Vitamin D Therapy May Reduce Erythropoietin Use
SEATTLE—Vitamin D supplementation in hemodialysis (HD) patients who are deficient in 25-hydroxyvitamin D (25-D) may decrease the need for erythropoietin (EPO), according to researchers.
Victoria A. Kumar, MD, and Philip Yang, MD, of Southern California Permanente Medical Group in Los Angeles obtained baseline 25-D levels from 126 who received HD for more than six months in an HD unit. Of these, 112 (89%) had 25-D levels below 30 ng/mL, the study definition of deficiency.
Patients with levels between 10 and 30 ng/mL received ergocalciferol 50,000 units/month for a total of four doses, whereas patients with levels of 10 ng/mL or less received 50,000 units/week for a total of four doses, followed by 50,000 units/month for a total of three doses. The investigators targeted a hemoglobin level between 10.5 and 12 g/dL.
After excluding 11 patients who received HD for less than six months and another 20 who met other exclusion criteria, 81 patients remained for analysis. Their mean 25-D level increased from 15.3 pg/mL at baseline to 28.5 pg/mL after four months of ergocalciferol treatment. The median EPO dose decreased nonsignificantly from 21,933 units/month at baseline to 18,400 units/month at follow-up, Dr. Kumar reported at the 30th Annual Dialysis Conference here.
Of the 81 patients, 36 achieved final 25-D levels of 30 ng/mL or higher (responders). Their median EPO dose was 20,208 units/month at baseline and 19,000 units/month at follow-up. Among the 45 nonresponders, the median EPO dose decreased from 20,208 to 16,900. The declines in EPO dose were not significant.
However, 57% of patients required a lower EPO dose during the follow-up period than at baseline, prior to ergocalciferol supplementation, said Dr. Kumar, Director of Home Dialysis. For this subgroup, the median dose was 26,242 units/month prior to ergocalciferol treatment. The dose declined significantly compared with baseline to 15,819 and 15,450 units/month during treatment and at follow-up, respectively.
In addition, 35 patients (43%) required a significantly higher monthly dose of EPO after ergocalciferol treatment. These patients received a median of 17,667 units/month prior to ergocalciferol treatment. The dose rose nonsignificantly to 24,700 units/month during treatment and significantly to 26,350 units/month at follow-up.
The mean age, gender, HD vintage, diabetes status race, and 25-D levels did not differ between the groups. Monthly levels of serum calcium, phosphorus, albumin, and intact parathyroid hormone did not change significantly for either responders or nonresponders following ergocalciferol treatment.
Dr. Kumar told colleagues that significantly more nonresponders than responders used a central venous catheter for vascular access.