Objective To evaluate the effectiveness of universal salt iodization(USI) for the control of IDD in Hebei province since it was implemented in 1995,identify the problems currently encountered in the implementation of ...Objective To evaluate the effectiveness of universal salt iodization(USI) for the control of IDD in Hebei province since it was implemented in 1995,identify the problems currently encountered in the implementation of USI and provide practical proposals for addressing these problems.Methods Probability proportionate to size sampling(PPS) was employed in the surveillance of IDD,for which a total of 1200 school children aged 8-10 years were randomly selected from 30 counties around the whole province during each IDD survey.The iodine content of salt was determined quantitatively with the titration method.The iodine content of urinary samples was measured by the method of ammonium persulfate oxidation.Results The coverage of iodized salt increased from 65.0% in 1995 to 98.0% in 1999,then decreased to 88.1% in 2005 which was below the national standard of 90%.The median urinary iodine of children aged 8-10 years varied between 160.1 μg/L and 307.4 μg/L,which was above the national standard.The proportion of urinary samples with iodine content above 300 μg/L was over 30% in 2005,implying exorbitant iodine nutrition among the children.The goiter rate(TGR) among children aged 8-10 years dropped from 11.8% in 1995 to 2.7% in 2005,indicating that the spread of endemic goiter was under control.Conclusion Preliminary elimination of IDD was achieved by USI in Hebei province.Nevertheless,some problems still existed in USI such as non-iodized salt competition,over iodization and un-standardized iodization.In order to address these problems,the management and supervision of salt market needs to be strengthened to prevent non-iodized salt from reaching households updating equipment and modifying techniques are also necessary to ensure the quality of iodized salt to clarify the causes of excessive urinary iodine content,the various sources of iodine from the diet need to be investigated in the future.展开更多
Objective 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. Methods ...Objective 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. Methods 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. Results 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 m L and 1.50 m L, 2.60 m L and 1.37 m L, 2.63 m L and 1.25 m L, 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. Conclusion 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.展开更多
Background: Iodine deficiency disorders(IDD) refer to diseases that are caused by insufficient iodine intake, and the best strategy to prevent IDD is the addition of iodine to dietary salt. Because iodine deficiency i...Background: Iodine deficiency disorders(IDD) refer to diseases that are caused by insufficient iodine intake, and the best strategy to prevent IDD is the addition of iodine to dietary salt. Because iodine deficiency is a common cause of goiter, the prevalence as effectively controlled after the implementation of universal salt iodization(USI) in China. However, there is substantial controversy as to whether the incidence of thyroid disorders is related to iodized salt intake. Therefore, we aimed to clarify whether the risk of goiter can be promoted by USI.Methods: A longitudinal continuous study based on the national monitoring results of IDD in China was performed for 3 consecutive years. We recorded the following indicators of IDD from 31 provinces: goiter number, two degrees of goiter(the degree of goiter severity) and cretinism(three endemic diseases), iodized salt intake, median urinary iodine concentration(UIC), soil iodine content and coverage rates of iodized salt. One-way Analysis of Variance(ANOVA) and linear regression analyses examined the differences between the three groups and correlations, respectively. Data were collected from the Chinese national IDD surveillance data in 2011-2013, and the background values of Chinese soil elements were published in 1990.Results: A reference male's daily intake of maximum iodine was 378.9μg, 379.2μg and 366.9μg in 2011, 2012, and 2013, respectively. No statistical association between daily iodized salt intake and the three endemic diseases was observed in 2011-2013(P >0.05). No association was observed between daily iodized salt intake and the UIC of children in 2011(P>0.05). Linear regression revealed no significant correlation between the soil iodine content and three endemic diseases. The present study indicated no difference in the daily iodized salt intake in each province during three years(F=0.886, P=0.647). The coverage rate of iodized salt remained above 98.7%, and goiter rates were stable in 2011-2013.Conclusion: There was no significant association between iodized salt intake and the three endemic diseases, suggesting that the current nutrition level of iodized salt did not cause the high goiter prevalence.展开更多
