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Thyroxine-binding globulin in blood
Medical expert of the article
Last reviewed: 05.07.2025
Reference values (norm) for the concentration of thyroxine-binding globulin in the blood serum in adults are 13.6-27.2 mg/l; during pregnancy (more than 5 months) - 56-102 mg/l. The ability of TSH to bind T 4 in adults is 100-250 μg/l.
Thyroxine-binding globulin binds the bulk of T3 ( 80%) (the remaining 20% are transported by albumin and prealbumin - 10% each) and T4 ( 75%). 10% of T4 binds albumin, 15% - prealbumin.
The thyroxine-binding globulin test is useful for the differential diagnosis of changes in T3 and T4 concentrations in primary thyroid diseases and as a result of primary changes in thyroxine-binding globulin .
Diseases and conditions in which the concentration of thyroxine-binding globulin in the blood serum changes
Thyroxine binding globulin is elevated |
Thyroxine binding globulin is decreased |
Use of estrogens, phenothiazines, oral contraceptives, methadone |
Severe diseases Surgical stress Protein deficiency Malabsorption of various etiologies Protein-losing enteropathies Active acromegaly Genetic predisposition Use of androgens, glucocorticosteroids in high doses, corticotropin, phenytoin |