The Value of FT4/TSH Ratio in the Differential Diagnosis of Graves' Disease and Subacute Thyroiditis

Overview

Journal Front Endocrinol (Lausanne)

Specialty Endocrinology

Date 2023 Jul 3

PMID 37396175

Authors

Yingjie Zhang

Yu Wang

Miao Liu

Lingge Wei

Jianmin Huang

Ziqian Dong

Meichao Guan

Weijie Wu

Jianqing Gao

Xiaojie Huang

Xin Guo

Peng Xie

Affiliations

Soon will be listed here.

Abstract

Objective: To explore the value of the FT4/TSH ratio in the etiological diagnosis of newly diagnosed patients with thyrotoxicosis.

Methods: The retrospective study was conducted on 287 patients with thyrotoxicosis (122 patients with subacute thyroiditis and 165 patients with Graves' disease) and 415 healthy people on their first visit to our hospital. All patients underwent thyroid function tests including the measurement of T3, T4, FT3, FT4, TSH, T3/TSH, and T4/TSH. The receiver operating characteristic (ROC) curve was employed to evaluate the value of FT4/TSH in the differential diagnosis of Graves' disease and subacute thyroiditis, and compared with other related indicators.

Results: The area under the curve of FT4/TSH for diagnosing Graves' disease and thyroiditis was 0.846, which was significantly larger than the area under the curve of T3/T4 ratio (< 0.05) and FT3/FT4 ratio (< 0.05). When the cut-off value of the FT4/TSH ratio was 5731.286 pmol/mIU, the sensitivity was 71.52%, the specificity was 90.16%, the positive predictive value was 90.77% and the negative predictive value was 70.06%. The diagnostic accuracy was 79.44%.

Conclusion: FT4/TSH ratio can be used as a new reference index for the differential diagnosis of thyrotoxicosis.

Citing Articles

Evaluation of the Dysregulation of Cholesterol and Glucose Levels in Graves' Disease Using Clinical Data Analysis.

Kareem Z, Al-Kazazz F, Rheima A, Sultan A Rep Biochem Mol Biol. 2025; 13(2):159-166.

PMID: 39995640 PMC: 11847589. DOI: 10.61186/rbmb.13.2.159.

References

Kahaly G, Bartalena L, Hegedus L, Leenhardt L, Poppe K, Pearce S . 2018 European Thyroid Association Guideline for the Management of Graves' Hyperthyroidism. Eur Thyroid J. 2018; 7(4):167-186. PMC: 6140607. DOI: 10.1159/000490384. View

Giovanella L, Avram A, Iakovou I, Kwak J, Lawson S, Lulaj E . EANM practice guideline/SNMMI procedure standard for RAIU and thyroid scintigraphy. Eur J Nucl Med Mol Imaging. 2019; 46(12):2514-2525. DOI: 10.1007/s00259-019-04472-8. View

Amino N, Yabu Y, Miki T, Morimoto S, KUMAHARA Y, Mori H . Serum ratio of triiodothyronine to thyroxine, and thyroxine-binding globulin and calcitonin concentrations in Graves' disease and destruction-induced thyrotoxicosis. J Clin Endocrinol Metab. 1981; 53(1):113-6. DOI: 10.1210/jcem-53-1-113. View

Gorges J, Ulrich J, Keck C, Muller-Wieland D, Diederich S, Janssen O . Long-term Outcome of Subacute Thyroiditis. Exp Clin Endocrinol Diabetes. 2019; 128(11):703-708. DOI: 10.1055/a-0998-8035. View

Shigemasa C, Abe K, Taniguchi S, Mitani Y, Ueda Y, Adachi T . Lower serum free thyroxine (T4) levels in painless thyroiditis compared with Graves' disease despite similar serum total T4 levels. J Clin Endocrinol Metab. 1987; 65(2):359-63. DOI: 10.1210/jcem-65-2-359. View

Wu Z, Zhu Y, Zhang M, Wang C, Zhou L, Liu W . Serum Ratio of Free Triiodothyronine to Thyroid-Stimulating Hormone: A Novel Index for Distinguishing Graves' Disease From Autoimmune Thyroiditis. Front Endocrinol (Lausanne). 2021; 11:620407. PMC: 7821852. DOI: 10.3389/fendo.2020.620407. View

