Free thyroxine estimation for the screening of hyper- and hypothyroidism in an adult population.

Serum free thyroxine (FT4), total T4 (T4) and total T3 (T3) were determined by radioimmunoassay in 1,114 adults during a periodic health evaluation to detect unsuspected thyroid dysfunction. As a result, 3 patients with hyperthyroidism, 4 with hypothyroidism, 3 taking thyroid medication, 4 with chronic thyroiditis, 1 with simple goiter and 3 women under estrogen administration were found. Free T4 values were within the normal limits in the present four subjects taking estrogens, but all of them showed high T4 and one high T3 values. FT4 and T4 were low in four patients with hypothyroidism, but two of them showed normal T3 values. For the screening of hyperthyroidism, FT4 was the most reliable measurement and determination of either FT4 or T4 was suitable for the screening of hypothyroidism, but T3 measurement did not diagnose all patients with hypothyroidism, but T3 measurement did not diagnose all patients with hypothyroidism.

[1]  M. de Visscher,et al.  Serum free thyroxine and thyroxine binding proteins in male adolescents. , 1966, The Journal of clinical endocrinology and metabolism.

[2]  M. Surks,et al.  High incidence of decreased serum triiodothyronine concentration in patients with nonthyroidal disease. , 1975, The Journal of clinical endocrinology and metabolism.

[3]  L. V. dos Remedios,et al.  Detecting unsuspected thyroid dysfunction by the free thyroxine index. , 1980, Archives of internal medicine.

[4]  D. Appleton,et al.  THE SPECTRUM OF THYROID DISEASE IN A COMMUNITY: THE WHICKHAM SURVEY , 1977, Clinical endocrinology.

[5]  D. Solomon,et al.  Thyroxine: just a prohormone or a hormone too? , 1973, The Journal of clinical endocrinology and metabolism.

[6]  K. Sterling,et al.  Free thyroxine in human serum: simplified measurement with the aid of magnesium precipitation. , 1966, The Journal of clinical investigation.

[7]  G. J. Neumann.  The determination of normal ranges from routine laboratory data. , 1968, Clinical chemistry.

[8]  R. Utiger.  Serum Triiodoth Ronine in Man , 1974 .

[9]  K. Torizuka,et al.  Re-evaluation of thyroxine binding and free thyroxine in human serum by paper electrophoresis and equilibrium dialysis, and a new free thyroxine index. , 1970, The Journal of clinical endocrinology and metabolism.

[10]  R. Demura,et al.  Effect of estrogen on serum total and free thyroxine and triiodothyronine in a thyroxine-binding globulin deficient family. , 1973, The Tohoku journal of experimental medicine.

[11]  D. Solomon,et al.  Misleadingly low free thyroxine index and usefulness of reverse triiodothyronine measurement in nonthyroidal illnesses. , 1979, Annals of internal medicine.

[12]  R. Utiger.  Serum triiodothyronine in man. , 1974, Annual review of medicine.

[13]  D. Solomon,et al.  Reciprocal Changes in Serum Concentrations of 3,3′,5′-Triiodothyronine (Reverse T3) and 3,3′5-Triiodothyronine (T3) in Systemic Illnesses , 1975 .

[14]  J. Virtamo,et al.  Inherited decrease of the binding capacity of thyroxine-binding globulin (TBG). , 1970, Acta endocrinologica.

[15]  T. A. Bayley,et al.  The metabolic significance of thyroxine-binding globulin. Studies in a family with decreased thyroxine-binding globulin. , 1969, Acta endocrinologica.

[16]  M. Surks,et al.  BINDING OF THYROXINE BY SERUM PROTEINS EVALUATED BY EQUILIBRUM DIALYSIS AND ELECTROPHORETIC TECHNIQUES. ALTERATIONS IN NONTHYROIDAL ILLNESS. , 1963, The Journal of clinical investigation.

[17]  R. Cavalieri,et al.  The kinetics of distribution between plasma and liver of 131-I-labeled L-thyroxine in man: observations of subjects with normal and decreased serum thyroxine-binding globulin. , 1966, The Journal of clinical investigation.

[18]  R. J. Henry,et al.  DETERMINATION OF THE FREE THYROXINE CONTENT OF SERUM. , 1964, The Journal of clinical endocrinology and metabolism.

[19]  D. Solomon,et al.  In search of an inhibitor of thyroid hormone binding to serum proteins in nonthyroid illnesses. , 1979, The Journal of clinical endocrinology and metabolism.

[20]  J. Oppenheimer,et al.  Factors influencing the concentration of free and total thyroxine in patients with nonthyroidal disease. , 1966, The Journal of clinical endocrinology and metabolism.

[21]  C. Hollander,et al.  EFFECT OF AN OVULATORY SUPPRESSANT ON THE SERUM PROTEIN-BOUND IODINE AND THE RED-CELL UPTAKE OF RADIOACTIVE TRI-IODOTHYRONINE. , 1963, The New England journal of medicine.

[22]  J. Plager,et al.  Effect of preliminary purification of 131-I-thyroxine on the determination of free thyroxine in serum. , 1967, The Journal of clinical endocrinology and metabolism.

[23]  D. Baldwin,et al.  Incidence of thyroid disorders in Connecticut. , 1978, JAMA.

[24]  K. Yoshinaga,et al.  A solid-phase radioimmunoassay for free thyroxine in serum compared with equilibrium dialysis method. , 1980, The Tohoku journal of experimental medicine.

[25]  R. Utiger,et al.  Triiodothyronine radioimmunoassay. , 1972, The Journal of clinical investigation.

[26]  F. Clark,et al.  ASSESSMENT OF THYROID FUNCTION BY THE COMBINED USE OF THE SERUM PROTEIN-BOUND IODINE AND RESIN UPTAKE OF 131-I-TRIIODOTHYRONINE. , 1965, The Journal of clinical endocrinology and metabolism.