Table3. The Result of the Serum Thyroid Factors in different Grades of Thyroid Ultrasonographic Indexes (G0- G4).

Variables	G0	G1	G2	G3	G4	P-value
Serum free T4 (pmol/L)	13.42±2.51	13.98±4.07	13.87±2.52	13.42±2.59	14.22±3.70	0.979*
Serum free T3 (pmol/L)	4.25±0.88	4.70±2.06	4.11±0.86	3.50±1.52	3.28±1.44	0.14*
Serum TSH (mIU/mL)	4.76±4.08	4.66±4.41	5.24±4.72	5.92±2.98	5.18±0.88	0.223*
TPO-Ab titer (IU/mL)	206.59±160.3	287.14±145.75	285.82±197.41	280.54±238.48	335.7±165.11	0.032**
Tg-Ab titer (IU/mL)	677.04±365.63	375.94±458.87	755.77±405.09	981.16±722.38	1321.7±769.01	0.301**

TSH thyroid stimulating hormone, Tg-Ab anti-thyroglobulin, TPO-Ab anti-thyroid peroxidase antibody. ^* Variables are compared by one way ANOVA with Tukey post hoc tests. ^** Variables are compared by Kruskal Wallis.