Assessment of phosphorus and calcium metabolism and its clinical management in hemodialysis patients in the community of Valencia

Aim: The objective of the study was to determine the situation concerning mineral metabolism and bone disease in hemodialysis (HD) patients living in the community of Valencia (Spain), as well as the clinical practices for bone disease control in relation to the laboratory targets recommended in the National Kidney Foundation Dialysis Outcomes Quality Initiative (K/DOQI) guidelines. Methods: In December 2003, a cross-sectional study was performed including 2392 patients (1485 males and 907 females) from 43 different centers in the council of Valencia (the entire HD population). Mean age was 65.8 +/- 14 yrs. Cut-off levels for the study of calcium, phosphorus, calcium-phosphorus product (Ca x P) and parathyroid hormone (PTH) were performed following the recommendations of the K/DOQI guidelines. Results: The mean values for calcium were 9.57 +/- 0.7 mg/dL, phosphorus 4.97 +/- 1.5 mg/dL, intact PTH (iPTH) 297 353 pg/mL, Ca x P 47.5 +/- 15 mg(2)/dL(2). Hypocalcemia (< 8.4 mg/dL) was present in 5% of patients, whereas 17.8% of patients presented hypercalcemia (> 10.2 mg/dL), 60.3% of whom received vitamin D. Hypophosphoremia (< 3.5 mg/dL) was present in 16% of patients, and 29% of patients presented hyperphosphoremia (> 5.5 mg/dL). Ca x P was < 55 mg(1)/dL(2) in 73% of patients. Thirty one percent of patients presented secondary hyperparathyroidism (HPTH > 300 pg/mL), being severe in 12% (> 600 pg/mL); 43% of patients presented iPTH < 150 pg/mL. Only 7.3% of patients achieved the four recommendations provided in the K/DOQI guidelines. Vitamin D treatment was administered in 48% of patients. Conclusions: The population undergoing dialysis in the community of Valencia achieved targets based on the clinical recommendations of the K/DOQI guidelines as follows: 45% of patients achieved targets for calcium, 55% for phosphorus, 73% for Ca x P and 26% for iPTH levels. Surprisingly, only 7.3% of patients achieved all four targets.