Differentiating Graves’ Disease from Subacute Thyroiditis Using Ratio of Serum Free Triiodothyronine to Free Thyroxine Ratio in Graves' Disease and Subacute Thyroiditis
Article Sidebar
Main Article Content
Abstract
Background: Graves’ disease and subacute thyroiditis are common causes of hyperthyroidism that share overlapping clinical features, making differentiation challenging. Accurate diagnosis is crucial for appropriate management to prevent adverse outcomes.
Objective: To differentiate Graves’ disease from subacute thyroiditis using the ratio of serum free triiodothyronine (FT3) to free thyroxine (FT4).
Methods: This prospective observational study was conducted at the Department of Diabetes, Endocrinology, and Metabolic Diseases, Hayatabad Medical Complex, Peshawar, from November 2023 to May 2024. A total of 248 patients diagnosed with Graves’ disease (n = 158) or subacute thyroiditis (n = 90) were included. Clinical, biochemical, and imaging data were collected, and the FT3/FT4 ratio was calculated. Data were analyzed using SPSS v25, with independent samples t-tests and ROC curve analysis performed.
Results: The mean FT3/FT4 ratio was significantly higher in Graves’ disease (4.5 ± 0.8) compared to subacute thyroiditis (2.1 ± 0.5), p = 0.001. An FT3/FT4 ratio >3.0 had a sensitivity of 87% and specificity of 85%, with an AUC of 0.92.
Conclusion: The FT3/FT4 ratio is a reliable diagnostic tool for differentiating Graves’ disease from subacute thyroiditis, offering high sensitivity and specificity.
Article Details
This work is licensed under a Creative Commons Attribution 4.0 International License.
References
Sriphrapradang C, Bhasipol A. Differentiating Graves' disease from subacute thyroiditis using ratio of serum free triiodothyronine to free thyroxine. Ann Med Surg. 2016;10:69-72. doi:10.1016/j.amsu.2016.07.024.
Zhang Y, Wang Y, Liu M, Wei L, Huang J, Dong Z, et al. The value of FT4/TSH ratio in the differential diagnosis of Graves' disease and subacute thyroiditis. Front Endocrinol. 2023;14:1148174. doi:10.3389/fendo.2023.1148174.
Kahaly GJ, Bartalena L, Hegedüs L, Leenhardt L, Poppe K, Pearce SH. European Thyroid Association guideline for the management of Graves' hyperthyroidism. Eur Thyroid J. 2018;7:167-86. doi:10.1159/000490384.
Görges J, Ulrich J, Keck C, Müller-Wieland D, Diederich S, Janssen OE. Long-term outcome of subacute thyroiditis. Exp Clin Endocrinol Diabetes. 2020;128:703-8. doi:10.1055/a-0998-8035.
Baral S, Shrestha PK, Pant V. Serum free T3 to free T4 ratio as a useful indicator for differentiating destruction-induced thyrotoxicosis from Graves' disease. J Clin Diagn Res. 2017;11. doi:10.7860/JCDR/2017/28293.10180.
Wu Z, Zhu Y, Zhang M, Wang C, Zhou L, Liu W, et al. Serum ratio of free triiodothyronine to thyroid-stimulating hormone: A novel index for distinguishing Graves' disease from autoimmune thyroiditis. Front Endocrinol. 2020;11:620407. doi:10.3389/fendo.2020.620407.
Narkar RR, Mishra I, Baliarsinha AK, Choudhury AK. Rapid differential diagnosis of thyrotoxicosis using T3/T4 ratio, FT3/FT4 ratio, and color Doppler of thyroid gland. Indian J Endocrinol Metab. 2021;25:193-7. doi:10.4103/ijem.ijem_137_21.
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. doi:10.1155/2018/4836736.
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;52:537-42. doi:10.1507/endocrj.52.537.
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;52:29-36. doi:10.1507/endocrj.52.29.
Uludağ SS, Akıncı O, Güreş N, Tunç E, Erginöz E, Şanlı AN, et al. Effectiveness of pre-operative routine blood tests in predicting complicated acute appendicitis. Turk J Trauma Emerg Surg. 2022;28:1590-6. doi:10.14744/tjtes.2021.13472.
Naderan M, Babaki AE, Shoar S, Mahmoodzadeh H, Nasiri S, Khorgami Z. Risk factors for the development of complicated appendicitis in adults. Turk J Surg. 2016;32:37-42.
Avanesov M, Wiese NJ, Karul M, Guerreiro H, Keller S, Busch P, et al. Diagnostic prediction of complicated appendicitis by combined clinical and radiological appendicitis severity index. Eur Radiol. 2018;28:3601-10.
Ayrık C, Karaaslan U, Dağ A, Bozkurt S, Toker İ, Demir F. Predictive value of leucocyte count, neutrophil percent, and C-reactive protein concentration “cut-off value” on the diagnosis of appendicitis. Turk J Trauma Emerg Surg. 2016;22:76-83.
Delgado-Miguel C, Muñoz-Serrano AJ, Delfa SB, Cerezo VN, Estefanía K, Velayos M, et al. Neutrophil-to-lymphocyte ratio as a predictor of peritonitis in acute appendicitis in children. Cir Pediatr. 2019;32:185-9.
Van Rossem CC, Leeuwenburgh MM, Stoker J, Boermeester MA. Scoring system to distinguish uncomplicated from complicated acute appendicitis. Br J Surg. 2015;102:970-90.
Kahramanca S, Ozgehan G, Seker D, Gökce EI, Seker G, Tunç G, et al. Neutrophil-to-lymphocyte ratio as a predictor of acute appendicitis. Turk J Trauma Emerg Surg. 2014;20:19-22.
Pehlivanlı F, Aydin O. Role of platelet-to-lymphocyte ratio as a biomedical marker for the pre-operative diagnosis of acute appendicitis. Surg Infect. 2019;20:631-6.