**1.1 High mortality in dialysis patients**

Dialysis patients have extraordinarily high mortality rates. Cardiac disease is the major cause of death accounting for 43% of all-cause mortality among patients receiving hemodialysis and peritoneal dialysis [Henry et al., 2002; US Renal Data System Annual Data Report Bethesta, 2005]. In previous report, patients with end-stage kidney disease (chronic kidney disease (CKD) stage 5) on dialysis, in comparison with the general population, also have a 3- to 30-fold increase in mortality, depending on the age group examined, and cardiovascular disease accounts for more than half of all deaths, with myocardial infarction, ischaemic cardiomyopathy, stroke and peripheral vascular disease making up the bulk of deaths (Foley et al., 1998). The marked excess in cardiovascular mortality in CKD, compared with the general population, is not explained by the presence of traditional Framingham risk factors, such as diabetes, smoking, hypertension and elevated cholesterol levels ( Zoccali, 2000; Longenecker et al., 2002). With vascular calcification and arterial stiffness being observed in young and middle-aged dialysis patients without conventional cardiovascular risk factors (London et al., 2003), the search for non-traditional risk factors has led to increasing evidence of a multitude of factors that contribute to ectopic calcification in CKD.
