Stone composition and vascular calcifications in patients with nephrolithiasis

Kidney stone disease is associated with cardiovascular outcomes; it is unclear whether stone composition is associated with differential cardiovascular risk. To analyze such association, we performed a cross-sectional study in which data were collected for patients who underwent at least one stone composition analysis from January 01 2015 to May 30 2018. The original dataset was linked with the imaging database to identify those patients with at least one abdominal CT scan examination during the period of interest. In total, 180 patients were included. The outcome of interest was the presence of any abdominal aortic calcifications (AAC) computed from CT scans. There were 108 (60.0%) patients with AAC. Calcium phosphate content was associated directly with eGFR, inversely with age, and was higher among females. Uric acid content was associated directly with age and inversely with eGFR, was higher among males, patients with diabetes and high blood pressure. After adjustment for age and gender, there was a significant association between calcium phosphate content and AAC (OR 1.25, 95% CI 1.00, 1.56, p=0.045). No interaction by gender was found between calcium phosphate content and AAC (p=0.84). In conclusion, we demonstrated a significant direct association of AAC and the amount of calcium phosphate was found, suggesting an increased cardiovascular risk. Our study suggests that some subtypes of kidney stone disease deserve a closer cardiovascular risk assessment.