Prevalence of Thyroid Nodules and Its Relationship with Iodine Status in Shanghai: a Population-based Study

The prevalence of TNs was nearly 30% and increased with age. The relationship between UIC and prevalence of TNs is U-shaped, with an increase in risk when the UIC was <140 μg/L and >400 μg/L. Very low or high UIC levels need attention and correction.