Iodization of dietary salt is recommended to prevent and control iodine deficiency disorders. The kinetic study of dietary iodized salt proves to be of interest not only for the determination of the conditions of prod...Iodization of dietary salt is recommended to prevent and control iodine deficiency disorders. The kinetic study of dietary iodized salt proves to be of interest not only for the determination of the conditions of production of iodine, but also for a good knowledge of the kinetic and thermodynamic parameters of the reaction. In this work, two salt brands were studied and one of them was used for the kinetic study. The kinetic study showed that the reaction proceeded slowly at a medium rate. Since the reaction admits a global order equal to 1, potassium iodide has no influence on this reaction rate. The concentration of iodate ions introduced in the dietary salt is a kinetic parameter that affects the reaction rate. Calculated rate constant was inversely proportional to time. The study has therefore determined experimentally kinetic parameters of the reaction between iodate and iodide ions.展开更多
This study determined concentrations of iodine, consistent with WHO iodine fortification standards, in commercial edible salts mostly consumed in Harper. The following hypothesis was put forward in the research study;...This study determined concentrations of iodine, consistent with WHO iodine fortification standards, in commercial edible salts mostly consumed in Harper. The following hypothesis was put forward in the research study;H<sub>1</sub>: the iodine content of the two brands of iodized salts is different from the WHO iodine fortification levels;H<sub>0</sub>: the iodine content of the two brands of iodized salts is not different from the WHO iodine fortification levels. The hypothesis was tested in MS Excel 2010 and 2016 via the T-Test function giving p-value = 0.1476 and p-value = 0.0395 indicative of no significant difference in the iodine concentration of the salts compared with the lower limit of WHO standard 20 mg·Kg<sup>-1</sup> and huge contrast in the iodine concentration of the salts compared with the upper limit of WHO standard 40 mg·Kg<sup>-1</sup> respectively. The UV spectrophotometric method was used to analyze and measure the iodine concentration in the twelve (12) samples of two different brands bought from grocery stores in Harper city. Results indicated that all samples of the two (2) brands of iodized salts contained iodine of no significant difference relative to the lower limit of WHO standard but far below the upper limit of the WHO standard. The study therefore recommends monitoring of commercial iodized salts by appropriate authorities in Harper to ascertain the WHO iodization fortification standards before reaching consumers.展开更多
Objective:To monitor iodized salt consumption and evaluate iodine deficiency status in 2014 in China.Materials and Methods:In 2014,a nationwide cross-sectional survey was conducted in 31 provinces (in this study,provi...Objective:To monitor iodized salt consumption and evaluate iodine deficiency status in 2014 in China.Materials and Methods:In 2014,a nationwide cross-sectional survey was conducted in 31 provinces (in this study,provinces,autonomous regions and municipalities in China's Mainland were named as provinces).Probability proportional to size sampling method was adopted to recruit children ages 8-10 and pregnant women.47,467 children's and 18,994 pregnant women's urine samples were collected and 47,706 children's thyroid volumes were examined.Iodine content in salt was determined with 46,900 edible salt samples from children's households;urinary iodine concentration (UIC) was tested from children and pregnant women's urine samples;thyroid volume of children was assessed by ultrasound.Results:The national coverage rate of iodized salt and consumption rate of qualified iodized salt were 96.3％ and 91.5％,respectively.Median iodine content in iodized salt was 25.2 mg/kg.In 22 of 31 provinces,the provincial coverage rates of iodized salt were over 95％.And consumption rates of qualified iodized salt were more than 90％ in 21 provinces.In this study,the national median urinary iodine concentration (MUIC) of children in China was 197.9 μg/L.At the provincial level,MUIC of children in 19 provinces was 100-199 μg/L,which in 12 provinces was 200-299 μg/L.The national MUIC of pregnant women in 2014 was 154.6 μg/L,slightly higher than the lower limit of the WHO criteria for adequate (150-249 μg/L).At the provincial level,MUIC of pregnant women in 18 provinces was 100-149 μg/L,which in 13 provinces was 150-249 μg/L.The national prevalence of goiter among children in 2014 was 2.6％,of which only Shandong province (5.6％) exceeded the national standard (5％).Conclusions:In China,iodine deficiency disorders (IDD) has been eliminated since 2005.And in 2014,the IDD-free status still remained.展开更多
