High-dose cholecalciferol to correct vitamin D deficiency in haemodialysis patients.

BACKGROUND: Vitamin D has emerged as an important survival factor in patients with chronic kidney disease. Non-activated vitamin D may also have beneficial effects on bone, cardiovascular and immune functions. Cholecalciferol is the prevalent non-activated vitamin D in Europe, but there is no valid prospective data available about its use in haemodialysis patients. Thus, we initiated a prospective study to evaluate dosing, safety and tolerability of cholecalciferol supplementation in haemodialysis patients. METHODS: The prospective study included 64 haemodialysis patients. During replenishment phase patients received 20 000 IU cholecalciferol/week for 9 months. In the open maintenance phase (15 months), patients were randomized to a treated group (20 000 IU cholecalciferol/month) and an untreated group, which did not receive cholecalciferol. RESULTS: Calcidiol [25(OH)D] deficiency (<37.5 nmol/l; <15 microg/l) was detected in 61/64 patients (95%). During the replenishment phase, calcidiol increased significantly from 16.65 +/- 9.6 to 79.48 +/- 27.15 nmol/l (6.66 +/- 3.84 microug/l to 31.79 +/- 10.86 microg/l) (P < 0.001). Recommended levels (>75 nmol/l; >30 microg/l; K/DOQI) were achieved in 57% of patients. Calcium increased from 2.28 +/- 0.17 to 2.37 +/- 0.19 mmol/l (9.1 +/- 0.69 mg/dl to 9.49 +/- 0.75 mg/dl) (P<0.01). Phosphorus, calcium-phosphorus product and parathyroid hormone showed no significant changes. Fifty-nine patients progressed to the maintenance phase. Analysis per protocol showed a significant drop of calcidiol in the treated [83.98 +/- 31.73 versus 78.5 +/- 38.75 nmol/l (33.59 +/- 12.69 versus 31.4 +/- 15.5 microg/l) (P < 0.001)] and untreated groups [86.35 +/- 40.75 versus 53.4 +/- 26.2 nmol/l (34.54 +/- 16.3 versus 21.36 +/- 10.48 microg/l) (P < 0.001)]. The comparison of the treated and the untreated groups showed no significant differences at the beginning of the maintenance phase: 83.98 +/- 31.73 versus 86.35 +/- 40.75 nmol/l (33.59 +/- 12.69 versus 34.54 +/- 16.3 microg/l). At the end they differed significantly: 78.5 +/- 38.75 versus 53.4 +/- 26.2 nmol/l (31.4 +/- 15.5 versus 21.36 +/- 10.48 microg/l) (P < 0.001). CONCLUSION: Vitamin D deficiency is present in a majority of haemodialysis patients. Supplementation with cholecalciferol is safe, well tolerated and reasonable to replenish vitamin D stores in haemodialysis patients. However, only 57% of patients achieved recommended calcidiol levels, thus favouring additional dose-finding studies.

Hypercalcemia after transplant nephrectomy in a hemodialysis patient: a case report.

INTRODUCTION: Hypercalcemia is a complication often seen in chronic hemodialysis patients. A rare cause of this condition is sarcoidosis. Its highly variable clinical presentation is challenging. Especially in patients suffering chronic kidney graft failure the nonspecific constitutional symptoms of sarcoidosis like fever, weight loss, arthralgia and fatigue may be easily misleading. CASE PRESENTATION: A 51 year old male developed hypercalcemia, arthralgia and B-symptoms after explantation of his kidney graft because of suspected acute rejection. The removed kidney showed vasculopathy and tubulointerstitial nephritis, which had not been overt in the biopsy taken half a year earlier. Despite explantation and withdrawal of the immunosuppression the patient's general condition deteriorated progressively. A rapid rise in serum calcium finally provoked us to check for sarcoidosis. CT scans of the lungs, broncho-alveolar-lavage and further lab tests confirmed the diagnosis. CONCLUSION: This case demonstrates that withdrawal of immunosuppressive drugs sometimes unmasks sarcoidosis. It should be considered as differential diagnosis even in hemodialysis patients, in whom other reasons for hypercalcemia are much more common.

Low serum leptin predicts mortality in patients with chronic kidney disease stage 5.

OBJECTIVE: Leptin, secreted from adipose tissue, regulates food intake, energy expenditure, and immune function. It is unknown whether leptin predicts mortality in patients with chronic kidney disease stage 5 on hemodialysis therapy. RESEARCH METHODS AND PROCEDURES: We performed a prospective cohort study of 71 patients with chronic kidney disease stage 5 in an outpatient hemodialysis center. Subjects were recruited in June 1998 and followed for 83 months. Survival was compared by the Kaplan-Meier method. RESULTS: After 83 months of follow-up, 48 patients (68%) had died. Serum leptin concentrations at study entry were lower among all deceased patients compared with those patients who survived (5.2 +/- 9.0 microg/L; n = 48; vs. 7.7 +/- 7.8 microg/L; n = 23; p = 0.005). Baseline serum leptin concentrations were significantly lower in patients who died from cardiovascular diseases (4.7 +/- 9.4 microg/L, n = 32) or infections (4.0 +/- 2.7 microg/L; n = 10; each p < 0.05), but not cancer (9.4 +/- 7.9 microg/L; n = 6), than in survivors (7.7 +/- 7.8 microg/L; n = 23; p = 0.003). The relative risk for mortality in patients with serum leptin concentrations below the median (<2.6 microg/L) compared with patients above the median was 1.96 (95% confidence interval, 1.01 to 3.79; p = 0.04). Survival was shorter in patients with leptin concentrations below the median compared with those whose leptin concentrations were above the median (all-cause mortality, chi(2) = 5.05; p = 0.02). DISCUSSION: Low serum leptin concentration is an independent predictor of mortality in patients with chronic kidney disease stage 5 on hemodialysis therapy.