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
Euthyroidism0.2–5.09–22 60–140
Overt hypothyroidism>5.0<9<60
Subclinical hypothyroidism>5.09–2260–140
Overt hyperthyroidism<0.2>22>140
Subclinical hyperthyroidism<0.29–2260–140
Thyroid stimulating hormone (TSH) level dependent thyroid dysfunction definitions
Euthyroidism0.4–5.09–2260–140
High normal euthyroidism0.2–0.49–2260–140
Subclinical hyperthyroidism (reduced TSH)0.1–0.29–2260–140
Subclinical hyperthyroidism (suppressed TSH)<0.19–2260–140