不同水碘地区重点人群碘营养水平及其干预效果研究

目的研究不同水碘地区停供碘盐对特需人群碘营养的影响,以探讨停供碘盐的饮水碘含量的切点值。方法选择水碘50~100(A)、100~150(B)、150~300(C)和>300μg/L(D)不同水平4个自然村,进行居民户饮用水、食用盐和儿童甲状腺肿大率(甲肿率)调查,动态检测停供碘盐前后学龄儿童和育龄妇女尿碘水平变化。结果A、B、C、D4组的水碘中位数为93.20、143.23、194.10和805.85μg/L,盐碘中位数为25.38、28.21、30.01和32.87mg/kg,甲肿率为15.9%、5.9%、12.7%和24.0%。干预前4组居民尿碘中位数(MUI)为384.60、374.85、439.90和1260.10μg/L;尿碘水平100~300μg/L的比例各占32.3%、28.3%、13.6%和1.0%,>300μg/L的各占67.7%、70.8%、86.4%和99.0%,尿碘水平均向高值偏移。干预1、2个月后4组居民尿碘水平均有不同程度下降。A、B2组居民尿碘水平在2个月后降到300μg/L之内其碘营养适宜,而C、D2组碘营养依旧明显过量。A、B、C3组尿碘水平向高值偏移程度在干预后都明显减小。尿碘与水碘之间均呈正相关(P<0.001)。无论儿童还是妇女其干预后的尿碘水平均低于干预前水平,A组尤其明显。水碘与尿碘和甲肿率之间均为正相关(P<0.001)。结论水碘90μg/L左右地区停供碘盐之后人群碘营养处于适宜水平,可以安全地停止食用碘盐;水碘>100μg/L地区人群碘营养仍然明显过量,故不宜实行全民食盐加碘措施。

Study on iodine nutritional status of target population due to different iodine concentrations in drinking water after stopped iodized salt

OBJECTIVE: To investigate the iodine nutritional status of key population living areas with iodine excess in drinking water before and after stopped iodized salt supply to provide strategies of control excessive iodine. METHODS: The levels of iodine in drinking water, edible salt of household and urine of school-age children and child-beard age women were investigated at four villages A, B, C and D which iodine concentrations of 50-100, 100-150, 150-300 and more than 300microg/L. The results of iodine in water, edible salt, urine and thyroid goiter were observed before stopping iodized salt. The levels of urinary iodine in four groups were tested after stopped iodized salt one or two month later. RESULTS: The medians of iodine concentration in inhabitants from four groups A, B, C and D were 93.20, 143.23, 194. 10 and 805.85microg/L of drinking water, in edible salt 25.38, 28.21, 30.01 and 32.87mg/kg. Goiter rate was 15.9%, 5.9%, 12.7% and 24.0%, respectively. The median of urinary iodine (MUI) was 384.60, 374.85, 439.90 and 1260.10microg/L. The proportion of urinary iodine level of 100-300microg/L was 32.3%, 28.3%, 13.6% and 1.0%, of more than 300microg/L was 67.7%, 70.8%, 86.4% and 99.0% with iodized salt supply. MUI of all groups with non-iodized salt decreased significantly after two month, especially in group A and B. The proportion of urinary iodine levels of 100-300microg/L was obviously more than before, but group more than 300microg/L was less than before. The similar changes of MUI were in children and women, but degree of change was obviously in group A. Their MUI were in normal after two month. There were significant difference in MUI of denizens including children and women before and after intervene. There was no difference of MUI in group C and D at the same time. There were significant correlations between urinary iodine and water iodine concentration (P < 0.001). MUI in group C, D was more than 300microg/L, but evident differences were found among 4 groups under different levels of water iodine (P < 0.001). The nutritious status of iodine was markedly excessive in group B, C and D of objects. CONCLUSION: Iodine nutritional status in inhabitants drinking water iodine concentration about 90microg/L was in normal, iodized salt supply could be safely stopped at the regions. Regardless iodized or non-iodized salt supply, there was inefficient in those areas with water iodine much more than 100microg/L. It is suggested that iodized salt must be stopped for controlling excessive iodine in the areas.