Background: UK guidance on the assessment and management of thyroid disease was set out in NICE guideline NG145 in 2019 and is expected to result in an increase in radioactive iodine (RAI) being offered as a first-line definitive treatment for hyperthyroidism. Methodology: In this work we analyse longitudinal UK Biobank data to assess all-cause mortality and comorbidity risks associated with the main treatment modalities for 793 participants with hyperthyroidism, specifically antithyroid drugs (ATDs), RAI and thyroidectomy. Results: Participants treated with RAI showed reduced all-cause mortality compared with those treated with ATD alone (time to event ratio: 1.8, 95% CI: 0.9–3.6), albeit the result did not reach statistical significance, as did those treated by thyroidectomy (time ratio: 2.0, 95% CI: 1.1–3.9). For treated patients, odds ratios were generally elevated for osteoporosis, cardiovascular events and atrial fibrillation, but again did not reach statistical significance except for those patients treated by ATDs, with an odds ratio for atrial fibrillation of 2.2 (95% CI: 1.2–4.1) versus controls. Conclusion: Our findings were consistent with those previously reported in the literature and do not reveal any evidence from the UK Biobank to contradict the safety of RAI being offered as a first-line treatment. The data are also suggestive, however, that treatments do not fully eliminate risks of complications related to hyperthyroidism. This reinforces the need for both clear communication where there may be risks of complications such as osteoporosis as well as clinical support for patients even after definitive treatment.

Background Longitudinal studies of thyroid function have demonstrated differing results. It remains unclear whether changes in thyroid function affect the diagnosis of subclinical thyroid dysfunction with aging.Methods Survivors of the Whickham cohort study were evaluated on 2 occasions between the years 2008 and 2012 and 2016 and 2019. Serum TSH, free T4 (FT4), free T3 (FT3), and thyroid peroxidase antibody (TPOAb) were measured on both occasions using the same assay under similar conditions. Individuals with known thyroid disease or on medications affecting thyroid function were excluded. Comorbidities were noted, functional mobility was assessed by the timed up-and-go test, and muscle function was evaluated by the hand grip strength test.Results In 204 individuals (mean age 77.0 [+/- 6.6] years, 114 [56%] female), followed over a median (interquartile range) of 7.8 (7.3-8.2) years, serum TSH increased by 0.29 mU/L (12.4%), FT3 and TPOAb reduced by 0.1 pmol/L (-2.1%) and 0.6 U/L (-11.2%), and there were no significant changes in FT4 levels. The calculated upper limit of serum TSH increased over the follow-up period from 4.74 mU/L to 6.28 mU/L. The relationship between serum TSH and FT4 at both time points was not significantly different. Utilizing standard laboratory reference ranges, the prevalence of subclinical hypothyroidism increased from 3.5% at baseline to 9.0% at follow-up. However, adopting a visit-specific TSH reference range reduced the prevalence of subclinical hypothyroidism at both time points to 2.0%.Discussion Thyroid function demonstrates subtle but significant changes with age. Utilizing standard reference ranges tends to increase the diagnosis of subclinical hypothyroidism in older euthyroid individuals. Our data suggest that adopting age-appropriate TSH reference ranges may reduce the risk of diagnosing and (potentially unnecessarily) treating subclinical hypothyroidism.

