Median-lower normal levels of serum thyroxine are associated with low triiodothyronine levels and body temperature in patients with central hypothyroidism

Hirata, Yasuhiko; Fukuoka, Hidenori; Iguchi, Genzo; Iwahashi, Yasuyuki; Fujita, Yasunori; Hari, Yusuke; Iga, M; Nakajima, Shinsuke; Nishimoto, Yuki; Mukai, Miki; Hirota, Yushi; Sakaguchi, Kazuhiko; Ogawa, Wataru; Takahashi, Yutaka

doi:10.1530/eje-15-0130

Cited by 10 publications

(5 citation statements)

References 35 publications

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“…In central hypothyroidism and total thyroidectomy, patients with medianlower normal levels of serum FT 4 exhibited lower serum FT 3 levels and lower body temperature. These results support the association with body temperature and serum T 3 levels to T 4 in patients with central hypothyroidism and total thyroidectomy [16]. Athyreotic patients who have undergone a total thyroidectomy live in a chronic state of abnormal thyroid hormone status for the remainder of their lives.…”

Section: Discussionsupporting

confidence: 81%

Thyroid function related symptoms during levothyroxine monotherapy in athyreotic patients

Miyauchi

Hisakado

et al. 2019

Endocr J

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Previous reports by us and other investigators showed that among athyreotic patients on levothyroxine (LT 4) following total thyroidectomy patients with normal serum thyroid-stimulating hormone (TSH) levels had mildly low serum free triiodothyronine (FT 3) levels, whereas patients with mildly suppressed serum TSH levels had normal serum FT 3 levels and patients with strongly suppressed serum TSH had elevated serum FT 3 levels. The objective of this study was to clarify which of these three patient groups are closer to their preoperative euthyroid condition based on reported subjective symptoms. We prospectively studied 148 consecutive euthyroid patients with papillary thyroid carcinoma who underwent a total thyroidectomy. Symptoms reflecting thyroid function documented preoperatively and following 12 months of LT 4 after thyroidectomy were compared. In 65 patients with strongly suppressed TSH levels significant changes in symptoms with tendencies towards thyrotoxicosis were seen with regards to heat and cold tolerance (p < 0.01), bowel movements (p < 0.05), and hand tremors (p < 0.05). In 33 patients with normal TSH levels, significant changes in symptoms with tendencies towards hypothyroidism were seen with regards to heat and cold tolerance (p < 0.05) and activity (p < 0.05). Lastly, in 50 patients with mildly suppressed TSH levels and FT 3 levels equivalent to preoperative levels, all symptom items remained equivalent to their preoperative levels. Symptoms reflecting thyroid function in patients on LT 4 following total thyroidectomy suggested that patients with mildly suppressed TSH levels were closest to a euthyroid status. These data provide useful findings regarding the management of patients following total thyroidectomy.

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Section: Discussionsupporting

confidence: 81%

Thyroid function related symptoms during levothyroxine monotherapy in athyreotic patients

Miyauchi

Hisakado

et al. 2019

Endocr J

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“…Hirata et al studied patients with central hypothyroidism and athyreotic patients who underwent total thyroidectomy. In central hypothyroidism and total thyroidectomy patients, those with median-lower to normal levels of serum fT4 exhibited lower serum fT3 levels and lower body temperature (25). These data support an important role of serum fT3 levels in the manifestation of symptoms, which has implications for clinical decision making on dose adequacy, particularly in athyreotic patients.…”

Section: Discussionmentioning

confidence: 99%

Serum Thyroid Hormone Balance in Levothyroxine Monotherapy-Treated Patients with Atrophic Thyroid After Radioiodine Treatment for Graves' Disease

