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

Abstract

Key Points Kidney stones are common in patients with autosomal dominant polycystic kidney disease compared with matched controls with CKD.The increase in imaging seen in patients with autosomal dominant polycystic kidney disease correlates with the kidney stone burden in these patients. Background Patients with autosomal dominant polycystic kidney disease (ADPKD) may have more imaging studies than patients with other forms of CKD. We characterized the imaging burden of patients with ADPKD relative to a CKD population to determine which factors lead to increased imaging in patients with ADPKD. 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. Eight hundred seven patients with ADPKD were matched to 4035 CKD controls on the basis of 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 effect of kidney stone diagnosis was further evaluated. Chi-square and t tests were used to evaluate demographic variables, and Kruskal Wallis 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 magnetic resonance imagings (P = 0.02) compared with controls. In patients with preserved renal function (eGFR >60 ml/min per 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 patients with ADPKD, pyelonephritis; cyst complications; lower eGFR; diabetes; coronary artery disease; kidney stones; lower body mass index; and being male, Black, and younger increased the likelihood of having more imaging studies. Conclusions The higher prevalence of abdominal imaging studies in patients with ADPKD correlated with the increased incidence of kidney stones observed in this population.