Real-life practice of thyroid hormone use in hypothyroid and euthyroid patients: A detailed view from the THESIS questionnaire survey in France

Aim. - To describe practices of French physicians regarding thyroid hormone therapy, focusing on available LT4 formulations. Material and methods. - Members of the French Endocrine Society (FES) and affiliated societies (the Endocrine Tumor Group, French College of Teachers of Endocrinology, Diabetes and Metabolic Diseases and the Union of Endocrinology, Diabetology, Metabolic Diseases and Nutrition Specialists) were invited to participate in an online survey. Results. - Five hundred and thirty four of the 2,094 persons contacted (25.5%) completed the survey and were included in the analysis. The vast majority (99.4%) reported that levothyroxine (LT4) is the treatment of choice for hypothyroidism. 7.1% and 14.2% of respondents respectively considered liothyronine (LT3) or a combination of LT4 and LT3 for the treatment of hypothyroidism, mainly when symptoms persisted despite achieving normal TSH concentrations with LT4 therapy. For 44% of respondents, thyroid hormone treatment is never indicated in euthyroid patients, while the remainder would consider treating euthyroid patients with a goiter growing over time (40.2%) and/or euthyroid women with positive anti-TPO antibodies and infertility (31.7%). LT4 tablets were the preferred LT4 formulation. A significant proportion of FES members expected no major clinical differences upon changing to formulations such as soft-gel capsules or liquid solutions, even in specific scenarios such as poor biochemical control or suspicion of malabsorption. Conclusion. - The treatment of choice for hypothyroidism in France is LT4. LT3-based therapy is considered by some physicians in case of persistent symptoms of hypothyroidism despite normal TSH level. A significant proportion of respondents (66.0%) would consider treating euthyroid patients, contrary to the present state of knowledge. These outdated practices should be addressed by professional bodies such as the FES. Crown Copyright (c) 2021 Published by Elsevier Masson SAS. All rights reserved.

Automated summary

This study aimed to analyze the practices of French physicians in thyroid hormone therapy, specifically focusing on the use of various LT4 formulations. The majority of physicians in France prefer levothyroxine (LT4) as the treatment of choice for hypothyroidism. However, some physicians consider using liothyronine (LT3) or a combination of LT4 and LT3 when hypothyroidism symptoms persist despite normal TSH levels. There is also a significant proportion of physicians who would consider treating euthyroid patients, contrary to current knowledge. They also found that LT4 tablets were the most preferred formulation.