By
Dan Vergano, Medical Tribune News Service
A
supplement that helps weight lifters ``pump up'' may do the same
for people with muscular diseases, Canadian researchers report.
Physicians have long known that creatine, a compound formed in
muscles and present in meat, dwindles in patients with muscular
dystrophy and other diseases that cause weakness. Body-builders
and athletes often take it as a dietary supplement, influenced
by studies and advertising suggesting that the compound allows
muscles to work harder for longer periods of time. Few studies
have examined its potential to help patients with muscle weakness,
until now.
In
the study, reported in the March issue of the journal Neurology
and led by Dr. Mark Tarnopolsky of McMaster University Medical
Center in Ontario, people with muscular dystrophy, inherited muscle
weakness and defective heart muscles were given creatine supplements
in a pair of trials. The first trial involved 81 patients who
received 10 grams of creatine a day for five days. Study participants
measured the strength of their hands, knees and ankles before
and after taking the supplement, with the help of researchers.
Knee strength increased the most, 13 percent on average, in participants,
but increased in small but significant amounts in other parts
of the body as well.
In
the second part of the study, 21 patients underwent supplementation
with creatine or a similar-tasting dummy pill for five days. Knee
strength increased more than 10 percent for creatine-takers in
that trial.
``I'm
cautiously optimistic about creatine,'' Tarnopolsky commented.``This
does offer a glimmer of hope to people with muscle diseases,''
agreed pediatric neurologist Leon Charash, chairman of the Muscular
Dystrophy Association's medical advisory committee. Doctors abandoned
creatine as therapy for muscular dystrophy in the 1950s, noted
Charash, which makes its reappearance as a treatment ``more intriguing.''
``These
are potentially interesting findings, but the study has some limitations,''
said neuromuscular disease specialist Ralph Kuncl, director of
the Neuromuscular Lab at Johns Hopkins University in Baltimore.
Even though patients in the second trial did not know who was
taking creatine and who received a placebo, the researchers did
know, which can affect findings, even on an unconscious level,
noted Kuncl. He also cautioned that the increased strength seen
in the study represents a small increase overall and might not
even be noticed by patients outside the laboratory.
``The
vote is not in [on creatine],'' said Kuncl, who added he would
advise his patients against taking the supplement until more researchers
complete studies of the compound.
Other experts are less cautious. ``I think this is a well-done
study which does show a convincing benefit of creatine,'' said
Flint Beal, a researcher at Cornell University Medical Center
in New York City. He recently completed a study of mice with a
form of Lou Gehrig's disease, a deadly ailment marked by severe
muscle weakness. As reported in the March Nature Medicine, Beal
found creatine extended the lives of his rodent test subjects.
