TABLE 3.

Thyroid hormones at baseline and after administration of rhTSH in control cats and in RAI‐treated cats divided into three groups according to response to TSH administration (see Section 2)

Variable	Control group	RAI‐euthyroid	RAI‐equivocal	RAI‐hypothyroid
tT4 (μg/dL)	2.0 [1.7‐2.3] 1,2	1.8 [1.6‐2.1] 3,4	1.6 [1.4‐1.7]1,5	1.0 [0.8‐1.3]2	1,2,3,4,5 P < .001
fT4 (ng/dL)	1.3 [1.1‐1.6] 1,2,3	1.1 [0.9‐1.4] 1,4,5	0.9 [0.6‐1.1] 2,4,6	0.35 [0.27‐0.56] 3,5,6	1 P = .04 2,3,4,5,6 P < .001
TSH (ng/mL)	0.04 [<0.03‐0.07] 1,2,3	0.13 [0.07‐0.24] 1,4,5	0.31 [0.17‐0.58] 2,4,6	1.4 [0.39‐5.4] 3,5,6	1,2,3,5 P < .001 4 P = .002 6 P = .003
After‐stimulation tT4 (μg/dL)	5.0 [3.9‐5.8] 1,2,3	3.4 [2.8‐4.2] 1,4,5	1.9 [1.7‐2.1] 2,4,6	1.2 [0.9‐1.5]3,5,6	1,2,3,4,5,6 P < .001
T4 ratio	2.41 [2.09‐2.82]1,2,3	1.85 [1.56‐2.13] 1,4,5	1.30 [1.16‐1.38]2,4,6	1.15 [1.04‐1.23] 3,5,6	1,2,3,4,5 P < .001 6 P = .003

Note: Data are presented as median [interquartile range]. Values with the same superscript numbers are significantly different to one another.

Abbreviations: RAI, radioiodine‐I¹³¹; rhTSH, recombinant human thyroid stimulating hormone; TSH, thyroid stimulating hormone.