Figure 2.

FT₃ (A), FT₄ (B) and TSH (C) levels in l-T₄-treated patients stratified by disease and conversion efficiency. The disease entities were closely associated with categories of the thyroid volume (see Table 1 and text). The red box refers to poor converters (calculated deiodinase activity <23 nmol/s), green to intermediate converters (deiodinase activity 23–29 nmol/s) and blue to good converters (deiodinase activity >29 nmol/s). Remarkably, absolute FT₃ concentrations were lowest in the poor converter group in all disease categories, while FT₄ levels were highest in the poor converters. Wilcoxon test, revealed significant differences compared to each first group; *P<0.05, **P<0.001. AIT, autoimmune thyroiditis; goitre, goitre post surgery for benign nodular thyroid disease.