文摘Objective To evaluate the effectiveness of universal salt iodization(USI) for the control of IDD in Hebei province since it was implemented in 1995,identify the problems currently encountered in the implementation of USI and provide practical proposals for addressing these problems.Methods Probability proportionate to size sampling(PPS) was employed in the surveillance of IDD,for which a total of 1200 school children aged 8-10 years were randomly selected from 30 counties around the whole province during each IDD survey.The iodine content of salt was determined quantitatively with the titration method.The iodine content of urinary samples was measured by the method of ammonium persulfate oxidation.Results The coverage of iodized salt increased from 65.0% in 1995 to 98.0% in 1999,then decreased to 88.1% in 2005 which was below the national standard of 90%.The median urinary iodine of children aged 8-10 years varied between 160.1 μg/L and 307.4 μg/L,which was above the national standard.The proportion of urinary samples with iodine content above 300 μg/L was over 30% in 2005,implying exorbitant iodine nutrition among the children.The goiter rate(TGR) among children aged 8-10 years dropped from 11.8% in 1995 to 2.7% in 2005,indicating that the spread of endemic goiter was under control.Conclusion Preliminary elimination of IDD was achieved by USI in Hebei province.Nevertheless,some problems still existed in USI such as non-iodized salt competition,over iodization and un-standardized iodization.In order to address these problems,the management and supervision of salt market needs to be strengthened to prevent non-iodized salt from reaching households updating equipment and modifying techniques are also necessary to ensure the quality of iodized salt to clarify the causes of excessive urinary iodine content,the various sources of iodine from the diet need to be investigated in the future.
文摘Objective 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. Methods 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. Results 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 m L and 1.50 m L, 2.60 m L and 1.37 m L, 2.63 m L and 1.25 m L, 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. Conclusion 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.
基金supported by the National Natural Science Foundation of China(No.81372125)
文摘Background: Iodine deficiency disorders(IDD) refer to diseases that are caused by insufficient iodine intake, and the best strategy to prevent IDD is the addition of iodine to dietary salt. Because iodine deficiency is a common cause of goiter, the prevalence as effectively controlled after the implementation of universal salt iodization(USI) in China. However, there is substantial controversy as to whether the incidence of thyroid disorders is related to iodized salt intake. Therefore, we aimed to clarify whether the risk of goiter can be promoted by USI.Methods: A longitudinal continuous study based on the national monitoring results of IDD in China was performed for 3 consecutive years. We recorded the following indicators of IDD from 31 provinces: goiter number, two degrees of goiter(the degree of goiter severity) and cretinism(three endemic diseases), iodized salt intake, median urinary iodine concentration(UIC), soil iodine content and coverage rates of iodized salt. One-way Analysis of Variance(ANOVA) and linear regression analyses examined the differences between the three groups and correlations, respectively. Data were collected from the Chinese national IDD surveillance data in 2011-2013, and the background values of Chinese soil elements were published in 1990.Results: A reference male's daily intake of maximum iodine was 378.9μg, 379.2μg and 366.9μg in 2011, 2012, and 2013, respectively. No statistical association between daily iodized salt intake and the three endemic diseases was observed in 2011-2013(P >0.05). No association was observed between daily iodized salt intake and the UIC of children in 2011(P>0.05). Linear regression revealed no significant correlation between the soil iodine content and three endemic diseases. The present study indicated no difference in the daily iodized salt intake in each province during three years(F=0.886, P=0.647). The coverage rate of iodized salt remained above 98.7%, and goiter rates were stable in 2011-2013.Conclusion: There was no significant association between iodized salt intake and the three endemic diseases, suggesting that the current nutrition level of iodized salt did not cause the high goiter prevalence.
