Table 3.

Demographic and labororatory parameters of the study groups according to the etiology of primary hypothyrodism.

	Autoimmune (n = 1,117)	Postsurgical (n = 588)	Post radioactive ablation (n = 50)	P
Age (yrs)	45.4 ± 13.2	50.2 ± 11.6	52.5 ± 10	n.s.
Gender (M/F)	101/1,016	65/523	11/39	n.s.
Duration of disease (yrs)	4.99 ± 5.8	7.05 ± 6.9	7.15 ± 6.5	<0.0001
Daily dose of LT4 (μg/day)	88.1 ± 45.3	112.6 ± 47.7	109.7 ± 52.4	<0.0001
Daily dose of LT4 (μg/kg)	1.18 ± 0.57	1.49 ± 0.7	1.47 ± 0.83	<0.001
TSH (mIU/L)	4.53 ± 11.4	6.03 ± 14.7	2.93 ± 3.3	<0.0001
fT4 (ng/dL)	1.22 ± 0.32	1.28 ± 0.4	1.40 ± 0.40	<0.0001

Yrs, years; M, male; F, female; LT4, levothyroxine; fT4, free T4; TSH, thyroid-stimulating hormone.