Effects of N-acetylcysteine on Low T3 Syndrome

Acute Myocardial Infarction Clinical Trial

Official title: Evaluation of the Effects of N-acetylcysteine on Thyroid Hormone Levels in the Low T3 Syndrome

Status Completed

Clinical Trial Summary

The propose of this study is to determine whether N-acetylcysteine is effective in reversing the changes in thyroid hormones seen in critical illness, known as the low T3 syndrome.

Clinical Trial Description

The low T3 syndrome or nonthyroidal illness is characterized by low levels of T3, normal or high normal levels of rT3, low or normal levels of T4 and inappropriately normal or low levels of TSH. These changes affect up to 75% of patients and have prognostic implications.

Interleukin-6 (IL6) seems to have a causative role in the pathogenesis of nonthyroidal illness. There is evidence that the reduction in serum T3 was inversely associated with serum IL-6, while the rT3 have a positive association. The mechanism of action of cytokines on the metabolism of thyroid hormones has not been determined and the potential role of cytokines on the deiodases has been the focus of research.

In a cell culture model study, IL-6 was able to suppress the conversion of T4 to T3 by deiodases type 1 and 2 and stimulate the inactivation of T3 by deiodase type 3, a situation similar to nonthyroidal illness. The use of N-acetylcysteine prevented this alterations, been consistent with the hypothesis that IL6 inhibits the function of the deiodases by increasing the oxygen reactive species and by consuming gluthathione or some gluthathione dependent cofactor.

Considering the absence of human studies evaluating the use of N-acetylcysteine in nonthyroidal illness, the aim of this study is to investigate whether NAC has in vivo effect on changes of thyroid hormones. ;

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Subject), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Acute Myocardial Infarction
• Coronary Artery Disease
• Euthyroid Sick Syndrome
• Euthyroid Sick Syndromes
• Heart Diseases
• Ischemic Heart Disease
• Myocardial Infarction
• Myocardial Ischemia
• Syndrome

• NCT number: NCT01501110
• Study type: Interventional
• Source: Federal University of Rio Grande do Sul
• Status: Completed
• Phase: Phase 4
• Start date: November 2011
• Completion date: November 2013