[Why do patients with kidney diseases end up with a heart of stone? Disturbances in calcium-phosphate balance and chronic inflammation important causes].

Despite rapid improvement in dialysis technology during the last 20 years the mortality rate is still very high in patients with end-stage renal disease (ESRD), and is in fact comparable to that of many cancer patients with metastases. The main cause of mortality in ESRD is cardiovascular disease (CVD), and cardiac mortality for dialysis patients aged 45 years or younger is more than 100-fold greater than in the general population. Recent evidence suggests that the high cardiovascular mortality rate in this patient population is associated with extensive vascular and valvular calcification. Although hyperphosphatemia may be the major cause of vascular calcification in this patient group it has been suggested that chronic inflammation also contributes to this process. Indeed, recent evidence suggests that inflammatory mediators, such as pro-inflammatory cytokines and adipocytokines, may promote vascular calcification in vitro. Moreover, a2-Heremans Schmid glycoprotein (fetuin), an intrinsic inhibitor of the calcification process, is down-regulated during chronic inflammation. Lower levels of fetuin have recently been found to predict mortality in ESRD. Thus, further studies are needed to elucidate the roles of calcium-free phosphate binders as well as focused anti-inflammatory treatment strategies in the prevention of vascular and valvular calcification in ESRD.