FIG. 1.

(A–C) Predicted means from linear regression analyses with thyroid function parameters as exposure and [3,5-T2] concentration as outcome in SHIP, either using the whole study population (solid) or a euthyroid subsample (dashed). (D) Boxplots indicate time courses of [3,5-T2] measurements during an LT4 challenge for 8 weeks among 16 healthy male volunteers [bas—baseline; w4(T4)/w8(T4)—four/eight weeks on 250 μg/day LT4; w12/w16–four/eight weeks after the LT4 application was finished]. Gray lines indicate individual time courses for the 16 volunteers. For none of the tested relationships, significant associations with [3,5-T2] could be detected. 3,5-T2, 3,5-diiodothyronine; LT4, levothyroxine. Color images are available online.