Portland, Ore.

Results show promise, however, scientists caution more research is necessary

A national clinical trial partially conducted at OHSU has shown that high dosages of a naturally occurring compound, coenzyme Q10, slowed by 44 percent the progressive deterioration in function that occurs in the disease. The greatest benefit was seen in everyday activities, such as feeding, dressing, bathing and walking. A total of 80 patients took part in the trial, including 12 participants from the Pacific Northwest. OHSU had the highest patient participation for all of the research centers taking part in the trial.

The study's coordinators caution that while encouraging, the therapy needs to be tested in a larger trial with hundreds of patients before this treatment can be recommended.

Published in the Oct. 15, 2002, issue of the American Medical Association's Archives of Neurology, the study was conducted at 10 sites by the Parkinson Study Group, under the direction of principal investigator Clifford Shults, M.D., professor of neurosciences, University of California, San Diego (UCSD) School of Medicine, and chief of the Neurology Service at the VA San Diego Healthcare System. Julie Carter, A.N.P., associate director of the OHSU Parkinson Center of Oregon and principal investigator of OHSU's Center for Neuroprotection in Parkinson's Disease, directed the study at OHSU.

Parkinson's disease is a degenerative disorder of the brain in which patients develop tremor, slowness of movement and stiffness of muscles. It affects approximately 1 percent of Americans older than the age of 65. Although certain drugs, such as levodopa, can reduce the symptoms of Parkinson's disease, no treatment has been shown to slow the progressive deterioration in function.

In the Parkinson Study Group national clinical trial, 80 parkinsonian patients who had early disease and did not yet need medications typically used to treat Parkinson's disease (such as levodopa), were randomly assigned to receive coenzyme Q10 four times a day at a dosage of 300, 600 or 1200 mg/day, or a placebo, also taken four times a day. Prior to beginning the study, the patients were evaluated with a medical history, physical exam, laboratory tests, and a battery of clinical assessments of Parkinson's disease. Participants were re-evaluated with tests to assess the severity of the Parkinson's disease at regular intervals and followed until the time that they needed treatment with medications used to treat the symptoms of Parkinson's disease, or for a maximum of 16 months.

By the eighth-month visit, the scores among the four groups had clearly separated and established a pattern of the groups taking the lowest and intermediate dosages (300 and 600 mg/day) being similar and lower than placebo, and the scores for the group receiving the highest dosage (1200 mg/day) being substantially lower than the other groups. The lower score reflected less impairment and better function. This pattern persisted to the end of the study. The benefit was seen in assessment of mental function and mood, activities of daily living and motor skills.

"While this study holds promise for Parkinson's patients, much more research is necessary," said Carter. "This was a relatively small study and it's results must now be further studied in a larger trial involving hundreds of patients. It would be premature to recommend that patients with Parkinson's disease take high doses of coenzyme Q10."

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