Factors influencing thyroid volume in Chinese children

BACKGROUND/OBJECTIVES: This paper aims to compare children's thyroid volume (Tvol) by age and gender in Zhejiang province in order to explore the factors influencing Tvol in this area. SUBJECTS/METHODS: This survey was a cross-sectional survey of a provincial representative sample of Zhejiang province children aged 6–12 years. The children were asked to provide a urine sample for the determination of urinary iodine concentration (UIC) and thyroid ultrasonography was performed for the determination of Tvol. RESULTS: The median (25th, 75th percentile) of UIC in children aged 6–12 years in Zhejiang province was found to be 170.0(111.2, 244.4) μg/l. The median (25th, 75th percentile) of Tvols was found to be 3.1(2.3, 4.2) ml. There were significant differences among the different age groups on BSA (Z=−17.911, P=0.000) and Tvol (Z=−1.996, P=0.046) but not on UIC and body mass index (P>0.05). Tvol was in significant association with BSA (P=0.000) but was not associated with UIC (P>0.05). Age, gender and BSA were significant in multiple linear regression (P<0.05). CONCLUSIONS: The median UIC of children aged 6–12 years falls in the optimal iodine status as recommended by WHO/UNICEF/ICCIDD. However, urinary iodine nutritional status had little effect on the Tvol in children aged 6–12 years in Zhejiang province. Age, gender and BSA were the influencing factors of Tvol.