Prevalence of thyroid diseases and status of iodine nutrition in the population of different water iodine areas in Xi'an City / 中华地方病学杂志

ABSTRACT

Objective:To analyze the thyroid health status of residents in different water iodine areas in Xi'an City and understand the iodine nutritional level of the population.Methods:Using the stratified cluster sampling method, the towns in Xi'an City were divided into 3 levels of < 10, 10-100, and > 100 μg/L according to the median of water iodine of 2017. One street (township) was selected from each level, two communities (natural villages) were selected from each street (township), and 100 households were selected from each community (natural village) to carry out the survey. One drinking water sample was collected from each household for determination of water iodine content. Residents over 18 years old were selected as the subjects of the survey, and their urine iodine content test and thyroid B-ultrasound examination were carried out.Results:A total of 343, 227, 226 water samples were collected in 3 regions with water iodine content, and the median water iodine was 4.14, 38.95, 124.15 μg/L, respectively. A total of 1 308 people were investigated. The detection rate of abnormal thyroid morphology was 9.86% (129/1 308), the detection rate of abnormal echo was 10.86% (142/1 308), and the detection rate of thyroid space-occupancy was 33.94% (444/1 308). The detection rate of nodules was 26.22% (343/1 308). The detection rates of thyroid abnormal echo, space-occupying, and nodules in women were higher than those in men[11.75% (120/1 021) vs 7.67%(22/287), 35.85% (366/1 021) vs 27.18% (78/287), 27.82% (284/1 021) vs 20.56% (59/287), χ 2=3.868, 7.509, 6.101, P < 0.05]. The differences of detection rates of thyroid abnormal echo, space-occupying, and nodules were statistically significant in different age groups (χ 2=11.223, 68.032, 64.543, P < 0.05); the detection rate of thyroid abnormal echo was different in different water iodine areas (χ 2=6.297, P < 0.05). The detection rate of multiple thyroid nodules in women was higher than that in men [11.75% (120/1 021) vs 7.32% (21/287), χ 2=4.584, P < 0.05]; the detection rates of single nodules, multiple nodules, nodule diameter ≤1 cm and nodule diameter > 1 cm were different in different age groups (χ 2=26.010, 31.807, 22.859, 10.392, P < 0.05); the detection rate of thyroid nodule diameter > 1 cm in water iodine < 10 μg/L area was higher than that in water iodine 10-100 and > 100 μg/L areas ( P < 0.05). A total of 755 urine samples were collected, and the median urine iodine was 217.00 μg/L, there were satistically signficant differences in urine iodine levels among residents in different water iodine areas( H=93.806, P < 0.05). Conclusions:The detection rate of thyroid diseases in Xi'an City is relatively high, and the adult iodine nutrition is at a super-suitable level. The detection rate of thyroid nodules increases with age, women are higher than men, so follow-up and early diagnosis and treatment should be strengthened.