Use of thyroid hormones in hypothyroid and euthyroid patients: a THESIS* questionnaire survey of Polish physicians. *THESIS: Treatment of hypothyroidism in Europe by specialists: an international survey

Abstract

Introduction: Over the past several years new evidence on management of hypothyroidism has emerged and has influenced recommendations from professional bodies. The presentation of hypothyroid patients has also changed and increasingly new cases are diagnosed by indiscriminate screening often identifying cases with minor biochemical disturbances. Little is known about the physician responses and attitudes to this changing landscape. THESIS (Treatment of Hypothyroidism in Europe by Specialists: an International Survey) is a large-scale survey of European physicians who treat patients with hypothyroidism. Here we document current practices of Polish physicians relating to the use of thyroid hormones in hypothyroid and euthyroid patients. Material and methods: Members of the Polish Society of Endocrinology were invited to participate in the web-based THESIS survey.Results: 423 (54.6% of the 774 invited) completed the survey. The majority of respondents (74.2%) would prescribe thyroid hormones for euthyroid patients for certain indications, such as female infertility with elevated thyroid antibodies (63.4%), simple goiter (40.9%), unexplained fatigue (12.1%), obesity (9.7%), hypercholesterolemia (9.0%) and depression (9.2%). Nearly all physicians (96.0%) declared that the treatment of choice for hypothyroidism is levothyroxine (LT4). However, around one-third (30.3%) were also using LT4 and liothyronine (LT3) combination treatment; LT3 alone was rarely prescribed (1.7%) and none prescribed desiccated thyroid extract. The majority of respondents preferred LT4 tablets. Among alternative formulations, liquid LT4 was most commonly recommended for patients unable to take LT4 in the fasting state (26.0%) and patients with malabsorption (19.9%). Respondents considered prescribing dietary supplements (such as selenium and iodine) in hypothyroid patients with coexisting autoimmune thyroiditis (29.6%) or at the patients' request (32.2%). LT4 + LT3 combination therapy was used by 32.2% when symptoms persisted notwithstanding normal serum TSH concentration. Psychosocial factors, comorbidities and the burden of chronic disease were considered as the most likely causes for persistent symptoms. Conclusions:Apart from clinical practice recommendations, other factors influence the thyroid hormone therapy patterns. Moreover, certain areas of clinical practice were identified (the use of thyroid hormones in euthyroid subjects and the use of dietary supplements) which are not in accordance with the current evidence.

Use of Thyroid Hormones in Hypothyroid and Euthyroid Patients: A 2020 THESIS Questionnaire Survey of Members of the Swedish Endocrine Society

“…While the vast majority considered L-T4 the initial treatment of choice for hypothyroidism, 78.5% of the respondents would prescribe L-T4 + L-T3 combination therapy in the presence of persistent symptoms suggestive of hypothyroidism. This number was similar to the results of the Danish (71%) (29) but a lot higher than in the Italian (40%) (24), Romanian (35.9%) (26), and Polish (32.2%) (27) surveys. A survey by the American Thyroid Association revealed similar findings to ours, with a high percentage of physicians willing to prescribe combination therapy under specific circumstances such as persisting hypothyroid symptoms (46).…”

“…The Swedish response rate (28.2%) was slightly lower than the average of the other published national THESIS studies (33%) which has so far varied between 25.8% (Spain) (28) and 54.4% (Poland) (27). The fact that both the invitation email and the reminder were sent at the time of the peaking second wave of the covid-19 pandemic in Sweden offers a possible explanation.…”

“…Interestingly, 49.5% reported that treatment with thyroid hormone was never indicated for biochemically euthyroid patients, while almost the same proportion (47.3%) of the Swedish respondents would consider L-T4 treatment in case of high levels of TPO-antibodies and female infertility. Similar proportions of Romanian (36.4%) (26), Italian (37.3%) (24), Danish (42.1%) (29) and Spanish (48.5%) (28) and even a larger proportion of the Polish (63.4%) (27) respondents indicated that they would do likewise. Anti-TPO positivity has been associated with increased risk of miscarriage (32) and adverse obstetrical outcomes (33,34), however, recent evidence has not supported these findings (35).…”

T4+T3 Combination Therapy: An Unsolved Problem of Increasing Magnitude and Complexity

“… Relationship between the proportion of respondents willing to use thyroxine (T4)+triiodothyronine (T3) combination therapy in five European countries in patients with persistent symptoms despite a normal thyroid stimulating hormone on levothyroxine, and their annual per capita gross domestic product (GDP) in 2019 given as percentage of the world’s average. BG, Bulgaria [ 37 ]; RO, Romania [ 35 ]; PL, Poland [ 36 ]; IT, Italy [ 33 ]; DK, Denmark [ 34 ]. …”

“… TSH, thyroid stimulating hormone; LT4, levothyroxine; THESIS, Treatment of Hypothyroidism in Europe by Specialists: an International Survey. a Respondents from Denmark [ 34 ], Romania [ 35 ], Poland [ 36 ], and Bulgaria [ 37 ]; b Figures indicate range (lowest %–highest %) of respondents’ answers. …”