Table 3.
Correlation of urinary iodine levels with thyroid biomarkers
| Visit 1 | Visit 2 | Visit 3 | Visit 4 | Visit 5 | Visit 6 | Visit 7 | Visit 8 | Visit 9 | Visit 10 | Visit 11 | Visit 12 | Median over the 12 visits | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| TSH, mIU/L | 0.04 | 0.07 | 0.03 | 0.03 | 0.02 | 0.03 | 0.08 | 0.08 | 0.01 | 0.01 | 0.06 | 0.01 | 0.05 |
| fT4, pmol/L | 0.01 | 0.06 | 0.01 | 0.02 | 0.03 | 0.00 | 0.10 | 0.03 | 0.01 | 0.01 | 0.18 | 0.01 | 0.04 |
| fT3, pmol/L | 0.00 | 0.08 | 0.07 | 0.10 | 0.00 | 0.06 | 0.44 | 0.00 | 0.12 | 0.03 | 0.11 | 0.07 | 0.11 |
| Thyroglobulin, ng/mL | 0.01 | 0.14 | 0.05 | 0.24 | 0.19 | 0.04 | 0.01 | 0.00 | 0.02 | 0.02 | 0.01 | 0.26 | 0.06 |
| Thyroid volume, mL | 0.12 | 0.02 | 0.02 | 0.01 | 0.00 | 0.02 | 0.08 | 0.01 | 0.00 | 0.01 | 0.00 | 0.03 | 0.05 |
Data are given as R2 derived from linear regression with the respective thyroid biomarker as outcome and urinary iodine as exposure. fT3, free triiodothyronine; fT4, free thyroxine; TSH, thyroid-stimulating hormone.