FRIDAY, Sept. 20 (HealthDay News) -- Blood tests might be able to help identify Parkinson's disease patients with the greatest risk of developing dementia, a new study suggests.

A genetic mutation called GBA leads to early onset of Parkinson's and severe mental decline in about 4 percent to 7 percent of Parkinson's patients. It also alters the way the body metabolizes certain kinds of fats.

Mayo Clinic researchers found that Parkinson's patients who do not have this genetic mutation have higher levels of these fats in their blood. They also discovered that Parkinson's patients with high levels of these fats in their blood are more likely to have mental impairment and dementia, according to the study, which was published online Sept. 18 in the journal PLoS One.

Mental impairment is a frequent symptom in Parkinson's disease and can be even more debilitating for patients and challenging for their caregivers than the characteristic movement issues such as trembling, stiffness, poor coordination and balance problems, the Mayo researchers noted.

They said that early identification of Parkinson's patients at greatest risk of developing dementia is important for preventing or delaying the start and progression of mental impairment. Changing the levels of these fats in the blood could be one way to do that, the study suggests.

There is also a possibility that assessing the levels of these fats in the blood could help predict who will develop Parkinson's disease, and research is being conducted in this area.

"There is currently no cure for Parkinson's, but the earlier we catch it, the better chance we have to fight it," study first author Michelle Mielke said in a Mayo Clinic news release. "It's particularly important we find a biomarker and identify it in the preclinical phase of the disease, before the onset even begins."

More information

The U.S. National Institute of Neurological Disorders and Stroke has more about Parkinson's disease.