),(110.04 ± 9.37),(81.06 ± 9.94),(86.63 ± 19.59)μg/L,respectively; the levels of iodine content in thyroid gland were (0.21 ± 0.09),(0.29 ±0.08),(0.24 ± 0.05),(0.50 ± 0.10),(0.37 ± 0.13),(0.42 ± 0.12)g/kg,respectively; the levels of urinary iodine median were 87.5,68.1,105.5,746.5,828.3,1014.2 μg/L,respectively.The variance analysis results of factorial design showed iodine and casein significantly influenced the serum iodine level(F =27.95,18.52,all P ＜0.05),however,there was no interaction between the two(F =0.81,P ＞ 0.05); iodine significantly influenced the iodine content in thyroid gland(F =31.35,P ＜ 0.05),the presence of iodine interacted with casein(F =3.34,P ＜0.05).In twelve months,the levels of serum iodine were (88.54 ± 12.33),(72.45 ± 7.73),(72.93 ± 13.61),( 106.26 ± 12.00),(90.03 ± 7.90),( 104.88 ± 11.67)μg/L,respectively; the levels of iodine content in thyroid gland were (0.58 ± 0.12),(0.40 ± 0.14),(0.69 ± 0.16),(0.84 ± 0.13),(0.89 ± 0.13),(1.02 ± 0.11 )g/kg,respectively;the levels of urinary iodine median were 104.8,121.5,102.7,829.1,1080.8,895.2 μg/L,respectively.The variance analysis results of factorial design showed iodine and casein significantly influenced the iodine content in serum and thyroid gland (F =42.78,7.42 and 66.62,7.90,all P ＜ 0.05),however,there was no interaction between the two(F =1.93,2.31,all P ＞ 0.05).Conclusions Long-term intake of iodine can significantly increase the iodine content in serum,thyroid gland and urine,but casein may accelerate iodine excretion and partly reduce the effect.
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Objective To study whether the measure of consumption of iodized salt to prevent iodine deficiency disorders could lead to residents excessive iodine intake in the coastal areas in China.Methods A large population-based cross-sectional study was carried out in four typical costal provinces along the coastline from north to south,including Liaoning,Shanghai,Zhejiang and Fujian.In addition to survey all of its area of Shanghai,the other three provinces' investigation was carried out at urban and rural levels,respectively,including 5 costal cities,5 costal villages and 3 inland rural areas(as a control point) in each province.In each investigated spot,the local water iodine,residents qualified iodized salt consumption rate,per capita daily intake of salt and urinary iodine levels in different populations were investigated.Results A total of 7552 copies of drinking water samples,7996 salt samples and 9873 urine samples of different populations(adults,lactating women,pregnant women and children) were collected from the 4 provinces.Except the coastal cities and counties of Zhejiang province,the qualified iodized salt consumption rates at household were all greater than 90％ in the investigated spots.The median urinary iodine(MUI) of adults and children investigated in the costal areas were in the range of 100 - 299μg/L.The MUIs of lactating women of all investigated areas were all greater than 100 μg/L.The MUI of pregnant women was at an insufficient iodine level which was lower than 150 μg/L in Shanghai,the costal cities of Zhejiang and the coastal counties of Fujian.Conclusions The overall level of iodine nutrition of coastal residents is appropriate; and it is insufficient among pregnant women in some coastal areas; coastal areas should adhere to the salt iodization measures to control iodine deficiency disorders.
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Objective Take alkaline ashing method as golden standard to explore the accuracy of chloric acid digestion method in determination of human milk iodine. Methods Sixty one breast milk samples collected in Hexi district of Tianjin was measured by the method for determination of iodine in foodstuff by As3+-Ce4+ catalytic spectrophotometry (referred to as the alkaline ashing method) published in 2008 and the method for determination of iodine in urine by As3+-Ce4+ catalytic spectrophotometry(referred to as acid digestion) published in 1999, respectively. were highly correlated(r = 0.960, t = 26.3, P < 0.01), and the regression equation was (Y) = - 28.1 + 0.808X, in which X was independent variable, that is the results of alkaline ashing method; (Y) was dependent variable, that is the estimated data of chloric acid digestion method. The average difference of the results measured by the two methods was 68.3 μg/L, and the results from chloric acid digestion was 38.9% which lower than that of alkaline samples were diluted by 3,4 and 5-fold and then digested by chloric acid, the liquid clarification rates were 80.3% ashing and chloric acid digestion method were, respectively, 165.4, 110.0 μg/L. Conclusions Compared with alkaline ashing method, the results determined by chloric acid digestion method are significantly lower. It is suggested that there are systemic errors in chloric acid digestion method, which means that alkaline ashing method can not be replaced by the chloric acid digestion method.
