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Objective To find out the current thyroid volume of school children and its influencing factors in Chongqing.Methods Probability sampling method(PPS) was used to select 30 counties in Chongqing in 2011.Forty children aged 8-10of 1 randomly selected school from every county chosen were enrolled in the study.Thyroid volume of children was examined by B-ultrasonograghy.Body height and body weight were measured.The relationship between gender,age,height and weight and thyroid volume was analyzed,respectively.Results One thousand three hundred and twenty-two children aged 8-10 were investigated.The median of thyroid volume was 3.53 ml.The goiter rate was 5.52％ (73/1322).Thyroid volume of female and male was 3.55 and 3.51 ml,respectively.There was no significant difference of thyroid volume between female and male (H =0.68,P ＞ 0.05).Thyroid volume of children aged 8,9 and 10 was 3.30,3.53 and 3.76 ml,respectively.There was a significant difference of thyroid volume among different age groups(H =52.49,P ＜ 0.01).Thyroid volume of children height (110-,120-,130-and ≥140 cm,respectively) was 2.96,3.22,3.59 and 4.13 ml.There was a significant difference of thyroid volume among different height groups (H =149.23,P ＜ 0.01).Thyroid volume of children weight(17-,20-,30-and ≥40 kg,respectively) was 2.71,3.31,3.91 and 4.74 ml.There was a significant difference of thyroid volume among different weight groups(H =138.44,P ＜ 0.01).For the coefficients of simple and partial correlation,there was a significant correlation between thyroid volume and age,height and weight (P ＜ 0.05).The Spearman coefficient was 0.2411,0.3950 and 0.4285,respectively.The partial correlation coefficient was 0.0640,0.1154 and 0.2319,respectively.The standard partial coefficient of age,height and weight was 0.640,0.1154 and 0.3410,respectively.The proportion of the standard partial coefficients was 1 ∶ 1.8 ∶ 5.3.The function of body weight to thyroid volume was 5.3 times that of age and 3.0 times that of body height.Conclusions The goiter rate of schoolchildren in Chongqing is relatively high.Thyroid volume is affected by age,body height and body weight.The relationship between thyroid volume and iodine nutrition needs further study.
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Objective To analyze the characteristics of urinary iodine and edible iodized salt,and to provide suitable iodine concentration in iodized salt.Methods Sample testing was carried out to detect iodine concentration in marketed salt and child urine before salt iodization (1994).After salt iodization (2001-2010),sample testing was carried out to detect salt iodine level in manufacture,market(2001-2010) and resident household(1997-2010).Urine of children aged 8 to 10 were sampled by PPS method from 1997 to 2005.In 2009,urinary iodine of 20 children was determined in each of 5 schools,which were sampled from 5 counties located at North,South,East,West and center of Chongqing.Based on the urinary iodine and salt iodine levels before salt iodization,the relationship of urinary iodine and consumption of iodized salt was calculated.Suitable iodine concentration in iodized salt was put forward.x2 test and trend analyze approach(F-test) were used for statistical analysis.Results Before salt iodization,salt iodine level was not tested in 204 edible salt samples; the median of urinary iodine was 53.14 μg/L in 1374 children.After salt iodization,form 2001 to 2010,the average iodine levels in manufacture and wholesale salt were between 29.72-36.25 mg/kg and 30.65-36.13 mg/kg,respectively,both of them decreased significantly(F =35.35,140.59,all P ＜ 0.01),and show a downward trend.Batch quality passing rate of industry iodized salt was 100％ except in 2001,which was 92.86％.Batch quality passing rate of market iodized salt were between 88.68％-99.77％,specifically in 2001 (88.68％),in 2002(92.57％) and in 2003 (96.22％).There was no significant difference in other years (all P ＞ 0.05).The median of urinary iodine were between 238.80-328.00 μg/L,more than 35％ fall into ＞ 300 μg/L; while salt iodine increased 1 mg/kg,urinary iodine increased 5.51 μg/L-7.40 μg/L; The medium of urinary iodine of children were between 140.05-383.00 μg/L in 40 counties or districts in 2009.Reducing the iodine concentration in edible iodized salt to 20 mg/kg,the median of urinary iodine can be kept at 163.34 μg/L to 201.14 μg/L.Conclusions Iodine in iodized salt is above sufficient in Chongqing.Salt iodine should be reduced to 20 mg/kg,which will meet various population's need.