Kawasaki

Danno

et al. 2019

Thyroid

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Background: Some studies reported that among athyreotic patients on levothyroxine (LT4) after total thyroidectomy, patients with normal serum thyrotropin (TSH) levels had mildly low serum free triiodothyronine (fT3) levels, whereas patients with mildly suppressed serum TSH levels had normal serum fT3 levels. The reduction of the thyroid volume (TV) after radioiodine treatment for Graves' disease is well known; however, a few studies evaluated thyroidal function including serum triiodothyronine (T3) levels of hypothyroid patients on LT4 after radioiodine treatment in detail.Methods: We retrospectively studied 446 patients treated with LT4 for radioiodine-induced hypothyroidism and who had undergone ultrasonography. We compared serum fT4 and fT3 levels in hypothyroid patients on LT4 who presented an atrophic thyroid change after radioiodine treatment, with those in the euthyroid matched control group with intact thyroids. We also stratified patients with normal TSH levels according to TV and evaluated serum thyroid hormone levels.Results: In 356 of 446 (80%) patients, TV was lower than the lower limit of the 95% reference range of controls. Excluding 43 patients with high serum TSH levels, we assessed thyroid function test results in 313 patients with atrophic thyroid glands. Of these cases, eight patients with strongly suppressed TSH levels had serum fT3 levels that were significantly higher than those in controls (p < 0.001). Overall, 27 patients with mildly suppressed TSH levels had serum fT3 levels equivalent to those in controls (p = 0.386), whereas 278 patients with normal TSH levels had serum fT3 levels that were significantly lower than those in controls (p < 0.001). We also assessed fT3 levels relative to TV in 326 patients with normal TSH levels. Of these cases, in 267 patients with TV less than 5 mL and in 46 patients with TV between 5 and 10 mL, serum fT3 levels were significantly lower than those in controls (p < 0.001). In 13 patients with TV more than 10 mL, serum fT3 levels were equivalent to those in controls (p = 0.844).Conclusions: Serum thyroid hormone balance in most patients on LT4 after radioiodine treatment for Graves' disease was similar to that in athyreotic patients on LT4. Mild TSH suppression with LT4 is needed to achieve normal fT3 levels in such patients.

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“…The determination of FT4 acquires a more relevant role in the evaluation of replacement therapy than in primary hypothyroidism. Several groups [49,56,58,60] reported that concentrations of FT4 in the upper part of normal range might represent an appropriate target in most treated CeH patients (Recommendation 26).…”

Section: How Should Ceh Patients Be Managed and Treated?mentioning

confidence: 99%

2018 European Thyroid Association (ETA) Guidelines on the Diagnosis and Management of Central Hypothyroidism

Persani¹,

Brabant

Dattani³

et al. 2018

Eur Thyroid J

160

145

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Objectives: Central hypothyroidism (CeH) is a rare form of hypothyroidism characterized by insufficient thyroid stimulation due to disturbed pituitary and/or hypothalamic functioning. Due to its origin and the whole clinical context, CeH represents a challenging condition in clinical practice as it is characterized by suboptimal accuracy of clinical and biochemical parameters for diagnosis and management. Since no expert consensus or guidance for this condition is currently available, a task force of experts received the commitment from the European Thyroid Association (ETA) to prepare this document based on the principles of clinical evidence. Study Design: The task force started to work in February 2017 and after a careful selection of appropriate references (cohort studies, case reports, expert opinions), a preliminary presentation and live discussion during the 2017 ETA meeting, and several revision rounds, has prepared a list of recommendations to support the diagnosis and management of patients with CeH. Results: Due to the particular challenges of this rare condition in the different ages, the target users of this guidance are pediatric and adult endocrinologists. Experts agreed on the need to recognize and treat overt CeH at all ages, whereas treatment of milder forms may be dispensable in the elderly (> 75 years). Conclusions: Despite the lack of randomized controlled clinical trials, the experts provide 34 recommendations supported by variable levels of strength that should improve the quality of life of the affected patients and reduce the metabolic and hormonal consequences of inadequate management.

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Median-lower normal levels of serum thyroxine are associated with low triiodothyronine levels and body temperature in patients with central hypothyroidism

Cited by 10 publications

References 35 publications

Thyroid function related symptoms during levothyroxine monotherapy in athyreotic patients

Thyroid function related symptoms during levothyroxine monotherapy in athyreotic patients

Serum Thyroid Hormone Balance in Levothyroxine Monotherapy-Treated Patients with Atrophic Thyroid After Radioiodine Treatment for Graves' Disease

2018 European Thyroid Association (ETA) Guidelines on the Diagnosis and Management of Central Hypothyroidism

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