Pourquoi et comment corriger le déficit en calcidiol chez les patients hémodialysés ?

Biochemical parameters after cholecalciferol repletion in hemodialysis: results From the VitaDial randomized trial

BACKGROUND

The 2009 KDIGO (Kidney Disease: Improving Global Outcomes) chronic kidney disease-mineral and bone disorder clinical practice guideline suggests correcting 25-hydroxyvitamin D3 (25[OH]D) levels<30ng/mL in patients treated with maintenance hemodialysis, but does not provide a specific treatment protocol.

STUDY DESIGN

2-center, double-blind, randomized, 13-week, controlled trial followed by a 26-week open-label study.

SETTING & PARTICIPANTS

55 adult maintenance hemodialysis patients with 25(OH)D levels<30ng/mL were recruited from June 2008 through October 2009.

INTERVENTION

Cholecalciferol, 25,000IU, per week orally versus placebo for 13 weeks, then 26 weeks of individualized cholecalciferol prescription based on NKF-KDOQI (National Kidney Foundation-Kidney Disease Outcomes Quality Initiative) guidelines.

OUTCOMES

Primary end point was the percentage of patients with 25(OH)D levels≥30ng/mL at 13 weeks. Secondary outcomes included the percentage of patients with normal calcium, phosphorus, and intact parathyroid hormone (iPTH) blood levels. Safety measures included incidence of hypercalcemia and hypervitaminosis D.

MEASUREMENTS

Blood calcium and phosphate were measured weekly; iPTH, 25(OH)D, 1,25-dihydroxyvitamin D3 (1,25[OH]2D), and bone turnover markers, trimonthly; fetuin A and fibroblast growth factor 23 (FGF-23) serum levels and aortic calcification scores were determined at weeks 0 and 39.

RESULTS

The primary end point significantly increased in the treatment group compared with the placebo group (61.5% vs 7.4%; P<0.001), as well as 1,25(OH)2D levels (22.5 [IQR, 15-26] vs 11 [IQR, 10-15]pg/mL; P<0.001) and the proportion of patients achieving the target calcium level (76.9% vs 48.2%; P=0.03). Incidence of hypercalcemia and phosphate and iPTH levels were similar between groups. The second 26-week study phase did not significantly modify the prevalence of 25(OH)D level≥30ng/mL in patients issued from the placebo group.

LIMITATIONS

Small size of the study population.

CONCLUSIONS

Oral weekly administration of 25,000IU of cholecalciferol for 13 weeks is an effective, safe, inexpensive, and manageable way to increase 25(OH)D and 1,25(OH)2D levels in hemodialysis patients. Further evaluation of clinical end points is suggested.

High-Dose Cholecalciferol Supplementation for Vitamin D Deficiency in Haemodialysis Patients

Vitamin D deficiency, which is a recognized problem in haemodialysis (HD) patients, has been associated with higher all-cause mortality. There are no guidelines concerning vitamin D supplementation in HD patients. This study aimed to assess the effects of once-monthly supplementation with high-dose cholecalciferol (vitamin D3) in HD patients. Patients with 25-hydroxyvitamin D (25[OH]D) levels of < 75 nmol/l received 40 000 IU of cholecalciferol once-monthly for 3 months in succession. Every 4 months, 25(OH)D levels were measured and, based on the findings, cholecalciferol therapy was continued for another cycle if necessary. Six cycles were completed in the 24-month study period. The majority of HD patients had mild or severe vitamin D deficiency at baseline. Monthly supplementation with cholecalciferol at 40000 IU was well tolerated, safe and inexpensive. The treatment regime was effective for vitamin D insufficiency but did not prove to be enough to restore 25(OH)D levels in HD patients with mild or severe vitamin D deficiency.

[Surgical treatment of secondary hyperparathyroidism in patients with chronic renal failure]

OBJECTIVE

To identify the indications for subtotal parathyroidectomy (PTX) in secondary hyperparathyroidism (SHPT) and report postoperative, early and late complications of PTX.

PATIENTS AND METHODS

We conducted a retrospective study of subjects with chronic renal failure operated in Tunisian hospitals who received subtotal PTX over 10 years from January 1997 to December 2007. We analyzed the clinical, biological and radiological parameters pre- and postoperatively.

RESULTS

We included 70 patients with average age of 39.4 years, 55.7% men and 44.3% in dialysis for 7.75 ± 4.8 years before PTX. The initial nephropathy was interstitial in 50% of cases. No cases of diabetic nephropathy have been reported. The clinical signs were bone pain (88.6%), muscle pain (85.6%), pruritus (81.4%). Radiological signs of osteitis fibrosa were observed in the majority of patients mainly resorption of extremities (92.9%), thinning of cortical (85.7%) and osteosclerosis (87.1%). The most common indication of PTX (85.7% of cases) was the persistence of serum PTH of more than 800 pg/ml associated with hypercalcemia and/or hyperphosphatemia refractory to medical treatment. A subtotal PTX (3/4 or 7/8) was performed after ultrasound and scintigraphy in the majority of cases. The histology of the parathyroid glands showed diffuse hyperplasia (51.4%), nodular hyperplasia (45.7%) and adenoma (2.8%). The postoperative evolution was marked by an improvement of the clinical and radiological criteria in 80% of cases. A PTH level of less than 15 pg/ml was rarely observed (10% of cases), and a PTH level of more than 300 pg/ml concerned 13% of patients. We noted a low morbidity and mortality (no cases laryngeal paralysis or cervical hematoma).

CONCLUSION

Surgical treatment of SHPT in Tunisia is very effective in our experience. The biological results are comparable to treatment with calcimimetics, not available in Tunisia and whose price is higher. An early treatment of disorders of bone and mineral metabolism should reduce the incidence of SHPT.