Nonthyroidal illness syndrome in acute pancreatitis patients: an 8-year cohort study

Background Nonthyroidal illness syndrome (NTIS) is common in critical illness and is associated with poor prognosis. The aim of this study was to find the prevalence, charateristics, and prognosis of NTIS and its correlation with outcomes in AP patients. Methods A retrospective review of AP patients with a diagnosis of NTIS from Jan 2012 to September 2020 was performed. The serum thyroidal hormone (TH) disturbances, as well as the demographic characteristics and clinical outcomes of the study patients, were collected and analyzed. Results Over the eight years, 183 included AP patients were diagnosed as NTIS, constituting an incidence of 64.7%. Patients with NTIS were admitted with worse condition based on the higher APACHE II score, SOFA score, Balthazar's CT score, CRP and lower albumin than euthyroid patients. Also, these patients had a longer ICU duration (3, 2-10 vs 2, 0-3, days, P = 0.039) and tended to be more likely to develop infected pancreatic necrosis (IPN) (15.3% vs 6.3%, P = 0.087) and gastrointestinal fistula (6% vs 0%, P = 0.082) than euthyroid patients. Free triiodothyronine (FT3) was found the best performance in predicting death compared by other well-recognized biomarkers. Conclusion NTIS is common in AP patients within 7 days after the onset of the disease. NTIS is associated with the worse characteristics at admission and poor outcome during the course. FT3 should be investigate as a potential biomarker in the prediction of death in AP patients.