Effect of the presence of remnant thyroid tissue on the serum thyroid hormone balance in thyroidectomized patients

M, Ito; Miyauchi, Akira; Kang, Shino; Hisakado, Mako; Yoshioka, Waka; Ide, Akane; Kudo, Takumi; Nishihara, Eijun; Kihara, Minoru; Ito, Yasuhiro; Kobayashi, Kaoru; Miya, Akihiro; Fukata, Shuji; Nakamura, Hirotoshi; Amino, Nobuyuki

doi:10.1530/eje-15-0138

Cited by 39 publications

(45 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The patients with strongly suppressed TSH levels had significantly higher serum fT3 levels. Thus, the results obtained for the present patients who underwent a total thyroidectomy during LT4 therapy were consistent with the authors' previous studies (2,12) and with those of Gullo et al . (4), Hoermann et al .…”

Section: Discussionsupporting

confidence: 94%

Biochemical Markers Reflecting Thyroid Function in Athyreotic Patients on Levothyroxine Monotherapy

Miyauchi

Hisakado

et al. 2017

Thyroid

Self Cite

View full text Add to dashboard Cite

Background: Some investigators reported that among athyreotic patients on levothyroxine (LT4) monotherapy following total thyroidectomy, the patients with normal serum thyrotropin (TSH) levels had mildly low serum free triiodothyronine (fT3) levels, whereas the patients with mildly suppressed serum TSH levels had normal serum fT3 levels, and the patients with strongly suppressed serum TSH had elevated serum fT3 levels. The objective of the present study was to clarify which of these three patient groups is closer to their preoperative euthyroid condition.Methods: A total of 133 consecutive euthyroid patients with papillary thyroid carcinoma who underwent a total thyroidectomy were prospectively studied. The patients' serum levels of lipoproteins, sex hormone-binding globulin, and bone metabolic markers measured preoperatively were compared with the levels measured at postoperative LT4 therapy 12 months after the thyroidectomy.Results: The postoperative serum sex hormone-binding globulin (p < 0.001) and bone alkaline phosphatase (p < 0.01) levels were significantly increased in the patients with strongly suppressed TSH levels (≤0.03 μIU/mL). The postoperative serum low-density lipoprotein cholesterol levels were significantly increased (p < 0.05), and the serum tartrate-resistant acid phosphatase-5b levels were significantly decreased (p < 0.05) in the patients with normal TSH (0.3 < TSH ≤5 μIU/mL). In the patients with mildly suppressed TSH (0.03 < TSH ≤0.3 μIU/mL) and fT3 levels equivalent to their preoperative levels, all metabolic markers remained equivalent to their preoperative levels.Conclusions: The serum biochemical markers of thyroid function in patients on LT4 following total thyroidectomy suggest that the patients with mildly suppressed TSH levels were closest to euthyroid, whereas those with normal TSH levels were mildly hypothyroid and those with strongly suppressed TSH levels were mildly hyperthyroid. These data may provide novel information on the management of patients following total thyroidectomy for thyroid cancer or benign thyroid disease.

show abstract

Section: Discussionsupporting

confidence: 94%

Biochemical Markers Reflecting Thyroid Function in Athyreotic Patients on Levothyroxine Monotherapy

Miyauchi

Hisakado

et al. 2017

Thyroid

Self Cite

View full text Add to dashboard Cite

show abstract

“…The present results extend our previous findings in LT 4 -treated patients to more physiological conditions [4]. This may have important implications as the relationship between TSH and thyroid hormones is fundamentally different in treated patients and in euthyroid individuals [4,9,16,17,18,19,20]. The present findings suggest an additional concept of relational stability.…”

Section: Discussionsupporting

confidence: 87%

Relational Stability of Thyroid Hormones in Euthyroid Subjects and Patients with Autoimmune Thyroid Disease

