Jostel's TSH index

Jostel's TSH index (TSHI or JTI), also referred to as Jostel's thyrotropin index or Thyroid Function index (TFI) is a method for estimating the thyrotropic (i.e. thyroid stimulating) function of the anterior pituitary lobe in a quantitative way.[1][2] The equation has been derived from the logarithmic standard model of thyroid homeostasis.[3][4][5][6] In a paper from 2014 further study was suggested to show if it is useful,[7] but the 2018 guideline by the European Thyroid Association for the diagnosis of uncertain cases of central hypothyroidism regarded it as beneficial.[2]

Jostel's TSH index
SynonymsJostel's thyrotropin index
Reference range1.3–4.1
MeSHD013960

How to determine JTI

Jostel's TSH index can be calculated with

from equilibrium serum concentrations of thyrotropin (TSH), free T4 (FT4) and a correction coefficient derived from the logarithmic standard model (β = 0.1345).

An alternative standardised form (standardised TSH index or sTSHI) is calculated with.[1]

as a z-transformed value incorporating mean (2.7) and standard deviation (0.676) of TSHI in a reference population[5]

Reference ranges
ParameterLower limitUpper limitUnit
TSHI1.3[1]4.1[1]
sTSHI-2[1]2[1]

Clinical significance

The TSH index is reduced in patients with secondary hypothyroidism resulting from thyrotropic insufficiency.[1][8][9] For this indication, it has, however, up to now only been validated in adults.[10] JTI was also found reduced in cases of TACITUS syndrome (non-thyroidal illness syndrome) as an example of type 1 thyroid allostasis.[11][12] Conversely, an elevated thyroid function index may serve as a biomarker for type 2 allostasis and contextual stress.[13][14]

Jostel's TSH index may decrease under therapy with the antidiabetic drug metformin, especially in women under oral contraceptives.[15]

A longitudinal study in euthyroid subjects with structural heart disease found that JTI predicts the risk of malignant arrhythmia including ventricular fibrillation and ventricular tachycardia.[16] This applies to both incidence and event-free survival.[16] It was therefore concluded that an elevated set point of thyroid homeostasis may contribute to cardiovascular risk. A positive correlation of JTI to SIQALS 2,[14] a score for allostatic load, suggests that thyroid hormones are among the mediators linking stress to major cardiovascular endpoints.[17]

Another study demonstrated the TSH index to inversely correlate to thyroid's secretory capacity and thyroid volume.[18] It is unclear if this finding reflects shortcomings of the index (i.e. low specificity in the setting of subclinical hypothyroidism) or plastic responses of the pituitary gland to beginning hypothyroidism.

