Serum uric acid level as a marker for mortality and acute kidney injury in patients with acute paraquat intoxication

Abstract

Background. Paraquat (PQ) is a non-selective herbicide that generates reactive oxygen species (ROS) in vivo. Uric acid emerged as a marker of oxidative stress and may enhance ROS-mediated injury in acute PQ intoxication. Therefore, we investigated the association between uric acid levels and mortality and acute kidney injury (AKI) in the present study. Methods. From January 2007 to December 2008, patients who arrived at our hospital with acute PQ intoxication (n = 513) were included in the study. Patients were divided into two groups (hyperuricaemia vs non-hyperuricaemia) based on uric acid levels. Mortality and AKI were analysed in reference to uric acid level. Results. Patient mortality was higher in the hyperuricaemia group than the non-hyperuricaemia group (68.4% vs 38.3%, P < 0.05). The incidence of AKI and kidney failure was 64% and 43.3%, respectively. Hyperuricaemia increased the risk of mortality and kidney failure to 3.7- and 3.3-fold after adjustments for age, sex and the estimated amounts of PQ ingestion. Mean serum uric acid level was higher in death group than survival group and higher in kidney failure group than non-AKI group and non-failure group. Conclusions. Baseline serum uric acid level might be a good clinical marker for patients at risk of mortality and AKI after acute PQ intoxication.