"Thiamin supplements may help protect heart failure patients",
news-medical.net, January 16, 2006,
Link: http://www.news-medical.net/?id=15403
Among patients hospitalized with heart failure, about one in three has
deficient levels of thiamin, although thiamin deficiency was less
common among those patients who were taking vitamin supplements,
according to a new study in the Jan. 17, 2006, issue of the Journal of
the American College of Cardiology.
"We found that one-third of congestive heart failure patients admitted
to our hospital had red blood cell levels of thiamin that were lower
than normal and would suggest deficiency. In contrast to some previous
studies, we did not find a relationship between the development of
thiamin deficiency and the amount or duration of diuretic use and
urinary thiamin excretion. In fact, what was important was that a
relatively small dose of thiamin from a multi-vitamin was protective
against developing thiamin deficiency," said Mary E. Keith, Ph.D. from
St. Michael's Hospital in Toronto, Ontario, Canada.
Dr. Keith said that heart failure may increase the body's need for
certain nutrients, including thiamin, so even patients who are eating
relatively well may not be getting enough of them. At the same time,
the illness may make it harder to maintain a proper diet. She said that
this study helps focus attention on the role of diet in managing
serious conditions, such as heart failure.
"Physicians and the public have exclusively focused on drug therapy to
the detriment of at least one of the foundations of good
health-appropriate nutrition," she said.
Thiamin, also called vitamin B1, helps the body to digest carbohydrates
and perform other functions. Like other B vitamins, thiamin is not
stored in the body, so poor diet can lead to deficiency in a relatively
short period of time and possibly worsen the symptoms of heart failure.
Although thiamin deficiency has not been extensively studied among
heart failure patients, the researchers said that there are several
reasons to be concerned about the problem. For instance, many heart
failure patients have poor diets, and some earlier studies have
indicated that diuretic medicines prescribed to help treat the
condition may increase the losses of thiamin.
This study is the largest study yet of thiamin deficiency among
hospitalized heart failure patients, and it included participants with
various degrees of illness. The researchers, including lead author
Stacy A. Hanninen, R.D., M.S.C., measured the thiamin levels of 100
consecutively admitted patients with heart failure. They also measured
the thiamin levels of 50 healthy people. The heart failure patients
were almost three times as likely to be deficient in thiamin as the
control subjects (33 percent versus 12 percent, p = 0.007).
"Our sample is quite representative of our hospitalized population of
heart failure patients. We also used a direct measurement of thiamin
status--the erythrocyte thiamin pyrophosphate--which is more specific
than earlier assays that indirectly measured enzyme activity. Finally,
our study also investigated factors other than diuretic medication,
such as diet, medical status and demographic factors that might be
contributing to the development of thiamin deficiency," Dr. Keith said.
In contrast to earlier studies, these results did not show an
association between the use of diuretic medications and thiamin
deficiency. However, Dr. Keith said that their report is not the final
word on this point.
"The relationships between thiamin loss, thiamin status and diuretic
use are not definitively established and controversy remains. Our
population was a cross-section of hospitalized patients who had
differing levels of disease severity and had differing doses of
diuretics prior to their admission, which may have accounted for the
lack of relationship between diuretic dose and thiamin deficiency," she
said.
Dr. Keith also pointed out that although they observed that patients
taking supplements were less likely to be deficient in thiamin, the
association did not reach statistical significance (p = 0.06). Further
studies are needed to determine whether improving thiamin levels,
either with supplements or via other means, will improve heart failure
symptoms.
Professor John G.F. Cleland, F.A.C.C., from the University of Hull in
Hull, U.K, who was not connected with this study, said that there are
many reasons for heart failure patients to have difficulties
maintaining proper nutrition, so it is surprising that so little
attention has been paid to nutrition in heart failure.
"Patients with advanced heart failure commonly suffer from cardiac
cachexia, but little is known about the mechanisms underlying this
problem or how to treat it. Deficiency in one dietary component, such
as thiamin, is unlikely to occur in isolation and might be a marker for
shortages of other micronutrients. Recent research suggests that
targeted multi-micronutrient supplementation may improve quality of
life and left ventricular function in elderly patients with heart
failure," Dr. Cleland said.
Jill Kalman, M.D. from the NYU Medical Center in New York, N.Y., who
also was not connected with this study, said the results help point the
way toward improving care for heart failure patients.
"If we can start to point out where there are certain metabolic
deficiencies in heart failure, learn where we can replace them in an
effective and safe fashion, and make a difference eventually in terms
of outcomes, I think that's where this is an important article," Dr.
Kalman said.
Dr. Kalman said that it is also important to find out whether any heart
failure treatments may be causing metabolic deficiencies.