INTRODUCTION:Severe Graves' disease is a life-changing condition with poor outcomes from currently available treatments. It is caused by directly pathogenic thyroid-stimulating hormone receptor-stimulating antibodies (TRAb), which are secreted from plasma cells. The human anti-CD38 monoclonal antibody daratumumab was developed to target plasma cells which express high levels of CD38, and is currently licensed for treatment of the plasma cell malignancy, myeloma. However, it can also deplete benign plasma cells with the potential to reduce TRAb and alter the natural history of severe Graves' disease. This study aims to establish proof of concept that daratumumab has efficacy in patients with severe Graves' disease and will provide important data to inform a choice of dosing regimen for subsequent trials. METHODS AND ANALYSIS:The Graves-PCD trial aims to determine if daratumumab modulates the humoral immune response in patients with severe Graves' disease, and if so, over what time period, and to find an optimal dose. It is a single-blinded, randomised, dose-finding, adaptive trial using four different doses of daratumumab or placebo in 30 adult patients. Part 1 of the trial is dose-finding and, following an interim analysis, in part 2, the remaining patients will be randomised between the chosen dose(s) from the interim analysis or placebo. The primary outcome is the percentage change in serum TRAb from baseline to 12 weeks. ETHICS AND DISSEMINATION:The trial received a favourable ethical opinion from London-Hampstead Research Ethics Committee (reference 21/LO/0449). The results of this trial will be disseminated at international meetings, in the peer-reviewed literature and through partner patient group newsletters and presentations at patient education events. TRIAL REGISTRATION NUMBER:ISRCTN81162400.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Clinical EndocrinologyVolume 98, Issue 5 p. 741-742 LETTER Levothyroxine absorption test: A therapeutic strategy for improving medication adherence Bruna Barbar, Bruna Barbar orcid.org/0000-0003-3534-8165 Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorSalman Hossen, Salman Hossen Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorRichard Quinton, Richard Quinton orcid.org/0000-0002-4842-8095 Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK Translational & Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne, UKSearch for more papers by this authorAndy James, Andy James Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorPetros Perros, Petros Perros orcid.org/0000-0001-7320-5574 Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorSimon Pearce, Simon Pearce Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK Translational & Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne, UKSearch for more papers by this authorCatherine Napier, Catherine Napier Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK Translational & Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne, UKSearch for more papers by this authorEarn Gan, Earn Gan Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorAnna Mitchell, Anna Mitchell orcid.org/0000-0002-9946-183X Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorYaasir H. Mamoojee, Corresponding Author Yaasir H. Mamoojee [email protected] Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK Correspondence Yaasir H. Mamoojee, Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK. Email: [email protected]Search for more papers by this author Bruna Barbar, Bruna Barbar orcid.org/0000-0003-3534-8165 Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorSalman Hossen, Salman Hossen Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorRichard Quinton, Richard Quinton orcid.org/0000-0002-4842-8095 Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK Translational & Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne, UKSearch for more papers by this authorAndy James, Andy James Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorPetros Perros, Petros Perros orcid.org/0000-0001-7320-5574 Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorSimon Pearce, Simon Pearce Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK Translational & Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne, UKSearch for more papers by this authorCatherine Napier, Catherine Napier Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK Translational & Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne, UKSearch for more papers by this authorEarn Gan, Earn Gan Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorAnna Mitchell, Anna Mitchell orcid.org/0000-0002-9946-183X Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorYaasir H. Mamoojee, Corresponding Author Yaasir H. Mamoojee [email protected] Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK Correspondence Yaasir H. Mamoojee, Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK. Email: [email protected]Search for more papers by this author First published: 28 February 2023 https://doi.org/10.1111/cen.14902Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. REFERENCES 1Gonzales KM, Stan MN, Morris JC, Bernet V, Castro MR. The levothyroxine absorption test: a four-year experience (2015–2018) at the Mayo Clinic. Thyroid. 