Hoermann¹,

Midgley²,

Larisch³

et al. 2016

Eur Thyroid J

View full text Add to dashboard Cite

Background/Aim: Operating far from its equilibrium resting point, the thyroid gland requires stimulation via feedback-controlled pituitary thyrotropin (TSH) secretion to maintain adequate hormone supply. We explored and defined variations in the expression of control mechanisms and physiological responses across the euthyroid reference range. Methods: We analyzed the relational equilibria between thyroid parameters defining thyroid production and thyroid conversion in a group of 271 thyroid-healthy subjects and 86 untreated patients with thyroid autoimmune disease. Results: In the euthyroid controls, the FT₃-FT₄ (free triiodothyronine-free thyroxine) ratio was strongly associated with the FT₄-TSH ratio (tau = -0.22, p < 0.001, even after correcting for spurious correlation), linking T₄ to T₃ conversion with TSH-standardized T₄ production. Using a homeostatic model, we estimated both global deiodinase activity and maximum thyroid capacity. Both parameters were nonlinearly and inversely associated, trending in opposite directions across the euthyroid reference range. Within the panel of controls, the subgroup with a relatively lower thyroid capacity (<2.5 pmol/s) displayed lower FT₄ levels, but maintained FT₃ at the same concentrations as patients with higher functional and anatomical capacity. The relationships were preserved when extended to the subclinical range in the diseased sample. Conclusion: The euthyroid panel does not follow a homogeneous pattern to produce random variation among thyroid hormones and TSH, but forms a heterogeneous group that progressively displays distinctly different levels of homeostatic control across the euthyroid range. This suggests a concept of relational stability with implications for definition of euthyroidism and disease classification.

show abstract

“…This becomes clinically relevant, because the set point has been demonstrated to differ in the same patient from health to disease, e.g., before and after thyroidectomy (27, 88, 93, 94). Hence, the equilibria in individuals appropriate for their healthy state do not remain unaltered and cannot act as equivalent targets for their diseased state.…”

Section: Interrelational Measures and Emerging New Concepts Of Thyroimentioning

confidence: 99%

Relational Stability in the Expression of Normality, Variation, and Control of Thyroid Function

et al. 2016

View full text Add to dashboard Cite

Thyroid hormone concentrations only become sufficient to maintain a euthyroid state through appropriate stimulation by pituitary thyroid-stimulating hormone (TSH). In such a dynamic system under constant high pressure, guarding against overstimulation becomes vital. Therefore, several defensive mechanisms protect against accidental overstimulation, such as plasma protein binding, conversion of T4 into the more active T3, active transmembrane transport, counter-regulatory activities of reverse T3 and thyronamines, and negative hypothalamic–pituitary–thyroid feedback control of TSH. TSH has gained a dominant but misguided role in interpreting thyroid function testing in assuming that its exceptional sensitivity thereby translates into superior diagnostic performance. However, TSH-dependent thyroid disease classification is heavily influenced by statistical analytic techniques such as uni- or multivariate-defined normality. This demands a separation of its conjoint roles as a sensitive screening test and accurate diagnostic tool. Homeostatic equilibria (set points) in healthy subjects are less variable and do not follow a pattern of random variation, rather indicating signs of early and progressive homeostatic control across the euthyroid range. In the event of imminent thyroid failure with a reduced FT4 output per unit TSH, conversion efficiency increases in order to maintain FT3 stability. In such situations, T3 stability takes priority over set point maintenance. This suggests a concept of relational stability. These findings have important implications for both TSH reference limits and treatment targets for patients on levothyroxine. The use of archival markers is proposed to facilitate the homeostatic interpretation of all parameters.

show abstract

Effect of the presence of remnant thyroid tissue on the serum thyroid hormone balance in thyroidectomized patients

Cited by 39 publications

References 32 publications

Biochemical Markers Reflecting Thyroid Function in Athyreotic Patients on Levothyroxine Monotherapy

Biochemical Markers Reflecting Thyroid Function in Athyreotic Patients on Levothyroxine Monotherapy

Relational Stability of Thyroid Hormones in Euthyroid Subjects and Patients with Autoimmune Thyroid Disease

Relational Stability in the Expression of Normality, Variation, and Control of Thyroid Function

Contact Info

Product

Resources

About