Consequences of the implementation of “K/DOQI Clinical Practice Guidelines for Bone Metabolism and Disease in Chronic Kidney Disease” in a population of patients on chronic hemodialysis

Background: After application of K/DOQI recommendations, a large proportion of our patients failed to reach the proposed targets. This study examined the causes of these findings. Methods: Patients (n=163) were compared in 2 periods (8 months before and after application of K/DOQI guidelines). Serum calcium (Ca), phosphorus (P), parathyroid hormone (PTH) and calcium × phosphate product (Ca x P); mean dialysate Ca content; mean doses of vitamin D; and average prescription of Ca-based phosphate binders and sevelamer in both periods were analyzed. Results: Prescription of Ca salts as phosphate-binding agents decreased and prescription of sevelamer increased in an attempt to maintain serum Ca levels between 8.4 and 9.5 mg/dL post-K/DOQI. Increased serum PTH levels were associated with decreased serum Ca levels (relative risk [RR] = 41.1, p<0.001) and increased serum P levels (RR=6.81, p<0.01). Use of dialysis fluids with Ca content of 2.5 mEq/L was associated with an increased risk of having PTH levels >300 pg/mL (RR=11.4, p<0.003). Vitamin D metabolites had to be discontinued in 26 patients (37.1% of those receiving them from study start) due to hyperphosphoremia or hypercalcemia post-K/DOQI; and serum PTH significantly increased (445.8 ± 238.2 pg/mL vs. 715.2 ± 549.5 pg/mL; p<0.001). Ninety-three patients (57%) did not receive vitamin D at study start; in 20 of those (21.5%), vitamin D had to be started post-K/DOQI. Conclusions: Clinical guidelines do not appear to be sufficient to overcome all difficulties arising in daily management of these patients.