National Institute of Neurological Disorders and Stroke

Study Suggests Coenzyme Q10 Slows Functional Decline
in Parkinson's Disease

For release: Monday, October 14, 2002

Results of the first placebo-controlled, multicenter clinical
trial of the compound coenzyme Q10 suggest that it can
slow disease progression in patients with early-stage
Parkinson's disease (PD). While the results must be
confirmed in a larger study, they provide hope that this
compound may ultimately provide a new way of treating
PD.

The phase II study, led by Clifford Shults, M.D.,
of the University of California, San Diego (UCSD)
School of Medicine, looked at a total of 80 PD patients
at 10 centers across the country to determine
if coenzyme Q10 is safe and if it can slow the rate
of functional decline. The study was funded by the
National Institute of Neurological Disorders and Stroke
(NINDS) and appears in the October 15, 2002,
issue of the Archives of Neurology.1

"This trial suggested that coenzyme Q10 can slow
the rate of deterioration in Parkinson's disease,"
says Dr. Shults. "However, before the compound
is used widely, the results need to be confirmed
in a larger group of patients."

PD is a chronic, progressive neurological disease
that affects about 500,000 people in the United States.
It results from the loss of brain cells that produce the
neurotransmitter dopamine and causes tremor,
stiffness of the limbs and trunk, impaired balance
and coordination, and slowing of movements.
Patients also sometimes develop other symptoms,
including difficulty swallowing, disturbed sleep,
and emotional problems. PD usually affects people
over the age of 50, but it can affect younger people
as well. While levodopa and other drugs can ease
the symptoms of PD, none of the current treatments
has been shown to slow the course of the disease.

The investigators believe coenzyme Q10 works
by improving the function of mitochondria, the
"powerhouses" that produce energy in cells.
Coenzyme Q10 is an important link in the chain
of chemical reactions that produces this energy.
It also is a potent antioxidant - a chemical that
"mops up" potentially harmful chemicals generated
during normal metabolism. Previous studies carried
out by Dr. Shults, Richard Haas, M.D., of UCSD
and Flint Beal, M.D., of Cornell University have
shown that coenzyme Q10 levels in mitochondria
from PD patients are reduced and that mitochondrial
function in these patients is impaired.
Animal studies have shown that coenzyme Q10
can protect the area of the brain that is damaged
in PD. Dr. Shults and colleagues also conducted
a pilot study with PD patients which showed that
consumption of up to 800 mg/day of coenzyme
Q10 was well-tolerated and significantly increased
the level of coenzyme Q10 in the blood.

All of the patients who took part in the new study
had the three primary features of PD - tremor,
stiffness, and slowed movements - and had been
diagnosed with the disease within 5 years
of the time they were enrolled. After an initial
screening and baseline blood tests, the patients
were randomly divided into four groups. Three
of the groups received coenzyme Q10 at three
different doses (300 mg/day, 600 mg/day,
and 1,200 mg/day), along with vitamin E, while
a fourth group received a matching placebo that
contained vitamin E alone. Each participant
received a clinical evaluation 1 month later
and every 4 months for a total of 16 months
or until the investigator determined that the
patient needed treatment with levodopa.
None of the participants or the study investigators
knew which treatment each patient had received
until the study ended.

The investigators found that most side effects
of coenzyme Q10 were mild, and none of the
patients required a reduction of their dose.
The percentage of people receiving coenzyme
Q10 who reported side effects was not significantly
different from that of the placebo group.
During the study period, the group that received
the largest dose of coenzyme Q10 (1,200 mg/day)
had 44 percent less decline in mental function,
motor (movement) function, and ability to carry out
activities of daily living, such as feeding or dressing
themselves. The greatest effect was on activities
of daily living. The groups that received 300 mg/day
and 600 mg/day developed slightly less disability
than the placebo group, but the effects were less
than those in the group that received the highest
dosage of coenzyme Q10.

The groups that received coenzyme Q10 also had
significant increases in the level of coenzyme Q10
in their blood and a significant increase in
energy-producing reactions within their
mitochondria.

The results of this study suggest that doses
of coenzyme Q10 as high as 1,200 mg/day
are safe and may be more effective than
lower doses, says Dr. Shults. The findings are
consistent with those of a recently published
study of patients with early Huntington's disease
- another degenerative neurological disorder -
that showed slightly less functional decline
in groups that received 600 mg/day
of coenzyme Q10.

The new study also used an efficient phase II
clinical trial design - developed by biostatistician
David Oakes, Ph.D., of the University of Rochester,
and other study investigators - which should be
useful for testing other drugs that might slow
the progression of PD, says Dr. Shults.

The design allowed the researchers to study
the effects of three doses plus a placebo in less
than 3 years, and to obtain useful data about
the compound's effectiveness.

Dr. Shults and his colleagues strongly caution
patients against taking coenzyme Q10 until a
larger, definitive trial can be conducted.

Because coenzyme Q10 is classified as a dietary
supplement, it is not regulated by the U.S. Food
and Drug Administration. The versions of the
supplement sold in stores may differ, they may not
contain potentially beneficial amounts of the
compound, and taking coenzyme Q10 over a
number of years may be costly, says Dr. Shults.
In addition, the current study included only
a small number of patients, and the findings
may not extend to people in later stages of PD
or to those who are at risk but have not been
diagnosed with the disorder, he notes. Finally,
if many people begin taking coenzyme Q10
because of these early results, it might make it
impossible for investigators to find enough
patients to carry out definitive studies
of the compound's effectiveness and the
proper dosages, since patients must not be
taking any treatments in order to be considered
for enrollment in a definitive trial.

The investigators are now planning a larger
clinical trial that will examine the effects
of 1,200 mg/day of coenzyme Q10, and possibly
a higher dose as well, in a larger number
of patients.

The NINDS is a component of the National
Institutes of Health in Bethesda, Maryland,
and is the nation's primary supporter
of biomedical research on the brain
and nervous system.

1Shults CW, Oakes D, Kieburtz K, Beal F, Haas R,
Plumb S, Juncos JL, Nutt J, Shoulson I, Carter J,
Kompoliti K, Perlmutter JS, Reich S, Stern M,
Watts RL, Kurlan R, Molho E, Harrison M, Lew M,
and the Parkinson Study Group.
"Effects of coenzyme Q10 in early Parkinson disease:
evidence of slowing of the functional decline.
" Archives of Neurology, October 2002, Vol. 59,
No. 10, pp. 1541-1550.

Reporters: for more information,
contact Natalie Frazin or Margo Warren,
301-496-5751.

Reviewed October 14, 2002

SOURCE: National Institute of Neurological Disorders and Stroke
http://www.ninds.nih.gov/news_and_events/pressrelease_parkinsons_coenz
ymeq10_101402.htm?format=printable

* * *
Murray Charters <[log in to unmask]>
http://www.geocities.com/murraycharters/

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