Effect of a dietitian-managed bone algorithm on serum phosphorus level in maintenance hemodialysis patients.

OBJECTIVE: This study examined the effectiveness of a registered dietitian (RD)-managed bone metabolism algorithm compared with a non-RD (registered nurse and the nephrologist)-managed one on serum phosphorus (PO4) and related clinical outcomes (corrected serum calcium [cCa] level, intact parathyroid hormone [iPTH] level, incidence of parathyroidectomy) among in-center maintenance hemodialysis (MHD) patients. DESIGN AND SETTING: The study was an 18-month retrospective review of adult MHD patients (n = 252) at 5 outpatient dialysis centers in western Massachusetts and Connecticut before and after change in the management of a comprehensive bone metabolism treatment algorithm (intravenous vitamin D, phosphate-binding medication, calcimimetic) from non-RD to RD. Calendar-matched timepoints representing 3-month averages during the non-RD- and RD-managed periods of the same algorithm were used for analyses. Comparisons of outcomes at non-RD-managed timepoint 2 (February 2009-April 2009) and RD-managed timepoint 6 (February 2010-April 2010) were performed considering potential demographic and clinical confounders. RESULTS: On average, serum PO4 level was lower during the RD-managed timepoint 6 (5.17 ± 1.23 mg/dL; mean ± standard deviation) compared with non-RD-managed timepoint 2 (5.23 ± 1.24 mg/dL), although the difference between these calendar-matched timepoints was not statistically significant (F = .108, P = .74) after controlling for age, dietary intake (equilibrated normalized protein catabolic rate), and dialysis adequacy (equilibrated Kdrt/V). Mean cCa at RD-managed timepoint 6 (8.76 ± 0.65 mg/dL) was not significantly different from non-RD-managed timepoint 2 (8.79 ± 0.74), and the difference between serum iPTH level at timepoint 6 (363.0 ± 296.8 pg/mL) compared with timepoint 2 (319.8 ± 251.5 pg/mL) was nonsignificant (F = .650, P = .42) after controlling for age. There were fewer parathyroidectomies during the RD-managed period (0.8%) compared with the non-RD-managed period (1.6%). CONCLUSIONS: RDs may be equally effective as non-RDs in bone metabolism algorithm management with respect to serum PO4, cCa, and iPTH control in MHD patients. Further research is needed to prospectively evaluate the effect of RD management on these bone mineral outcomes.

Prevalence of vitamin D [25(OH)D] deficiency and effects of supplementation with ergocalciferol (vitamin D2) in stage 5 chronic kidney disease patients.

OBJECTIVE: This study investigated the prevalence of vitamin D deficiency, its association with nutrition-related parameters, and the effects of ergocalciferol supplementation in stage 5 chronic kidney disease (CKD). Measures of interest included serum albumin, glycosylated hemoglobin (HgA1c), hemoglobin, phosphorus, corrected calcium, parathyroid hormone (iPTH), equilibrated normalized protein catabolic rate (enPCR), and quality-of life-survey physical component score (SF-36 PCS). DESIGN AND SETTING: This retrospective study was conducted at five dialysis centers in western Massachusetts. Patient records were examined for a 6-month period in 2006, after initiation of a protocol to assess serum 25(OH)D and implement treatment with ergocalciferol if the level of serum 25(OH)D were <40 ng/mL. RESULTS: Over 90% (i.e., 92.4%) of patients had vitamin D levels of less than 40 ng/mL; 80% had vitamin D levels at 31 ng/mL or less. Ergocalciferol supplementation (50,000 IU/week x 24) was associated with significant improvements in serum 25(OH)D from baseline (18.4 +/- 9.0 ng/mL; mean +/- SD) to 6 months (42.0 +/- 24.7 ng/mL) (P < .0005). The level of glycosylated hemoglobin decreased from 6.9% +/- 1.9% at baseline to 6.4% +/- 1.5% at 6 months (P < .0005), while hemoglobin improved from 12.1 +/- 1.6 g/dL to 12.3 +/- 1.4 g/dL (P < .0005). Corrected calcium decreased from 8.7 +/- 0.8 mg/dL to 8.5 +/- 0.9 mg/dL at 6 months (P = .002). Phosphorus and iPTH exhibited a downward trend, though not significantly. Albumin remained stable, while enPCR increased (0.91 +/- 0.23 at baseline, vs. 0.98 +/- 0.32 at 6 months) (P = .01). The SF-36 PCS scores did not differ significantly from baseline (35.4 +/- 11.8) at 6 months (35.0 +/- 11.1). CONCLUSIONS: Vitamin D [25(OH)D] deficiency appears to be widely prevalent in stage 5 CKD. Repletion with ergocalciferol may assist in improving glycemic control in the management of diabetes. Additional research is needed to confirm these results and determine the optimal levels of serum 25(OH)D.