文摘Iodization of dietary salt is recommended to prevent and control iodine deficiency disorders. The kinetic study of dietary iodized salt proves to be of interest not only for the determination of the conditions of production of iodine, but also for a good knowledge of the kinetic and thermodynamic parameters of the reaction. In this work, two salt brands were studied and one of them was used for the kinetic study. The kinetic study showed that the reaction proceeded slowly at a medium rate. Since the reaction admits a global order equal to 1, potassium iodide has no influence on this reaction rate. The concentration of iodate ions introduced in the dietary salt is a kinetic parameter that affects the reaction rate. Calculated rate constant was inversely proportional to time. The study has therefore determined experimentally kinetic parameters of the reaction between iodate and iodide ions.
文摘This study determined concentrations of iodine, consistent with WHO iodine fortification standards, in commercial edible salts mostly consumed in Harper. The following hypothesis was put forward in the research study;H<sub>1</sub>: the iodine content of the two brands of iodized salts is different from the WHO iodine fortification levels;H<sub>0</sub>: the iodine content of the two brands of iodized salts is not different from the WHO iodine fortification levels. The hypothesis was tested in MS Excel 2010 and 2016 via the T-Test function giving p-value = 0.1476 and p-value = 0.0395 indicative of no significant difference in the iodine concentration of the salts compared with the lower limit of WHO standard 20 mg·Kg<sup>-1</sup> and huge contrast in the iodine concentration of the salts compared with the upper limit of WHO standard 40 mg·Kg<sup>-1</sup> respectively. The UV spectrophotometric method was used to analyze and measure the iodine concentration in the twelve (12) samples of two different brands bought from grocery stores in Harper city. Results indicated that all samples of the two (2) brands of iodized salts contained iodine of no significant difference relative to the lower limit of WHO standard but far below the upper limit of the WHO standard. The study therefore recommends monitoring of commercial iodized salts by appropriate authorities in Harper to ascertain the WHO iodization fortification standards before reaching consumers.
文摘Objective:To monitor iodized salt consumption and evaluate iodine deficiency status in 2014 in China.Materials and Methods:In 2014,a nationwide cross-sectional survey was conducted in 31 provinces (in this study,provinces,autonomous regions and municipalities in China's Mainland were named as provinces).Probability proportional to size sampling method was adopted to recruit children ages 8-10 and pregnant women.47,467 children's and 18,994 pregnant women's urine samples were collected and 47,706 children's thyroid volumes were examined.Iodine content in salt was determined with 46,900 edible salt samples from children's households;urinary iodine concentration (UIC) was tested from children and pregnant women's urine samples;thyroid volume of children was assessed by ultrasound.Results:The national coverage rate of iodized salt and consumption rate of qualified iodized salt were 96.3％ and 91.5％,respectively.Median iodine content in iodized salt was 25.2 mg/kg.In 22 of 31 provinces,the provincial coverage rates of iodized salt were over 95％.And consumption rates of qualified iodized salt were more than 90％ in 21 provinces.In this study,the national median urinary iodine concentration (MUIC) of children in China was 197.9 μg/L.At the provincial level,MUIC of children in 19 provinces was 100-199 μg/L,which in 12 provinces was 200-299 μg/L.The national MUIC of pregnant women in 2014 was 154.6 μg/L,slightly higher than the lower limit of the WHO criteria for adequate (150-249 μg/L).At the provincial level,MUIC of pregnant women in 18 provinces was 100-149 μg/L,which in 13 provinces was 150-249 μg/L.The national prevalence of goiter among children in 2014 was 2.6％,of which only Shandong province (5.6％) exceeded the national standard (5％).Conclusions:In China,iodine deficiency disorders (IDD) has been eliminated since 2005.And in 2014,the IDD-free status still remained.
