Predictive value of thyroid hormone assessment in septic patients in comparison with C-reactive protein

Introduction: Thyroid dysfunction is associated with mortality in critically ill patients. We investigated the predictive value of the thyroid hormone compared to CRP in septic patients.Methods: 80 patients were included in a prospective, randomized study done in the critical care department.Results: FT3, FT4, and TSH levels on the fifth day were below the normal range in 61.3%, 31.2%, and 23.8% patients respectively. There was a significant decrease in the FT3 level on admission compared to the fifth day (p < 0.001). By comparison of thyroid hormone levels in patients with sepsis, severe sepsis and septic shock; we found the mean level of FT3 was lower in patients with septic shock (1.3 ± 0.4 pg/ml) and severe sepsis (1.7 ± 0.2 pg/ml) as compared to patients with sepsis (2.4 ± 1.2 pg/ml). The mean FT3 level increased in survivors (2.9 ± 1.03 pg/ml) compared to non survivors (1.9 ± 0.89 pg/ml) (p < 0.001). Correlation of FT3 on the 5th day to CRP (r = −0.332, p = 0.039), FT3 on 5th day to IL-6 (r = −0.339, p = 0.035) in non survivors. Correlation of FT3 on the 5th day to APACHE II (r = −0.359, p = 0.025) and SOFA score (r = −0.427, p = 0.007). ROC curves indicated that FT3 on the 5th day had the greatest power for predicting ICU mortality (sensitivity 87.2% and specificity 73.2%). CRP (sensitivity 100% and specificity 92.7%) is a better tool than IL-6 (sensitivity 92.3% and specificity 80.5%) in predicting mortality in sepsis.Conclusion: FT3 levels were negatively correlated to CRP and IL-6 levels as well as APACHE II, SOFA scores. FT3 may be used as a marker of disease severity and a predictor of mortality