2019; 29(12): 1734- 1742. 2Kumar R, Shaukat F. Adherence to levothyroxine tablet in patients with hypothyroidism. Cureus. 2019; 11(5):e4624. 3Walker JN, Shillo P, Ibbotson V, et al. A thyroxine absorption test followed by weekly thyroxine administration: a method to assess non-adherence to treatment. Eur J Endocrinol. 2013; 168(6): 913- 917. 4Ghosh S, Pramanik S, Biswas K, et al. Levothyroxine absorption test to differentiate pseudomalabsorption from true malabsorption. Eur Thyroid J. 2019; 9(1): 19- 24. Volume98, Issue5May 2023Pages 741-742 ReferencesRelatedInformation

Clinical EndocrinologyVolume 99, Issue 6 p. 515-516 LETTER Diagnostic accuracy of morning serum cortisol concentration in predicting secondary adrenal insufficiency Bruna Barbar, Bruna Barbar Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorCampbell Mathieson, Campbell Mathieson Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorChris Boot, Chris Boot Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorRichard Quinton, Richard Quinton orcid.org/0000-0002-4842-8095 Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK Translational & Clinical Research Institute, Newcastle University, Newcastle Upon Tyne, UKSearch for more papers by this authorAndy James, Andy James Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorPetros Perros, Petros Perros Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorSimon Pearce, Simon Pearce orcid.org/0000-0001-8384-8063 Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK Translational & Clinical Research Institute, Newcastle University, Newcastle Upon Tyne, UKSearch for more papers by this authorCatherine Napier, Catherine Napier Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK Translational & Clinical Research Institute, Newcastle University, Newcastle Upon Tyne, UKSearch for more papers by this authorEarn Gan, Earn Gan Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorAnna Mitchell, Anna Mitchell orcid.org/0000-0002-9946-183X Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorYaasir H. Mamoojee, Corresponding Author Yaasir H. Mamoojee [email protected] orcid.org/0000-0002-6823-0473 Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK Correspondence Yaasir H. Mamoojee, Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK. Email: [email protected]Search for more papers by this author Bruna Barbar, Bruna Barbar Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorCampbell Mathieson, Campbell Mathieson Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorChris Boot, Chris Boot Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorRichard Quinton, Richard Quinton orcid.org/0000-0002-4842-8095 Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK Translational & Clinical Research Institute, Newcastle University, Newcastle Upon Tyne, UKSearch for more papers by this authorAndy James, Andy James Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorPetros Perros, Petros Perros Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorSimon Pearce, Simon Pearce orcid.org/0000-0001-8384-8063 Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK Translational & Clinical Research Institute, Newcastle University, Newcastle Upon Tyne, UKSearch for more papers by this authorCatherine Napier, Catherine Napier Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK Translational & Clinical Research Institute, Newcastle University, Newcastle Upon Tyne, UKSearch for more papers by this authorEarn Gan, Earn Gan Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorAnna Mitchell, Anna Mitchell orcid.org/0000-0002-9946-183X Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UKSearch for more papers by this authorYaasir H. Mamoojee, Corresponding Author Yaasir H. Mamoojee [email protected] orcid.org/0000-0002-6823-0473 Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK Correspondence Yaasir H. Mamoojee, Department of Endocrinology, Royal Victoria Infirmary, Newcastle Upon Tyne, UK. Email: [email protected]Search for more papers by this author First published: 09 April 2023 https://doi.org/10.1111/cen.14919 Bruna Barbar and Campbell Mathieson are both first authors. