Skip to main content

Effect of N-acetylcysteine on serum thyroid hormone levels in nonthyroidal illness syndrome

Introduction

Nonthyroidal illness syndrome (NTIS) refers to changes in thyroid hormone levels affecting up to 75% of critically ill patients. Cytokines and oxidative stress have been implicated as causative factors, as they derange deiodinase reactions. Interestingly, the addition of N-acetylcysteine (NAC) in a cell model prevented the effect of IL-6 on deiodinases, probably through a mechanism that restores catalytic activity of the enzyme [1]. NTIS is an independent marker of poor prognosis during myocardial infarction (MI) [2]. Here, we investigate whether NAC administration would prevent the decrease in serum thyroid hormone levels observed in patients with MI.

Methods

This was a randomized, multicenter clinical trial. Patients with MI within 12 hours of evolution who underwent primary percutaneous coronary intervention were eligible. Patients were randomized to receive NAC (1,200 mg, intravenous, every 12 hours) or placebo for 48 hours. Baseline characteristics, clinical history and serial blood samples for measurements of thyroid hormones were collected. Primary outcome was the variation of serum T3 levels. Statistical tests used included χ2 test analyses for proportions and Student's t test analyses for means.

Results

Sixty-seven patients were included. There were no differences between groups with respect to baseline clinical characteristics. When compared with baseline, the levels of serum T3 decreased in the placebo group at 12 hours of follow-up (98.6 vs. 86.8 μg/dl, P = 0.001), as expected for the NTIS. Interestingly, the T3 descendent curve was attenuated in patients who were randomized to NAC (100.4 vs. 96.9 μg/ dl, P = 0.396) (Figure 1). Similar serum T3 levels were observed in both groups at 48 hours and on the 5th day. Serum TSH levels were virtually identical between the two groups. In the comparison between groups, the mean T3 serum levels were higher in the NAC treatment group at 12 hours than in the placebo group (P = 0.045).

Figure 1
figure1

abstract

Conclusion

This is the first clinical trial designed to investigate the effect of NAC on NTIS in humans. We show that patients with myocardium infarction who received NAC treatment on admission had attenuation of the degree of T3 level decrease compared with those who received placebo. As expected, NAC did not interfere with central feedback, as TSH levels presented a similar rise in both groups, probably as a marker of recovery from acute illness. However, whether this effect is able to prevent mortality or to ameliorate patient outcome remains to be elucidated.

References

  1. 1.

    Wajner SM, Goemann IM, Bueno AL, Larsen PR, Maia AL: J Clin Invest. 2011, 121: 1834-1845. 10.1172/JCI44678

    PubMed Central  CAS  Article  PubMed  Google Scholar 

  2. 2.

    Wang F, Pan W, Wang S, Pan S, Ge J: Crit Care. 2012, 16: R11. 10.1186/cc11151

    PubMed Central  Article  PubMed  Google Scholar 

Download references

Acknowledgements

Clinical Trials: NCT01501110.

Author information

Affiliations

Authors

Corresponding author

Correspondence to J Vidart.

Rights and permissions

This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and Permissions

About this article

Cite this article

Vidart, J., Wajner, S., Schaan, B. et al. Effect of N-acetylcysteine on serum thyroid hormone levels in nonthyroidal illness syndrome. Crit Care 17, P37 (2013). https://doi.org/10.1186/cc12653

Download citation

Keywords

  • Percutaneous Coronary Intervention
  • Primary Percutaneous Coronary Intervention
  • Multicenter Clinical Trial
  • Thyroid Hormone Level
  • Serial Blood Sample