Correlation between urinary iodine, salt iodine, and thyroid nodules in children aged 8 - 10 years and pregnant women in different regions of Fujian Province / 中华地方病学杂志

ABSTRACT

Objective:To understand the correlation between urinary iodine, salt iodine and thyroid nodules in children aged 8 - 10 years and pregnant women in different regions of Fujian Province, and to explore the influencing factors of thyroid diseases.Methods:A cross-sectional study was conducted in Dongshan County and Pingtan County of Fujian Province from September to November 2019. According to the inclusion criteria, 140 pregnant women and 270 children aged 8 - 10 years were selected in Dongshan County, and 189 pregnant women and 368 children aged 8 - 10 years were selected in Pingtan County. Random urine and edible salt samples were collected to determine iodine content, and iodine nutrition was evaluated in each population. Thyroid was examined by B ultrasound and questionnaire survey of thyroid diseases was carried out. The correlation between urinary iodine, salt iodine and thyroid nodules in children aged 8 - 10 years and pregnant women in different regions was analyzed.Results:There were statistically significant differences in the median urinary iodine among children in different genders (male: 151.30 μg/L, female: 130.30 μg/L) and regions (Dongshan County: 160.30 μg/L, Pingtan County: 129.70 μg/L, P < 0.05); there was no significant difference in the median urinary iodine among children of different ages (8, 9, 10 years old: 141.60, 128.05, 150.30 μg/L, P > 0.05). The median urinary iodine among pregnant women was 119.30 μg/L, and there was no significant difference in median urinary iodine among pregnant women in different stages and regions ( P > 0.05). The medians of salt iodine from children and pregnant women were 20.30 and 23.65 mg/kg, respectively. Urinary iodine in children was positively correlated with salt iodine ( r = 0.13, P < 0.05). However, there was no correlation between urinary iodine and salt iodine in pregnant women ( P > 0.05). The detection rate of thyroid nodules in children was 21.79% (139/638). There was significant difference in the detection rate of thyroid nodules in children of different ages ( P < 0.05). The detection rate of thyroid nodules in pregnant women was 4.26% (14/329). There was no correlation between detection rate of thyroid nodules and urinary iodine or salt iodine in children and pregnant women ( P > 0.05). Thyroid volume of children in the two counties was within the normal range, and there was no correlation between thyroid volume and urinary iodine or salt iodine ( P > 0.05). Conclusions:The iodine nutrition of children in Dongshan County and Pingtan County is suitable (100 - 199 μg/L), while iodine deficiency (< 150 μg/L) exists in pregnant women. Urinary iodine in children is related to salt iodine, and urinary iodine increased with increase of salt iodine. The prevalence of thyroid nodules in children of different ages is different, which requires further study. The detection rate of thyroid nodules in children and pregnant women is not correlated with urinary iodine and salt iodine.