Treatment of hyperphosphatemia with sevelamer hydrochloride in dialysis patients: effects on vascular calcification, bone and a close look into the survival data

In chronic kidney disease patients, bone and mineral abnormalities have a major impact on morbidity and mortality. Hyperphosphatemia has been associated with increased mortality and with the development of cardiovascular calcification, an independent predictor of mortality. Vascular calcifications have been associated with low bone turnover, low bone volume and lower activation frequency. In dialysis patients, the treatment of hyperphospathemia with calcium based compounds, when compared with sevelamer, is associated with more frequent episodes of hypercalcemia, suppression of intact parathyroid hormone and with progression of coronary calcifications. In the presence of adynamic bone disease, calcium load has a significantly higher impact on aortic calcifications and stiffening. A randomized, prospective, open label study, evaluated patients with bone biopsies at the beginning and after 1 year treatment period with sevelamer hydrochloride or calcium carbonate. Sevelamer treatment resulted in no statistically significant changes in bone turnover or mineralization compared with calcium carbonate, but bone formation rate increased and trabecular architecture improved only with sevelamer. In incident dialysis patients, treatment with sevelamer has been associated with better survival, while in prevalent patients a clear benefit could only be demonstrated in older patients and in patients treated for more than 2 years. In conclusion, the treatment of hyperphosphatemia with sevelamer hydrochloride, a non-calcium and non-metal containing phosphate binder, is associated with a beneficial effect on vascular calcification progression, bone disease and most likely with a survival benefit in some hemodialysis patients populations.