Clinical Thyroidology for the Public summarizes selected research studies discussed in the previous month’s issue of Clinical Thyroidology, an official publication of the American Thyroid Association. Editor-in-chief, Alan Farwell, MD, FACE

Volume 17 Issue 3

March is Medullary Thyroid Cancer Awareness Month

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Clinical Thyroidology for the Public Volume 17 Issue 3 (PDF file, 2.19 MB)



Why do so many patients receiving levothyroxine treatment for hypothyroidism have persistent symptoms?
In the majority of patients with hypothyroidism, symptoms either improve or resolve when thyroid hormone levels are returned to the normal range with thyroid hormone therapy. However, some patients might still have some symptoms despite thyroid levels being normalized. This study analyzed how many have new or persistent symptoms after the use of levothyroxine to treat hypothyroidism.
Hidalgo J et al 2023 Real practice assessment of persistent symptoms after initiation of levothyroxine. Endocr Pract. Epub 2023 Oct 30:S1530-891(23)00730-9. PMID: 37913925.

Levothyroxine treatment of subclinical hypothyroidism in pregnancy did not improve brain development testing scores in children up to 2 years of age.

Thyroid hormone plays an important role in baby’s development during pregnancy. Guidelines agree that overt hypothyroidism in pregnancy should be treated. However, it is less clear whether subclinical hypothyroidism in pregnancy should be treated because studies have not yet shown clear benefit in treating with levothyroxine. The researchers of this study aimed to evaluate potential benefit of levothyroxine treatment of overt and subclinical hypothyroidism during pregnancy on the child’s subsequent brain development.
Zhao Z et al 2023 Impact of levothyroxine therapy for maternal subclinical and overt hypothyroidism on early child neurodevelopment: A prospective cohort study. Clin Endocrinol (Oxf ). Epub 2023 Oct 20. PMID: 37859522

TSH spontaneously normalizes in many older adults with subclinical hypothyroidism

Subclinical hypothyroidism is a mild form of hypothyroidism defined by TSH levels above the normal range and normal thyroid hormone levels in the blood. However, sometimes mildly elevated TSH levels normalize after a few months. This study was done to better understand how common this normalization occurs, and which patients are more likely to normalize.
Van der Spoel E et al 2023 Incidence and determinants of spontaneous normalization of subclinical hypothyroidism in older adults. J Clin Endocrinol Metab. Epub 2023 Oct 20:dgad623. PMID: 37862463.

Unnecessary surgery is performed in the majority of indeterminate cytology thyroid nodules managed without molecular testing

About 15-20% of thyroid biopsies fall into the indeterminate category, meaning that the cells obtained by the biopsy are not entirely normal nor abnormal. One of the main advantages of molecular testing in indeterminate thyroid nodules is the possibility of reducing the use of unnecessary thyroid surgery to make a diagnosis. The authors of this study aimed to evaluate the frequency of unnecessary thyroid surgery for indeterminate nodules without the aid of molecular tests in Europe.
Mavromati M et al. Unnecessary thyroid surgery rate for suspicious nodule in the absence of molecular testing. Eur Thyroid J. 2023;12(6):e230114; doi: 10.1530/ETJ-23-0114. PMID: 37855426.

Is a lobectomy a treatment option for papillary thyroid cancer when thyroid nodules remain in the opposite lobe after surgery?

Treatment for papillary thyroid cancer with a thyroid lobectomy is becoming more common. However, a major disadvantage of lobectomy is that the remaining thyroid not removed during surgery may also contain or, at some point may form, another papillary thyroid cancer, especially if nodules are already present in this remaining thyroid tissue. The authors study the risk of papillary thyroid cancer being present, or developing over time, for people who underwent thyroid lobectomy for treatment of papillary thyroid cancer.
Pak SJ et al Contralateral low-to-intermediate suspicion nodule is not a contraindication for lobectomy in patients with papillary thyroid carcinoma. Thyroid. Epub 2023 Aug 25. PMID: 37624735

Safety of levothyroxine plus liothyronine (T4/ T3) therapy in postsurgical hypothyroidism

While the standard of care for treatment of hypothyroidism is levothyroxine, some patients have continued symptoms while on levothyroxine alone. Because of this, some have tried a combination of levothyroxine and liothyronine (T4/T3 therapy) to try to treat continue symptoms on levothyroxine alone in patients with postsurgical hypothyroidism. In this study, investigators evaluated the effects of T4/T3 therapy on heart function parameters in healthy patients that have undergone thyroidectomy for thyroid cancer.
Biondi B et al. Preliminary results of a double-blind randomized controlled trial evaluating the cardiometabolic effects of levothyroxine and liothyronine compared to levothyroxine with placebo in athyreotic low-risk thyroid cancer patients. Thyroid. 2023;33(12):1402-1413; doi: 10.1089/ thy.2023.0135. PMID: 37725587.