Vascular calcifications are associated with nephrolithiasis. While studies have demonstrated correlations with vascular disease and calcium stones in kidney stone formers (KSF), an etiologic link has remained elusive. As a non-contrast CT scan (NCCT) is typically part of a stone evaluation, our objective was to evaluate the association of NCCT-based assessment of abdominal aortic calcifications (AAC) with 24-hour urine parameters and stone composition.
97 KSF were included with CT imaging and 24-hour urine studies. For each patient, semi-automated CT software was utilized to provide an AAC Agaston score from the celiac axis to the aortic bifurcation. Univariate analysis was performed to compare patients with or without AAC. Multivariate logistic regression was performed to assess for variables associated with 24-hour urine parameters and stone composition.
Presence of AAC was associated with hypertension, diabetes, peripheral vascular disease and coronary artery disease. Patient with any AAC showed lower 24-hour urine citrate (399 vs 593 mg/day, p<0.001) and lower 24-hour urine pH (5.862 vs 6.328, p=0.003). When controlling for age, system comorbidities, the presence of AAC was associated with low urine pH <6 (OR 2.86, p=0.032) and hypocitraturia <320 mg/d (OR 4.37, p=0.005). Receiver operating characteristic curve showed increasing AAC was associated with low urine pH (AUC 0.683, p=0.002) and uric acid stone formation (AUC 0.698, p=0.045).
NCCT-based diagnosis of AAC is associated with low urine pH, hypocitraturia and uric acid stone formation. The presence of AAC could be an additional prognosticator for the utility of alkalinization therapy.
Journal of endourology. 2017 Jun 12 [Epub ahead of print]
Nishant D Patel, Ryan D Ward, Juan Camilo Calle, Eric Remer, Manoj Monga
Cleveland Clinic Foundation, Urology , 9500 Euclid Ave, Q10-1 , Cleveland, Ohio, United States , 44195 ; ., Cleveland Clinic Foundation, Imaging, Cleveland, Ohio, United States ; ., Cleveland Clinic, Nephrology , 9500 Euclid Ave , Cleveland, Ohio, United States , 44195 ; ., Cleveland Clinic, Radiology, Cleveland, Ohio, United States ; ., Cleveland Clinic, Urology, Cleveand, Ohio, United States ; .