Devereaux D, Tewelde S . Hyperthyroidism and thyrotoxicosis. Emerg Med Clin North Am. 2014; 32(2):277-92. DOI: 10.1016/j.emc.2013.12.001. View

Antonelli A, Fallahi P, Elia G, Ragusa F, Paparo S, Ruffilli I . Graves' disease: Clinical manifestations, immune pathogenesis (cytokines and chemokines) and therapy. Best Pract Res Clin Endocrinol Metab. 2020; 34(1):101388. DOI: 10.1016/j.beem.2020.101388. View

Prakash R . Prediction of remission in Graves' disease treated with long-term carbimazole therapy: evaluation of technetium-99m thyroid uptake and TSH concentrations as prognostic indicators. Eur J Nucl Med. 1996; 23(2):118-22. DOI: 10.1007/BF01731833. View

10.

Ross D, Burch H, Cooper D, Greenlee M, Laurberg P, Maia A . 2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and Other Causes of Thyrotoxicosis. Thyroid. 2016; 26(10):1343-1421. DOI: 10.1089/thy.2016.0229. View

11.

De Leo S, Lee S, Braverman L . Hyperthyroidism. Lancet. 2016; 388(10047):906-918. PMC: 5014602. DOI: 10.1016/S0140-6736(16)00278-6. View

12.

Zornitzki T, Mildiner S, Schiller T, Kirzhner A, Ostrovsky V, Knobler H . Subacute Thyroiditis-Still a Diagnostic Challenge: Data from an Observational Study. Int J Environ Res Public Health. 2022; 19(15). PMC: 9368122. DOI: 10.3390/ijerph19159388. View

13.

Chen X, Zhou Y, Zhou M, Yin Q, Wang S . Diagnostic Values of Free Triiodothyronine and Free Thyroxine and the Ratio of Free Triiodothyronine to Free Thyroxine in Thyrotoxicosis. Int J Endocrinol. 2018; 2018:4836736. PMC: 6008621. DOI: 10.1155/2018/4836736. View

14.

Laurberg P, Vestergaard H, Nielsen S, Christensen S, Seefeldt T, Helleberg K . Sources of circulating 3,5,3'-triiodothyronine in hyperthyroidism estimated after blocking of type 1 and type 2 iodothyronine deiodinases. J Clin Endocrinol Metab. 2007; 92(6):2149-56. DOI: 10.1210/jc.2007-0178. View

15.

Baral S, Shrestha P, Pant V . Serum Free T to Free T Ratio as a Useful Indicator for Differentiating Destruction Induced Thyrotoxicosis from Graves' Disease. J Clin Diagn Res. 2017; 11(7):OC12-OC14. PMC: 5583931. DOI: 10.7860/JCDR/2017/28293.10180. View

16.

Yoshimura Noh J, Momotani N, Fukada S, Ito K, Miyauchi A, Amino N . Ratio of serum free triiodothyronine to free thyroxine in Graves' hyperthyroidism and thyrotoxicosis caused by painless thyroiditis. Endocr J. 2005; 52(5):537-42. DOI: 10.1507/endocrj.52.537. View

17.

Yanagisawa T, Sato K, Kato Y, Shimizu S, Takano K . Rapid differential diagnosis of Graves' disease and painless thyroiditis using total T3/T4 ratio, TSH, and total alkaline phosphatase activity. Endocr J. 2005; 52(1):29-36. DOI: 10.1507/endocrj.52.29. View

18.

Sharma A, Stan M . Thyrotoxicosis: Diagnosis and Management. Mayo Clin Proc. 2019; 94(6):1048-1064. DOI: 10.1016/j.mayocp.2018.10.011. View

19.

Sriphrapradang C, Bhasipol A . Differentiating Graves' disease from subacute thyroiditis using ratio of serum free triiodothyronine to free thyroxine. Ann Med Surg (Lond). 2016; 10:69-72. PMC: 4990637. DOI: 10.1016/j.amsu.2016.07.024. View

20.

Thienpont L, Van Uytfanghe K, Poppe K, Velkeniers B . Determination of free thyroid hormones. Best Pract Res Clin Endocrinol Metab. 2013; 27(5):689-700. DOI: 10.1016/j.beem.2013.05.012. View