An association between uric acid levels and renal arteriolopathy in chronic kidney disease: a biopsy-based study.

Uric acid (UA) can induce renal arteriolopathy in animal models. Whether there is an association between UA and renal arteriolopathy in patients with chronic kidney disease (CKD) is unknown. Here, we examined the cross-sectional association of serum UA levels with renal arteriolar hyalinosis and wall thickening. Arteriolar parameters were assessed by semiquantitative grading (max: grade 3) of arterioles in 167 patients with CKD (mean age, 42.4 years; 86 men and 81 women) who underwent renal biopsy. The mean serum UA level was 6.4 mg dl(-1). We observed hyalinosis in 94 patients (56%) and wall thickening in 119 patients (71%). As the UA level tertile increased, the proportion of higher-grade (grade 2 and 3) hyalinosis and wall thickening increased (hyalinosis, P<0.0001 and wall thickening, P=0.0002, for trend). Multiple logistic analysis adjusted for age ≥40 years, sex, hypertension status, diabetes mellitus status and estimated glomerular filtration rate <60 ml min(-1) per 1.73 m(2) showed that hyperuricemia (UA ≥7 mg dl(-1)) was significantly associated with a higher risk of hyalinosis (adjusted odds ratio: 3.13; 95% confidence interval: 1.23-7.94; P=0.02) and higher-grade (equal to or higher than the mean value) wall thickening (adjusted odds ratio: 2.66; 95% confidence interval: 1.11-6.38; P=0.03). Hence, these results suggest that hyperuricemia may be related to renal arteriolar damage in patients with CKD.