547. Risk factors that can predict adrenal insufficiency in fever of unknown origin

Abstract

Abstract Background Adrenal insufficiency is one of the causes of fever of unknown origin (FUO), however, it is often mistaken for an infectious disease, leading to unnecessary antibiotic use. The purpose of this study is to find out risk factors that can predict adrenal insufficiency in FUO patients so that set a target to recommend the adrenocorticotropic hormone (ACTH) stimulation test. Methods This study was conducted retrospectively in a tertiary hospital with 846 beds in South Korea. All adult inpatients (age ≥ 19 years) who have requested a consult with the department of infectious disease (ID) for FUO between 1 July, 2019 and 30 June, 2020 were included in the study. Among them, those who underwent an ACTH stimulation test and had a fever of 37.8°C or higher within 48 hours of the ACTH stimulation test were finally included in the study subjects. Results A total of 202 FUO patients were enrolled and 61 (30.1%) were finally diagnosed with adrenal insufficiency. Patient with adrenal insufficiency had higher charlson comorbidity index score than others (2.36±1.88 vs. 1.85±2.06, P=0.016). In addition, higher proportion of patients who used immunosuppressant (31.1% vs. 6.4%, P< 0.001) and/or corticosteroid (19.7% vs. 3.5%, P< 0.001) within 3 months were observed in adrenal insufficiency group. Patients with adrenal insufficiency tended to show hypotension (21.3% vs. 10.6%, P=0.044), lower white blood cell count [10^3/uL] (9.27±6.30 vs. 10.54±5.82, P=0.025), lower hemoglobin (4.38±9.96 vs. 1.70±2.10, P=0.023), lower albumin (8.25±0.94 vs. 8.49±0.60, P=0.009), and higher creatinine (1.39±1.61 vs. 1.05±1.57, P=0.044) than those without adrenal insufficiency. In a multivariate analysis, use of immunosuppressant within 3 months (OR 6.06, 95% CI 1.82–20.13, P = 0.003), use of corticosteroid within 3 months (OR 8.23, 95% CI 1.35–50.17, P = 0.022), sodium ≥ 136.7 (OR 3.43, 95% CI 1.49–7.88, P = 0.004), and calcium ≥ 8.4 (OR 0.31, 95% CI 0.14-0.71, P = 0.005) were proven to be factors that can predict adrenal insufficiency in FUO patients. Conclusion When FUO patients have a history of immunosuppressant/corticosteroid use within 3 months, and/or shows sodium ≥ 136.7, or calcium < 8.4 at initial laboratory test, performing ACTH stimulation test is recommended. Disclosures All Authors: No reported disclosures.