Thyroid hormone metabolism in thyroid disease as reflected by the ratio of serum triiodothyronine to thyroxine
In 77 euthyroid subjects the mean ratio between serum triiodothyronine (S-T3) in nmol/l X 10(3) and serum thyroxine (S-T4) in nmol/l was 22.4 with a standard deviation of 4.3. The distribution of the ratio was close to Gaussian. It was not changed in subjects under estrogen effect. The ratio was increased in hypothyroid subjects suggesting a mechanism preserving S-T3 better than S-T4 in thyroid fa
