Iodine nutritional status after the implementation of the new iodized salt concentration standard in Zhejiang Province, China

BMC Public Health

Guangming Mao¹  Wenming Zhu¹  Zhe Mo¹  Gangqiang Ding¹  Xiaoming Lou¹  Yan Zou¹ 

[1] Zhejiang Provincial Center for Disease Control and Prevention, 3399 Binsheng Road, Hangzhou 310051, P.R. China

关键词: Children;    Probability proportional to size sampling;    Comparison;    Urinary iodine concentration;   

Others  :  1128643
DOI  :  10.1186/1471-2458-14-836

 received in 2014-04-01, accepted in 2014-08-07,  发布年份 2014

【 摘 要 】

Background

Iodine deficiencies were prevalent in China until the introduction of universal salt iodization (USI) in 1995. In 2012, the standard salt iodine concentration was adjusted to 20-30 mg/kg. The success of USI for the control of iodine deficiency disorders requires monitoring its effect at a population level.

Methods

Two cross sectional surveys of a representative sample of children aged 8–10 years in Zhejiang Province were carried out in 2011 and 2013. Data on participants’ socio-demographic characteristics were collected from the children using a structured questionnaire. Spot urine samples were collected and delivered to local Center for Disease Control and Prevention laboratory for measuring urinary iodine concentration. In 2011, out of 420 selected children aged 8–10 years, 391 were recorded and provided urine samples. In 2013, out of 1560 selected children aged 8–10 years, 1556 were recorded and provided urine samples.

Results

The median urinary iodine concentration of subjects in the 2013 survey was 174.3 μg/L, significantly lower than that of 2011(p = 0.000). The median urinary iodine concentration of subjects living in urban and rural areas in the 2013 survey was 169.0 μg/L, and 186.1 μg/L respectively, significantly lower than that of 2011 only for subjects living in urban areas (p = 0.000). There were no significant differences for subjects living in rural areas in the survey in 2011 and in 2013 (p = 0.086).

Conclusions

At the time the new local iodization policy put forward, iodine nutrition was generally adequate in both urban and rural areas, suggesting that the new policy for adjusting the standard salt iodine concentration is effective. Our data also indicate that the reason people living in urban areas had a lower urinary iodine concentration than people in rural areas may be due to their preference for using non-iodized salt in the last 2 or 3 years. Maintaining USI at an appropriate level is an important part of preventing iodine deficiency disorders and should always be based on regular monitoring and comparison of urinary iodine concentration by province.

