MO116COMPARISON OF THE CHARACTERISTICS BETWEEN UNILATERAL AND BILATERAL RENAL STONES AND THEIR ASSOCIATION WITH KIDNEY INJURY IN CHINESE POPULATION

Abstract

Abstract Background and Aims Urinary stone disease (USD) has been associated with increased risk for chronic kidney disease (CKD) and end-stage renal disease (ESRD) in Western populations. However, the comparison of metabolic disorders between unilateral and bilateral renal stones and their association with CKD have not been fully examined. It is also unclear whether there is an increased risk for kidney tubular injury makers such as N-acetyl-ß-D-glucosaminidase (NAG) and alpha-1-microglobulin (α1-MG) in different stone formers. Method We performed a cross-sectional study of 10,281 participants in rural China in 2014. All subjects underwent a renal ultrasound to detect USD; stone formers were grouped into one or two sides of USD by ultrasound exams. CKD was defined as a decreased estimated glomerular filtration rate (eGFR, <60mL/min/1.73m2) and/or albuminuria (ACR≥30mg/g). Increased urine NAG and α1-MG were defined as the values of NAG and α1-MG above the 75th percentile of the sample distribution. Results The mean age of the study population was 55.4±10.0 years; 47.1% were males. Among all participants, 4.9% (n=507) had unilateral renal stone, and 0.7% had bilateral renal stones. The proportion of CKD in non-stone formers, unilateral and bilateral renal stones were 11.0%, 19.2%, and 29.7%, respectively (p for trend<0.001). Bilateral renal stone formers tend to have a higher proportion of hypertension and diabetes. In multivariate analyses after adjustment for multiple confounders, bilateral renal stones were significantly associated with an increased risk of decreased eGFR (OR 3.38; 95% CI 1.05-10.90), albuminuria (OR 3.01; 95% CI 1.76-5.13), CKD (OR 3.18; 95% CI 1.88-5.36), increased NAG (OR 1.95; 95% CI 1.21-3.16) and α1-MG (OR 2.54; 95% CI 1.56-4.12) compared with non-stone formers. Conclusion In the present study, bilateral renal stone formers tend to have a higher proportion of metabolic disorders and are also associated with a higher risk of CKD and kidney tubular injury. Further studies are needed to confirm the increased risk for ESRD.