Relationships between abdominal aortic calcification, glomerular filtration rate, and cardiovascular risk factors in patients with non-dialysis dependent chronic kidney disease

Background: Abdominal aortic calcification (AAC) is an established risk factor for cardiovascular events in patients with chronic kidney disease (CKD). We hypothesized that AAC is associated with a decline in glomerular filtration rate (GFR) as well as with some other cardiovascular risk factors. Materials and methods: This is a cross-sectional analysis of baseline data from a randomized controlled clinical trial (RENEXC). A total of 151 patients (aged 66 ± 14 years) with an average measured GFR (mGFR) of 22.5 ± 8.2 mL/min/1.73m², not on renal replacement therapy, irrespective of number of comorbidities, were included. GFR was measured with iohexol clearance and estimated using cystatin C- and creatinine-based equations (eGFR). AAC was evaluated with lateral lumbar X-ray using the scoring system described by Kauppila. All patients underwent laboratory analyses, 24-hour ambulatory blood pressure monitoring, and standard echocardiography. Multiple linear regression analyses controlling for sex, age, cardiovascular comorbidities, and hypertension were performed. Results: The prevalence of AAC in this group of patients was 73%, and 47% had severe calcification (AAC score ≥ 7). More men (76%) had AAC than women (69%). AAC score was associated with mGFR (p = 0.03), eGFR (p = 0.006), plasma albumin (p = 0.006), plasma phosphate (p = 0.01), pulse pressure (p = 0.004), left ventricular mass (LVM) (p = 0.02), left atrial volume (LAV; p < 0.001), and left atrial volume index (LAVI; p = 0.001). Conclusion: AAC was highly prevalent in CKD. The degree of calcification in the abdominal aorta was strongly associated with a decline in GFR, a decrease in plasma albumin, an increase in plasma phosphate, an increase in pulse pressure, and cardiac structural changes, such as an increase in LVM, LAV, and LAVI.