【 授权许可】

   
2014 Zou et al.; licensee BioMed Central Ltd.

【 参考文献 】

• [1]UNICEF: The State of the World’s Children 2012: Children in an Urban World. New York, NY: United Nations Children’s Fund; 2012.
• [2]Boy E, Mannar V, Pandav C, de Benoist B, Viteri F, Fontaine O, Hotz C: Achievements, challenges, and promising new approaches in vitamin and mineral deficiency control. Nutr Rev 2009, 67:S24-S30.
• [3]Khajedaluee M, Rajabian R, Seyyednozadi M: Education achievements and goiter size ten years after iodized salt consuming. Int J Prev Med 2013, 4(8):876-880.
• [4]Stanbury JB, Ermans AE, Bourdoux P, Todd C, Oken E, Tonglet R, Vidor G, Braverman LE, Medeiros-Neto G: Iodine-induced hyperthyroidism: occurrence and epidemiology. Thyroid 1998, 8:83-100.
• [5]Momčilović B, Prejac J, Višnjević V, Skalnaya MG, Mimica N, Drmić S, Skalny AV: Hair iodine for human iodine status assessment. Thyroid 2014. [Epub ahead of print]
• [6]Lee J, Kim JH, Lee SY, Lee JH: Iodine status in Korean preschool children as determined by urinary iodine excretion. Eur J Nutr 2014, 53:683-688.
• [7]World Health Organization/United Nations Children’s Fund/International Council for the Control of Iodine Deficiency Disorders: Assessment of iodine deficiency disorders and monitoring their elimination. Geneva: WHO; 2001. WHO/NHD/01.1
• [8]Zimmermann MB, Jooste PL, Pandav CS: Iodine-deficiency disorders. Lancet 2008, 372:1251-1262.
• [9]WHO, UNICEF, ICCIDD: Assessment of iodine deficiency disorders and monitoring their elimination. A guide for programme managers. 3rd edition. Geneva: World Health Organization; 2007.
• [10]Schaafsma A, Deurenberg P, Calame W, van den Heuvel EG, van Beusekom C, Hautvast J, Sandjaja , Bee Koon P, Rojroongwasinkul N, Le Nguyen BK, Parikh P, Khouw I, SEANUTS Study Group: Design of the South East Asian Nutrition Survey (SEANUTS): a four-country multistage cluster design study. Br J Nutr 2013, 110(Suppl 3):S2-S10.
• [11]World Health Organization/UNICEF/International Council for Control of Iodine Deficiency Disorders: Elimination of Iodine Deficiency Disorders: A Manual for Health Workers. Cairo: WHO Regional Office for Eastern Mediterranean; 2008.
• [12]Ministry of Health: Method for determination of iodine in urine by As3+−Ce4+ catalytic spectrophotometry, WS/T 107–2006. P. R. China; 2006.
• [13]Wu Y, Li X, Chang S, Liu L, Zou S, Hipgrave DB: Variable iodine intake persists in the context of universal salt iodization in China. J Nutr 2012, 142:1728-1734.
• [14]WHO/UNICEF/ICCIDD: Assessment of iodine deficiency disorders and monitoring their elimination: A guide for programme managers. Geneva, Switzerland: World Health Organization; 2007:32-34.
• [15]Black RE, Victora CG, Walker SP, Bhutta ZA, Christian P, de Onis M, Ezzati M, Grantham-McGregor S, Katz J, Martorell R, Uauy R, Maternal and Child Nutrition Study Group: Maternal and child undernutrition and overweight in low-income and middle-income countries. Lancet 2013, 382(9890):427-451.
• [16]Abuye C, Berhane Y, Ersumo T: The role of changing diet and altitude on goitre prevalence in five regional states in Ethiopia. East Afr J Public Health 2008, 5:163-168.
• [17]Teng W, Shan Z, Teng X, Guan H, Li Y, Teng D, Jin Y, Yu X, Fan C, Chong W, Yang F, Dai H, Yu Y, Li J, Chen Y, Zhao D, Shi X, Hu F, Mao J, Gu X, Yang R, Tong Y, Wang W, Gao T, Li C: Effect of iodine intake on thyroid diseases in China. N Engl J Med 2006, 354(26):2783-2793.
• [18]Teng X, Shan Z, Chen Y, Lai Y, Yu J, Shan L, Bai X, Li Y, Li N, Li Z, Wang S, Xing Q, Xue H, Zhu L, Hou X, Fan C, Teng W: More than adequate iodine intake may increase subclinical hypothyroidism and autoimmune thyroiditis: a cross-sectional study based on two Chinese communities with different iodine intake levels. Eur J Endocrinol 2011, 164:943-950.
• [19]Meng F, Zhao R, Liu P, Liu L, Liu S: Assessment of iodine status in children, adults, pregnant women and lactating women in iodine-replete areas of China. PLoS One 2013, 8:e81294.
• [20]Wang PZ, Zhang Q, Zhou W: Analysis of a random telephone survey result of knowledge in prevention and treatment of iodine deficiency disorders in urban communities of Jiangsu province. Clin J Endemiol 2011, 30:649-654.
• [21]Izzeldin SH, Crawford MA, Ghebremeskel K: Salt fortification with iodine: Sudan situation analysis. Nutr Health 2009, 20:21-30.
• [22]König F, Andersson M, Hotz K, Aeberli I, Zimmermann MB: Ten repeat collections for urinary iodine from spot samples or 24-hour samples are needed to reliably estimate individual iodine status in women. J Nutr 2011, 141:2049-2054.
• [23]Skeaff SA, Thomson CD, Wilson N, Parnell WR: A comprehensive assessment of urinary iodine concentration and thyroid hormones in New Zealand schoolchildren: a cross-sectional study. Nutr J 2012, 11:31.