Investigation on iodine nutritional status and intelligent development in target populations in Akesu Prefecture of Xianjing Autonomous Region / 中国地方病学杂志

ABSTRACT

Objective To investigate the iodine nutritional status of school children, lactating women and infants in iodine deficient areas of Baicheng and Wushi Counties in Xinjiang Autonomous Region. Methods According to the geographic location of east, south, west and north of county, 10 primary schools of 8 townships were selected. In each school, 10 children among each gender and age group from 8 to 10 years old were selected. A total of 300 school children were chosen. One hundred and four infants aged 0-2 years old and their mother were selected in 8 townships. Iodine content in edible salt at household level, the urinary iodine in school children and lactating women, total goiter rate(TGR) and the status of the intelligence quotient (1Q) of school children, the status of psychological development of infants were observed. Direct titration assay for testing the salt iodine, colorimetric ceric-arsenic assay and vitriolic ammonium assimilation were used for testing urinary iodine. The size of thyroid gland was measured by palpation. The Combined Raven Test for Chinese Rural was used to test the IQ. The psychological development of infants was tested by Danver Development Screening Test (DDST). Results The coverage rate of iodized salt at household level was 73.1% (123/182), however, the proportion of households using adequately iodized salt was 64.1% (118/182). The medium of urinary iodine in school children was 103.7 μ/L, with 47.8%(75/157) less than 100 μg/L and 28.0% (44/157) less than 50 μg/L; it was 123.0 μg/L in Baieheng County, with 44.4%(28/63) less than 100 μg/L and 33.3%(21/63) less than 50 μg/L; it was 100.3 μg/L in Wushi County, 50.0%(47/94) less than 100 μg/L and 24.5%(23/94) less than 50 μg/L. The medium of urinary iodine in locating women was 143.3 μg/L, it was 119.7 μg/L and 184.6 μg/L in Baicheng and Wushi Counties, respectively. The total rate of goiter in school children was 14.3%(43/300), it was 10.8%(13/120) and 16.6%(30/180) in Baicheng and Wushi Counties, respectively. The average IQ in school children was 80.6±11.6, it was 83.0±11.6 and 79.0±11.7 in Baicheng and Wushi Counties, respectively. The proportion of mental retardation in school children (IQ≤69) was 13.0% (39/300), it was 6.7% (8/120) and 17.2%(31/180) in Baicheng and Wushi Counties, respectively. In addition, the proportion of psychological development in infants being normal, suspicious and abnormal was 78.8%(82/104), 12.5% (13/104) and 8.7%(9/104), respectively. Conclusion This study confirms the fact that there is also existence of mental retardation in children and infants, caused by iodine deficiency.