A team of researchers from the Massachusetts General Hospital’s Institute for Neurodegenerative Disease (MGH-MIND) and the Harvard School of Public Health (HSPH) have discovered that the rate at which Parkinson’s disease progresses is a reflection of the level of urate in the bloodstream.  It seems the higher the level of urate, a naturally occurring antioxidant, the slower the progression of the disease.

The research is based on previous epidemiological studies that seem to indicate a lower risk of developing Parkinson’s disease when there is a higher level of urate in the blood.  Parkinson’s disease is known to be present years before symptoms become apparent and the progression of the disease never stops.  With that background in mind, the  research team based its study on the hypothesis that the beneficial effect of urate might slow progression of the disease long enough to prolong the need to take traditional medications for it.

The team used data from the University of Rochester’s Parkinson Study Group’s PRECEPT trial, which monitored patients recently diagnosed with Parkinson’s to determine whether or not an experimental medication would slow progression of the disease.  Progression was measured by imaging dopamine-producing brain structures and the need for standard Parkinson’s drug therapies.  Urate levels in blood samples from about 800 study participants in the PRECEPT trial were also compared.

The MGH/HSPH team discovered that the patients with the highest levels of urate at the outset of the study were at half the risk of needing drug therapy than those with lower urate levels.  These same participants also seemed to have lost the least number of dopamine-producing neurons, according to their brain scans.

The findings varied little between the PRECEPT study’s control and treatment groups.  There was significant variance, however, between the men in the study and the women.  Men normally have higher urate levels than women and it was the men with the most elevated levels of urate that enjoyed the slowest progression of the disease.  An elevated urate level is rare in women, making the current study insignificant with regard to women with Parkinson’s.

Lead author of the study, Michael Schwarzschild, MD, PHD, MGH-MIND, expressed the hope that urate-based drug therapies can be developed to slow the neurodegeneration characterized by the disease.

Phase 2 of the study was announced on April 14, wherein 90 people who have been recently diagnosed but not yet in need of treatment will be given either a placebo or inosine, a precursor to urate.  This phase of study is funded by the Michael J. Fox Foundation for Parkinson’s Research.

The April 2008 issue of the Archives of Neurology carries the full details of the current study.