Relationship between disease severity and thyroid function in Chinese patients with euthyroid sick syndrome

Area of Science:

• Endocrinology
• Critical Care Medicine
• Clinical Biochemistry

Background:

• Euthyroid sick syndrome (ESS) is a common condition in critically ill patients, often associated with increased mortality.
• ESS is characterized by altered thyroid hormone levels, typically lower triiodothyronine (T3) and free triiodothyronine (fT3).

Purpose of the Study:

• To investigate the relationship between disease severity and thyroid function in critically ill Chinese patients diagnosed with ESS.
• To identify potential biomarkers for disease severity within the context of ESS.

Main Methods:

• A cohort of 51 critically ill Chinese patients were assessed.
• Acute Physiology and Chronic Health Assessment II (APACHE II) scores were recorded within 24 hours of admission.
• Thyroid function tests, including TSH, fT3, fT4, tT3, tT4, and rT3, were performed on the second day. Patients were categorized into euthyroid, decreased fT3/fT4, and decreased TSH groups.

Main Results:

• All patient groups exhibited elevated APACHE II scores and reverse triiodothyronine (rT3) levels.
• A significant positive correlation was observed between APACHE II scores and rT3 levels (P=.004, r=0.379).
• No statistically significant differences in thyroid function or APACHE II scores were noted between the three patient groups (P>.05).

Conclusions:

• Critically ill Chinese patients with ESS generally present with a severe health status.
• Elevated rT3 levels are indicative of more severe disease in this patient population.
• rT3 may serve as a potential indicator of disease severity in critically ill patients with ESS.