Thyroglobulin can be a functional biomarker of iodine deficiency, thyroid nodules, and goiter in Chinese pregnant women.

Background and Objectives: Thyroglobulin (Tg) is considered a sensitive indicator of iodine status for children and adults, but its usefulness for pregnant women is unknown. The aim of this study was attempting to explore the relationship between Tg and iodine status and the association between elevated Tg and thyroid diseases. Methods and Study Design: A total of 2163 pregnant women were recruited in this study. The ratio of urine iodine concentration and urine creatinine concentration (UI/Cr) was measured in spot urine samples. Serum thyroid hormones and thyroglobulin were measured. Thyroid nodules and thyroid volume were diagnosed by ultrasound. Results: The geometric mean of serum Tg was significantly higher in the UI/Cr <100 mu g/g group (10.94 [2.47] mu g/L) and the UI/Cr >500 mu g/g group (11.48 [2.35] mu g/L) than in the 150-249 mu g/g group (9.64 [2.32] mu g/L). The generalized linear model analysis showed that Serum log(10) Tg concentration was much higher in the UI/Cr <100 mu g/g group (beta=0.052, p=0.026) than in the 150-249 mu g/g group. Multivariate logistic regression models demonstrated that elevated Tg may be a risk factor for both goiter (OR=8.30) and thyroid nodules (OR=2.73). Conclusions: Pregnant women with UI/Cr <100 mu g/g have a higher Tg, and those with elevated Tg concentrations have a higher risk of thyroid nodules and goiter. Tg can be a functional biomarker of iodine deficient, thyroid nodules and goiter.