[Hyperphosphatemia and cardiovascular risk in patients on dialysis]

Abstract

Cardiovascular diseases are the leading causes of mortality among patients with end-stage renal disease (ESRD), with arterial disease and left ventricular hypertrophy being the two principal factors of the high mortality rate in this population. In addition to traditional risk factors (age, gender, diabetes, hypertension, lifestyle, hyperlipidemia, smoking, hyperhomocystinemia), inflammation, oxidative stress and disorders of mineral metabolism may contribute to cardiovascular risk in patients with uremic syndrome. High serum phosphate may influence vascular calcifications directly and indirectly, by worsening secondary hyperparathyroidism. Several treatment options are available for the treatment of hyperphosphatemia and secondary hyperparathyroidism in patients with ESRD. The treatment approach includes a diet low in phosphorus, with less than 1 g/kg/day of protein. Vitamin D supplementation is an important part of treatment. Phosphate binding agents are in most of the patients necessary in addition to diet. Aluminum hydroxide has been widely used for many years. It is very potent, but also very toxic, with severe encephalopathy as the most dangerous side effect. Calcium salts are less potent, and were considered safe for use in patients on dialysis. However, improvement in the understanding of vascular calcifications has demonstrated that calcium overload significantly contributes to widespread atherosclerosis in patients with ESRD. Sevelamer-hydrochloride is a novel non-aluminum, non-calcium containing phosphate binder, which is capable of reducing the levels of phosphorus as well as of low-density lipoprotein cholesterol, and increasing high-density lipoprotein cholesterol.