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Objective To survey the prevalence rates of adult carotid atherosclerosis in water-sourceoriginated high iodine area in Shandong province in 2008 and discuss the relationship between water-sourceoriginated high iodine and carotid atherosclerosis occurrence. Methods Yuncheng county was chosen as observation area which included Dachenlou, Weigai, Liuyi and Ershilipu villages. Juye county was chosen as control that included Zhangxi, Bihainan, Xiaguan and Qiji villages. Two hundred and ninety-nine participants aged over 40 from water-source-originated high iodine areas and 323 residents aged over 40 from normal iodine areas were investigated.Portable-type B mode color Doppler was performed to examine the carotid artery of all participants. The adult carotid atherosclerosis was diagnosed and graded through the ultrasonograms. Results The prevalence rates of adult carotid atherosclerosis in the 4 water-source-originated high iodine villages of Dachenlou, Weigai, Liuyi and Ershilipu were 47.1% (33/70) ,62.2% (51/82) ,67.5% (52/77) and 58.6% (41/70), respectively and the prevalence rates of adult carotid atherosclerosis in the 4 normal iodine villages of Zhangxi, Bihainan, Xiaguan and Qiji were 40.7%(35/86),40.8% (31/76),38.2% (34/89) and 37.5% (27/72), respectively. The prevalence rates of adult carotid atherosclerosis standardized by age in the 4 high iodine villages and the 4 normal iodine villages were 45.81% ,58.18% ,61.63%,55.34% and 34.66%,36.25%,43.01% ,41.30%, respectively. The prevalence rates were higher in high iodine villages than that in control villages(T = 26, P ＜ 0.05 ). There were 136 people scored "0", 120 people scored "1 -3",43 people scored "4 - 7", and total 299 people. There were 201 people scored "0", 87 people scored "1 - 3", 35 people scored "4 - 7", and total 323 people. The expected prevalence rates and severity of adult carotid atherosclerosis was significantly different between high iodine area and normal iodine area (x2 = 17.54,18.42, all P ＜ 0.01).Conclusion The prevalence rate and severity of adult atherosclerosis in water-source-originatod high iodine area is higher than that in normal iodine area.
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Objective To investigate the occurrence of new cretinism cases and the prevalence of endemic goiter, and the reason of lower coverage rate of iodized salt in the iodine deficiency disorders(IDD) high-risk areas of China, so as to put forward target prevention measures for these areas. Methods A hundred and one counties from 11 provinces(autonomous regions, municipality), such as Tibet, Qinghai, Xinjiang, Gansu, Ningxia, Sichuan, Hainan, Chongqing, Yunnan, Guangxi, Inner Mongolia, were chosen into the survey by simple random sampling. In the counties of high risk, typical sampling principle was used. In the selected townships, searching for new cretinism cases were carried out in the children under 10 years old, the thyroid volume of children aged 8-10 years old were determined by B-ultrasonography methods and their urinary iodine (UI) were determined by As3-Ce<'4+> catalytic spectrophotometry, the intelligence quotient(IQ) values of children aged 8-10 years old were measured by the combined Raven Test in China. In the household survey, the housewives were asked to fill in the questionnaire, the iodized salt coverage rates and the UI levels of child-bearing age women were investigated, the salt iodine content was determined using self-quantitative kit. Epi Info software