See also

References
  1. Jostel A, Ryder WD, Shalet SM (October 2009). "The use of thyroid function tests in the diagnosis of hypopituitarism: definition und evaluation of the TSH Index". Clin. Endocrinol. (Oxf). 71 (4): 529–34. doi:10.1111/j.1365-2265.2009.03534.x. PMID 19226261.
  2. Persani, L; Brabant, G; Dattani, M; Bonomi, M; Feldt-Rasmussen, U; Fliers, E; Gruters, A; Maiter, D; Schoenmakers, N; van Trotsenburg, ASP (October 2018). "2018 European Thyroid Association (ETA) Guidelines on the Diagnosis and Management of Central Hypothyroidism". European Thyroid Journal. 7 (5): 225–237. doi:10.1159/000491388. PMC 6198777. PMID 30374425.
  3. Reichlin S, Utiger RD (February 1967). "Regulation of the pituitary-thyroid axis in man: relationship of TSH concentration to concentration of free and total thyroxine in plasma". J Clin Endocrinol Metab. 27 (2): 251–255. doi:10.1210/jcem-27-2-251. PMID 4163614.
  4. Cohen, J. L., Thyroid-stimulation hormone and its disorders. In: Becker, K. L. (Hrsg.) Principles and Practice of Endocrinology and Metabolism. S. 144–52, J. B. Lippincott Company, Philadelphia, PA, USA, 1990
  5. Dietrich, JW; Landgrafe, G; Fotiadou, EH (2012). "TSH and Thyrotropic Agonists: Key Actors in Thyroid Homeostasis". J Thyroid Res. 2012: 351864. doi:10.1155/2012/351864. PMC 3544290. PMID 23365787..
  6. Dietrich, Johannes W.; Landgrafe-Mende, Gabi; Wiora, Evelin; Chatzitomaris, Apostolos; Klein, Harald H.; Midgley, John E. M.; Hoermann, Rudolf (2016-06-09). "Calculated Parameters of Thyroid Homeostasis: Emerging Tools for Differential Diagnosis and Clinical Research". Frontiers in Endocrinology. 7: 57. doi:10.3389/fendo.2016.00057. PMC 4899439. PMID 27375554.
  7. Fliers, Eric; Korbonits, Marta; Romijn, J. A. (2014). Clinical Neuroendocrinology. Elsevier. p. 146. ISBN 9780444626127.
  8. Chiloiro, Sabrina; Tartaglione, Tommaso; Capoluongo, Ettore Domenico; Angelini, Flavia; Arena, Vincenzo; Giampietro, Antonella; Bianchi, Antonio; Zoli, Angelo; Pontecorvi, Alfredo; Colosimo, Cesare; De Marinis, Laura (1 August 2018). "Hypophysitis outcome and factors predicting responsiveness to glucocorticoid therapy: a prospective and double-arm study". The Journal of Clinical Endocrinology & Metabolism. 103 (10): 3877–3889. doi:10.1210/jc.2018-01021. PMID 30085134.
  9. Persani, L; Cangiano, B; Bonomi, M (1 January 2019). "The diagnosis and management of central hypothyroidism in 2018". Endocrine Connections. 8 (2): R44–R54. doi:10.1530/EC-18-0515. PMC 6373625. PMID 30645189.
  10. Schoenmakers, N; Alatzoglou, KS; Chatterjee, VK; Dattani, MT (2015). "Recent advances in central congenital hypothyroidism". J Endocrinol. 227 (3): R51-71. doi:10.1530/JOE-15-0341. PMC 4629398. PMID 26416826.
  11. Fan, S; Ni, X; Wang, J; Zhang, Y; Tao, S; Chen, M; Li, Y; Li, J (February 2016). "Low Triiodothyronine Syndrome in Patients With Radiation Enteritis: Risk Factors and Clinical Outcomes an Observational Study". Medicine. 95 (6): e2640. doi:10.1097/MD.0000000000002640. PMC 4753882. PMID 26871787.
  12. Bingyan, Zhan; Dong, Wei (7 July 2019). "Impact of thyroid hormones on asthma in older adults". Journal of International Medical Research. 47 (9): 4114–4125. doi:10.1177/0300060519856465. PMC 6753544. PMID 31280621.
  13. Lei, MK; Beach, SR; Simons, RL; Barr, AB; Cutrona, CE; Philibert, RA (Mar 2016). "Stress, relationship satisfaction, and health among African American women: Genetic moderation of effects". J Fam Psychol. 30 (2): 221–32. doi:10.1037/fam0000140. PMC 4749476. PMID 26376424.
  14. Dietrich, Johannes Wolfgang; Hoermann, Rudolf; Midgley, John E. M.; Bergen, Friederike; Müller, Patrick (26 October 2020). "The Two Faces of Janus: Why Thyrotropin as a Cardiovascular Risk Factor May Be an Ambiguous Target". Frontiers in Endocrinology. 11: 542710. doi:10.3389/fendo.2020.542710.
  15. Krysiak, Robert; Kowalcze, Karolina; Wolnowska, Monika; Okopień, Bogusław (5 January 2020). "The impact of oral hormonal contraception on metformin action on hypothalamic‐pituitary‐thyroid axis activity in women with diabetes and prediabetes: A pilot study". Journal of Clinical Pharmacy and Therapeutics. doi:10.1111/jcpt.13105. PMID 31903641.
  16. Müller, Patrick; Dietrich, Johannes W.; Lin, Tina; Bejinariu, Alexandru; Binnebößel, Stephan; Bergen, Friederike; Schmidt, Jan; Müller, Sarah-Kristin; Chatzitomaris, Apostolos; Kurt, Muhammed; Gerguri, Shqipe; Clasen, Lukas; Klein, Harald H.; Kelm, Malte; Makimoto, Hisaki (January 2020). "Usefulness of Serum Free Thyroxine Concentration to Predict Ventricular Arrhythmia Risk in Euthyroid Patients with Structural Heart Disease". The American Journal of Cardiology. 125 (8): 1162–1169. doi:10.1016/j.amjcard.2020.01.019. PMID 32087999.
  17. Tawakol, A; Ishai, A; Takx, RA; Figueroa, AL; Ali, A; Kaiser, Y; Truong, QA; Solomon, CJ; Calcagno, C; Mani, V; Tang, CY; Mulder, WJ; Murrough, JW; Hoffmann, U; Nahrendorf, M; Shin, LM; Fayad, ZA; Pitman, RK (25 February 2017). "Relation between resting amygdalar activity and cardiovascular events: a longitudinal and cohort study". Lancet. 389 (10071): 834–845. doi:10.1016/S0140-6736(16)31714-7. PMID 28088338.
  18. Hoermann, R; Midgley, JEM; Larisch, R; Dietrich, JW (19 July 2018). "The Role of Functional Thyroid Capacity in Pituitary Thyroid Feedback Regulation". European Journal of Clinical Investigation. 48 (10): e13003. doi:10.1111/eci.13003. PMID 30022470. S2CID 51698223.
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