Hyperuricemia is associated with progression of IgA nephropathy

IgA nephropathy (IgAN) is one of the world's most common glomerular diseases. Hyperuricemia was recently defined as risk factor for chronic kidney disease. We aimed to investigate the impact of baseline serum uric acid levels on progression of IgAN.

A total of 93 patients with IgAN were screened. Demographic information and biochemical data were recorded. eGFR (using the CKD-EPI = Chronic Kidney Disease Epidemiology Collaboration formula) was used as renal function marker. Baseline and sixth month eGFR values were calculated. Progression of renal disease was defined as the difference between baseline eGFR and sixth month eGFR (delta eGFR).

Mean age of the patients was 40 ± 11 years (60% were males). Baseline mean eGFR was 77.9 ± 30.2 mL/min, and baseline mean serum uric acid was 5.65 ± 1.68 mg/dL. Importantly, baseline serum uric acid levels were found to be associated with the change in eGFR (r = 0.252, p = 0.01). In multivariate analysis (adjusted R(2) = 0.171, p = 0.031), adjusting for age, gender, baseline eGFR, blood pressure, baseline albumin concentration and ACEI and/or ARB use revealed that the baseline serum uric acid levels significantly predicted the change in eGFR.

Baseline serum uric acid concentration is directly proportional to the rate of decline in renal functions in patients with IgAN. Uric acid-lowering treatments may be beneficial for the prevention of progression of IgAN. However, randomized controlled studies are needed for this purpose.