was used to analyze the determination results. Results In the 101 high-risk counties, 249 were diagnosed as new cretinism cases from 4122 suspected cases searched. The goiter rate of children aged 8-10 years old by B-ultrasound was 8.28% (4434/53 541), 44 counties had goiter rates in the range of 5%-20%, 5 counties had goiter rates in the range of 20%-30%, and 3 counties had goiter rates of 30%. The mean IQ of children was 85.44, and the percentage of IQ value less than 70 was 16.52%(8713/52 745). The median urinary iodine(MUI) of children was 154.69 μg/L, the percentage of UI less than 50 μg/L was 17.26% (9069/52 558). Twenty-five counties had a MUI of children less than 100 μg/L. The MUI of housewives was 107.14 μg/L, the percentage of UI less than 50 μg/L was 27.50% (3722/13 534). MUI of housewives in 46 counties were less than 100.0 μg/L. The coverage rate of iodized salt at household level was 77.85%(13 150/16 891). The coverage rate of iodized salt was 52.80%(1585/3002), 44.72% (631/1411) and 72.82% (1850/2506) in Tibet, Hainan and Qinghai, respectively. More than 10% residents of Tibet, Sichuan, Hainan, Gansu and Qinghai complained that iodized salt was not convenient to buy. There were 71.39%(7652/10 719) of observed people ate crude salt. The average price of crude salt price(0.30-1.20 Yuan/kg) was lower than iodized salt(1.20-3.00 Yuan/kg). Conclusions In these IDD high-risk areas, the risk of endemic goiter and cretinism prevalence is threatening. The IDD monitoring should be carried out successively in these high-risk areas. The prevention measures, increasing iodized salt coverage rate and establishing the sustainable mechanism for eliminating IDD should be strengthened. Emergent iodine fortification measure for high risk region people should be implemented as soon as possible, a long term effective mechanism of eliminating IDD should be established.
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Objective To observe the effects of casein and excessive iodine on histomorphalogY and ultrastructure of mouse thymicL Methods Based on 2 × 3 factorial design,the experimental mice were divided into 6 groupg Animal models were estabhshed by feeding the mice with different levels of iodine water and casein food.The levels of iodine were 50,600 μg/L in drinking water and 0(Ⅰ),10%(Ⅱ),20%(Ⅲ)of casein in food respectively.After 12 months,the thyroid weight was measured and the morphology of thyroid was observed under optical and electron microscope.Results Factorial analysis showed that iodine factors obviously affected the thyroid absolute and relative weiights of mice(F=16.23,9.47,P＜0.01),and there was interaction between casein and iodine(F=5.29,4.68,P＜0.01 or＜0.05).Compared wiht 150Ⅰ[(5.91±0.82)rag,(117.0±22.2)mg/kg]and 50Ⅲ[(4.90±0.63)rag,(106.1±13.3)mg/kg]groups.thyroid absolute and relative weights of the mice increased in 600 Ⅰ[(7.60±2.40)mg,(143.3±43.2)mg/kg]and 600Ⅲ[(8.63±1.88)mg,(166.2±39.4)mg/kg]groups(P＜0.05 or＜0.01),respectively.But compared with 600 Ⅰ and 600Ⅲ groups.they were reduced obviously in 600Ⅱ[(5.76±1.13)mg,(109.8±16.5)mg/kg]group(P＜0.05 or＜O.01).Colloid goiter,lymphocyte infiltration were found,some of the follicles epithelial cells appeared active under light and electron microscope in iodine excels group,which,however,decreased obviously along with the increase of casein dose.Conclusions Long-term excessive iodine may cause colloid goiter and inflammation injury of mice,possibly leading the development of thyroiditis in mice,which may be partly reduced by casein.
