Naturally elevated levels of the antioxidant urate may slow the progression of Parkinson's disease in men. Researchers from the MassGeneral Institute for Neurodegenerative Disease (MGH-MIND) and Harvard School of Public Health (HSPH) examined data from an earlier study and found that, among recently diagnosed Parkinson's patients, those with the highest urate levels had a significantly slower rate of disease progression during the two-year study period.
The report appears in the April 2008 Archives of Neurology and may lead to urate-based therapies for the disorder.
Parkinson's disease – characterized by tremors, rigidity, difficulty walking and other symptoms – is caused by the destruction of brain cells that produce the neurotransmitter dopamine. Several epidemiologic studies, including the HSPH-based Health Professionals Follow-up Study, have found that healthy people with elevated levels of urate, a normal component of the blood, may have a reduced risk of developing Parkinson's disease.
“Because the neurodegenerative process that leads to Parkinson's disease starts years before the onset of symptoms and progresses throughout the disease course, we reasoned that blood urate could be slowing the rate of neurodegeneration and hypothesized that urate's beneficial effect might extend beyond the time of diagnosis,” says Alberto Ascherio, MD, DrPH, of HSPH, the study's senior author.
To investigate this hypothesis, the MGH/HSPH team analyzed information from the PRECEPT trial conducted by the Parkinson Study Group, based at the University of Rochester. That study followed a group of recently diagnosed Parkinson's patients to see if an experimental medication could delay disease progression, measured by the need to begin standard drug therapy and by imaging of the brain structures that produce dopamine. Blood samples from about 800 PRECEPT trial participants were analyzed for urate levels, which were compared to information about symptom progression of the trial participants and the imaging study results.