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Objective To analyze the spatial distribution characteristics of non-iodized salt at household level based on geographic information system (GIS) in Chongqing.Methods The database of non-iodized salt at county level from 2001 to 2010 was established in Chongqing.By using GIS technology,the spatial distribution and spatial autocorrelation were analyzed by ArcGIS 9.3 software.Results The rate of non-iodized salt was fluctuated between 2.35％-5.78％ during 2001-2006 and the rate was reduced to less than 2.00％ after 2007.The result of spatial autocorrelation analysis on non-iodized salt from 2001 to 2006 indicated that Moran's Ⅰindex was 0.145578,0.078801,0.108033,0.091957,0.127749,0.214302,respectively(Z value was 3.066275,1.977321,2.541619,2.309972,2.900446,3.874203,respectively,all P ＜ 0.05).The spatial distribution of non-iodized salt had marked spatial cluster through Chongqing region from 2001 to 2006.The result of local spatial autocorrelation analysis from 2001 to 2006 indicated that Fengdu and Fuling were two high-risk areas(all P ＜ 0.05).Dianjiang,Yubei,Jiangbei,Wulong and Banan were also confirmed as high-risk areas in 2001,2005 and 2006(all P ＜ 0.05).The results also indicated that the distribution of non-iodized salt in the seven high-risk areas was positively correlated.The result of spatial autocorrelation analysis on non-iodized salt from 2007 to 2010 indicated that Moran's Ⅰ index was 0.018361,0.016186,0.040769,-0.059691,respectively (Z value was 1.093310,0.787361,1.071811,-0.583820,respectively,all P ＞ 0.05).The spatial distribution of non-iodized salt was at random on the whole from 2007 to 2010.However,there were four local high-risk areas.The distribution in Fengdu and Dianjiang was positively correlated,while that in Jiangjin and Shizhu was negatively correlated.Conclusions The distribution of non-iodized salt at households level in Chongqing is changed from spatial distribution before 2006 to random distribution after 2007,but there are high value areas,which should be taken as the focus of monitoring.
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Objective Through a two-year follow up program,this study was to analyze the urinary iodine frequency of a cohort in the intervention trial,concerning different doses of salt iodization,so as to explore the selection of appropriate concentration of salt iodization.Methods A multistage cluster sampling method was used to select three townships in two countries for community intervention with different doses [ ( 15 ± 5 ) mg/kg,(25 ± 5 ) mg/kg,( 35 ± 5 ) mg/kg ] of salt iodization.Results After intervention,the median of urinary iodine was reduced among the population.The urinary iodine frequencies of (15 ± 5) mg/kg and (25 ± 5) mg/kg among groups of children were mainly concentrated in 100-200 μg/L and 200-300 μg/L paragraphs in A county.While the 300 μg/Lparagraph had an overall decline in B county,the 100 μtg/L and 200 μg/L paragraph ratio increased but the trend seemed to be slow.The 100-300 μg/L paragraph of the four treatment groups took a larger proportion and kept smooth in a more ideal state.However,the control group still maintained at above 250 μg/L level.Conclusion The iodine supplementation should be gradually implemented in Chongqing.The doses of salt iodization should be reduced from the current (35 ± 15)mg/kg to (25 ± 5) mg/kg in the economically developed areas.At the same time,we need to continuously follow the changes of the condition.
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Objective To investigate the nutritional status of iodine among residents in Chongqing, and to facilitate scientific prevention and control of iodine deficiency disorders. Methods Select 9 towns in each of the 40 districts (counties) in Chongqing, and collect 40 resident edible salt samples in each of the selected town to detect salt iodine by direct titrimetry. Select 5 towns on the site of the east, west, south, north and middle of every district (county), select 20 children aged 8 to 10 in each of the selected town to collect urine samples and detect urinary iodine by As-Ce catalytic spectrophotometric assay. Results The median of iodine of 14 217 salt specimens by household was 292 mg/kg with a coverage rate of qualified iodized salt of 98.90%( 14 061/14 217). The consumption rate of qualified iodized salt was 95.59%( 13 590/14 217). The median of urinary iodine for 4050 children aged 8 to 10 was 247.20μg/L, of which < 50 μg/L accounted for 4.60%(186/4050), 50-99μg/L accounted for 7.28% (295/4050), 100 - 199 μg/L accounted for 26.44% (1071/4050), 200 - 299 μg/L accounted for 25.58% (1036/4050), 300 μg/L or more, accounted for 36.10% (1462/4050). However, no significant difference was observed between different age groups(x2 = 3.77, P > 0.05). At district (county) level, the median of urinary iodine in 10(25.00%) districts (counties) was 100 - 200 μg/L, that in other 23(57.50%) districts (counties) was 200 - 300 μg/L, and that in other 7(17.50%) districts/counties was greater than 300 μg/L, and statistical significance was observed between different districts/counties (x2 = 441.95, P < 0.01). Conclusions Current iodine nutrition among residents in Chongqing is adequate. While there is excess, need to reduce the amount of salt iodization.
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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 analyze the change of urinary iodine in a cohort of intervention trial and to observe the role of different doses on salt iodization and related impact factors on nutritional condition of iodine. Methods Multistage cluster sampling was used to sample three townships in two counties for community intervention with different doses (15 ± 5, 25 ± 5, 35 ± 5)mg/kg. Results Compared to the (35 ± 5)mg/kg group, the urine iodine levels of three experimental townships were gradually declining in county B when time went on, and the (15 ± 5) mg/kg group showed anobvious results, at 6,12,18 and 24 months, with the urine iodine level as 180.00,186.10,150.04,191.28 μg/L respectively, which were in accordance with the WHO standard and reached to appropriate range (187.96μg/L) at the 18 month. The townships at county Y under intervention had declined slightly, but the urine iodine levels did not reach the WHO standard. The thyroid volume declined from 3.65 ml to 3.40 ml in two counties and the difference between them was statistically significant. Conclusion To some extent, reducing the iodine concentration in salt, had a role of lowering the urine iodine level and reducing the strumous rate.
