Table 1.

 Definitions of thyroid disease and thyroid dysfunction levels used in study

	Thyroid stimulating hormone (mIU/L)	Free thyroxine (pmol/L)	Total thyroxine (mmol/L)
Thyroid dysfunction definitions
Euthyroidism	0.2–5.0	9–22	60–140
Overt hypothyroidism	>5.0	<9	<60
Subclinical hypothyroidism	>5.0	9–22	60–140
Overt hyperthyroidism	<0.2	>22	>140
Subclinical hyperthyroidism	<0.2	9–22	60–140
Thyroid stimulating hormone (TSH) level dependent thyroid dysfunction definitions
Euthyroidism	0.4–5.0	9–22	60–140
High normal euthyroidism	0.2–0.4	9–22	60–140
Subclinical hyperthyroidism (reduced TSH)	0.1–0.2	9–22	60–140
Subclinical hyperthyroidism (suppressed TSH)	<0.1	9–22	60–140