Endocrine Abstracts

Objectives: The use of thyroid hormones (TH) to treat obesity is not supported by evidence based on efficacy and safety, and this is reflected in recommendations of major international guidelines on hypothyroidism and obesity. We aimed to explore views about this practice among European thyroid specialists and their associations with respondent characteristics.

Methods: Thyroid specialists from 28 countries were invited to participate in a questionnaire survey via national thyroid/endocrine professional organisations. The question about obesity was whether ‘thyroid hormones may be indicated in biochemically euthyroid patients with obesity resistant to life-style interventions’. Geographic regions were defined according to the UN Statistics Division. Gross national income (GNI) information stems from https://data.worldbank.org/.

Results: Out of 17,247 invitations 5,695 (65% women) valid responses were received (response rate 33.0%). Of these, 290 (5.1%) stated that TH were indicated as a treatment for obesity. This view was more common among non-endocrinologists (8.7% vs. 4.7%, P < 0.01), respondents working in 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 regard obesity as an indication for TH use than those from Eastern Europe (P < 0.01). GNI correlated inversely with the view that obesity was an indication for TH use (OR 0.969, CI: 0.961-0.977; P < 0.001, per 1000 US$). Of the 28 countries 21 have national guidelines for obesity, and 14 have for hypothyroidism too. The obesity guidelines did not influence the use of LT4 for obesity treatment in either univariate or multivariate models. The presence of thyroid guidelines was associated with less prescribing LT4 for obesity (univariate OR 0.68, 95%CI 0.53-0.88, multivariate OR 0.712, 95%CI 0.55-0.91).

Conclusions: Despite the lack of evidence and contrary to recommendations from guidelines (both national and international), about 5% of respondents to the THESIS survey stated that TH use is indicated as a treatment for obesity in euthyroid patients resistant to life-style interventions. This opinion was associated with working in the private sector, Eastern Europe, and countries with a low GNI. Our findings question the underlying motives and raise concerns about the ethical and safe use of TH by some European thyroid specialists if the attitudes expressed in the THESIS questionnaire represent actual practice.