Phosphorus control in peritoneal dialysis patients

Abstract

Hyperphosphatemia is independently associated with an increased risk of death among dialysis patients. In this study, we have assessed the status of phosphate control and its clinical and laboratory associations in a large international group of patients on chronic peritoneal dialysis (PD) treatment. This cross-sectional multicenter study was carried out in 24 centers in three different countries (Canada, Greece, and Turkey) among 530 PD patients (235 women, 295 men) with a mean+/-s.d. age of 55+/-16 years and mean duration of PD of 33+/-25 months. Serum calcium (Ca(2+)), ionized Ca(2+), phosphate, intact parathyroid hormone (iPTH), 25-hydroxy vitamin D(3), 1,25-dihydroxy vitamin D(3), total alkaline phosphatase, and bone alkaline phosphatase concentrations were investigated, along with adequacy parameters such as Kt/V, weekly creatinine clearance, and daily urine output. Mean Kt/V was 2.3+/-0.65, weekly creatinine clearance 78.5+/-76.6 l, and daily urine output 550+/-603 ml day(-1). Fifty-five percent of patients had a urine volume of <400 ml day(-1). Mean serum phosphorus level was 4.9+/-1.3 mg per 100 ml, serum Ca(2+) 9.4+/-1.07 mg per 100 ml, iPTH 267+/-356 pg ml(-1), ionized Ca(2+) 1.08+/-0.32 mg per 100 ml, calcium phosphorus (Ca x P) product 39+/-19 mg(2)dl(-2), 25(OH)D(3) 8.3+/-9.3 ng ml(-1), 1,25(OH)(2)D(3) 9.7+/-6.7 pg ml(-1), total alkaline phosphatase 170+/-178 U l(-1), and bone alkaline phosphatase 71+/-108 U l(-1). While 14% of patients were hypophosphatemic, with a serum phosphorus level lower than 3.5 mg per 100 ml, most patients (307 patients, 58%) had a serum phosphate level between 3.5 and 5.5 mg per 100 ml. Serum phosphorus level was 5.5 mg per 100 ml or greater in 28% (149) of patients. Serum Ca(2+) level was > or =9.5 mg per 100 ml in 250 patients (49%), between 8.5 and 9.5 mg per 100 ml in 214 patients (40%), and lower than 8.5 mg per 100 ml in 66 patients (12%). Ca x P product was >55 mg(2)dl(-2) in 136 patients (26%) and lower than 55 mg(2)dl(-2) in 394 patients (74%). Serum phosphorus levels were positively correlated with serum albumin (P<0.027) and iPTH (P=0.001), and negatively correlated with age (P<0.033). Serum phosphorus was also statistically different (P = 0.013) in the older age group (>65 years) compared to younger patients; mean levels were 5.1+/-1.4 and 4.5+/-1.1 mg per 100 ml, respectively, in the two groups. In our study, among 530 PD patients, accepted uremic-normal limits of serum phosphorus control was achieved in 58%, Ca x P in 73%, serum Ca(2+) in 53%, and iPTH levels in 24% of subjects. Our results show that chronic PD, when combined with dietary measures and use of phosphate binders, is associated with satisfactory serum phosphorus control in the majority of patients.

FGF-23, α-Klotho Gene Polymorphism and Their Relationship with the Markers of Bone Metabolism in Chronic Peritoneal Dialysis Patients

“…However, the course, clinical presentation and treatment of CKD-BMD in patients on peritoneal dialysis, is not necessarily identical with the haemodialysis patients. In peritoneal dialysis patients, factors such as steady-state biochemical control, relatively higher phosphorus intake and clearance, additional peritoneal loss of 25(OH) D3 and higher glucose load may affect the course of CKD-MBD making its nature different than haemodialysis patients [15,16]. In this study, we aimed to expand our knowledge on major metabolic parameters of bone mineral metabolism and their interactions in chronic peritoneal dialysis patients.…”

Differences in Dental Calculus Indices and Salivary Calcium and Phosphate Levels in Children With Chronic Kidney Disease Undergoing Hemodialysis and Peritoneal Dialysis Therapy

“…The higher amount of dental calculus in the HD group could also be related to the characteristics of their saliva itself and other manifestations of disturbed Ca/P homeostasis [1]. Yavuz et al stated that the type of dialysis may also be an important factor in the adequacy of Ca and P control in dialysis patients [9].…”

“…When this equilibrium is disturbed, it manifests as increased dental calculus formation [8]. The type of dialysis may also be an important factor in the adequacy of Ca and P control in dialysis patients [9]. Alteration of the composition of salivary secretion may be correlated with serum biomarkers in dialysis patients [10].…”

Residual Renal Function in Hemodialysis Patients

“…Preserved RRF is also associated with lower blood levels of uric acid, potassium (Morduchowicz, Winkler et al, 1994), and aluminium (Altmann , Butter et al, 1987), and higher levels of hemoglobin (Pecoits-Filho, Heimburger et al, 2002), presumably due to increased levels of endogenous erythropoietin. Hyperphosphatemia is prevalent in dialysis patients (Yavuz, Ersoy et al, 2008; and has been linked to vascular calcification and increased cardiovascular mortality in both HD and PD patients (Block, Hulbert-Shearon et al, 1998;Wang AY, Lai et al, 2006). RRF plays a major role in improving phosphate balance in both PD and HD patients ( (Morduchowicz, Winkler et al, 1994).…”