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Vitamin D injections may significantly
improve survival in dialysis patients
Only half of kidney failure patients
currently receive the treatment, more research needed
BOSTON - February 28, 2005 - The administration of intravenous
vitamin D appears to significantly improve the survival of patients
on dialysis, according to a study that will be published in the
April Journal of the American Society of Nephrology and has
been released ahead of print on the journal's website. Vitamin D
injections are currently recommended only for dialysis patients
with elevated levels of parathyroid hormone, but the report from
a Massachusetts General Hospital (MGH)-based research group suggests
that the treatment might help most dialysis patients live longer.
"We've been administering vitamin D injections for decades,
but the potential benefit on survival has never been studied,"
says Ravi Thadhani, MD, MPH, director of clinical research in MGH
Nephrology, the study's senior author. "This finding was
a surprise and should force us to think more broadly about who should
be treated."
Among the approximately 300,000 U.S. patients who receive dialysis
for chronic kidney failure, the annual mortality rate is 20 percent,
with cardiovascular disease the primary cause of death. In healthy
individuals, the kidneys convert vitamin D from food and over-the-counter
supplements into an activated form that the body can use. Kidney
failure patient cannot utilize dietary vitamin D and must receive
activated forms of the nutrient to avoid deficiency. Currently only
50 percent of kidney failure patients are treated with activated
vitamin D, since the therapy is recommended only for those who also
have elevated parathyroid levels.
In 2003 the same research group published
a study finding that a particular form of activated vitamin
D, paricalcitol, was associated with better survival than was calcitriol,
previously the standard activated vitamin D therapy. For the current
study, the reseachers asked the broader question of whether dialysis
patients receiving any form of activated vitamin D therapy would
live longer than those who did not.
Working with collaborators from Fresenius Medical Care North America,
based in Lexington, Mass., the researchers compiled information
on more than 50,000 patients who started dialysis at Fresenius centers
across the country between 1996 and 1999 and were followed into
2002. More than 37,000 of those patients received injections of
some form of activated vitamin D.
At the end of the two-year study period, 76 percent of those receiving
any form of activated vitamin D were still alive, compared with
59 percent of those not receiving the therapy. That more than 20
percent reduction in mortality was seen across all categories of
patients in the study - all races, ages and both genders. Even patients
with elevated calcium or phosphorus levels, which often lead to
the discontinuation of vitamin D therapy, lived longer if they received
the treatment.
These results must be confirmed by follow-up studies - including
randomized clinical trials - before more precise recommendations
for treatment can be made, but the researchers note that even many
patients who meet current guidelines for vitamin D therapy are not
receiving it.
"While these results need to be verified, we at least need
to be more aggressive in treating people that meet the current criteria,"
Thadhani says. "Thereafter we need to investigate what is the
mechanism conferring this survival benefit. We are actively pursuing
that with a focus on the effects on cardiovascular disease."
Thadhani is an assistant professor of Medicine at Harvard Medical
School.
The study's co-authors are first author Ming Teng, MD, MS, of Fresenius
Medical Care; Myles Wolf, MD, MMSC, and Carlos Camargo, MD, of the
MGH; Norma Ofsthun, PhD, and Michael Lazarus, MD, of Fresenius,
and Miguel Hernan, PhD, of the Harvard School of Public Health.
The research was supported entirely by internal MGH resources.
Massachusetts General Hospital, established in 1811, is the original
and largest teaching hospital of Harvard Medical School. The MGH
conducts the largest hospital-based research program in the United
States, with an annual research budget of more than $450 million
and major research centers in AIDS, cardiovascular research, cancer,
cutaneous biology, medical imaging, neurodegenerative disorders,
transplantation biology and photomedicine. In 1994, MGH and Brigham
and Women's Hospital joined to form Partners HealthCare System,
an integrated health care delivery system comprising the two academic
medical centers, specialty and community hospitals, a network of
physician groups, and nonacute and home health services.
Media Contact: Sue
McGreevey, MGH Public Affairs
Physician Referral Service: 1-800-388-4644
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