Kidney Stones Account for Increased Imaging Studies in Autosomal Dominant Polycystic Kidney Disease

Abstract

Introduction: ADPKD patients may have more imaging studies than patients with other forms of chronic kidney disease (CKD). We characterized the imaging burden of ADPKD patients relative to a CKD population to determine which factors lead to increased imaging in ADPKD patients. Methods: We retrospectively reviewed patients seen at Yale Nephrology between January 2012 and January 2021. We collected demographic, clinical, and imaging data through automated query and manual chart review. 807 ADPKD patients were matched to 4,035 CKD controls based on criteria of sex, race, ethnicity, CKD stage, hypertension, and diabetes, but not age. The number of abdominal imaging studies were compared between ADPKD and CKD groups, and the impact of kidney stone diagnosis was further evaluated. Chi-squared and t-tests were used to evaluate demographic variables, and Kruskal Wallace and negative binomial regression models were used to evaluate differences between abdominal imaging studies. Results: Patients with ADPKD had a greater number of total abdominal imaging studies (p<0.0001), ultrasounds (p<0.0001), and MRIs (p=0.02) compared to controls. In patients with preserved renal function (eGFR > 60 ml/min/m2), these differences persisted. Kidney stones were significantly more common among patients with ADPKD (p<0.0001). In multivariable assessment of imaging study counts using a negative binomial model controlling for kidney stones, ADPKD was no longer a significant predictor. In ADPKD patients, pyelonephritis, cyst complications, lower eGFR, diabetes, coronary artery disease, kidney stones, lower BMI, and being male, Black and younger increased the likelihood of having more imaging studies. Conclusion: The higher prevalence of abdominal imaging studies in ADPKD patients correlated with the increased incidence of kidney stones observed in this population.