PURPOSE: The use of thyroid hormones (TH) to treat obesity is unsupported by evidence as reflected in international guidelines. We explored views about this practice, and associations with respondent characteristics among European thyroid specialists. METHODS: Specialists from 28 countries were invited to a survey via professional organisations. The relevant question was whether "Thyroid hormones may be indicated in biochemically euthyroid patients with obesity resistant to lifestyle interventions". RESULTS: Of 17,232 invitations 5695 responses were received (33% valid response rate; 65% women; 90% endocrinologists). Of these, 290 (5.1%) stated that TH may be indicated as treatment for obesity in euthyroid patients. This view was commoner among non-endocrinologists (8.7% vs. 4.7%, p < 0.01), private practice (6.5% vs. 4.5%, p < 0.01), and varied geographically (Eastern Europe, 7.3%; Southern Europe, 4.8%; Western Europe, 2.7%; and Northern Europe, 2.5%). Respondents from Northern and Western Europe were less likely to use TH than those from Eastern Europe (p < 0.01). Gross national income (GNI) correlated inversely with this view (OR 0.97, CI: 0.96-0.97; p < 0.001). Having national guidelines on hypothyroidism correlated negatively with treating obesity with TH (OR 0.71, CI: 0.55-0.91). CONCLUSIONS: Despite the lack of evidence, and contrary to guidelines' recommendations, about 5% of respondents stated that TH may be indicated as a treatment for obesity in euthyroid patients resistant to life-style interventions. This opinion was associated with (i) respondent characteristics: being non-endocrinologist, working in private practice, treating a small number of hypothyroid patients annually and (ii) national characteristics: prevalence of obesity, Eastern Europe, low GNI and lack of national hypothyroidism guidelines.

1st Department of Internal Medicine of the Medical Faculty P J Šafárik University Košice Košice Slovakia

3rd Department of Medicine 1st Faculty of Medicine Charles University General University Hospital Prague Czech Republic

5 P Komisarenko Institute of Endocrinology and Metabolism of Academy of Medical Sciences of Ukraine Kyiv Ukraine

5th Department of Internal Medicine Medical Faculty of Comenius University and University Hospital Bratislava Slovakia

5th Medical Department Division of Endocrinology and Diabetes Medical Faculty Mannheim Heidelberg University Mannheim Germany

Cabinet Médical 2 Rue Bellefontaine Lausanne Switzerland

Clinic of Endocrinology and Metabolism Medical Faculty University Hospital Sofiamed Sofia University Saint Kliment Ohridski Sofia Bulgaria

Clinic of Endocrinology and Metabolism University Hospital Alexandrovska Sofia Bulgaria

Department of Endocrinology and Diabetes Centre Hellenic Red Cross Hospital Athens Greece

Department of Endocrinology and Metabolism Amsterdam UMC University of Amsterdam Amsterdam The Netherlands

Department of Endocrinology and Metabolism Koru Ankara Hospital Kizilirmak Ankara Turkey

Department of Endocrinology and Metabolism Regina Apostolorum Hospital Rome Italy

Department of Endocrinology and Nutrition Clínica Universidad de Navarra Pío XII 36 31080 Pamplona Spain

Department of Endocrinology Belarusian State Medical University Minsk Republic of Belarus

Department of Endocrinology Carol Davila University of Medicine and Pharmacy Bucharest Romania

Department of Endocrinology Diabetes and Metabolic Diseases Mladen Sekso University Hospital Center Sisters of Mercy Zagreb Croatia

Department of Endocrinology Diabetes and Metabolism University Hospital Essen University Duisburg Essen Essen Germany

Department of Endocrinology Diabetology and Nutrition Cliniques Universitaires St Luc Université Catholique de Louvain Brussels Belgium

Department of Endocrinology Hospital Universitario Puerta de Hierro Majadahonda Madrid Spain

Department of Endocrinology Metabolism and Internal Medicine Poznan University of Medical Sciences Poznań Poland

Department of Endocrinology No 1 N 5 Sklifosovsky Institute of Clinical Medicine 1 M Sechenov 1st Moscow State Medical University Moscow Russian Federation

Department of Endocrinology Odense University Hospital Odense Denmark

Department of Endocrinology Skåne University Hospital Malmö Sweden

Department of Endocrinology Tampere University Hospital Tampere Finland

Department of Internal Medicine and Endocrinology Medical University of Warsaw Warsaw Poland

Department of Internal Medicine Endocrine Unit UZ Brussel Vrije Universiteit Brussel Brussels Belgium

Department of Internal Medicine Medical University Sofia Sofia Bulgaria

Department of Medicine 1 Klinikum Vest GmbH Knappschaftskrankenhaus Recklinghausen Academic Teaching Hospital Ruhr University Bochum Recklinghausen Germany

Department of Medicine Universidad Autónoma de Madrid Madrid Spain

Department of Reproductive Endocrinology Institute of Endocrinology and Metabolism Named after 5 P Komissarenko National Academy of Medical Science of Ukraine Kyiv Ukraine

Department of Surgery Tampere University Hospital Tampere Finland

Diabetes and Endocrinology Section Beacon Hospital Beacon Court Dublin Ireland

Division of Endocrinology 5 Fazzi Hospital Lecce Italy

Division of Endocrinology Department of Internal Medicine Faculty of Medicine Gaziantep University Gaziantep Turkey

Division of Endocrinology Department of Medicine Faculty of Medicine University of Debrecen Debrecen Hungary

Division of Endocrinology Diabetes and Metabolism University of Lausanne Lausanne Switzerland

East Surrey Hospital Surrey and Sussex Healthcare NHS Trust Redhill Surrey UK

Endocrine Unit and Diabetes Centre Department of Clinical Therapeutics School of Medicine Alexandra Hospital National and Kapodistrian University of Athens Athens Greece

Endocrinology Diabetes and Metabolism Service Centro Hospitalar Universitário de Santo António Porto Portugal

Faculty of Medicine University of Belgrade Belgrade Serbia

Institute of Endocrinology Diabetes and Metabolic Disorders Univeristy Clinical Center of Serbia Belgrade Serbia

Institute of Translational and Clinical Research Newcastle University Newcastle Upon Tyne UK

Instituto de Investigación Sanitaria de Navarra Pamplona Spain

Instituto de Investigación Sanitaria Puerta de Hierro Segovia de Arana Majadahonda Madrid Spain

Internal Medicine 3 Division of Endocrinology and Metabolism Medical University of Vienna Vienna Austria

Robert Graves Institute Tallaght University Hospital Dublin Ireland

Rotterdam Thyroid Center Department of Internal Medicine Erasmus Medical Center Rotterdam The Netherlands

School of Medicine University College Dublin Dublin Ireland

Scientific Committee Associazione Medici Endocrinologi Milan Italy

Section of Clinical Medicine Faculty of Health and Medical Sciences University of Surrey Guildford Surrey UK

Thyroid and Osteoporosis Praxis Kumberg Austria

Thyroid Cancer Service Endocrinology and Metabolism Institute Beilinson Hospital and Davidoff Cancer Center Rabin Medical Center Sackler Faculty of Medicine Tel Aviv University Petah Tikva Israel

Thyroid Disease and Endocrine Tumor Department Sorbonne Universitè Hôpital Pitié Salpêtriére Paris France

Thyroid Practice for Radiofrequency Ablation Vienna Austria

Thyroid Task Force From the Sociedad Española de Endocrinología y Nutrición Madrid Spain

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