LOS ANGELES -

Michael Weinman has been living with Parkinson's disease for 14 years. The degenerative disease has slowly robbed him of the ability to perform everyday tasks.

"I used to be able to run, [but] I can’t run anymore," Weinman said. "I used to be able to carry my food to the table. I can’t do that [anymore]."

Weinman, however, has kept a positive attitude through it all.

"I try to focus on what I can do," he said.

"Definitely, he's a glass half-full," said Nessa, Weinman’s wife.

While Weinman's disease has progressed slowly, Parkinson's patients don't know whether their disease will be mild or severe when they are diagnosed.

"Nobody who is a neurologist and sees patients can very well predict who will rapidly decline eventually need a wheelchair quite fast," said Dr. Beate Ritz, chairwoman, department of epidemiology center for occupational and environmental health, UCLA Fielding School of Public Health.

Ritz and her colleagues studied recently diagnosed Parkinson's patients. They took blood samples and found those with higher levels of a metabolite called N8-acetyl spermidine declined much faster than those with lower levels.

"We found that this one metabolite seemed to really distinguish these two groups from each other," Ritz explained.

Weinman and his wife said they hope such research will help others. They also walk in the annual "Mike Hike," which has raised more than $40,000 for Parkinson's.

"Hopefully, in the future, they'll be able to treat it and recognize it sooner," Weinman said.

Doctors said the next step is to conduct a larger study on the metabolite as a predictor of faster progression.

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