my personal edition > renal failure > news


  E-Mail this DGReview to a colleague

DGReview

Long-term Haemodialysis Patients Show Survival Advantage When Treated with Paricalcitol Over Calcitriol for Secondary Hyperparathyroidism

Long-term haemodialysis patients treated with injectable vitamin D therapy for secondary hyperparathyroidism showed a significant survival advantage when treated with paricalcitol over those treated with calcitriol.

"The difference in survival was significant at 12 months and increased with time," writes Ming Teng, MD, of Massachusetts General Hospital, Boston, United States and colleagues. They caution however that additional research is required before any conclusions can be made regarding the use of paricalcitol for the management of secondary hyperparathyroidism.

In this historical cohort study, Dr. Teng and colleagues examined the survival rate among 29,021 long-term haemodialysis patients receiving paricalcitol and 38,378 receiving calcitriol, over 36 months. The researchers found that among patients receiving paricalcitol, the mortality rate was 3417 per 19,031 person-years compared with 6805 per 30,471 person-years for those treated with calcitriol.

When the data was analysed according to strata including age, sex, race, presence of diabetes, primary cause of renal failure, levels of calcium, phosphorus, and parathyroid hormone as well as duration of dialysis and vascular access, paricalcitol conferred a significant survival benefit in 28 or 42 strata. Additionally, the 2- year survival rate among 16,483 patients who switched regimens was 73% in those who changed from calcitriol to paricalcitol compared with 64% among those who changed from paricalcitol to calcitriol.

The researchers caution, however, that clinical conclusions should not be drawn until these findings can be confirmed by a prospective, randomised trial.

In a related editorial Tilman B. Drueke, MD, of the Hospital Necker, Paris, France and David A McCarron, MD, of the University of California, Davis, the United States note that certain characteristics of this study "warrant further consideration."

A major limitation is that the paricalcitol group had a 90 days longer duration of dialysis prior to study enrolment than did the calcitriol group. This created an absence of clinical and treatment data, according to Dr. Drueke and Dr. McCarron. The greater representation of blacks in the paricalcitol group (39% compared with 36% receiving calcitriol) could be important due to the increased risk for severe hyperparathyroidism in black patients with chronic kidney failure. The well-documented low intake of dietary calcium and high intake of dietary phosphorus under normal conditions in the black population, "would set the stage for subtle degrees of overstimulation of the parathyroid gland, even before the onset of renal disease," the researchers write. They conclude that findings of the current study do not show the superiority of paricalcitol in the management of chronic kidney disease, however the data does provide, "strong justification for a randomised, controlled trial of vitamin D analogues in the management of hyperparathyroidism."
N Engl J Med 2003;349:446-56.

E-Mail this DGReview to a colleague

To print, use this version