Higher plasma uric acid levels were not associated with increased risk for acute kidney injury in patients admitted to the ICU, nor did such levels contribute to adverse clinical outcomes following renal replacement therapy for patients who had AKI, according to a published study.
“Elevations in plasma uric acid levels are common in patients with decreased kidney function from [chronic kidney disease] CKD and AKI,” Anand Srivastava, MD, MPH, of Northwestern University Feinberg School of Medicine in Chicago, and colleagues wrote. “Multiple studies have found associations between higher uric acid levels and increased risk for the development of chronic systemic illnesses, such as hypertension, cardiovascular disease and CKD. Few studies have investigated the potential role of uric acid in inciting or perpetuating AKI in critically ill patients.”
Researchers sought to determine whether higher uric acid levels were a risk factor for the development of AKI and its prognosis. To do this, a prospective observational study was conducted for two cohorts of critically ill patients. The first cohort included 208 patients without AKI who were admitted to the ICU between December 2008 and December 2016. The second cohort included 250 patients who had AKI and required renal replacement therapy. Researchers measured uric acid level upon ICU admission (median, 4.7 mg/dL) or before the initiation of renal replacement therapy (median, 11.1 mg/dL).
For the cohort without AKI, the primary outcome of the study was the development of AKI and the secondary outcome was 90-day mortality. For the cohort with AKI, the primary outcome was 60-day mortality. Secondary outcomes included 28-day mortality and recovery of kidney function through day 28.
Higher plasma uric acid levels were not associated with increased risk for acute kidney injury in patients admitted to the ICU, nor did such levels contribute to adverse clinical outcomes following renal replacement therapy for patients who had AKI.
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Of the ICU cohort, 19.2% developed AKI. While researchers found higher plasma uric acid levels were associated with incident AKI (OR = 1.78) in unadjusted analyses, the association was not significant (adjusted OR = 1.49) after adjusting for age, diabetes and severity of illness.
Of the cohort with initial AKI, 50% died within 60 days. Researchers found no statistically significant association between plasma uric acid levels and 60-day mortality, 28-day mortality or renal recovery in either the unadjusted or adjusted models.
“In this study involving two cohorts of critically ill patients, we were unable to identify an association between uric acid level and subsequent risk for AKI or its complications,” the researchers wrote. “Our results do not support the hypothesis that uric acid level predisposes to AKI in ICU patients or mortality in patients with established severe AKI.” – by Melissa J. Webb
Disclosures: Srivastava reports consulting for Horizon Pharma. Please see the study for all other authors’ relevant financial disclosures.