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To explore the status of iodine nutrition and iodine deficiency disorders in the pasturing areas and agricultural regions in Tibet.30 families were selected respectively in pastoral Dangxiong county and agricultural Qushui county of Lasa. Drinking water and edible salt were collected for testing the iodine contents. In each type of the following populations including children aged 8 - 10, women of child-bearing age and male adults, 50 subjects were randomly sampled to examine their urinary iodine contents. Among them, 50 children and 50 women were randomly selected for goiter examination by palpation.Water iodine content was less than 2 µg/L, both in pasturing area and in agricultural areas. There was no iodized salt used in the families of pasturing areas, while 90% people consumed iodized salt in agricultural areas. The median of urinary iodine in pasturing area was 50.2 µg/L, significantly lower than that of agricultural area (193.2 µg/L). However, the goiter rate of children and women in pasturing area was significantly lower than that in agricultural area.Although iodine intake of populations in pasturing area of Tibet was severely deficient, there was no epidemic of Iodine Deficiency Disorders. This phenomenon noticed by the researchers deserved further investigation.

To explore the association between excessive iodine intake and lipid disorder in human bodies.Based on the NTTST sample survey on water iodine in Suining of Jiangsu province, this study involved 81 residents whose drinking water containing excessive iodine and 101 residents who drank water with normal iodine content. Blood samples were tested and compared on lipids (TG, TC, HDL-C, LDL-C, apoA1, apoB) between the two groups, after adjusting the influences of age and gender. The study also compared the abnormal rate of each lipid indicator between the two groups. Corresponding RR values and 95% confidence interval were calculated. Correlation between iodine content in drinking water and blood lipid was also studied.apoA1 in the group with excessive iodine intake was significantly lower than that in the normal iodine group, while there were no significant differences between the two groups in other lipid indicators. The abnormal rate of HDL-C of excess iodine group (16.88%) was significantly higher than the rate of normal iodine group (7.22%) while there were no significant differences between the two groups in other lipid indicators. Both apoA1 and HDL-C in the excess iodine group had a negative correlation with water iodine, while the other indicators of two groups had no correlation with water iodine.Drinking water with excess iodine might increase the risk of lipid disorder.

To compare the changes of urinary iodine levels among the family members with iodine content of 5 - 150 microg/L in drinking water, before and after non-iodized salt intervention through a field trail study.Family members who routinely drank water with iodine content 5 - 150 microg/L were chosen to substitute non-iodized salt for their current iodized salt for 2 months, and urine samples of the family members were collected for determination of iodine change before and after intervention was carried out.Median urinary iodine of school children, women with productive age and male adults exceeding 370 microg/L before intervention and the frequency distribution of urinary iodine were all above 70%. Our results revealed that iodine excess exited in three groups of family members. After intervention, all median urinary iodine level seemed to have decreased significantly, and groups with drinking water iodine 5.0 - 99.9 microg/L reduced to adequate or close to adequate while the group that drinking water iodine was 100 - 150 microg/L reached the cut-off point of excessive iodine level (300 microg/L).Results from your study posed the idea that the iodine adequate areas should be defined as the areas with iodine content of 5.0 - 100 microg/L in drinking water, and edible salt not be iodized in these areas. Areas with iodine content of 100 - 150 microg/L in drinking water should be classified as iodine excessive.

To understand the national situation of quality and consumption of iodized salt at production and household levels.Detailed surveillance method could be found in 'national iodized salt surveillance scheme', issued by MOH in 2004. The iodine concentrations in salt (except some special kinds of salt) were detected by direct titration with national standard of GB/T 13025.7-1999, in which the iodine content in qualified iodized salt was set as between 20 and 50 mg/kg and that in non-iodized salt was set as below 5 mg/kg.At production level, the national lot qualified rate was 98.36% and all the provincial lot qualified rate of production level was over 90%. At household level, the national iodized salt coverage rate of household was 96.87% and the national qualified iodized salt coverage rate was 93.75%. 4 provinces (Tibet, Hainan, Xinjiang and Guangdong) had an iodized salt coverage rate lower than 90%. Further, the qualified iodized salt coverage rate of 5 provinces (Tibet, Hainan, Xinjiang, Guangdong and Qinghai) was below 90%. In 2006,80 counties did not conduct the iodized salt surveillance and non-iodized salt coverage rate of 185 counties was higher than 10%. In the respect of the qualified iodized salt coverage rate at household level, there were about 10 percent lagging behind the national goal that 95% of all the counties in China should achieve virtual elimination of iodine deficiency disorder before 2010.At national level,the lot qualified rate at production level and the iodized salt coverage rate at household level maintained comparatively well. However, at county level, there were 75 counties whose iodized salt coverage rate was below 70%.

