Non-thyroidal illness syndrome predicts outcome in adult critically ill patients: a systematic review and meta-analysis

Abstract

We performed a systematic review and meta-analysis to comprehensively determine the prevalence and the prognostic role of nonthyroidal illness syndrome (NTIS) in critically ill patients. We included studies that assessed thyroid function by measuring the serum thyroid hormone level and in-hospital mortality in adult septic patients. Reviews, case reports, editorials, letters, animal studies, duplicate studies, and studies with irrelevant populations and inappropriate controls were excluded. A total of 6869 patients in 25 studies were included. The median prevalence rate of NTIS was 58% (IQR 33.2-63.7). In univariate analysis, triiodothyronine (T3) and free T3 (FT3) levels in non-survivors were relatively lower than that of survivors (8 studies for T3; standardized mean difference (SMD) 1.16; 95% confidence interval (CI), 0.41–1.92; I2 = 97%; P < 0.01). Free thyroxine (FT4) levels in non-survivors were also lower than that of survivors (12 studies; SMD 0.54; 95% CI, 0.31–0.78; I2 = 83%; P < 0.01). There were no statistically significant differences in TSH levels between non-survivors and survivors. NTIS was independently associated with increased risk of mortality in critically ill patients (OR = 2.21, 95% CI 1.64.- 2.97, I2 = 65% p < 0.01) The results favor the concept that decreased thyroid function might be associated with a worse outcome in critically ill patients. Hence, the measurement of TH could provide prognostic information on mortality in adult patients admitted to ICU.

An unusual evolution of thyroid function after therapeutic plasma exchange in Graves’ disease with cholestatic jaundice: A case report

“…[16] The concept that NTIS represents an independent predictor of poorer outcome in critically ill patients is increasingly being consensus. [17] Coronavirus disease 2019 (COVID-19), a new global pandemic with sudden outbreak, rapid spread, and alarming mortality, has drawn lots of attention worldwide. It was reported that approximately 14.47% (34/235) of COVID-19 patients were associated with NTIS to some degree and NITI was also associated with the severity of prognosis of COVID-19.…”

Impact of thyroid hormone replacement therapy on the course and functional outcome of aneurysmal subarachnoid hemorrhage

“…During acute pathologic conditions, such as sepsis, myocardial infarction, stoke or after complex surgical procedures necessitating prolonged intensive care treatment, a substantial portion of individuals (according to a recent large meta-analysis, about 58% of patients [ 43 ]) develop a condition defined as nonthyroidal illness syndrome (NTIS), also known as the euthyroid sick syndrome or the sick euthyroid syndrome. NTIS is characterized by decreased serum thyroid hormone levels without a corresponding increase in thyroid-stimulating hormone secretion.…”

“…NTIS has been significantly associated with high complication rates and poor prognoses across various diagnostic groups. A recent meta-analysis confirmed NTIS as an independent predictor of mortality in critically ill patients [ 43 ]. Reduced concentrations of thyroid hormones may be implicated in altered cardiac inotropism and chronotropism, altered vasoactive properties, diminished cognitive status with lethargy, inability to control bacterial infections, respiratory muscle weakness, reduced synthesis of pulmonary surfactant, and decrease of lung compliance resulting in the impairment of lung function [ 43 ].…”

“…Thyroid hormones are essential representatives of the endocrine system, exerting a strong impact on cellular growth, differentiation, and energetic regulation in various organ systems [ 43 ]. Normal levels of thyroid hormones are required for normal anabolism—both excess and deficiency exert an inhibitory effect [ 4 ].…”