1 Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, P.R. China.
2 Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China.
Thyroid. 2019 Mar;29(3):405-411. doi: 10.1089/thy.2018.0412.
The iodine nutritional status of the Chinese population has been greatly improved in recent years. Therefore, the reference values for thyroid volume (Tvol) in children with sufficient iodine intake need to be updated. The study aimed to update the reference values for Tvol in children with sufficient iodine intake in order to define goiter in the context of sustained iodine sufficiency.
A cross-sectional study was conducted in children with sufficient iodine intake in China. Twice-repeated 24-hour urine samples were collected from each child to estimate habitual daily iodine intake. Serum thyroid function tests were measured. Tvol was assessed by ultrasound. From the sample of euthyroid children with sufficient iodine intakes, the 50th and 97th percentiles for Tvol by age and body surface area (BSA) were calculated using quantile regression.
A total of 679 children aged 8-13 years with sufficient iodine intake (188 μg/day [145-235 μg/day]) were included in the analysis. The mean Tvol of the children was 4.1 ± 1.6 mL, and no differences were found between boys and girls in any age or BSA group. Quantile regression models demonstrated that BSA was a strong positive predictor of Tvol (p < 0.0001), while age only had a significant effect on median Tvol (p = 0.013). Sex was not a significant predictor of Tvol in children.
The reference values for Tvol in Chinese children have been updated. This study indicates that the upper limit of (97th percentile) Tvol was dependent on BSA, while the median Tvol was determined by both age and BSA.
近年来，中国人群的碘营养状况得到了极大改善。因此，需要更新碘摄入充足儿童的甲状腺容积（Tvol）参考值。本研究旨在更新碘摄入充足儿童的 Tvol 参考值，以便在持续碘充足的情况下定义甲状腺肿。
在中国碘摄入充足的儿童中进行了一项横断面研究。对每个儿童采集两次 24 小时尿液样本，以估计习惯性日碘摄入量。测量血清甲状腺功能检查。通过超声评估 Tvol。从摄入充足碘的甲状腺功能正常儿童样本中，使用分位数回归计算 Tvol 按年龄和体表面积（BSA）的第 50 和 97 百分位数。
共纳入 679 名碘摄入充足（188μg/天[145-235μg/天]）的 8-13 岁儿童。儿童的平均 Tvol 为 4.1±1.6mL，在任何年龄或 BSA 组中，男孩和女孩之间的 Tvol 无差异。分位数回归模型表明 BSA 是 Tvol 的强正预测因子（p<0.0001），而年龄仅对中位数 Tvol 有显著影响（p=0.013）。性别不是儿童 Tvol 的显著预测因子。
更新了中国儿童 Tvol 的参考值。本研究表明，Tvol 的上限（97 百分位数）取决于 BSA，而中位数 Tvol 则由年龄和 BSA 共同决定。