To draft out the simplified scheme of iodized salt monitoring program to compare with the current scheme, and to study its feasibility.8 counties from 4 provinces were selected at different coverage rate of iodized salt. Conduct the monitoring program using the current scheme and the simplified scheme, then compare the results.The monitoring results of the current scheme showed the coverage rate of iodized salt and adequate iodized salt were 88.1% and 84.8% and the data of the simplified scheme were 85.2% and 79.8% respectively. Five counties reached above 90% of both the coverage rates of iodized salt and adequate iodized salt and the results showed no significant difference between the two schemes. The rates of other three counties were low, and the difference was significant between Dulan and Linxia counties. To the whole samples, the difference was also significant.The simplified scheme could be applied to those that the coverage rate of iodized salt was quite high or the non-iodized salt was well-distrbuted. However, for those areas with low coverage rate, it might not be suitable. As for the whole nation, it might not be popularized due to the gap of coverage rate between western and eastern areas.

To analyze the feasibility of reducing the concentration of iodized salt based on the results of iodized salt monitoring from the year of 2004 to 2006.Special software for iodized salt monitor and SAS 9.0 were used to analyze salt monitoring data and urine iodine data of women at reproductive age in high-risk areas in 2006.Based on the data from monitoring program, adequate iodized salt coverage increased constantly in China. The quality of iodized salt was stable with less than 2 mg/kg iodine loss at production level but most was at 3 mg/kg iodine loss under estimation during the process of distribution from factory to households. Individual daily intake of iodized salt was higher than the recommendation from WHO but the average level of urinary iodine excretion of women and school children was more than adequate.To decrease the concentration of iodine in edible salt was necessary in China. Our findings provided recommendation on the concentration of iodine in edible salt that should be adjusted from the current concentration of 35 mg/kg to 25-28 mg/kg, and the variation should be controlled from the current range of +/- 15 mg/kg to +/- 10 mg/kg.

To evaluate the influence of different salt iodine concentration on urinary iodine excrition among the target population and to determine the appropriate level of salt iodization to the local people.In the 31-day random control trial, 1099 subjects from 399 families were randomly distributed into four groups and were supplied with iodized-salt with different iodine concentration of (6 +/- 2)mg/kg, (15 +/- 2)mg/kg, (24 +/- 2)mg/kg and (34 +/- 2)mg/kg, respectively. The original family salt was retrieved, whose iodine content was determined in those subjects' families with single-blind method. Baseline survey was conducted including salt and urinary iodine of the subjects. From the 27th day after the intervention, the urinary samples of the subjects were continuously collected for 5 days and urinary iodine was tesed respectively. Meanwhile, daily meal investigation was conducted to evaluate the influences originated from food.The median of local water iodine content was 3.05 microg/L and the average salt iodine concentration was (36.4 +/- 5.4)mg/kg while 98.8% of the household consumed sufficient iodized-salt. The medians of baseline urinary iodine of the subjects were 293.6 microg/L in city, and 508.8 microg/L in the countryside. The urinary iodine medians of four groups in the day of 28th after intervention were 97.2 microg/L, 198.6 microg/L, 249.4 microg/L, and 330.7 microg/L respectively in the city group, while they were 100.5 microg/L, 193.0 microg/L, 246.3 microg/L and 308.3 microg/L seperately in the countryside group. There was no statistically significant differences among the medians of urine iodine in the 27th, 28th, 29th, 30th and 31st day after intervention (P0.05).The target areas were with iodine deficiency which possessed high coverage of qualified iodized-salt at household level. The average urinary iodine level of the subjects was slightly higher than the standard level, according to the baseline survey. The intervetion trail showed that the salt iodine concentration of 15-24 mg/kg was sufficient to the local people.

To understand the situation of quality and consumption of iodized-salt at production and household levels through monitoring on salt.9 townships were chosen in each county at different locations. In each township, two villages were selected in the center of the township and another two villages in remote settings. In each village, 8 households were selected for salt collection. The iodine concentrations in salt (except some special kinds of salt) were detected by method of direct titration with criteria in GB/T 13025.7-1999, in which the iodine content in qualified iodized-salt was set as 20 to 50 mg/kg and that in non-iodized-salt it was below 5 mg/kg.Except for Tibet and Xinjiang, lot qualified rate of production level was 97.39% at the national level. Except for Xinjiang, the qualified rate of iodized-salt of household level was 96.45%; qualified iodized-salt coverage rate was 93.47%; noniodized-salt coverage rate was 3.09%. The results of the iodized-salt monitoring in 2004 maintained almost the same level as that in 2002. At production level,lot qualified rate of iodized-salt in Sichuan and Qinghai provinces were below 90%. At household level the qualified rate of iodized-salt in Sichuan and Hainan were below 90%. The coverage rates of qualified iodized-salt were below 90% for the total 7 provinces. In 5 provinces, the non-iodized-salt coverage rates were above 10%.At national level the qualification of iodized-salt at production level was satisfactory. The coverage rates of qualified iodized-salt were below 90% not only in western but in some eastern provinces(including Beijing), which indicated that importance should be attached to the western areas and some newly discovered areas with problems as well. Through continual improvement of qualified iodized-salt coverage, sustained IDD elimination will be achieved.