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Release Date: May 13, 2008; Valid for credit through May 13, 2009
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Oral Calcitriol May Reduce Mortality in Chronic Kidney Disease CME
News Author: Laurie Barclay, MD
CME Author: Désirée Lie, MD, MSEd
May 13, 2008 — In patients with chronic kidney disease (CKD) and hyperparathyroidism who have not received dialysis, intake of oral calcitriol (oral activated vitamin D) reduced mortality rates by 26%, according to the results of a study published online in the May 7 issue of Journal of the American Society of Nephrology.
"Parenteral vitamin D is associated with improved survival among long-term hemodialysis patients," write Abigail B. Shoben, from the Puget Sound Veterans' Affairs (VA) Medical Center, University of Washington in Seattle, and colleagues. "Among nondialyzed patients with chronic kidney disease (CKD), oral activated vitamin D reduces parathyroid hormone [PTH] levels, but the impact on clinical outcomes is unknown."
Using the VA Consumer Health Information and Performance Sets database, the investigators examined associations of oral calcitriol use with mortality and dialysis dependence in 1418 nondialysis patients with CKD and hyperparathyroidism. Selection criteria were stages III to IV CKD, hyperparathyroidism, and the absence of hypercalcemia before calcitriol use. Incident calcitriol users and nonusers were matched by age and estimated kidney function.
During a median follow-up of 1.9 years, 408 patients (29%) died, and 217 (16%) began long-term dialysis. Oral calcitriol use was associated with a 26% lower risk for death (95% confidence interval [CI], 5% - 42% lower; P = .016) and a 20% lower risk for death or dialysis (95% CI, 1% -35% lower; P = .038), after adjustment for demographic factors, comorbid conditions, estimated kidney function, medications, and baseline levels of PTH, calcium, and phosphorous.
The association of calcitriol with reduced mortality was not statistically different across PTH levels at baseline. Risk for hypercalcemia was greater with calcitriol use.
"Oral calcitriol use is associated with lower mortality in nondialysis patients with CKD," the study authors write.
Limitations of this study include potential for confounding by indication; relative paucity of clinical serum PTH measurements; lack of generalizability to younger, more diverse CKD populations; and lack of data on forms of vitamin D other than calcitriol.
"These data are among the first to show oral calcitriol use in relation to clinical outcomes in patients with CKD and add to a growing body of observational data linking vitamin D use with improved survival," the study authors conclude. "Randomized trials represent the next appropriate step for evaluating the health consequences of vitamin D."
The National Institutes of Health supported this study. One of the authors has disclosed various financial relationships with Abbott, Shire, and Amgen.
J Am Soc Nephrol. Published online May 7, 2008. |