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. REFERENCES 1Montes-Villarreal J, Perez-Arredondo LA, Rodriguez-Gutierrez R, et al. Serum morning cortisol as a screening test for adrenal insufficiency. Endocrine Practice. 2020; 26(1): 30-35. 10.4158/EP-2019-0327 PubMedWeb of Science®Google Scholar 2Struja T, Briner L, Meier A, et al. Diagnostic accuracy of basal cortisol level to predict adrenal insufficiency in cosyntropin testing: results from an observational cohort study with 804 patients. Endocrine Practice. 2017; 23(8): 949-961. 10.4158/EP171861.OR PubMedWeb of Science®Google Scholar 3Woods CP, Argese N, Chapman M, et al. Adrenal suppression in patients taking inhaled glucocorticoids is highly prevalent and management can be guided by morning cortisol. Eur J Endocrinol. 2015; 173(5): 633-642. 10.1530/EJE-15-0608 CASPubMedWeb of Science®Google Scholar 4Clark PM, Neylon I, Raggatt PR, Sheppard MC, Stewart PM. Defining the normal cortisol response to the short Synacthen test: implications for the investigation of hypothalamic–pituitary disorders. Clin Endocrinol. 1998; 49: 287-292. 10.1046/j.1365-2265.1998.00555.x CASPubMedWeb of Science®Google Scholar 5Javorsky BR, Raff H, Carroll TB, et al. New cutoffs for the biochemical diagnosis of adrenal insufficiency after ACTH stimulation using specific cortisol assays. J Endocr Soc. 2021; 5: 1-11. CASWeb of Science®Google Scholar 6Vogeser M, Kratzsch J, Ju Bae Y, et al. Multicenter performance evaluation of a second generation cortisol assay. Clin Chem Lab Med. 2017; 55(6): 826-835. 10.1515/cclm-2016-0400 CASPubMedWeb of Science®Google Scholar 7Manosroi W, Phimphilai M, Khorana J, Atthakomol P. Diagnostic performance of basal cortisol level at 0900-1300h in adrenal insufficiency. PLoS One. 2019; 14(11):e0225255. 10.1371/journal.pone.0225255 CASPubMedWeb of Science®Google Scholar Volume99, Issue6December 2023Pages 515-516 ReferencesRelatedInformation

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Autoimmune Addison's disease (AAD) arises from a complex interplay between multiple genetic susceptibility polymorphisms and environmental factors. The first genome wide association study (GWAS) with patients from Scandinavian Addison's registries has identified association signals at four novel loci in the genes LPP, SH2B3, SIGLEC5, and UBASH3A. To verify these novel risk loci, we performed a case-control association study in our independent cohort of 420 patients with AAD from the across the UK. We report significant association of alleles of the LPP and UBASH3A genes [odds ratio (95% confidence intervals), 1.46 (1.21-1.75)and 1.40 (1.16-1.68), respectively] with AAD in our UK cohort. In addition, we report nominal association of AAD with SH2B3 [OR 1.18 (1.02-1.35)]. We confirm that variants at the LPP and UBASH3A loci confer susceptibility to AAD in a UK population. Further studies with larger patient cohorts are required to robustly confirm the association of SH2B3 and SIGLEC5/SPACA6 alleles.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

center dot PURPOSE: Thyroid eye disease (TED) can be difficult to manage. The range of available treatments is expand-ing rapidly; however, cost is a concern and some patients do not respond. The Clinical Activity Score (CAS) was devised as a measure of disease activity and a potential predictor of response to anti-inflammatory treatment. De-spite the widespread use of the CAS, inter-observer vari-ability has not been investigated. The aim of the study was to determine the inter-observer variability of the CAS in patients with TED. center dot DESIGN: Prospective reliability analysis. center dot METHODS: Nine patients with a spectrum of clinical features of TED were assessed by 6 experienced observers on the same day. Agreement among the observers was an-alyzed using the Krippendorff alpha. center dot RESULTS: The Krippendorff alpha for the total CAS was 0.532 (95% CI = 0.199-0.665), whereas alpha val-ues for the individual components of the CAS varied between 0.171 (CI = 0.000-0.334) for lid redness and 0.671 (CI = 0.294-1.000) for spontaneous pain. Assum-ing that a CAS value >3 implies suitability of the patient for anti-inflammatory treatment, the calculated Krippen-dorff alpha for agreement among assessors on whether treatment should be given or not given was 0.332 (95% CI = 0.0011-0.5862). center dot CONCLUSIONS: This study has shown unreliable inter -observer variability in total CAS and most individual CAS components, thus highlighting the need for improv- ing the performance of the CAS or seeking other meth-ods to assess activity. (Am J Ophthalmol 2023;252: 94-100. Crown Copyright (c) 2023 Published by Elsevier Inc. All rights reserved.)

