2017年西安市城乡健康成人碘营养及甲状腺功能调查

Status of iodine nutrition and thyroid function of healthy adults in urban and rural areas of Xi'an City

目的 了解西安市城乡健康成人碘营养水平及甲状腺功能状态,探讨碘摄入对甲状腺功能的影响。 方法 采用多阶段分层整群抽样方法,在西安市城市和农村分别抽取2个街道(乡镇),每个街道(乡镇)抽取1个社区(行政村),每个社区(行政村)抽取100户居民,每户采集饮用水水样、食用盐盐样及16岁以上成人尿样和空腹血样,检测水碘、盐碘、尿碘以及甲状腺功能。 结果 共采集354份水样,水碘中位数为4.50 μg/L,城市组水碘≥10 μg/L的比例高于农村组[48.21%(94/195)比20.13%(32/159),χ^2 = 30.123,P < 0.05],城市水碘最高值达244.10 μg/L;共采集354份盐样,盐碘中位数为19.62 mg/kg,城市组合格碘盐比例高于农村组[78.97%(154/195)比69.18%(110/159),χ2 = 12.523,P < 0.05];城市组、农村组尿碘中位数分别为236.00、196.00 μg/L,城市组高于农村组(Z = - 3.121,P < 0.05),且城市组尿碘水平频数分布与农村组不同(χ2 = 24.440,P < 0.05)。城市组甲状腺素(T4)均值低于农村组[nmol/L:(89.43 ± 19.70)比(93.57 ± 16.89),t = - 2.098,P < 0.05];城市组、农村组抗甲状腺球蛋白抗体(TgAb)阳性率分别为21.54%(42/195)、13.21%(21/159),抗甲状腺过氧化物酶抗体(TPOAb)阳性率分别为13.33%(26/195)、6.92%(11/159),其中城市组TgAb阳性率高于农村组(χ2 = 4.155,P < 0.05)。城市组、农村组甲状腺功能紊乱率分别为14.87%(29/195)、12.58%(20/159),组间比较差异无统计学意义(P > 0.05),其中以亚临床甲状腺功能减低(亚甲减)为主,分别为7.18%(14/195)、6.92%(11/159)。 结论 西安市城市健康成人碘摄入处于超适宜量水平,农村健康成人碘摄入处于适宜量水平,西安市首次发现部分地区存在高水碘,碘摄入水平增高,可能促进亚甲减发生。

Objective To find out the iodine nutrition and thyroid function of adults in rural and urban areas of Xi′an City, and to analyze the relationship between iodine intake and thyroid function. Methods Two streets (townships) were selected in urban and rural areas of Xi′an City according to multi-stage stratified cluster sampling, one community (administrative village) was selected in each street (township), and 100 residents were selected from each community (administrative village). Drinking water, household salt, urine and blood samples of people over the age of 16 were collected to test water iodine, salt iodine, urinary iodine and thyroid function. Results A total of 354 drinking water samples were examined, and the median of water iodine was 4.50 μg/L in Xi′an, and iodine concentrations of ≥10 μg/L in urban group was higher than that of rural group [48.21% (94/195) vs 20.13% (32/159), χ^2 = 30.123, P < 0.05]. The highest value of urban water iodine was 244.10 μg/L. A total of 354 edible salt samples were examined, and the median of salt iodine was 19.62 mg/kg in urban and rural areas of Xi′an. The edible rate of qualified iodized salt in urban group was higher than rural group [78.97% (154/195) vs 69.18% (110/159), χ^2 = 12.523, P < 0.05]. The median of urinary iodine of urban and rural groups were 236.00 and 196.00 μg/L, respectively, and urban group was higher than rural group (Z = - 3.121, P < 0.05). The frequency distribution of urinary iodine in urban group was different from rural group (χ^2 = 24.440, P < 0.05). The mean value of thyroxine (T4) in urban group was lower than that of rural group, and there was statistical difference [nmol/L: (89.43 ± 19.70) vs (93.57 ± 16.89), t = - 2.098, P < 0.05]. The positive rates of anti-thyroglobulin antibody (TgAb) of urban and rural groups were 21.54%(42/195) and 13.21% (21/159), the positive rate of TgAb was higher in urban than in rural (χ^2 = 4.155, P < 0.05). The positive rates of thyroid peroxidases antibody (TPOAb) were 13.33% (26/195) and 6.92% (11/159), respectively. There were no statistically significant differences of thyroid dysfunction in urban and rural groups [14.87% (29/195) vs 12.58% (20/159), P > 0.05]. Subclinical hypothyroidism in all thyroid dysfunction was the main thyroid disorder, which was 7.18% (14/195) and 6.92% (11/159) in urban and rural groups. Conclusions Xi′an urban healthy adult iodine intake is at an ultra-appropriate level. In rural areas, the intake of iodine in healthy adults is at an appropriate level. The areas of high water iodine are found in Xi′an for the first time. Increased iodine intake may promote the occurrence of subclinical hypothyroidism.