C Shows Promise
in Heart Failure Patients
NEW YORK (Reuters Health)
- Therapy with vitamin C may help heart failure patients by improving
the function of their blood vessels, results from a small study
However, researchers say it is too early to recommend the vitamin
as a treatment for congestive heart failure.
In a study that looked at vitamin C treatment in 34 patients
with congestive heart failure--as well as how the vitamin affected
cells in the test tube--German and French researchers found that
the vitamin appeared to keep cells in the blood vessel wall from
dying. They say this protection from cell death could explain
previous study findings suggesting that vitamin C benefits blood
vessel function in people with congestive heart failure.
Researchers led by Dr. Stefanie Dimmeler, of the University of
Frankfurt in Germany, report the findings in the October 30th
issue of Circulation: Journal of the American Heart Association.
Congestive heart failure occurs when the heart cannot pump efficiently
enough to meet the body's needs, resulting in symptoms such as
fatigue and shortness of breath. Heart failure usually results
from an underlying heart condition such as coronary artery disease.
Heart failure patients also show poor function in the blood vessel
walls, and research suggests that damaging forms of oxygen called
reactive oxygen species accumulate in the blood as the condition
progresses, Dimmeler told Reuters Health. This oxidative stress,
she explained, may contribute to dysfunction in the blood vessel
wall--called the endothelium--by killing off endothelial cells.
Vitamin C is an antioxidant, which means it helps remove cell-damaging
oxygen compounds from the body. ``Therefore,'' Dimmeler said,
``we questioned whether antioxidative treatment of heart failure
patients with vitamin C against these reactive oxygen species
can reduce endothelial cell death.''
She and her colleagues gave 34 patients either vitamin treatment
or an inactive placebo. Treated patients first received an intravenous
dose of vitamin C, followed by 3 days of oral supplements. All
were on standard drug treatment for heart failure.
Before treating the patients, the researchers had found in experiments
that exposing endothelial cells to vitamin C kept certain inflammatory
proteins from pushing the cells to ``commit suicide''--a process
Similarly, when they examined blood samples from the patients,
they found that those who received vitamin C showed far less evidence
of apoptosis in endothelial cells than they had before treatment.
Placebo patients showed no such change.
According to Dimmeler, these findings may help researchers better
understand the mechanisms behind heart failure, and suggest that
either dietary vitamin C or heart failure drugs with added antioxidant
properties could slow the course of the disease.
``However,'' she said, ``(vitamin C) has not yet been proven
to prevent disease progression in congestive heart failure.''
SOURCE: Circulation 2001;104.
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