Abstract To evaluate the association between serum γ-glutamyl transpeptidase activity (GGT) and thyroid function, we measured the GGT, alkaline phosphatase, free thyroxine index (FT4I), free triiodothyronine index (FT3I), and thyrotropin (TSH) levels in patients with hyperthyroidism and hypothyroidism and in normal subjects. Ten of 16 hyperthyroid patients had elevations of GGT activity. There was no difference in mean FT4I or FT3I between the groups with high GGT and normal GGT levels. Six months after treatment with radioactive iodine, serum GGT levels decreased, while there was no significant change in mean serum alkaline phosphatase levels. Mean serum GGT levels were decreased in patients with hypothyroidism and correlated well with serum TSH levels. Replacement therapy with levothyroxine sodium caused an elevation in mean serum GGT levels in six hypothyroid patients. Thus, serum GGT activity is frequently increased in patients with hyperthyroidism and may be decreased in patients with hypothyroidism. Euthyroidism results in restoration of normal GGT levels. (Arch Intern Med 1982;142:79-81) References 1. Kimberg DV: Liver , in Werner SC, Ingbar SH (eds): The Thyroid. Hagerstown, Md, Harper & Row Publishers Inc, 1971, pp 569-573. 2. Dooner HP, Parada J, Aliaga C, et al: The liver in thyrotoxicosis. Arch Intern Med 1967;120:25-32.Crossref 3. Cassar J, Joseph S: Alkaline phosphatase levels in thyroid disease. Clin Chim Acta 1969;23:33-37.Crossref 4. Ashkar FS, Miller R, Smoak WM, et al: Liver disease in hyperthyroidism. South Med J 1971;64:462-465.Crossref 5. Talukdar CK, Ray D, Kulpati DD, et al: Liver in thyrotoxicosis. J Indian Med Assoc 1975;65:37-40. 6. Thompson P, Strum D, Boehm T, et al: Abnormalities of liver function tests in thyrotoxicosis. Milit Med 1978;143:548-551. 7. Cooper DS, Kaplan MM, Chester Ridgway E, et al: Alkaline phosphatase isoenzyme patterns in hyperthyroidism. Ann Intern Med 1979;90:164-168.Crossref 8. Lum G, Gambino R: Serum gamma glulamyl transpeptidase activity as an indicator of disease of liver, pancreas or bone. Clin Chem 1972;18:358-362. 9. Boone DJ, Tietz NW, Weinstock A: Significance of gamma glutamyl transferase (GGT) activity measurements in alcohol-induced hepatic injury. Ann Clin Lab Sci 1977;7:25-28. 10. Chopra IJ: A radioimmunoassay for measurement of thyroxine in unextracted serum. J Clin Endocrinol Metab 1972;34:938-947.Crossref 11. Mitsuma T, Colucci J, Shenkman L, et al: Rapid simultaneous radioimmunoassay for triiodothyronine and thyroxine in unextracted serum. Biochem Biophys Res Commun 1972;46:2107-2113.Crossref 12. Nusynowitz ML, Waliszewski J: Evaluation of a new surface adsorbent triiodothyronine (T3) uptake test. Am J Clin Pathol 1971;56:523-525. 13. Sawin CT, Chopra D, Albano J, et al: The free triiodothyronine (T3) index. Ann Intern Med 1978;88:474-477.Crossref 14. Odell WD, Wilber JF, Utiger RD: Studies of thyrotropin physiology by means of radioimmunoassay. Recent Prog Horm Res 1967;23:47-85. 15. Bowers GN, McComb RB: A continuous spectrophotometric method for measuring the activity of serum alkaline phosphatase. Clin Chem 1966;12:70-89. 16. Szasz G: A kinetic photometric method for serum gamma-glutamyl transpeptidase. Clin Chem 1969;15:124-136. 17. Snedecor GW: Statistical Methods Applied to Experiments in Agriculture and Biology , ed 5. Ames, Iowa, Iowa State University Press, 1956. 18. Gerlach U, Paul L, Latzel H: Isoenzymes of alkaline phosphatase in hyperthyroidism. Enzymol Biol Clin 1970;11:251-256. 19. Szewczuk A: A soluble form of γGT in human tissues. Clin Chim Acta 1966;14:608-614.Crossref 20. Albert Z, Orlowska J, Orlowski M, et al: Histochemical and biochemical investigations of αGT in tissues of man and laboratory rodents. Acta Histochem 1964;18:78-89. 21. Rollason JG, Pincherle G, Robinson D: Serum gamma glutamyl transpeptidase in relation to alcohol consumption. Clin Chim Acta 1972;39:75-80.Crossref 22. Dragosics B, Ferenci P, Pesendorfer F, et al: Gamma-glutamyltranspeptidase (GGTP): Its relationship to other enzymes for diagnosis of liver disease , in Popper H, Schaffner F (eds): Progress in Liver Diseases , New York, Grune & Stratton Inc, 1976, vol 5, pp 436-449.
Archives of Internal Medicine – American Medical Association
Published: Jan 1, 1982