Low Serum Uric Acid as an Independent Predictor of Mortality and Poor Prognosis: A Retrospective Cohort Study

Background: While hyperuricemia has been widely studied in cardiovascular and renal diseases, the prognostic impact of low serum uric acid (UA) remains unclear. Emerging evidence suggests hypouricemia may be linked to increased mortality and adverse outcomes. This study aimed to assess the relationship between low UA levels and poor outcomes, including mortality and intensive care unit (ICU) admission, in hospitalized patients. Methods: This retrospective cohort study included 1679 hospitalized patients (744 females, 935 males) from the Internal Medicine Clinic. Patients were categorized into normal and low UA groups based on sex-specific thresholds (male: <3.4 mg/dL, female: <2.4 mg/dL). The primary outcome was in-hospital mortality; secondary outcomes were ICU admission and discharge status. Logistic regression models adjusted for age, chronic kidney disease (CKD), hypertension (HT), and coronary artery disease (CAD). A Prognostic Uric Acid Score (PUAS) was developed using significant predictors and evaluated by Receiver Operating Characteristic (ROC) analysis. Results: Low UA levels were significantly associated with higher ICU admission and mortality (p = 0.012). Multivariate analysis identified age (OR: 1.032), low UA (OR: 2.285), and CKD (OR: 1.571) as predictors of poor prognosis. PUAS showed moderate performance (AUC: 0.664), with a cutoff score of 3.5 optimizing sensitivity and specificity. Conclusions: Low UA levels independently predict mortality and poor prognosis in hospitalized patients. These findings support routine UA monitoring and suggest hypouricemia may be a useful prognostic biomarker. Further studies are needed to understand clinical implications and guide UA-targeted interventions.