Objective The specific mechanisms driving autoimmunity in Graves' disease (GD) remain largely unknown. Kappa-deleting recombination excision circles (KRECs) are circular DNA molecules generated during B cell maturation in the bone marrow which provide a measure of B cell production and proliferation. We aimed to investigate the association between KRECs and B cell subpopulations, with thyroid status and clinical outcome in GD patients. Methods Kappa-deleting recombination excision circles were measured by quantitative real-time PCR using a triple-insert plasmid control in 132 GD patients and 140 healthy controls. In addition, KRECs in GD patients on withdrawal of antithyroid drug (ATD) and 6-10 weeks later were analysed according to a clinical outcome at 1 year. Flow cytometry was performed on isolated CD19(+) B cells to quantitate 7 B lymphocyte subpopulations in 65 GD patients. Results Circulating KRECs were higher in GD vs. controls (P = 1.5 x 10(-9)) and demonstrated a positive correlation to thyroid hormones and autoantibodies (free thyroxine: P = 2.14 x 10(-5), rho = .30; free triiodothyronine: P = 1.99 x 10(-7), rho = .37; thyroid stimulating hormone receptor autoantibodies: P = 1.36 x 10(-5), rho = .23). Higher KRECs in GD patients 6-10 weeks after ATD withdrawal were associated with relapse of hyperthyroidism at 1 year (P = .04). The KRECs were positively correlated to the total CD19(+) B cell count (P = 3.2 x 10(-7)). Conclusions This study reports a robust association between KRECs and GD, highlighting the importance of B cells in the pathogenesis of GD and the influence of thyroid status on B cell activity. The findings indicate a potential role for KRECs as a marker of disease activity and outcome in GD.

Summary:This is a report of a rare case of Graves' hyperthyroidism associated with severe bilateral Graves' orbitopathy, in a patient with an anophthalmic eye socket. On clinical review her prosthetic eye (left eye) was tilting upwards, along with worsening of Graves' orbitopathy (GO) in the only seeing eye. As she refused IV glucocorticoids, she was offered rituximab which only caused a transient improvement in the clinical activity score of the eye. She had persistent right upper lid retraction of 6 mm, associated with lagophthalmos. To protect her seeing eye from corneal ulceration, the patient received a botulinum toxin injection to the right upper eyelid to induce blepharoptosis as an interim measure prior to right upper eyelid blepharotomy in April 2021. This patient remains biochemically euthyroid on block and replace therapy and her TRAb level is falling over time. Treatment for active GO is ongoing and the patient required a redo blepharotomy for painful corneal exposure in the right eye.Learning points:Graves' orbitopathy (GO) does not actually primarily affect the eyeball itself but the orbital contents as well. Patients with severe GO in an only seeing-eyed patient should be referred early to a multidisciplinary Joint Thyroid Eye clinic for expert review and management. Patient outcomes including sight loss are likely to be improved by the extended range of medical and surgical treatment modalities available at specialist clinics treating GO, including the use of immunomodulatory drugs like rituximab or teprotumumab.

Persistent symptoms in patients treated for hypothyroidism are common. Despite more than 20 years of debate, the use of liothyronine for this indication remains controversial, as numerous randomised trials have failed to show a benefit of treatment regimens that combine liothyronine (T3) with levothyroxine over levothyroxine monotherapy. This consensus statement attempts to provide practical guidance to clinicians faced with patients who have persistent symptoms during thyroid hormone replacement therapy. It applies to non-pregnant adults and is focussed on care delivered within the UK National Health Service, although it may be relevant in other healthcare environments. The statement emphasises several key clinical practice points for patients dissatisfied with treatment for hypothyroidism. Firstly, it is important to establish a diagnosis of overt hypothyroidism; patients with persistent symptoms during thyroid hormone replacement but with no clear biochemical evidence of overt hypothyroidism should first have a trial without thyroid hormone replacement. In those with established overt hypothyroidism, levothyroxine doses should be optimised aiming for a TSH in the 0.3-2.0 mU/L range for 3 to 6 months before a therapeutic response can be assessed. In some patients, it may be acceptable to have serum TSH below reference range (e.g. 0.1-0.3 mU/L), but not fully suppressed in the long term. We suggest that for some patients with confirmed overt hypothyroidism and persistent symptoms who have had adequate treatment with levothyroxine and in whom other comorbidities have been excluded, a trial of liothyronine/levothyroxine combined therapy may be warranted. The decision to start treatment with liothyronine should be a shared decision between patient and clinician. However, individual clinicians should not feel obliged to start liothyronine or to continue liothyronine medication provided by other health care practitioners or accessed without medical advice, if they judge this not to be in the patient's best interest.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)