Prognostic Significance of Serum Uric Acid in Patients Admitted to the Department of Medicine
Background. Hyperuricemia has been linked to proatherogenic processes, including increased oxidative stress and leukocyte activation, and was shown to predict adverse prognosis in heart failure, renal failure and hypertension. Recently, serum uric acid (SUA) was shown as an independent predictor of long term mortality in patients with cardiovascular (CVS) diseases. However, the prognostic significance of SUA for the short-term outcome of admitted medical patients is unknown.
Methods. Initial SUA, together with epidemiological, clinical and laboratory data were analyzed for a prospective cohort of 650 consecutive adult patients admitted to the department of internal medicine during a 3-months period.
Results. The mean, median and range of SUA on admission were 6.1±2.7, 5.6, and 1.2-24 mg/dL, respectively. Increased SUA was significantly correlated with age, male gender, co-morbidities (coronary heart disease, heart failure, hypertension, diabetes, renal failure and gout), use of diuretics, and current admission for CVS diseases, but not with current diagnosis of infection, malignancy, or inflammatory diseases, nor with CRP. However, SUA significantly correlated with mortality (7.7 vs 6 mg/L, p< 0.025), and was an independent predictor of mortality, in a multivariate regression analysis (OR 1.11, CI: 1.003-1.218, p= 0.04), with a significant difference in mortality between normal SUA (<6 mg/dL) with 5% mortality, and high SUA (>12 mg/dL), with 27% mortality.
Conclusions. Initial SUA is an independent predictor of mortality in admitted medical patients. Whether significant asymptomatic hyperuricemia should be treated, remains to be determined in further studies.