Control of mineral metabolism and bone disease in haemodialysis patients: Which optimal targets?

Abstract

Background There is a high drug treatment burden on patients receiving long-term dialysis therapy. Abnormalities of calcium and phosphate metabolism are associated with increased mortality, and attempts to correct these disturbances may improve survival.MethodsWe prospectively evaluated the targets of the currently used Kidney Disease: Improving Global Outcomes (KDIGO) guidelines in 8377 prevalent patients receiving intermittent haemodialysis therapy in France from July 2007 to December 2009.ResultsAdjusted Cox analyses showed that only one among six targets was predictive of mortality, i.e. a serum intact parathyroid hormone (iPTH) <130 pg/mL. A continuous risk analysis using fractional polynomials showed a 10% increase in hazard ratio (HR) for mortality for a serum phosphate <0.71 (2.2) and >1.98 (6.14) mmol/L (mg/dL), a non-corrected serum calcium <1.59 (6.37) and >2.41 (9.66) mmol/L (mg/dL) and a serum iPTH <100 and >1090 pg/mL.ConclusionThe findings of our observational study confirm the existence of a grey zone, in which precise biochemical targets are difficult to define, with the exception of avoiding extreme values. Given the absence of intervention trials proving the clinical usefulness of phosphorus control, and pending the results of large clinical trials on the effect of optimal PTH and calcium control on hard outcomes, the present findings may help to refine future recommendations for the treatment of chronic haemodialysis patients. © 2012 The Author.