| Iodine is one of the essential trace elements for human and according to the epidemiological survey data that the iodine deficiency has become one of the world’s four major public health problems. Iodized salt is the major effective measure to eliminate the iodine deficiency disease (IDD). Hunan province is one of the iodine deficient areas, so to strengthen the monitoring and control of the iodine nutrition level of the ordinary and special population groups is of great significance to maintain and promote the health of the residents in Hunan province. The 2014 iodine nutrition status survey is the first large-scale survey in Hunan province since implementation of the new standard of the iodized salt level (changed from 20-50 mg/kg to 21-39 mg/kg), and application of the national guidelines on iodine nutrition level adjustment based on the local status and condition. The results of the 2014 survey will reveal the current status of iodine nutrition level and the work on prevention and control of IDD in our province; it will also provide the direction for the next step of work in this area, which is of great significance.This paper describes an investigation and analysis of the iodine content of iodized salt in Hunan Province in 2004-2013, the urinary iodine level and thyroid volume in samples of 8-10 years old students and of pregnant women, the iodine content in the local residents’ cooking salts, and the iodine nutrition status of various population groups in Hunan Province in 2014. The main results of this study are presented as follows:1.In Hunan province over 2004-2013, the iodine content in iodized salt had the average value of 27.31-33.98 mg/kg with the median content of 27.58～33.7 mg/kg; both satisfied the requirements in the GB 5461～2000 and GB 26878～2011. The standard deviation was 5.66-9.17 mg/kg and the coefficient of variation was 17.49% ～29.44%. The qualified rate was in the range of 95.55% to 100% in terms of the iodine content in iodized salt. Those with the standard deviation>8% accounted for 40% and those with the coefficient of variation>21% accounted for 60%; both didn’t show steady changes with time. The unqualified cases were found mainly between 2004 and 2008; the qualified rate increased with time and since 2009 the qualified rate has achieved 100% on the iodine content in iodized salt.2.Despite adjustment of iodine content in 2011 (changed from 20-50 mg/kg to 21-39 mg/kg), the standard requirement for eliminating IDD is still satisfied. The level of iodine nutrition of pregnant women is found to be appropriate and the levels of other groups are slightly higher than the appropriate level. In 2009,2011 and 2014, the medians of urinary iodine content of the monitored students aged 8-10 years were 276.36,270.80 and 222.80 g/L respectively, which showed a downward trend. In 2011 and 2014, the medians of urinary iodine content of pregnant women were 221.90 and 177.20 g/L, which showed a substantial decline but still on the appropriate level. These results are consistent with the iodine content adjustment (reduction) level in 2011.3.In the group of 8-10 years old children in Hunan, the goiter rate was 1% and the median of urinary iodine content was 222.80 g/L. There were 7.87% with their urinary iodine at 100 g/L or lower and,1.93% with their urinary iodine at 50 g/L or lower. The coverage rate of iodized salt was 97.27% and the rate of qualified iodized salt was 91.07%. These results indicated a significant progress in prevention and control of IDD in Hunan through comprehensive measures especially the iodized salt. The key data of the urinary iodine content in different population groups and the goiter rate in 8-10 years children group provided by this study, after publication of the national standard "Iodine content of salt"(GB 26878-2011), indicated the Hunan’s adjustment of iodine content in salt in 2011 was a reasonable and successful regulating action.4.In this investigation, while the iodine nutritional statuses of most pregnant women, as a focus group of IDD prevention, in the province are found at the appropriate level, there are some people found at inappropriate levels of iodine nutrition status, these included 58.4% of students aged 8-10 years being at a high-iodine level and 37.7% of pregnant women at an iodine deficient level. This indicated with the same consumption of iodine in salt it might not be able to maintain the iodine nutrition status at the appropriate level for all the population groups. After adjustment (reduction) of iodine content in salt in 2011, there were no effective scientific measures to make up iodine shortage of some pregnant women who need more iodine intake than other population groups. This problem could not be solved by further adjusting the standard iodine content in salt. How to increase the intake of iodine of pregnant women without adjusting the standard iodine content in salt is a subject of further study and investigation. As for those 8-10 years old students with a high-iodine level, it might be resulted from lack of scientific nutrition knowledge and excessive consumption of unhealthy food and snack. The government health service department should improve administration in this area and the school should together with the parents to educate students, to enhance their knowledge in nutrition and to guide this group towards consumption of healthy food.Overall, based on the results of this investigation and according to the national standard on elimination of IDD (GB 16006-2008) it is verified that that the standard requirements on elimination of IDD have been satisfied at the provincial level. This indicated the primary measure of iodized salt together with other comprehensive measures have been effective in prevention and control of IDD in Hunan province. |
PDF Full Text Request