Markers of Arterial Stiffness Are Risk Factors for Progression to End-Stage Renal Disease among Patients with Chronic Kidney Disease Stages 4 and 5

Background: Factors associated with chronic kidney disease (CKD) contribute to an increased risk of cardiovascular disease and death. The impact of vascular disease on CKD progression is, however, less well studied. Methods: We examined the effect of markers of vascular disease on the risk of progression to end-stage renal disease (ESRD) in 35 patients with CKD stages 4–5. Superficial femoral artery calcification was assessed by CT scan. Augmentation index (AI) and pulse wave velocity (PWV) were measured by applanation tonometry. Results: After 12.4 (5.5–28.4) months, 22/35 patients (63%) had commenced dialysis. Cox regression analysis identified baseline estimated glomerular filtration rate (hazard ratio, HR, 0.54; 95% CI 0.41–0.70; p < 0.0001), urinary protein (HR 1.84; 95% CI 1.32–2.58; p = 0.0005), PWV (HR 1.30; 95% CI 1.07–1.60; p = 0.01), AI (HR 1.08; 95% CI 1.04–1.14; p = 0.0001) and pack years of smoking (HR 1.01; 95% CI 1.00–1.03; p = 0.02) as independent risk factors for time to ESRD (–2 log likelihood = 86.7; χ2 = 30.9; p < 0.0001). Repeat analysis using AI as a categorical variable revealed an HR of 17.5 (95% CI 4.43–68.9; p < 0.0001) for time to ESRD in those with AI above versus below the median. Conclusions: We have identified two markers of arterial stiffness as independent risk factors for progression to ESRD suggesting that vascular disease may contribute to CKD progression.