Figure 1.

(A) Thyroid volume (mL) and (B) goiter on the US rate (%) among the iodine status groups. Iodine status was categorized as iodine deficient (UIC < 100 μg/L), adequate (UIC 100–299 μg/L), mild excess (UIC 300–499 μg/L), moderate excess (UIC 500–999 μg/L), or severe excess (UIC ≥ 1000 μg/L). (A) The blue rhombus indicates the mean values of thyroid volume in each group. (B) Goiter-US was defined as thyroid volume greater than 97th percentile using the World Health Organization age- and body surface area-specific criteria. ^*P for trend <0.05. UIC, urine iodine concentration; US, ultrasound.