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Objective In order to compare the iodine deficiency disorders(IDD)prevalent slatus in Chun'an County between 2006 and 2007,and to provide the science information for iodine supplementation in different regions.Methods Three schools of Wangzhai,Pingmen and Wenchang which the goiter prevalenee was the most severe were selected in Chun'an County;and from each school,90 pupils aged 8-10 years were randomly selected.B-ultrasound examination of thyroids,urine iodine and salt iodine were measured.Results The goiter rate in B-ultrasound were 7.5%(20/267),median of urine iodine was 247.5 μg/L,mean of salt iodine was 32.7 ms/ks in 2006;and the goiter rate in B-uhrasound were 3.7%(10/271),median of urine iodine was 383.4 μg/L,mean of salt iodine was 33.5 mg/kg in 2007.The goiter prevalence in Wangzhai,Pingrnen and Wenehang township were 15.2%(14/92),6.0%(5/83)and 2.2%(2/92),respectively,and median of urine iodine were 360.1.211.3,189.3μg/L,respectively,in 2006;The goiter prevalence were 6.6%(6/91),3.3%(3/90)and 1.1%(1/90),respectively.and median of urine iodine were 388.6,41 1.5,327.8μg/L,respectively,in 2007.Family ineome of Wangzhai,Pingmen and Wenchang township were 1000,2000,3000 yuan,respectively.Conclusions Goiter prevalence was correlated with urinary iodine,nutritional state and economic condition,high urinary iodine contents and poor nutritional status lcad to a high goiter rate.
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<p><b>OBJECTIVE</b>To study the factors leading to the variation of children's total goiter rates, urine iodine and salt iodine in West China.</p><p><b>METHODS</b>Design effect (DEFF) was used to evaluate the variation of indicators.</p><p><b>RESULTS</b>DEFF of children's total goiter rate was about 3.0 in 9 provinces, and the proportion was 75.0%. The DEFF of urine iodine was 1.0 - 3.5 in 6 provinces, and the proportion was 50.0%. The DEFF of intake rate of qualified iodized salt was over 3.0 in 11 provinces. The DEFF of covering rate of iodized salt was about 3.0 in 4 provinces.</p><p><b>CONCLUSION</b>In order to provide scientific basis for IDD surveillance in China, other than bias due to methods of no-sampling, sample size should be further calculated in West China. Thus the main influencing factors of indicator variation could be measured with scientific and reasonable basis.</p>
Subject(s)
Child , Humans , China , Epidemiology , Goiter , Epidemiology , Iodine , Urine , Sample Size , Sodium Chloride, DietaryABSTRACT
Objective To discover and discuss the charac ter and statistics of frequency distribution of thyroid volume (TV) in Chinese c hildren aged 8,9,10 years for setting up an effective strategy to control the endemic goiter in China.Methods The TV is measured by B-ultrasonography.The da ta of a great sample collected from all country are treated with computer centra lly in Chinese Research Center for Endemic Disease Control.Results ①In 1999,the statistics of TV(ml) of children aged 8,9,10 years in China are 3.6 of mean,3.4 of median,3.0 of mode,5.9 of 95% point and 7.9 of 99% point.②The values of 95% point in frequency distribution of TV in 8,9,10 years of boy in order are 4.8,5.6 and 6.3,and in girl they are 5. 2,5.8 and 6.5.③The disparity in medians of TV of children is very significant between the studied provinces;the lowest is Shanghai,the mediums are Anhui and Sh anxi,and the higher ones are Chongqing,Guizhou and Xinjiang,and the medians of the TV in these three categories are 1.2,3.7 and 4.0 in order.④Differential effe cts of palpation method in detection of TV are discussed carefully in this paper .Conclusions The cause inducing to the significant diffe rences of children TV in several regions in China is not known yet,but it is not the nutritional problem of iodine certainly.
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Objective To observe the characteristics and statistics in the bi-variable distribution of thyroid volume (ml) and urine iodine level (μg/L) of children aged 8,9,10 years in China,1999.Methods Classing analysis.Results ①Data of 12982 cases collected from all country are analyzed with cluster method and three clusters are delimitated as follows;②in first cluster,according to the calculation of median,the volume of thyroid gland is small (2.2ml) and the level of urinary iodine is high (369.1μg/L);③in second cluster,the volume of thyroid gland is middle size (3.4ml) but the level of urinary iodine is significantly lower (88.0μg/L) than that in the first cluster;④in third cluster,the thyroid volume is highest (4.1ml) and the level of urine iodine is high (363.4μg/L),too;⑤the meanings of the classifying results are discussed in detail.Conclusions The results of the cluster analysis reported here and the typical analyses of the previous papers suggested that no low iodine problems be found out but the correlation between the increasing of thyroid volume and the higher level of urine iodine be observed by us in the studies.