Iodine nutritional status of 8-10 years old children after adjustment of salt iodine content in Hangzhou City Of Zhejiang Province

Abstract

Objective To explore the impact of iodine nutrition on 8 - 10 years old children after adjusting the iodine content in iodized salt in Hangzhou. Methods Twelve counties （ areas, cities ） were divided into urban, suburban and rural areas in Hangzhou. By population proportion survey （PPS）, every county（area, city） was divided into east, west, south, north and middle districts; one school was selected in each district; forty children （half male and half female） aged 8 - 10 years old in each school were selected; family salt and urine samples of each student were collected. The levels of salt and urinary iodine were measured by picrie sodium thiosulfate titrimetric （ GB 13025.7- 2012 ） and spectrophotometer method （WS/T 107-2006 ）, respectively. Results Two thousand seven hundred and twenty-five household salt samples were collected. The median of salt iodine, the iodized salt coverage rate, the qualification rate of iodized salt and the consumption rate of qualified iodized salt were 24.00 mg/kg, 4.35%（2 571/2 725）, 91.02%（2 340/2 57：1） and 85.87%（2 340/2 725）, respectively. The medians of salt iodine in urban, suburb and rural areas were 24.10, 22.12, 24.30 mg/kg, respectively. A total of 2 664 children urine samples were collected. The median of urinary iodine （MUI） of the children was 177.24 μg/L. The MUIs in urban, suburb and rural areas were 175.00, 178.55, 178.00 μg,/L, respectively; in male was 183.00μg/L and female was 170.50 μg/L. When non-iodized and unqualified iodized salt were taken, the differences of urinary iodine within groups were statistically significant in urban, suburb and rural areas（χ2 = 18.652, 14.686, all P 〈 0.05）. In rural area, the difference of urinary iodine of 8 - 10 years old children who ingested different types of iodized salt was statistically signifieant（χ2 = 39.07, P 〈 0.05）. Conclusion After adjustingthe iodine content of salt in Hangzhou, the iodine-nutritional status of 8 - 10 years old students is at a appropriate level. Key words: Children ; Iodine ; Salt