Thyroid Hormone Indices During Illness in Six Hypothyroid Subjects Rendered Euthyroid with Levothyroxine Therapy

Abstract

Alterations ensuing during a short stay in the hospital due to an acute illness in subjects with primary hypothyroidism rendered euthyroid with appropriate replacement therapy with Levothyroxine (LT4) are almost identical to those in normal subjects. These changes are probably secondary to altered thyroid hormone metabolism. The altered levels of thyroid hormones and TSH noted in these subjects are transient and therefore providers should refrain from initiating frequent changes in daily LT4 replacement dose during the acute illness in these subjects.

Thyroid hormones alterations during acute liver failure: possible underlying mechanisms and consequences

“…Although central acquired hypothyroidism may not be reflected by the correlations of liver dysfunction with thyroid hormones, some conclusions can be drawn from the changes in peripheral hormones. For instance, in a paper by Wadwekar and Kabadi [39] replacement with levothyroxine did not prevent thyroid hormones' decrease during acute illness, indicating that peripheral mechanisms and thyroid hormones metabolism may be the crucial element during NTIS. Therefore, hypoalbuminemia and IL-6 could represent peripheral mechanisms that could relate, but not necessarily etiologically, with NTIS during ALF.…”

Management of long-term hypothyroidism: a potential marker of quality of medicines reconciliation in the intensive care unit†

“…The measurement and interpretation of thyroid function in the critically ill is controversial and sometimes difficult due to the presence of sick euthyroid syndrome. [17] However, in this case series, there appears to be a normal inverse relationship between TSH and free T4, suggesting that TSH may be of utility to guide therapy for critical care patients who are on long-term thyroid-replacement therapy. T4 alone may be difficult to interpret in the acutely unwell patient.…”

“…There was no difference in severity of illness or hospital mortality, although it is difficult to attribute causality from a retrospective non‐randomised study. The measurement and interpretation of thyroid function in the critically ill is controversial and sometimes difficult due to the presence of sick euthyroid syndrome [17] . However, in this case series, there appears to be a normal inverse relationship between TSH and free T4, suggesting that TSH may be of utility to guide therapy for critical care patients who are on long‐term thyroid‐replacement therapy.…”

Interferências na absorção de levotiroxina e dificuldades no manuseio de pacientes com hipotireoidismo na unidade de terapia intensiva: relato de dois casos e revisão de literatura

“…In compensated primary hypothyroidism patients with LT4 replacement who are hospitalized for non-thyroidal acute disease, some natural T3, T4, rT3 and TSH changes have been observed. As shown by Wadwekar and Kabadi, (17) T3 and T4 levels drop to a trough level and an rT3 increase is seen on the 3 rd hospital day; TSH is initially reduced, but increases by the 7 th day before normalizing, probably secondary to transient thyroidal hormone metabolism changes. Additionally, recovery from critical illness is preceded by a circulating TSH level increase.…”