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Objective To undemtand the rhythm of urinary iodine level of children aged 8-10 in Chongqing city.Methods In April 2008,using the stratified random sampling method,we sampled 60 children aged 8-10 in a lodging primary school in Chongqing(20 per age group,half male and half female),the urine samples were collected in the morning and at 10:00,12:30,16:00,iodine in urine was detected by method of Ce and arsenic catalytic speetrophotometry(WS/T 107-2006).The difference of the urinary iodine level was compared by age,sex and time of day.Results The median urinary iodine of 60 children was 265.07μg/L on the overall.Irrespective of the stratification factors,excluding morning urinary iodine(366.75μg/L)and urinary iodine at 10:00(338.30 μg/L),the urinary iodine between 12:30(235.15μg/L)and 16:00(251.50μg/L)was not significant(all P>0.05),statistically significant differences(all P<0.05)were found between any two.The urinary iodine of 8-year-old group at different times of the day was significantly different(all P<0.05),except between morning urinary iodine (298.90 μg/L)and at 10:00,16:00(279.00,286.59 μg/L),between urinary iodine at 10:00 and 16:00(all P>0.05).The 9-year-old group's urinary iodine were not significantly different between morning urine(366.15μg/L)and 10:00(368.10 μg/L),and between 12:30(244.00 μg/L)and 16:00(186.30 μg/L,all P>0.05),significant differences were faund at other times of the day(all P<0.05).The 10-year-old group of urinary iodine changed very little before 12:30 (382.85,449.60,337.00 μg/L, all P > 0.05 ), followed by rapid decline to 16: 00 (269.35 μg/L), and compared with the morning urine and 10:00, there was significant difference(all P < 0.05).Regardless boys or girls, the urinary iodine at different times qf the day was significantly different (all P < 0.05),except between morning urinary iodine(337.32,309.28 μg/L) and at 10:00(316.15,288.27 μg/L), between urinary iodine at 12:30(251.18,211.45 μg/L) and 16:00(235.02,211.45 μg/L, all P > 0.05). Conclusions The change of urinary iodine level in children aged 8 - 10 was not obvious before noon, changes can be seen in the afternoon.Urinary iodine level before 10:00 is indicative.
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Objective To investigate the iodine nutritional status of targeted population in the high-risk areas of iodine deficiency disorders in Chongqing, so as to provide scientific evidence for establishing prevention and remedial measures. Methods Six towns were selected in Chengkou and Wuxi Counties to found suspected dementia patients born after first Jan, 1997. Two hundred children aged 8-10 years were investigated in every town. The thyroid volume, intelligence quotient(IQ) and urinary iodine of the children were examined. Forty women (pregnant and nursing women) were investigated in every town. The iodine content of salt from their home was measured. The thyroid volume was examined by palpation and B-uhrasound. IQ was measured by combined Raven Test in China(CRT-RC2). Urinary iodine was determined using the acid digest arsenic-cerium contacting method, and iodined salt was detected using direct titration method. Results Six suspected dementia patients were found in the local town hospital. Five eases were excluded. There was 1 case born in other place. The rates of goiter by palpation and B-ultrasound were 9.58%(92/960) and 8.89%(65/731), respectively. The median of urinary iodine of children and women was 319.15 μg/L and 248.42 μg/L, respectively. The mean of IQ of the children was 103.32. The coverage rate of iodine salt from residents was 98.82%(336/340). Conclusions The iodine nutrition of children was good and there is no newly occurred cretinism in Chengkou and Wuxi Counties. Goiter rate and median of urinary iodine aged 8-10 years and of women, coverage rate of iodine salt from resident has meet the standard set for basical elimination iodine deficiency disorders.
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Objective To determine the urinary iodine level of people in Yunyang and Bishan County of Chongqing and explore into its influencing factors. Methods Using multistage cluster stratified simple random sample method, Yunyang and Bishan County were chosen as research spots, then thirty children aged 8-10 in each 3 primary school of the 2 counties were selected using stratified randomization sampling method to inspected their urine and household salt for iodine and the iodine content in drinking water. Results Five hundred and seventy-one urine samples were inspected and the urinary iodine median was 261.47 μg/L. 5.78% (33/571) and 37.48%(214/571) of samples had an urinary iodine median less than 100 μg/L and more than 300 μg/L. The urinary iodine median of Yunyang County was higher than that of Bishan (H = 7.42, P < 0.01). The iodine salt coverage rate, the qualified rate and edible qualified iodine salt rate respectively were 99.64%(554/556), 94.22% (522/554) and 93.88% (522/556) in 556 samples of family table salt. Eighty-seven samples of drinking water were inspected, resulting an averaged iodine content of 8.81 and 2.97 μg/L, respectively in the 2 counties. Conclusions The 2 counties are all the area of iodine deficiency. The urinary iodine level, although meeting the demand of eliminating iodine deficiency diseases, is a little bit higher given that iodized salt of present doage has been taken for a long time. The content of iodized salt should be adjusted accordingly.