Kohagura K, et al. - The clinicians undertook this study to explore the effect of hyperuricemia (HU) on the association between blood pressure (BP) and proteinuria in patients with chronic kidney disease (CKD). They explained that HU potentiates susceptibility to hypertensive glomerular damage via disrupted autoregulation in patients with non-nephrotic CKD.

Methods

• This study included 109 patients with non-nephrotic CKD (55 men and 54 females) who underwent renal biopsy.
• Via arteriole grading, arteriolar hyalinosis was semiquantitatively evaluated.
• Association between BP and urine protein level was examined based on the presence of HU, which was defined as the use of urate-lowering drugs or serum uric acid levels of ≥7 and ≥5 mg/dl in males and females, respectively.

Results

• In the evaluation, median age, BP, estimated glomerular filtration rate, and urine protein level were 38 years, 124/74 mmHg, 82 ml/min/1.73 m ², and 0.8 g/gCr, respectively.
• In patients with HU (n = 59), log-transformed systolic BP was significantly associated with log-transformed urine protein level (r = 0.49, p < 0.0001).
• This was not reported in patients without HU (n = 50).
• Multiple regression analysis (R² = 0.21, p = 0.0001) revealed that the interaction between HU and log-transformed systolic BP with respect to proteinuria was significantly correlated with log-transformed urine protein level (β = 7.0, p= 0.03), independent of age, sex, and potential confounding factors.
• However, this statistical significance was completely eliminated after adjustment for the arteriolar hyalinosis index.