Both high and low serum uric acid (SUA) levels are associated with an increased risk for chronic kidney disease (CKD) in middle-aged men and women, study data presented at the virtual European Renal Association-European Dialysis and Transplant Association 58th congress suggest.
The study included 138,511 individuals with a mean age of 44.1 years who did not have kidney disease or cardiovascular disease at baseline. During a mean follow-up of about 4.7 years, CKD developed in 12,589 individuals.
In adjusted analyses, men with SUA levels less than 4.0 mg/dL had a significant 13% increased risk for CKD compared with men who had levels of 4.0-4.9 mg/dL, investigator Shingo Nakayama, MD, of Tohoku Medical and Pharmaceutical University in Sendai, Japan. Men with levels of 10.0-10.9 and 11.0 mg/dL or higher had significant 2.0- and 3.7-fold increased risks for CKD, respectively.
Among women, those with SUA levels less than 4.0 mg/dL had a significant 8% increased risk for CKD compared with those who had a level of 4.0-4.9 mg/dL, whereas women with levels of 8.0-8.9 and 9.0 mg/dL or higher had significant 2.4- and 3.2-fold increased risks, respectively.
The investigators defined CKD as an estimated glomerular filtration rate less than 60 mL/min/1.73 m2, presence of proteinuria, or both.
Noting that uric acid is one of the most important antioxidants in the human body, Dr Nakayama and colleagues postulated that low levels may increase the risk for CKD through decreased antioxidant activity.
High SUA is known to cause renal injury due to intraluminal deposition of uric acid crystals in the renal collecting duct, the authors pointed out. “Hyperuricemia also may induce endothelial dysfunction, activation of the renin-angiotensin system, and induction of inflammation and stimulation of vascular smooth muscle cell proliferation by induction of cyclooxygenase-2.”
Nakayama S, Satoh M, Murakami T, et al. Association between serum uric acid level and chronic kidney disease incidence stratified by sex in middle-aged adults. Presented at: ERA-EDTA 2021 held June 5-8. Abstract MO491.