Inflammation, mineral metabolism and progressive coronary artery calcification in patients on haemodialysis

Background. Coronary artery calcification (CAC) is an extensive and common complication in patients with end-stage renal disease (ESRD). The aim of this study was to assess prospectively the change in CAC over a 2-year period and to identify the factors that may be associated with CAC progression in ESRD patients. Methods. The final analysis was performed on 40 of 43 stable haemodialysis patients who initially entered into the study. The study population underwent multirow spiral computed tomography to derive CAC scores at baseline and after a minimum of 12 months (24 months in 30 patients, 18 months in four, and 12 months in the remaining six patients). To provide a stable estimate that was unbiased with respect to the baseline CAC, square root-transformed CAC scores were used for the analyses of the changes in CAC. Results. The median CAC score was 191 (range, 0-2403) mm(3) at baseline and increased to 253 (range, 0-2745) mm(3) at follow-up (P < 0.001) and the median annualized change in square root-transformed CAC score was 1.48 (range, -0.95-8.64) mm(3)/year. The annualized change of the square root-transformed CAC score positively correlated with the time-integrated levels of C-reactive protein (R = 0.521, P = 0.001), phosphorus (R = 0.433, P = 0.005) and calcium x phosphorus product (R = 0.394, P = 0.012), but did not correlate with the levels of fetuin-A or lipid parameters. Even after adjusting for age, gender and baseline CAC score, C-reactive protein levels were independently associated with CAC progression. Conclusion. These data suggest that chronic inflammation as well as altered mineral metabolism contributes to a rapid progression of CAC in ESRD patients. Additional, larger scale studies are required to confirm our findings.