Evaluation of iodine nutritional status of children and pregnant women in non-high iodine areas of Xuchang City / 中华地方病学杂志

ABSTRACT

Objective To evaluate the iodine nutritional status of children and pregnant women in non-high iodine areas with different water iodide levels that supplied with standard iodized salt. Methods In 2016 - 2018, after excluding high iodine towns, in each county 5 townships were selected according to the east, west, south, north, and middle orientation. If the township was concentrated in water supply, 1 sample of peripheral water was collected;If the water supply was dispersed, collected 10 water well samples in each village to test the water iodine content. And 40 children aged 8 - 10 years and 20 pregnant women were extracted to collect urine samples and household salt samples, and iodine of urine and salt samples were tested. Children's thyroid volume was examined by B-mode ultrasound. The differences of urinary iodine and child goiter rates among children and pregnant women in different water iodine content areas were analyzed. Results A total of 1282 water samples were collected from 30 townships in Xuchang City, and the median water iodine range of townships was 0.80 - 94.70 μg/L. A total of 1258 children aged 8 - 10 years were investigated, and the median salt iodine content of children homes was 26.8 mg/kg, ranging from 0 to 60.9 mg/kg; the median urinary iodine level of children was 211.5 μg/L, and the range was 8.3 - 833.6μg/L; 39 children with goiter were examined, and the children's goiter rate was 3.10％. A total of 616 pregnant women were investigated, and the median salt iodine content of pregnant women's homes was 26.9 mg/kg, ranging from 0 to 88.0 mg/kg; the median urinary iodine level of pregnant women was 182.2 μg/L, ranging from 9.7 to 609.6 μg/L. In the areas of the median water iodine 0 - < 10, 10 - < 50 and 50 - 100 μg/L, the median urinary iodine of 8 - 10 years old children were 202.6, 204.0, 320.5 μg/L, respectively, the difference between the three was statistically significant (H = 79.89, P < 0.01). And the area of 50 - 100 μg/L was significantly higher than 0 - <10.0, 10 - < 50 μg/L areas (P < 0.01); the children's goiter rate of the three areas was 1.58％ (10/634), 4.40％ (22/500) and 5.65％ (7/124), respectively; the median urinary iodine of pregnant women of the three areas respectively was 177.0, 180.9 and 238.0 μg/L, and the 50 - 100 μg/L areas was higher than 0 - < 10, 10 - < 50 μg/L areas(P <0.01). Conclusion The current standard iodized salt in non-high iodine areas in Xuchang City is basically suitable for most children and pregnant women with iodine nutrition, but the iodine nutrition of children with water iodine greater than 50 μg/L is excessive.