Bilateral renal stones up risk of CKD

Bilateral renal stones are a risk factor for chronic kidney disease (CKD) and higher levels of kidney tubular injury markers, suggests a study.

This cross-sectional study included 10,281 participants in rural China in 2014, all of whom underwent renal ultrasound to detect urinary stone disease. The researchers divided stone formers into groups with unilateral or bilateral renal stones via ultrasound examinations.

CKD was defined as a decreased estimated glomerular filtration rate (eGFR, <60 mL/minute/1.73 m²) and/or albuminuria (albumin-to-creatinine ratio ≥30 mg/gm). Increased N-acetyl-ß-D-glucosaminidase (NAG) and alpha-1-microglobulin (α1-MG) were defined as their values above the 75th percentile of the sample distribution.

Of the participants, 507 (4.9 percent) had unilateral renal stones and 75 (0.7 percent) bilateral renal stones. CKD was detected in 11.0 percent, 19.2 percent, and 29.7 percent of nonstone, unilateral, and bilateral renal stone formers, respectively (p_trend<0.001). Those with bilateral renal stones showed the highest number of metabolic components, such as elevated blood pressure and serum glucose.

Multivariate analyses after adjustment for multiple confounders revealed that bilateral renal stones correlated significantly with a higher risk of decreased eGFR (odds ratio [OR], 3.38, 95 percent confidence interval [CI], 1.05‒10.90), albuminuria (OR, 3.01, 95 percent CI, 1.76‒5.13), CKD (OR, 3.18, 95 percent CI, 1.88‒5.36), increased urine NAG-to-creatinine ratio (OR, 1.95, 95 percent CI, 1.21‒3.16), and α1-MG-to-creatinine ratio levels (OR, 2.54, 95 percent CI, 1.56–4.12) than lack of stones.

“Clinicians should pay attention to metabolic disorders in bilateral renal stone formers,” the researchers said.

In Western populations, urinary stone disease has been found to increase the risk of CKD and end-stage renal disease.