Cardiovascular calcification in nondialyzed patients with chronic kidney disease

Chronic kidney disease (CKD) has become a major health-care problem of global proportions. Progression to end-stage renal disease (ESRD), the need for renal replacement therapy, and the high annual death rate of dialysis patients are the most noticeable outcomes of CKD. Less appreciated, however, is the fact that most patients with CKD actually die mainly from cardiovascular disease, rather than progress to ESRD. Coronary artery calcification (CAC), a surrogate marker of atherosclerosis, is common in dialysis and CKD patients. Coronary artery calcium scores, as measured by ultrafast computed tomography, is an independent predictor of future cardiac events. Using this technique, several studies have documented extensive calcification in dialysis patients, a subject of several exhaustive reviews. Unfortunately, much less attention has been paid to calcification in nondialyzed patients with CKD. In this review, I will emphasize the fact that CVC is common in patients with CKD not yet on dialysis, develops early in the course of CKD, and worsens with the decline in renal function particularly among diabetics who progressed to ESRD. I will also discuss the pathogenesis of CVC in CKD patients and highlight the lack of a major role for abnormalities of mineral metabolism in the pathogenesis of calcification in CKD patients. In addition to the high prevalence of traditional risk factors for CAD, the presence of proteinuria, reduced renal function, diabetic nephropathy, and the rate of progression to ESRD may represent the main uremia-related factors that increase the risk for calcification in CKD. Finally, I will review the protective role of inhibitors of calcification in CKD.